Development of a Design Conceptfor Dialysis Concentrate Packages Master Thesis in Industrial Design EngineeringANNA HALLGREN CHALMERS TEKNISKA HÖGSKOLA Product and Production DevelopmentGöteborg, Sweden 2011 division of Design & Human Factors Engineering Development of a Design Conceptfor Dialysis Concentrate Packages ANNA HALLGREN Department of Product and Production DevelopmentCHALMERS UNIVERSITY OF TECHNOLOGYGöteborg, Sweden, 2011 Development of a Design Concept for Dialysis Concentrate PackagesANNA HALLGREN  ANNA HALLGREN, 2011 Department of Product and Production Development Division of Design & Human FactorsCHALMERS UNIVERSITY OF TECHNOLOGYSE- 412 96 GöteborgTelephone + 46 (0) 31-772 1000 Cover: A prototype of a concept for the secondary package. PREFACEThis master thesis was carried out in the spring of 2011 in cooperation with the medical technology company Gambro Lundia AB, located in Lund, Sweden. The thesis comprises 30 units of credit (i.e. 20 weeks of studies) and is the final work of the master´s program Industrial Design Engineering at Chalmers University of Technology.I would like to thank my examiner Anna-Lisa Osvalder and supervisor Lars-Ola Bligård at the department of Product and Production Development, division of Human Factors Engineering, Chalmers University of Technology for feedback and for guiding me trough the project and educated me in methodology and tools used for the analysis work. I also want to thank my supervisor Fredrik Ericsson at Ergonomidesign AB for support and feedback through the project and the master students at IKDC for welcoming me to the “exjobbs fika”.I also want to thank my contact Caroline Andersson at Gambro, the people in the brainstorming session, the participants in the usability test and all the other people at Gambro who has supported me and provided me with all their help. Last but not least I would like to thank the people at the dialysis wards in Lund, Karlskrona and Malmö for taking the time to be interviewed and letting me study their work. Göteborg, June 2011 ______________________________________ Anna Hallgren I ABSTRACTThere is a desire for dialysis concentrate packages that are lightweight, quick to mount to the machine and easy to dispose. The box packages today are cumbersome to open and flatten, for some sort of box packages the nurses have to jump on it before it can be disposed. The new concept shall support dialysis operators with an ergonomically designed user interface with good usability.The following three questions were set for the project.What needs and wants does the users have on a dialysis concentrate package?Which are the most important usability aspects for a concentrate package?How can a dialysis concentrate package with good usability look like?The final package concept consists of a primary concentrate package, a secondary box package and a design proposal for how the concentrate could be attached to the dialysis machine. The box concept uses a way of flattening which requires less force than the existing box. The package concept of the concentrate provides the user with a convenient grip and takes up a smaller volume after usage than the existing Gambro packages for dry concentrate. The improvements of the concentrate packages will lead to better working conditions for dialysis nurses and hopefully increase the level of satisfaction with concentrate packages. II SAMMANFATTNINGDet finns ett behov av dialyskoncentratförpackningar som är lätta viktmässigt, som går snabbt att montera på maskinen och som fungerar bra i sophanteringen. Många av dagens sekundärförpackningar är svåra att öppna och platta ihop, en del måste användaren hoppa på för att få den platt. Det nya konceptet som togs fram skulle förse dialyssjuksköterskorna med ett ergonomiskt utformat användargränssnitt med god användbarhet. För projektet sattes följande frågeställningar upp.Vilka behov och krav har användarna på en dialyskoncentrat-förpackning?Vilka är de viktigaste användbarhetsaspekterna hos en koncentrat förpackning?Hur kan en dialyskoncentratförpackning med god användbarhet se ut?Det slutliga konceptet består av en primärförpackning för dialyskoncentrat, en sekundär lådförpackning och ett design förslag på hur förpackningen skulle kunna monteras på maskinen. Lådförpackningen för dialyskoncentrat-förpackningarna har en vikningsprincip som är kräver mindre kraft att vika i ihop än ordinära existerande förpackningar. Förpackningskonceptet för koncentratet förser användaren med ett handvänligt grepp och tar upp minde utrymme i hanteringen efter användning jämfört med existerande Gambro förpackningar för tort dialyskoncentrat. Förbättringarna med den nya koncentratförpackningen leder till bättre arbetsförhållanden för dialyssjuksköterskor och ökar förhoppningsvis tillfredsställelsen med dialyskoncentrat-förpackningar. III TABLE OF CONTENT 1 INTRODUCTION............................................................................................................................ 1 2 DILALYSIS....................................................................................................................................... 3 3 THEORETICAL FRAMEWORK................................................................................................... 6 4 WORK PROCEDURE................................................................................................................... 11 5 METHODOLOGY......................................................................................................................... 13 6 NEEDFINDING............................................................................................................................. 17 7 FUNCTION AND TASK DESIGN............................................................................................... 28 8 INITIAL CONCEPT DEVELOPMENT....................................................................................... 35 9 FURTHER CONCEPT DEVELOPMENT................................................................................... 41 10 END RESULT OF THE CONCEPT DEVELOPMENT...........................................................58 11 DISCUSSION............................................................................................................................... 66 12 RECOMMENDATIONS............................................................................................................. 71 13 CONCLUSION............................................................................................................................. 72 REFERENCES................................................................................................................................... 73 Appendix A: Interview Questions.............................................................................................. 1 Appendix B: Existing Work Flow – HTA...................................................................................3 Appendix C: Sketches..................................................................................................................... 4 Appendix D: Task Allocation..................................................................................................... 10 Appendix E: Cognitive Walkthrough (CW)...........................................................................11 Appendix F: Predictive Human Error Analysis (PHEA)....................................................12 Appendix G: Verification of the Concept ..............................................................................13 Appendix H: Work Flow for Attachment of the New Concentrate Package – HTA...14 Appendix I: Test Plan for the Usability Test.........................................................................16 Appendix J: Data from User Tests........................................................................................... 20 Appendix K: Data from Interviews with Test Participants.............................................26 Appendix L: Arrangement on an EU - Pallet.........................................................................29 Appendix M: Proposals for the Rail........................................................................................ 30 IV 1 INTRODUCTIONIn this chapter background information to the project is described, as well as the purpose, goal, questions and delimitation. 1.1 BackgroundDialysis is medical treatment method used all over the world and saves many lives of people every day. The dialysis system function as an artificial kidney for people with lost or partial kidney function. This project concerns the handling with dialysis concentrates, which has an essential role in the dialysis treatment process.The handling of the concentrate is important to consider in order to provide good physical working conditions, support an intuitive usage and to prevent use errors. To implement the human factors in the development of medical equipment is required from authorities and also an area to work on in order to compete with competitors’ products.The collaborating company Gambro Lundia AB is a Swedish medical technology company developing and manufacturing products for dialysis e.g. dialysis machines, dialyzers and dialysis concentrates. The concept is first and foremost aimed to be implemented on the Gambro dialysis machine AK 96®. The AK 96® monitor is used both at dialysis wards at hospitals and at homes by patients themselves. It is a relatively basic dialysis machine without high-tech features. It is primary used in developing countries and for home dialysis because it has fewer functions, is less expensive and is small in relation to other dialysis machines. 1.2 PurposeThe project concerns a user centred approach applied on the development of concepts of containers for dialysis concentrate valid for dialysis machines. The concentrate package shall support dialysis operators with an ergonomically designed user interface for dialysis treatment. The interface should be as intuitive as possible and have good usability. 1.3 GoalThe goal is to make a new design in the lower segment that is better than Gambro´s existing packages from a user perspective. The new concentrate package will primarily be designed for one of Gambro´s hemodialysis machines (the AK 96® monitor), but should also be adaptable for other dialysis machines in the future. The issue of where and how the containers should be attached to the monitor will also be considered. The new package concept will also seek for improvements of the secondary package, the box. Concepts will be developed and in the end of the project prototypes of the final concepts of containers will be made in order to make usability tests with primary users. 1.4 QuestionsIn order to fulfil the purpose and goal the following questions where set for the project. • What needs and wants does the users have on a dialysis concentrate package? 1 • Which are the most important usability aspects for a concentrate package? • How can a dialysis concentrate package with good usability look like? 1.5 Delimitations • The user studies of the usage are limited to Swedish dialysis wards. • The graphics for the user interface on the screen menu are not developed within this project. • Detailed design, material selection and cost estimations are not specified in the overall concept design. 1.6 Thesis OutlineThe report is primarily written to be read by other students in the product development field. Hopefully it will also become a reference in the work and documentation of the further development of packages at Gambro.The report structure is illustrated in the picture below.The results are presented in four chapters named after the phases in the work procedure. Figure 1-1 Report structure. Introduction – introduction to the project. Dialysis – description of the dialysis process, the concentrate and the dialysis machine. Theoretical Framework – introduction to the theory of the project. Work Procedure – description to the work process. Methodology - the methods used are described briefly. Results – the results of the project are described in chronological order and divided into four chapters. Discussion - thoughts and reflections based on the project. Recommendations – recommendations to the company for further development. Conclusions – conclusions drawn from the project. 2 2 DILALYSISIn this section the dialysis treatment, dialysis machine and dialysis concentrate will be described so that readers who not are familiar with dialysis will get an introduction to the area. 2.1 Dialysis treatmentDialysis is a treatment method to compensate for lost or poor kidney function. The main function of the dialysis process is to do the kidneys job i.e. to regulate salt and water and to clean the blood. The kidney function can be damage by a chronic kidney disease or acute kidney injury. The most common reasons for kidney diseases are diabetes, urinary infections and genetic kidney disease (Larsson, 2000). Patients without any kidney function need the dialysis to continue their lives. Most of the dialysis patients have to come to the hospital at least three days a week and the treatment lasts for about 3.5-5h each time. Many patients may thanks to the dialysis live an active life and have a good quality of life even if they have a serious disease.There are two different types of dialysis processes, hemodialysis and peritoneal dialysis. Hemodialysis is the most commonly used dialysis treatment methods and is a treating method where the blood is circulating in the dialysis machine and cleaned by passing through a dialyzer where the waste products diffuse to the dialysis concentrate. The peritoneal dialysis is a treating method where the dialysis fluid is introduced into peritoneal cavity through a catheter in the abdomen and peritoneum function as a dialysis filter in a dialyzer (Gambro Basics). The master’s thesis work concerns development of concentrate package for hemodialysis only.The dialyzer of the dialysis machine is an artificial kidney. The dialyzer has a filter which main function is to separate the waste products from the blood. The blood pass on one side of the filter and on the other side there is a flow of dialysis concentrate. The waste products in the blood pass the membrane in the dialysis filter while the filter stops the protein molecules and corpuscles. Blood returning to patien t Intake of dialysis concentrate Dialysis concentrate to drain W as te p ro du ct s Blood from patie n t Blood Dialysis solutio n Figure 2-2 Principle of a dialysis filter. 3 2.2 The Dialysis MachineThe dialysis concentrate package will primarily be developed for the Gambro dialysis machine AK 96®. This machine is the smallest dialysis machines in Gambro´s product range hence a more basic machine than the larger ones. The AK 96® machine is mostly sold to dialysis wards in developing countries but it is also used for home dialysis where it is used by the patients themselves in their homes.The main parts of a dialysis machine are the blood pump which pumps the blood to the machine, the dialyzer that is cleaning the blood and an air trap to control that there are no air in the system. There are also a lot of controlling detectors such as blood pressure monitors, conductivity sensors for the concentrate etc.There is a range of different liquid solutions needed for the dialysis process. First there is a saline concentrate, used for the priming of the machine before the treatment starts. Further on there are two different dialysis concentrates A and B, which are mixed together and then flow through the dialyzer during the dialysis process. The concentrates are diluted with cleaned water before it comes to the dialyzer. To prevent the blood from clotting, heparin can be added in form of an injection in the tube of the flow path. 2.3 The Dialysis ConcentrateThe dialysis concentrate comes in contact with the blood in the dialyzer. The purpose of the dialysis concentrate is to balance the quantity of different substances, to uptake the waste products from the blood and to remove waste liquid. The concentrate has to have a mixture similar to the blood. The dialysis fluid is made from an acidic concentrate (A) and a bicarbonate concentrate (B). The acidic concentrate is available in different mixtures while the bicarbonate only is made of bicarbonate. The bicarbonate is available either as a liquid or as a dry concentrate. Each type of liquid is distributed in packages that are connected to the machine during the treatment. The A and B concentrates are mixed in the dialysis machine and then transported to the dialyser. A more detailed description of the existing concentrate products can be found in section 6.2. 4 Figure 2-3 The dialysis process. Figure 2-4 AK 96® monitor 5 Figure 2-4 Storage of concentrate at a dialysis ward. 3 THEORETICAL FRAMEWORKIn this chapter the theoretical background for the studies within the human factors area are presented. The following text is a brief introduction to the human factor engineering area and its primary purpose is to give an orientation for readers who are not familiar with this field. 3.1 Product InteractionProduct interfaces are everywhere a human has to interact with a product; it could for example be a vending machine, a coffeemaker, a teacup or a dialysis concentrate package. The principle of the human – product/technology interaction is that the human and product collaborates in a specified context in order to achieve a specified goal. The purpose of human technology interaction theory is to design a system that contributes to a functional and collaboration between human and the technology, where the human ability to operate the system is considered, while the effect of the human limitations are prevented. In order to achieve a good product interaction all components need to be considered; the human, the technology, the environment and the task. The product development within this project mainly considers static interface design i.e. products that doesn't change appearance over a sequence of actions. It can be compared to dynamic interfaces, which are represented in GPS, control rooms, cameras etc. 3.2 UsabilityA central theme in human cantered design is usability. There are many different definitions of usability. A commonly used definition is the ISO definition, (International Standard Organisation). …the effectiveness, efficiency and satisfaction which specified users can achieve specified goals in particular environments (ISO DIS 9241-11). This definition defines that the usability of a particular product depends on who the actual users are, the intended goal to achieve with the product and in what context the product is aimed to be used. The disadvantage of this definition when applied to this type of projects is that the fulfilment of the goal can be misunderstood. The goal with e.g. dialysis treatment is to treat the patient but this is not what the usability aspects aims to measure, the usability aims to the human interaction with the product. Another definition of usability is Nielsen´s definition. Nielsen defines usability with five components i.e. easy to learn, efficient to use, easy to remember, few errors and subjectively pleasing (Nielsen, 1993). This definition is more interaction oriented and is therefor more appropriate to use for this kind of project.By considering a high level of good usability in the product development process, the product can gain advantages over competitive products at the market. Usability is also important to consider in order to fulfil the safety requirements for the usage, to prevent health problems of users and last but not least; the usability of products used in the workplace can also have an effect on the level of job satisfaction amongst that organization´s workplace (Jordan, 1998). The better usability of the product, the more satisfied the users will be and more users will prefer the product and hence it contributes to good economy for the manufacturing company. The importance of 6 satisfaction was stated by Göransson (2001) as: It is what the user feels and thinks about the product that matters, not that much if the product is efficient to use.Below is an explanation of some good principles for the work of usable design. The following principles are considered within this project and are inspired by Jordan. -Compatibility- ensuring that the way a product works fits in with users expectations based on their knowledge of other types of products and the “outside world”-Considerations of user resources- the design of the interaction process of information and actions will consider the demands of the users resources during interaction.-Feedback- designing so that the system gives meaningful information to the users actions.-Error prevention and recovery- design to minimize the risk of errors and make it possible to recover from potential errors quickly.-User control- designing a product so that the user has control over the actions taken by the product.-Visual clarity- design so that information is displayed so that it can be read quick and easy.-Explicitness- designing cues for the function and how to operate the product.Further the level of usability can be measured in respect to the product´s effectiveness, efficiency and satisfaction. The evaluation is performed by predefined measureable goals for each aspect of usability. Jordan´s definitions of the three measures are:-Effectiveness - the extent to which a goal, or task, is achieved.-Efficiency - the amount of effort required to accomplish a goal. -Satisfaction - the level of comfort that the user feels when using a product and how acceptable the product is to users as a vehicle for achieving their goals. 3.3 AestheticsHistorically, medical device companies have focused on the effectiveness of the therapy or process that their device performs with little regard to the product´s aesthetic appearance. Users opinions of the usability of a product are affected by the product´s aesthetics, not just its inherent usability (Kossak, Gellatly, Jandrisits, 2007). Every artefact express something, either it is intentional or not the user will get an impression.The benefit of a conscious design language is important in many aspects. Consistent design strategy aims to control that the products are designed in a uniformed way even if there are many designers involved in the many different product development projects in a company. A strong characteristic in design within the brand will lead to branding.Aesthetics can also be used in the purpose of guiding the user in the function of the product and its interaction. A strategy for this is to use the gestalt laws. The study of gestalt is the way in which formal elements relate to one another, how they are organized into wholes, how they are arranged to create harmony, contrast, dynamism (Monö, 1997).The gestalt laws are principles based on the human perception. The gestalt laws consist of four categories, i.e. proximity, similarity, closure, and good continuation. Things that 7 have something in common such as buttons and regulators should be arranged close to each other. Things that have the same meaning or function should look similar. Closure means that the human use to read objects with missing parts as complete based on known knowledge. Continuation means that the human use to consider predictably extensions as part of e.g. a line and that line are then followed. Semantics is the study of the product sign as a message. Semantics deals with the message in the design i.e. what does the product want to describe, express, exhort, identify? The semiotic perception comes from signs that can be heard, seen, felt, smelt or tasted.The product has four semantic functions:to describe: purpose, mode of operationto express: propertiesto exhort: reactionsto identify: a product, its origin, kinship, location, nature or category(Monö, 1997)Semantics can effectively be used for expressing the function of the product, e.g. how it will be gripped and how it will be operated e.g. by rotation or pull. Other semantic functions are: What the product express by its shape, e.g. lightness, stability. What brand identity values will the product elicit? What social values will the product express? Monö describes the current product sign as the market´s conception of the way in which a product´s principal function is traditionally represented in its gestalt. 3.4 Physical ErgonomicsWhen designing for people a target population of users are defined. The principal factors to take into account are in general sex, age, nationality and occupation (Pheasant, Haslegrave, 2006). When designing products for a wide population with many nationalities the smallest and largest measures are considered and then measures are set that are considered to be acceptable for the target group. Anthropometric measures for different nationalities, ages and occupations are limited and therefore estimations have to be made based on the accessible data. For this project the standard standing posture was taken into consideration for estimating the height and placement of the concentrate package module. The body dimension, shoulder-grip length, was also taken into consideration for defining the placement of the module. The measures taken into consideration for this project is based on the user described in the section User Description in chapter 6. The Scheme of zones for convenient reach was studied when evaluating how well the concentrate attachment can be reached. In the design of medical equipment it is also essential to avoid involvement of inconvenient twisting, rotations, small grips and hard pressing. Many nurses already have tension in wrists and fingers. The grip strength varies a lot between individuals but varies also depending on what kind of grip the human is using. Some grips are more convenient for the user while other causes tension to a larger extent. The grip strength is greatest when the wrist is in its neutral position – reducing progressively as the wrist moves away from the neutral position in any direction e.g. flexion, extension, radial deviation and ulnar deviation. The grip strength is limited when the wrist is flexed because the flexors are shortened and 8 thus the capacity to generate tension is diminished. When the wrist is in its neutral position, the handle will be in an angle of 100-110 degrees to the axis of the forearm. (Pheasant, Haslegrave, 2006)If the working level is too high, the shoulders and upper limbs will be raised, leading to fatigue and strain in the muscles of the shoulder region. If any downward force is required in the task, the upper limbs will be in a position of poor mechanical advantage for providing it. If the working level is too low the trunk, the neck and head will be inclined forwards with consequent postural stress for the spine and its muscles. In general 100-250 mm below elbow height for downward pushing forces is recommended for adults. (Pheasant, Haslegrave, 2006)Approximately 90% percent of the population has a dominant right hand and the remaining 10% have a dominant left hand. The product design will preferably be designed for both left and right handed people, if one group has to be promoted, the right handed users will be chosen since this group is dominant. (Pheasant, Haslegrave, 2006) 3.5 Cognitive ErgonomicsIn order to make a product interface with good usability the designer must have some insights in the human cognitive processes. When interacting with a product the user must take a lot of decisions about their handlings. Decision making look different depending on what kind of action the human is to do and what strategy the human use for performing the task. In 1983 Jens Rasmussen developed a model to categorize decision making, it was called the SRK model. The SRK model describes the human decision making process as three levels of behaviour i.e. skill- rule- and knowledge based. On the skill based level are activities that are made unconsciousness. Rule based activities are made by routines, old knowledge and rules. The knowledge based activities need active problem solving, for example in the interaction with new products. These three levels are often combined in the decision making process. (Osvalder, Ulfvengren, 2008) For example when opening a new kind of box package first time, most users may use a combination of knowledge based problem solving combined with rule based decision making derived from the users previous knowledge of how a package is used to be opened. In a usage situation a user usually have a mental model for how an artefact is functioning and how it is supposed to be operated. The user uses the mental model in order to predict an occurrence, find reasons for errors, help for decision-making, understand task sequences, and recall information. The designer’s goal is to design the product so that the intended interaction matches the users’ mental model. If the product differs from the users mental model use errors can occur and the user can feel irritation.Use errors can be categorized into five error types that are based on why the user is performing a use error. This categorization is based on GEMS, Generic Error Modelling System. The categorization of use errors can be useful when e.g. evaluating a product or system. Once identified a reason for the error it is easier to find an appropriate solution for the problem. The five categories are: (L) Lapse –the user is forgetting the intention of the action. (S) Slip – failed attention during execution. (R) Rule-based mistake – 9 misapplication of good rules, i.e. well-known rules are used incorrectly to make a decision. (K) Knowledge-based mistake – wrong decisions based on own conclusions drawn from prior knowledge and known rules. (V) Violations –intended act or omission of act that violates present regulations and/or instruction e.g. breaking rules. (Reason, 1990) 10 4 WORK PROCEDUREThe work procedure of this master thesis will be based on the development process, Utvecklingsprocessen ur ett människa maskinperspektiv, (The Development Process from a Human-machine Perspective), developed by Lars-Ola Bligård. It is an iterative process with four continuous activities, i.e. planning, information collection, evaluation, documentation and six sequential phases i.e. identification of needs, function & task design, conceptual design, detailed design, mechanical design, use and maintenance. Each of the sequential phases includes a loop of analysis, idea generation and synthesis. This Master Thesis will include all of the four continuous phases and the three first sequential phases that end up with a conceptual design solution. Figure 4-5 Illustration over the work procedure. (Utvecklingsprocessen ur ett människa maskinperspektiv, Lars-Ola Bligård.) 4.1 Continuous ActivitiesDuring the product development there are activities that are ongoing during the whole process, i.e. planning, information collection, evaluation and documentation. These activities will be described further in this section. 4.1.1 PlanningThe planning is a dynamic phase that will be developed more into detail during the project and changes can be done as the project proceeds. The planning includes defining aims and goals and to set up a plan for when the activities will be done. 4.1.2 Information CollectionThe information collection is done continuously from the project start till the end.This phase aims to collect information about: the product, the usage, the environment, the company (Gambro), standards, technical solutions for the product and previous studies. 4.1.3 EvaluationThe evaluation aims to measure how the goals and requirements are fulfilled. 11 Evaluations are made continuously to detect weakness early in the development process in order to diminish the cost for changes. The evaluation will elevate the following five aspects: usefulness, utility, usability, function, risks; with testing and verification. 4.1.4 DocumentationThe documentation is done continuously and aims to clarify and communicate the development process. The documentation phase contains e.g. method descriptions, instructions for usability tests, protocols from observations, sketches, risk analyses, list of demand, documentation of the process etc. 4.2 Sequential PhasesIn the development process there are also some phases that are followed after one another. In this project three sequential phases where elaborated i.e. Needfinding, Function and Task Design and Overall Design. These phases will be described further in this . 4.2.1 NeedfindingThe goal of the first sequential phase is to describe the content and boundaries of the project work. The activities are e.g. to describe the stakeholders, research of existing products, use and users, define the need from the use and users etc. 4.2.2 Function and Task DesignThe aim of this sequential phase is to clarify the function and usage of the product. In this phase starts the development. The activities are e.g. function analysis, develop the aimed usage of the product, transform users needs to product demands, develop ideas and solutions for the interaction, aesthetics, and function. 4.2.3 Overall DesignThe goal of the concept development phase is to come up with an overall design of the product. This phase will result in product concepts of a concentrate package, a box and a concept for how the package will be attached to the dialysis machine. 12 5 METHODOLOGYIn this chapter the methods used are described briefly in alphabetical order. The aim is to introduce readers that are not familiar with the terms and methods. 5.1 BrainstormingBrainstorming is a method for generating of a large number of ideas. In the brainstorming session about 4-8 people are gathered, preferably from different expertise areas. The idea is to generate as many ideas as possible and to combine and build upon colleagues’ ideas, no criticism is allowed during the brainstorming session. (Cross, 2004) 5.2 Cognitive Walkthrough (CW)The Cognitive Walkthrough analysis aims to theoretically analyse if the user will complete the actions correctly. The potential use errors are categorized into five categories that explain why the user is performing a use error. The classification is: L (lapse), S (slip), R (rule-based mistake), K (knowledge based mistake), and V (Violations). These error types are described more into detail in section 3.5. (Bligård, & Osvalder, 2009) 5.3 Function AllocationThe function allocation method aims to specify what tasks will be performed by the human ant what should be performed by the machine. The purpose is to identify when it is needed or beneficial to let the machine support the human and what tasks the human do better than the machine. 5.4 Function AnalysisA function analysis aims to identify why the product exists, its main function, necessary functions and desirable functions and how this can be achieved. The analysis results in a list of requirements that is used as a checklist and for concept evaluation within the product design development. 5.5 Hierarchic Task Analysis (HTA)The HTA diagrams aims to identify, organize and represent the user interaction by breaking a task into subtasks. The task analysis ends up with a framework that defines the relationship between different subtasks within the task in respect to chronology and hierarchic level. The HTA diagrams also function as a ground structure to base analysis methods on further in the project. (Sandom, & Harvey, 2004) 5.6 Image BoardAn image board is a collection of images which purpose is to inspire and convey expressions. There are different types of image boards e.g. usage boards, styling boards 13 mood boards and lifestyle boards. The general idea of the image board is to collect inspiration on a particular theme and to communicate intensions within the project group or for the client. 5.7 InterviewsInterviews can be organized in different ways such as structured, semi structured and unstructured. Structured interviews are performed after predefined questions. Semi structured interviews contains open questions as well as closed questions. Unstructured is a more free type of interview and doesn’t follow any interview plan. (Lantz, 2007) 5.8 KJ AnalysisData from e.g. interviews and the user studies can be analysed by KJ analysis that is a method to group the information into categories. The method can be used to organize information from a data collection or brainstorming session etc. 5.9 Morphological MatrixA morphological matrix is a method used for categorizing and combining ideas into concepts in a structured way. A number of sub-problems or sub-areas are first specified. Then all the generated ideas are grouped into these categories. The next step is to combine the sub-ideas and form concepts. 5.10 Osborne´s Idea Spurring ChecklistThis is a method used in the idea generation phase. The idea of the method is to trigger new ideas for solving the problem by using the following eight words: Adapt? Modify? Magnify? Minify? Substitute? Rearrange? Reverse? Combine? (Österlin, 2004) 5.11 Predictive Human Error Analysis (PHEA)This is a theoretical error analysis where an expert is evaluating the concept. The aim of the analysis is to detect potential use errors.In the appliance of this method the category “detect” was replaced by “prevention”. The aim of adding “prevention” to the analysis was to start an investigation of how the concept can be improved for prevention of the actual use errors. 5.12 Rapid PrototypingRapid prototyping is a manufacturing process for prototypes or small series. A CAD-file with the product model is sent to a 3D printer that writes the product in a polymeric material. There are many different types of rapid prototyping processes at the market, some are writing the product by layers while there is another method is hardening the material at places where there will be material and the remaining material can easily be removed. 14 5.13 ScenarioA scenario is a storyline about the user´s use of the product. The persons involved in the use case are hypothetic users of the product and the description aims to be realistic and mirror a real use situation. (Cross, 2004) 5.14 Several Criteria Method - Elimination Method There are many different methods for concept evaluation. For this project Several-Criteria Method was used. This is a method where the concepts are evaluated against criteria. The level of fulfilment is graded 0 – 3 and a total score can be calculated of each concept. 5.15 Sketch ModelsSketch models are three-dimensional models that are created early in the concept generation phase in the purpose of evaluate a function, proportions, volume, geometry etc. The benefit of sketch models is that it is a quick way to make a representation of the product, often many versions of sketch models are made for the product during the design development. 5.16 System DescriptionA system description is performed in order to get an overview of the human-machine system and how the elements in the system are linked to each other. The system description visualizes how material, energy and information connect the elements in the system. 5.17 Use ProfileA use profile is a way to classify the users´ relation to product. The relation is investigated under the categories; use experience, influence and responsibility of use, emotional responsibility to the product and degree of interaction with the product. (Janhager, 2005) 5.18 User StudiesThe user studies aims to observe the actual usage in its real context. The user interaction with the product will be studied; unpacking, mounting, usage, demounting, as well as the product context; how the people are organized, activities around the product, other products or systems close to the product etc. From the user study essential requirements from the context and the usage situation are to be identified. (Jordan, 1998) 5.19 User TestsUser test is an evaluation method that can be used in different stages in the development process. The purpose is to evaluate how a concept or product is in a usage situation. E.g. Does the user understand how the product is aimed to be operated? Does the user´s 15 mental model correlate to what the product is communicating? Etc. 5.20 What if?What if? is a risk analysis method which is performed theoretically by an analyzer. The idea is to go through possible errors, hazardous situations and accident events and ask what if…happens? Then try to find an answer of the question and estimate the likelihood and consequences. (Bligård, in press) 16 6 NEEDFINDINGNeedfinding is the first of the three phases in the work procedure where results from the studies are presented. The needfinding phase aims to identify the product’s aim, the users, the environment and the usage. Advantages and disadvantages of the existing concentrate products have also been investigated together with the users in order to collect information about the users need, expectations and experiences. The information is based on information gained from user studies at three Swedish hospitals. 6.1 Dialysis concentratesToday the dialysis concentrates are available in different concentrations and mixtures and different kind of packages in different price ranges. The dialysis concentrates are packed either in large canisters, smaller bottles, cartridges or flexible packages of different sizes. Some packages are smaller since it has a higher concentration and are added with water in the machine. Normally one package is estimated to last for one treatment. The packages is usually delivered to the dialysis ward once a week and stored in a storage room until they will be used. 6.2 Existing Products - Advantages and Disadvantages In this section existing dialysis packages are evaluated from a users perspective, the information is based on interviews and user studies at dialysis wards in Sweden. The visited hospitals used Gambro products and hence the study is limited to these products. 6.2.1 Secondary Package –Cardboard BoxThe secondary packages are holding the concentrate from factory to the hospital. As an example the SelectBag® One is made of cardboard and has a weight of 6 kg when filled (6 packages in each). The concentrate packages are usually distributed to the dialysis wards in these cardboard packages and stored in storage rooms until they will be used. At some hospitals the pharmacy personnel unpack the packages. When the packages are unpacked the secondary packages are flattened and put in containers for recycling. When opening the new packages with knife it’s a risk for concentrate packages to break inside the package. There is also a risk that the nurses hurt their hands when opening and flattening the packages. One of the interviewed nurses expressed that it is difficult and time consuming to fold the empty packages, and she often has to jump on them in order to get them flat. Another interviewee pointed that the folding of the packages is a “dirty” job and often the next working situation is a “clean” working task with high ordinance of cleanness. 17 Figure 6-6 Secondary package 6.2.2 CanisterCanister packages are made of rigid plastics and contain either 6 litres or 10 litres of concentrate. The canister package is rarely used in Sweden but common in developing countries and some western countries e.g. Germany. At one of the visited dialysis ward they used the canister when they had machinery problems with the SelectBag® One. The canisters are connected to the dialysis machine by a pick-up tube that is put in the canister. When the tube is attached it is a gap around the opening that could be a hygienic risk for the patients. The canisters are heavy to carry when they are filled and they are bulky to store before and after usage. The lid is hard to open and they often use a special tool to open it. The users appreciate the handle of the can to ease the bearing. When the dialysis concentrate is in use the canister is usually standing on the floor and in some cases on the tray at the lower part of the machine. Sometimes the remaining concentrate after a dialysis treatment is saved up to one week. 6.2.3 SoftPac™ (Type 1)The SoftPac™ is a semi flexible package available in two sizes 3 litres and 5 litres. These packages are quiet heavy and hard to handle since they are difficult to grip and they doesn’t have any handles. The package has holes at the top where the package can be hooked to the dialysis machine. The package is connected to the machine by a connector. To empty the package after usage the user has to cut the package with a scissor. 6.2.4 SoftPac™ (Type 2)This is a flexible package of 5 litres volume, with a handle in one of the short sides. This package is connected by a spike. The flexible package is supposed to be hooked to the machine but the visited users find it too heavy to hook to the machine when the package is filled. Usually it is laid down and hooked only occasionally in the end of the dialysis in order to empty it properly. Another difficulty with hanging the package is the issue of see the opening, which is at a low height at the bottom of the package.The flexible package is bulky to handle before use and uptakes large space in the storage rooms. On the other hand it’s easy to handle after usage, when it is a flat. Before the package is connected to the machine, a membrane has to be removed from the package. This membrane is somewhat difficult to grab. 18 Figure 6-7 Canister. Figure 6-8 SoftPac™ (Type 1) Figure 6-9 SoftPac™ (Type 2) 6.2.5 SelectBag® OneThe SelectBag® One is a semi flexible package containing one litre which is connected to a holder at the left side of the dialysis machine. This packages is commonly used to the Gambro machine AK 200™ S, but doesn’t fit dialysis machines of other brands. The SelectBag® One package is popular among the nurses since it is small, light and easy to grip. The package is large enough for dialysis treatments of normal length but for long dialysis treatments it has to be changed during the ongoing treatment, which is time consuming.The Package has a lid to open before it’s connected to the holder. Some nurses experience this cap to be hard to open and it doesn’t provide any good grip. When put into the holder the membrane in the opening breaks. Most of the interviewed users appreciate the flexibility of the package but someone pointed out a risk for leakage if the user presses the packages too hard when the package is open.After the treatment there use to remain concentrate in the package. This liquid is supposed to be emptied automatically by the machine but the emptying process takes about 5-10 minutes and often the nurse doesn’t have the time to wait until it’s totally empty. The nurses want to start the disinfection program as soon as possible in order to get the machine ready for the next coming patient. Therefore the packages are thrown directly into the trash bin or in some cases emptied manually in the drain. Since the concentrate smells, this is not a good solution from a user perspective.There are sometimes troubles with the machinery when using the SelectBag® One on the AK 200™ S machine. When problems occur the machine sends alarms, gives error messages and the dialysis process stop. The nurses select the type of concentrate in the menu but it doesn’t correspond to the measured conductivity that results in an error message about wrong product. The way to come around this problem is to change to another kind of concentrate package e.g. cans. 6.2.6 BiCart® / SelectCart®The B concentrate and the salt are in cartridge packages in 19 Figure 6-10 SelectBag® One Figure 6-11 Cartridges. Figure 6-61 Attachment of cartridges and SelectBag® One on a AK 200™ S dialysis machine. The cartridge holders look the same as on the AK 96® dialysis machine today. form of powder. These packages are connected to the holders on the left side of the dialysis machine. Water is mixed with the powder inside the cartridges during the dialysis process and is automatically emptied after use, but about ¼ of the powder will usually remain after a treatment of normal length and is not possible to remove without tearing the package with some kind of tool. All visited users dispose the cartridge packages without emptying them. The users have difficulties with the caps at the top and bottom of the packages since they are too small to grip and hard to remove. There is a “parking place” for the caps aimed for placing the caps during the treatment, but these haven’t been used at the visited wards. Some throw them away; other users save them on other places until it’s time to remove the cartridges from the machine, replace the caps and throw it in the trash bin. Some dialysis wards had a cutting machine before to use for opening the BiCart® and SelectCart® packages in order to empty them and recycle the plastics. This cutting tool was dangerous and cumbersome to use according to the interviewees who had experience from this. 6.3 Summary of the Package Trial • All the interviewed nurses preferred flexible packages like the SelectBag® One before rigid plastic except one who liked packages like BiCart® better. • Small packages are preferred especially after treatment when the packages will be disposed. • The weight of the product is important, the lighter the better. • The time it takes to prepare the machine before a treatment, the priming, is very valuable and should not be too long. • To empty the concentrate container should be easy, fast and not cause health problems for the users. The best would be if the machine empties the container automatically, while the nurse is cleaning the machine. • The packages should be easy to dispose; small, lightweight garbage is preferred. 6.4 Task DescriptionThe primary user’s interaction with the concentrate packages are described by charts, HTA (Hierarchical Task Analysis) diagrams which describes the relation between the subtasks for performing the main task, in this case to connect the concentrate package to the machine. Interaction with two types of packages are analyzed, SelectBag® One and a canister. These diagrams can be found in appendix B. 6.5 InterviewsTen semi structured interviews where held with nurses from the visited hospitals. The results from the interviews where coherent to a large extent but some subjective thoughts about how they liked the products differed slightly among the individuals. The interviewees where both male and female and had between 4 and 24 years work 20 experience of dialysis. Also some more informal chatting with patients was held in order to hear about their picture of dialysis and how they found the dialysis equipment. Some of them operated the dialysis machines themselves. A few of the interviewed nurses had previous experience of central distributed concentrate i.e. the concentrate is delivered to the machine through pipes from a central at the ward. The amount of different concentrate packages and systems used gave a wide insight in the handling of concentrates today. The data gathered from the interviews and user studies where analysed by using KJ analysis. 6.6 Before During and After AnalysisBefore During and After, is a description of the overall interaction with the dialysis concentrate at the hospital. BeforeThe concentrate packages are delivered to the dialysis ward about once a week. The packages are packed in boxes e.g. six SelectBag® One packages a´ 1 kg in one cardboard box. Until the usage the packages are stored in a storage room at the dialysis ward. At some hospitals the packages are unpacked by the pharmacy personnel and then delivered to the wards on trolleys. In the preparation of the dialysis treatments the nurses pick up the concentrate packages of the right concentrations for each patient. Before the treatment starts, the nurse opens the concentrate package and connects it to the machine. The type of concentrate then has to be confirmed in the screen menu. DuringConcentrate packages can in some cases run out during an ongoing treatment. In this case the package has to be changed which causes an unwanted stop in the treatment. AfterAfter the treatment the concentrate package is detached from the machine. Remaining concentrate in canisters can be saved up to one week. In the SelectCart® and BiCart® packages there is usually some concentrate remaining after a treatment that cannot be emptied. The SelectBag® One automatically empties after the treatment. Then the package will be put in the trash bin. At some dialysis wards there is a system for sending the used packages for recycling. Finally the nurse cleans the machine and starts a disinfection program of the concentrate flow path. 6.7 System DescriptionDialysis concentrate is a part of a system and cannot be isolated; therefore a system description was performed. This system description is a simplified graphical overview of the elements involved in the dialysis treatment and illustrates how the interactions are organized. 21 Figure 6-7 Trolley with dialysis concentrates. Figure 6-8 System description over the dialysis treatment process.The system consists of three primary factors, the dialysis machine, the patient and the nurse. The machine consists of the main components; screen, dialyzer and software/hardware, which are placed in the inner area of the system description. Into the machine system come matter, energy and information in form of concentrates, water intake, power, and information from the nurse. During the treatment the patient is connected to the machine by tubes and blood from the patient is circulating through the dialyzer and UF liquid is taken from the patient. The system of the machine, nurse and patient is also affected by outer factors like lightening, other devises and noise.The nurse is interacting with both the patient and the dialysis machine. The nurse gets information about the status from the screen, gets alarms from the machine, gives information to the machine by interacting with the control panel and has a two-way communication with the patient. See picture above. 6.8 User DescriptionDesigning for usability includes designing for a specified user group. In the following text the aimed user group is described. The dialysis concentrates as well as the dialysis machines are primarily handled by nurses working at dialysis wards. The patients themselves in home environment can also handle the dialysis machine, but this is a minor market. The Gambro dialysis concentrates are distributed to hospitals all over the world. The nurses can be both male and female, of different nationalities and are aged about 20-65 years old. The education of the nurses can differ between different regions of the world. The experiences of dialysis treatment and the handling of concentrates differs a lot from user to user depending on how long time they have been working with dialysis. At the visited wards the learning period for the dialysis nurses differs between 6 weeks and three months. Within his period the nurse will be educated to operate the dialysis machine independently, needle the patients and learning other kind of work at the ward. The nurses always have colleagues to ask for help or for discussions whenever they need. Often they work in teams of two or three nurses per four - six patients. Apart 22 from the nurse there are also other types of users involved in the interaction with the product. Below the types of users are categorized according to the model of (Janhager, 2005). User type Nurse Manufacturer/ Salesperson/ Technician Nurse colleagues/ Physician Patient Primary user uses the product for its primary purpose. Side users are affected by the product´s functio n . Secondary users interact actively with the product but doesn’t use it for its primary purpose. The co-users are those who cooper- ate with the primary user or secondary user. Primary user Secondary user Co user Side user Who? Explanation Figure 6-9 Analysis model after Janhager 2005 applied on a dialysis machine The nurses start and finish between two and five dialysis machines each per day. Many dialysis nurses have ache in their hands and joints because of repetitive twisting and pressing moments in the daily work.The nurses have a large degree of responsibility in their handling with the dialysis, if something goes wrong it can affect the health of the patients. The Dialysis machines have a great system for detecting and warn the user for potential use errors. However some types of mistakes, laps and slips can still happen and the challenge in the product design is to prevent these and to make it possible recover from errors.Regarding use errors related to the dialysis concentrate there is a risk to connect wrong type of concentrate mixture. If this happen, the nurse have to look in the medical record and find out what the consequences will be for the patient. Sometimes the dialysis has to be interrupted and the concentrate has to be changed. The nurse can also ask a physician for advice. 6.9 Use ProfileThe following chart is an overview of the primary user’s relation to the concentrate product. It locates what important aspects to focus on in the interaction design. The aspects of high importance are located where the base of the triangle meets the coloured area. E.g. in the second row ergonomics and stress factors are considers to have an importance of high extent since the product has a high frequency of use. 23 Figure 6-10 Use profile applied on a dialysis machine. Analysis model after Janhager, (2005). One can see in the use profile analysis chart that the reliability and confidence are important aspects to consider since the user have great responsibility in the use situation. On the other hand the adaptability is of low or general importance as well as the semantics and aesthetics, due to the minor importance of social aspects and moderate level of cognitive and physical interaction. 6.10 Context DescriptionAt some wards the patients are treated in rooms of about four patients, while other dialysis wards have another organization with about ten patients in one room and a desk in the middle where the nurses control and overview the patients. It could be compared to an open office environment where many machines are placed in one room. There are more noises that affect the users in the larger rooms since there are more 24 people chatting as well as more noises from the machines that have a background noise and are sending out loudly alarms now and then. The patients have the ability to press an alarm button whenever they need help from the nurses. The patients´ alarm, as well as the machine alarms sends out in the corridor and in the lunchroom.The patients are coming regularly to the hospital, usually 2-5 days a week and the nurses know them well. The working day is planned in the morning, the nurses know which patients are coming and what treatment they will have and for how long each treatment is estimated to take. But unexpected changes can always happen depending on how the patient feels and if something happens in the treatment process.The dialysis machine is used daytime at the dialysis wards and the lightening in the room comes from the daylight and fluorescent lamps. At one of the visited dialysis wards, they used uplight laps as a complement, since they had experienced annoying screen glare on the machine monitors caused by florescent lamps.At the dialysis wards they often use two different types of A-concentrate packages, each of different types of concentrates in order to individualize it for the patients´ actual status. There is often a need to have a complement to the SelectBag® One since it causes problems in the start now and then. Another reason for using different concentrate packages is that they often have different types and a brand of machines and all packages doesn’t fit all types of machines. The Gambro BiCart®, SelectCart® and CleanCart® packages are for example designed to fit a special holding device which are only common on the Gambro dialysis machines. The customers are then forced to buy the whole concept from the company. Competitors are also using their own concepts of concentrate packages and holding devices. 6.11 Scenario It is seven a clock in the morning and the nurses at the dialysis ward are preparing the machines. Maria one of the nurses, is preparing an AK 200™ S dialysis machine for a normal HD (hemodialysis) treatment. She brings all equipment e.g. tubes, dialysis filter, needles and concentrates from the storage rooms. Then she mounts the concentrates to the machine and the tubes, dialyzer and the saline. Then she starts a priming program which aims to check if the system is ok and that there is no air in the tubes. Maria is documenting in the patient’s medical record what fabricate number (called LOT- number) there are of the equipment e.g. tubes, filter, dialysis machine and the concentrates. Some packages have a removable LOT- number sticker that can be placed in the medical record. Maria prefers the stickers since it is easy and prevents writing errors. 25 Figure 6-11Dialysis treatment. At half past eight John a 55 years old patient comes to the ward. The nurse Maria checks his weight and she calculates that he has got 2,2 liters more than his dry weight today. She asks if John wants to drink something during the dialysis. John wants a glass of juice and hence 2.4 litre of liquid will be removed today. The weight, flow rate and medicine are also documented. Maria sticks two needles into Johns so called fistula in his left forearm. Now it’s time to start the dialysis so she connects the tubes to Johns arm. The blood will circulate in the dialysis process for four hours. During the treatment Maria will come and check the blood pressure, pulse and the machine settings. John usually watches TV and eats breakfast during the dialysis treatment.The machine sends an alarm when it is finished. One of the dialysis tubes is reconnected to the saline bag and the blood in the tubes is given back to the patient. The machine starts to empty the A-concentrate package (SelectBag® One) and the liquid in the B-concentrate (BiCart®) and the salt (SelectCart®). Maria removes the second needle from John’s arm and gets some help from a colleague to remove the tubes from the machine and to clean it.The BiCart®, SelectCart® and SelectBag® One packages are removed and then Maria starts the heating program. Maria wants to start the heating program as soon as possible, since another patient will use the machine in the afternoon, so she often removes the SelectBag® One from the machine before it has been emptied and empties it manually, but it is acidic and smells terrible so she wishes there where a better way to empty the container.John´s weight is checked again and then it’s time to leave the dialysis centre for today. He visits the dialysis centre on Monday, Wednesday and Friday, every dialysis treatment is four hours long. It’s kind of a part time job, he says. 6.12 Design Specification Who is the user? The primary users are nurses at the dialysis ward or private operators using dialysis at their homes. The secondary user is the passive patient. Home dialysis is a minor market where the patient is operating the machines themselves and hence a patient could also be considered as a primary user. What is the product aimed for? The container will provide the dialysis process with concentrate. Where? The product is aimed to be used at the dialysis ward and in homes. The product will most probably initially be introduced in developing countries like the Chinese market. The package has benefits for clinical use even if it is more obvious for home use. How? The package is distributed to the hospital in box packages. The concentrate packages are then unpacked and connected to the machine before each treatment. When? The interaction with the product is mainly when preparing for a treatment and after the treatment when cleaning. 26 Why? The concentrate is used in the dialysis process to clean the blood. The package for the concentrate aims to hold the concentrate in the distribution before the usage and during the treatment. For how long time? The concentrate is used during the dialysis treatment. A normal dialysis treatment is about four hours long. The primarily user’s physical interaction with the product is when unpacking the concentrate packages, when mounting it to the machine and when taking it from the machine and handling the waste. 6.13 Aim of UsabilityThe aim of the usability for the project is to develop a concept for handling with dialysis concentrate by dialysis nurses primarily. It would be an advantage but not a must to make a design with a high level of intuitiveness so that a user can understand the interaction first time. The ability to do the right operations after learning the system is more important since expert users use it. The users operate the dialysis concentrates frequently every workday but it should be easy to remember the operation sequences after e.g. a couple of weeks of holiday. Further the system should satisfy the users in the user interaction, not irritate the users and it should prevent use errors and enable the ability for recovering. 6.14 Rules and GuidelinesIn the medical technology field there are many regulations for the product development in form of standards and guidelines. For human factors there are IEC 60601-1-6 and IEC 62366 to follow. An additional standard is used as a guideline to the process, namely the American National Standard HE75 that has to be fulfilled for products exported to the United States. The standards concern the process of developing user centred products for medical devices. The process must for example involve the users in the some activities of the development phases, such as usability testing of prototypes. 27 7 FUNCTION AND TASK DESIGNThe aim with the function and task design development is to specify the function and usage of the new product that will be developed. In this phase the requirements of the product is specified and a system goal, usability goals and utility goals are set. 7.1 System Description of the Dialysis FluidThe chart below is an illustration of the flow path and a description of the user interaction with the dialysis fluid. The picture is a metaphor of a heliocentric solar system where the user is the “sun”. Figure 7-12 System description of the dialysis fluid The primary user performs user actions in terms of physical interaction with the A-concentrate package, B-concentrate package and with the touch screen. The touch screen transfers the user actions to the:flow restrictor - wanted flow rateheater – wanted temperature of the dialysis fluidUF-measuring cells – settings for the draw liquid are set, where the differences of the volume in cell 1 and 2 is the drawn volume. The user can read information on the screen about the actual temperature of the dialysis liquid, the flow rate, the UF-volume, and the type of concentrate (conductivity cell). All 28 information is available in the screen menus whenever the user needs it. In the schematic picture above components of minor importance without interaction with the primary user are disregarded in this flow chart, e.g. valves and pumps.For the redesign it would be beneficial to provide the user with supporting information on the screen about how the concentrate packages are supposed to be attached to the machine, step by step. 7.2 Function AllocationIn order to decide what functions the user will make and what functions the machine will do, a function allocation analysis was made for the new package concept. Some functions are suitable or necessary to let the user do while others can be done automatically by the machine system. Today the LOT-number is a number on the package label that will either be written in the medical record or pasted in the analogue record by a sticker. A new technique is available for digital decoding of such LOT-numbers and it is assumed that this technique will be applied to the machine when the new package is launched. This kind of transference from human task to machine task is an advantage since the user will have one task less and the risk of decoding wrong number will also be decreased. The decision of when the concentrate has been mixed should be taken by the machine and communicated by information to the user. It is important that the user can see that the concentrate has been mixed and that the visual appearance of the solution doesn’t say anything else than the information from the machine. In the task allocation chart (appendix D) the human´s functions are at the left side while the machine´s functions are set to the right. The tasks related to the dialysis concentrate are marked with boxes and the arrows indicate the workflow. This Function Allocation analysis considers the main tasks; some tasks of minor importance have been neglected in order to highlight the main tasks that are essential for the design of the concentrate interaction. 29 7.3 Function and Task AnalysisIn the function and task diagram the identified requirements for the package concept are listed and categorized into three categories: Main function, Necessary function, Desirable function Task Requirements Assist the dialysis process with dialysis solution M Secondary or primary package that is impenetrable to water M Ability to mount without leak N Ability to see the concentrate through the package N Know when the concentrate has been mixed properly N Know that the solution has the right proportions N Ability to let the package stand when filled D Be connected to the dialyze machine M A connector placed at the base of the holder N Have a conic shape at the base of the concentrate container N Empty the concentrate container within 20 seconds D Ability to disinfect all components that will have contact with the dialysis fluid N Available in 4-5 formulations N Contain 1,8 litre of powder, i.e. 1800 g N Contain a chamber that can assist the FCH with dialysis fluid D Use Requirements Ability to handle easily when filled with liquid D Quick and intuitive to connect to the dialysis machine N Have the A concentrate on the right side and B-concentrate on the left side order to be consequent with existing “standards” D Clear differentiations of the different mixture packages N Lightweight and small N Be connected to the machine at a convenient height N Avoid interaction which can cause tension in e.g. fingers, arms, legs and back N Ability to fold/ flatten package after use D Have a removable LOT number on the concentrate package D Prevent wrong attachment of package N Max 10 minutes to do the FCH check + priming D Context Requirements Ability to connect to the AK 96 dialyze machine M Ability to connect to other brands/types of dialysis machines D Ability to clean around the connector N Not be in the way of other components N 30 Secondary Package Requirements Secondary or primary package that is impenetrable to water M Packages shall be arranged on an EU-pallet N Packages shall be easy to grip and carry N Packages shall contain a package leaflet (A5) N One package shall not weight more than 10 kg N 7.4 System GoalThe system goal is to provide the users with a good package concept for dialysis fluid that is based on dry concentrates. 7.5 Usability GoalsThe goals for the handling with the dialysis concentrate are listed below and derive from expertise estimations. The following goals are measurable and aim to be used in tests of design concepts later on by usability verification. 7.6 Measures for Efficiency The handling with the concentrate should have a high level of efficiency, in terms of reach the goal within a short time and with few errors.80% of the first time users should be able to prepare the dialysis concentrate within 10 minutes, without guidance. (The machine activities e.g. priming, are not included in the time estimation)80% of the first time users should be able to remove the package and clean the concentrate machinery within 5 minutes, without guidance. (Disinfection program is not included in the time estimation) 7.7 Measures for Effectiveness/ Guessability It would be an advantage but not a must to have a design with a high level of intuitiveness so that a user can understand the interaction first time.80% of first time users should be able to prepare the dialysis concentrate before the treatment. 7.8 Measures for Effectiveness/ Learnability Ability to do right operations after learning the system.80% of the users should be able to prepare the dialysis concentrate properly second time. 7.9 Measures for Effectiveness/ Memorability To remember the operation sequences after e.g. some weeks of holiday.90% of the users should be able to interact with the product correctly after 5 weeks absence. 7.10 Measures for Satisfaction The system should satisfy the users in the user interaction.Not more than 20% should feel irritation when handling with the concentrate package.80% of the users should feel confident and know that they have performed the task 31 properly first time.90% of the users should rate the package to be comfortable to use.These usability goals where updated later on and can be found in the test plan for the usability test in appendix I. 7.11 Utility Goals The following goals describe how well the machine will fulfil the system goal. The inputs to these aspects derive from investigations from the need identification. • The time it takes to prepare the concentrate for treatment should not exceed the time it takes to finish the priming • The machine should easily detect the right concentration, (conductivity). • Ability to disinfect the components that are in contact with the concentrate fluid. 7.12 AestheticsThe Gambro products don’t follow any design guidelines today. The design jobs are outsourced to design consulting firms in e.g. France and Italy. The lack of in-house designers and or design manager is probably a reason for the diversity in the design language of the product assortment. In 2007 a graphic profile was developed for Gambro, which provides design guidance for primarily two-dimensional designs such as labels, product sheets, package prints etc. The graphic identity manual provides user restrictions for the logo and colour scheme etc. These guidelines will be considered when dealing with the concept development of logo and label design within this project. 7.13 Aesthetic guidelines • Express honest • Express safe • Express hygienic • Fit in the Gambro product assortment 7.14 Environmental AspectsThe concentrate packages are consumption products with a short lifetime and hence it has a significant role from an environmental point of view, not least from the material perspective. The most important aspects to consider are the type of material used, the amount of material, the ability to recycle the material and the energy used in the usage situation. 7.15 Environmental Guidelines • The energy used for the disinfection should be minimized 32 • Reduce the weight. Do not over dimension • Reduce the volume in the transportation- make the package able to pile up • Make it possible to empty the package entirely • Simplify the flattening of the package material 7.16 Usability GuidelinesUsability guidelines aren’t measurable in the same way as usability requirements or usability goals. The guidelines aim to be guidance for the developing process in order to achieve a high level of usability. The guidelines derive from theoretical studies (T) and field studies (F). Clear differentiation in labeling design F Informative graphics or form ornaments guiding user actions T/F Good contrast of the text on the label T,F Be consistent T Provide feedback of the user’s actions and statues of the process T Feedback of what the machine is doing and how long it will take T/F Guiding instructions on screen for next user action, when nessesary T/F Explain reasons for errors and how it can be solved T Provide ability cancel and exit T Minimize the number of user input F 7.17 What if? – Risk Analysis A risk analysis was performed and applied on a general dialysis concentrate package concept. The purpose and goal of this analysis was to look for potential problems and errors with the developed package concepts and look for improvements and solutions. 1. What if the user chose the wrong concentrate from the storage room? If the dialysis treatment has started the nurse has to take a look in the patient’s medical record and determine what the consequences will be for the patient. In some cases the dialysis concentrate must be changed.1.1. What if the user has to replace the package? The dialysis treatment has to be stopped so that the dialysis concentrate package can be changed.1.2. What if the package is filled with liquid? The concentrate package has to be emptied by pressing a button in the screen menu, before it is removed. 2. What if the package breaks?Here we have two scenarios:-Before it is connected e.g. in the distribution- Then dry powder can leak out from the package.-After it is filled with liquid- Then the concentrate fluid can leak.2.1. What If the concentrate get in contact with skin? 33 Nothing serious happens, the concentrate isn’t fretting.2.2.What if the user doesn’t see that a new package is broken when connecting it? The package isn’t vacuumed any longer; the user will notice that the package has abnormal properties. 3. What if the package doesn’t empty? The user has to empty it manually by pressing a button in the screen menu.4. What if the machine doesn’t read the conductivity? This is a technical aspect that will not be considered within this master’s thesis. It is important that this issue will be solved for the final product since conductivity problems in general cause irritation and unsatisfied users, according to interviews with nurses.5. What if the package isn’t correctly connected to the machine? The machine will detect this problem. A description of it will appear on the screen with information about what is wrong and how it can be corrected by the user.6. What if the user doesn’t confirm that the treatment is finished? The concentrate package will not empty. A reminder will appear in the screen menu.7. What if the user doesn’t remove the package after treatment? The machine can not start the disinfection program. A message will appear on the screen with information about what is wrong and how the package can be removed. 34 8 INITIAL CONCEPT DEVELOPMENTAfter the need specification and the function analysis, the idea generation phase took form. Drawing pictures on papers carried out ideas, one idea led to another and so forth. Image boards in form of a function board and shape board was used for input as well as Osborne’s idea spurring checklist. Most of the ideas were based on the existing AK 96© machine as a starting-point and it was a help to have a specified product to relate the ideas to. The physical machine was available during the idea generation that was a good advantage and made it easier to estimate proportions, heights and volumes.The concentrate package concept contains three products: • a concentrate package which contains the concentrate • a concentrate module to which the concentrate package is attached • a box for transportation and storage of the concentrate packages 8.1 IdeationThe first brainstorming phase considered generation for overall concepts for how a concentrate could possibly look like and how and where it could be attached to the machine. Below are the main ideas from this ideation phase presented. Illustrations can be found in appendix C. 8.1.1 Cond-in-Bag (A)The container contains a simple conductivity meter (pad on the bag) that change colour when the appropriate conductivity has been reached (i.e. when the powder has been dissolved and the product is ready for use) 8.1.2 Supporting Holder (B)The dialysis concentrate is delivered in a flexible bag. The bag is filled with powder already from the manufacturing. In order to support and protect the bag it is hooked in a holder at one side of the dialysis machine. However the bag can be of a simple type since the holder will support it. 8.1.3 TopTray (C)The dialysis concentrate is packed in a large bag with a conic shaped bottom. The bag is connected to the top of the machine. The concept assumes that the machine has a concave top in order to fit the conic shape of the bag. Frames at the four sides will support the bag. The machine height should be able to adjust, so that the user can mount the package at a convenient height. The one-time bag can be of a simple type. 8.1.4 ConicBag (D)The package has the shape of a cone that is flat-welded at the top. The package has holes at the top aimed for hooking the package to one side of the machine (it could also be a clip or other fastening method). The user clicks the package’s connector to the inlet/outlet connector at the machine, and then she fastens the top of the package by hooks or similar. 35 8.1.5 ColoredCompartments (E)One oblong dialysis fluid container on each side of the dialysis machine, integrated in the machine. One compartment for the B- concentrate and one for the A- concentrate. The compartments are in red/ blue transparent polymer in order to visualize which one is for the acidic and bicarbonate respectively. The main idea of this concept is to have colour coded containers and to have the dialysis compartments nicely interacted with the machine at the front of the machine and the user interaction is at a convenient height. 8.1.6 Push (F)The powder package is pushed into a compartment with connection to a built-in container. The water inlet is suggested to be placed at the bottom of the powder package and the water flow will go up to the larger compartment above the powder package, where it will be mixed to a dialysis fluid. The best advantage of this idea is that less package material is needed since the package is smaller, the dialysis fluid is in a closed system and the user interaction is easy. 8.1.7 Re-Pac (G)The powder is packed in a relatively small package, about 2 litres. The user removes a foil and pours the powder into a container that can be reused. The dialysis fluid container could either be portable e.g. have wheels, or be stationary. Package material will be saved. Another advantage could be that the dialysis fluid can be mixed at another place in advance and then be connected to the machine, when its time to start the machine. 8.1.8 Cart (H)The dialysis concentrate is packed in a cartridge like the BiCart® package which has an inlet in the base and an opening at the top that is connected to a larger built-in compartment. The water will pass the cartridge and be mixed with the powder. 8.2 Brainstorming Workshop18 co-workers at Gambro participated in the workshop and were divided into three sub groups with competences and specialist knowledge within a wide range of disciplines. The first case for the workshop participants was to generate ideas that fulfilled two given constraints. Then the three groups gathered and shared their ideas and had discussions. Before the next session each group got additional constraints. After the last idea generation, the groups presented solutions by sketches and explanations for all the workshop participants. After the workshop the ideas where documented by short and concise explanations. The workshop generated in about forty different ideas in total for how the package can look like and how the connector can be designed etc. These ideas are not presented in the report. The workshop contributed with new discussions, new restrictions and possibilities, and some changes in the requirement list. 8.3 Task AnalysisThe task analysis in the previous chapter was updated and further developed into detail 36 according to the new information collected. The requirements are categorized for the concentrate package, module and box respectively. Main function (M), Necessary function (N), Desirable function (D) ID Task Requirements for the Overall Concept (T) Evaluation method T1 Assist the dialysis process with dialysis solution M check T2 Primary package that is impenetrable to water M check T3 Be connected to the dialyze machine M check T4 Available in 4-5 formulations M check T5 Contain 1,8 litre of powder, i.e. 1800 g M check T6 Know when the concentrate has been mixed properly N check T7 Know that the solution has the right proportions N check CONCENTRATE PACKAGE Task Requirements for the Concentrate Package (TC) TC1 Connection at the top and base of the package N check TC2 A filter must be implemented to the outlet connector on the package N check Use Requirements for the Concentrate Package (UC) UC1 Clear differentiations for the different mixture packages N test UC2 Lightweight and small N test Avoid interaction which can cause tension UC3 in e.g. fingers, arms, legs and back N test UC4 Ability to fold/ flatten package after use D check UC5 Have a removable LOT number on the concentrate package D check UC6 Have a LOT code on the package that can be read digital D check UC7 Avoid heavy load on the users body N check UC8 Ability to mount without leak N check UC9 Ability to see the concentrate through the package N check MODULE Task Requirements for the Module (TM) Ability to disinfect all components UM5 that will have contact with the dialysis fluid N check Use Requirements for the Module (UM) UM1 Attachment of concentrate to the machine at a convenient height N test/check UM2 No separate components that can be lost D check UM3 Avoid heavy load on the users body N check UM4 Design so that the package can´t be attached wrongly D test/check Context Requirements for the Module (CM) CM1 Ability to connect to the AK 96 dialyze machine M check CM2 Ability to connect to other brands/types of dialysis machines D check CM3 Ability to clean around the connections N check CM4 Not be in the way of other components on the machine N check 37 BOX Task Requirements for the Box (TB) TB1 Packages shall be arranged on an EU-pallet N check TB2 Packages shall contain a package leaflet (A5) N check TB3 Possible to pile efficiency N check TB4 Possible to pack efficiency in the factory N check TB5 Use cardboard as primary package material N check Use Requirements for the Box (UB) UB1 Packages shall be easy to grip and carry N test UB2 One package shall not weight more than 10 kg (Gambro´s guideline) N check UB3 Possible to flatten the package easily N check UB4 Avoid heavy load on the users body N check UB5 Avoid sharp edges for the handles D text/check UB6 Easy to open the package N test 8.4 Discussion of PossibilitiesAt this stage a number of ides and solutions had been developed and it was time to sum up its benefits and disadvantages. Here follows a discussion about the alternatives of sub solutions for the concept design. E.g. how a container can be attached to the machine, advantages and disadvantages with having an included VS separate container and a discussion about how the time aspect can be considered in the concept design. The discussion is based on literature, field studies and personal thoughts and opinions. 8.4.1 Placement of the ContainerIn order to provide the users with good physical ergonomics the attachment of the concentrate container should be at a convenient height that is easy to reach and control. The most convenient height is about 50-250 mm below the elbow height (Pheasant, Haslegrave, 2006). However from a mechanic point of view, it would be an advantage to set the concentrate container at a low height in order to achieve a low centre of gravity so that the machine becomes stable. A low placement of the container is a disadvantage in the users’ perspective, assumed that the users need to interact with the container by bending their knees and back. Some early ideas suggested a placement on the top of the machine, e.g. the TopTray and the BoyeFunnel, this placement is good from a functional point of view but poor for the users’ physical working situation since it forces the users to stretch their arms above the shoulders with a load of about 2 kg when the product is filled with concentrate. The challenge is to integrate the dialysis concentrate container to all the other equipment on a dialysis machine that competes with the space. Today the dialysis concentrates are attached at the sides of the dialysis machine and leave the front side for the tube set and screen etc. Since the concentrate in the normal case only needs interaction before and after treatment this priority seems reasonable.The total space of the dialysis machine is critic; the challenge is to make the machine as flexible as possible. The space at the dialysis ward is limited and many dialysis wards strive to take as many patients as they can in each room. A concentrate container placed at the side of the dialysis machine shouldn’t be too bulky since the width of the machine 38 is one of the critic parameter when it comes to stack many dialysis machines and beds side by side along the walls in a treatment room. Also in the home environment is the space limited and a compact machine is preferred also here. 8.4.2 Included VS Separate ContainerA dialysis concentrate container could either be included as a part of the dialysis machine or separated from the machine in form of an external one-use compartment. The advantage of having an included container in the machine would be a nicely uniformed design where the concentrate concept is integrated in the machine. Then the package for the concentrate could be just as small as the volume of the concentrate and hence package material can be saved. On the other hand does the included container need to be disinfected after the treatment, which means that a certain amount of disinfection liquid has to be heated up, then cleaning the compartment and finally the machine has to cool before next treatment can start. This process will probably be both time consuming and energy intensive. If an included compartment is be used, then it must be combined with an efficient way of disinfect the compartments. The alternative to the included container is to have a disposable separate container in which the concentrate is distributed. This container has to be big enough to take the added water. The separate container is only used once and hence it doesn’t need to be disinfected. The external container can be shaped in many ways and has many options for how and where it can be connected to the machine. 8.4.3 Time AspectsThe time is an important aspect when it comes to the effectiveness of the concentrate concept, especially at hospitals. It will take a certain time to dissolve the powder and a certain time to disinfect the machine between the treatments. It is important to shorten the time in order to increase the effectiveness in the work and organization at the dialysis wards. In the package design the time aspects can be considered by e.g. thinking about how the concentrate can be dissolved faster. Another way to shorten the start up time is to do things in parallel. It would be an advantage if the function check, priming and conductivity measurement could run at the same time as the concentrate dissolves. By talking to experts, function check and priming could run during the dissolved without causing any problem. The conductivity is a more challenging thing to solve since the conductivity meters in the machine need concentrate from the container in order to obtain a cond-value. If concentrate is taken from the container before the solution is dissolved the concentration will be unbalanced, this is not accepted. One way to measure the conductivity value of the concentrate would be to have a conductivity cell inside the container, sending out the value to the machine. The conductivity cell could also give redundant direct feedback to the user by changing colour to green when the solution is ready to use. However, for home dialysis the time aspect is less important, the patient is usually treated over the night while the patient is sleeping and the efficiency is less important when the machine only is used for one person. 39 8.5 Concept GenerationThe idea generation phase resulted in a bunch of ideas (see 8.1 and appendix C) which had to be categorized and evaluated, some was eliminated other pursued. The concepts where evaluated against the 10 most relevant and most important requirement from the Task Analysis.These requirements were: • Take up small volume in use • Small and lightweigt package before and after use • Potential for fast cond-check • Potential to fast dissolution • Potential to adapt the concept profile to BiCart • Potentail for low production cost for package • Potential to emty the package automatic after use • Potential to stack and pile efficiant in a secondary package • Adaptable to the AK 96 dialyze machine • Ability to disinfect all components easilyFrom the elimination matrix, the concept based on a flexible bag (E) was considered as having the best qualities for further development. 40 9 FURTHER CONCEPT DEVELOPMENTIn this section the further development of the concentrate package will be described. The methods used for the idea generation were primary sketching and making physical sketch models. Analysis methods such as Predictive Human Error Analysis and Cognitive Walkthrough were used in order to evaluate and improve the concepts. 9.1 Paper Models Figure 8-1The shape of the package, proportions, handle design and placement of inlet and outlet was investigated by paper models. 41 Figure 9-2 Test of package principle. Figure 9-4 The handles are folded. The purpose of the paper models (figure 9-1, 9-2, 9-4) was to try out different shapes, searching for an ideal shape and look for variations in handle design etc. The green circles are symbolizing the area that will be connected to the machine. The package has two connections to the machine, one for the water to come in at the top and one to deliver the concentrate, placed at the lower part of the bag. The bag is provided with a handle that aims to support the load of the filled concentrate package when the user is to attach the package to the machine. The user will hang the package and then fasten the package to the machine by the two connections. The handle is placed right above the centre of mass so that the package will be hanging balanced in its right position. A balanced package does not need any support and the users two hands are hence free to attach the inlet and outlet of the package to the machine while the package is hanging in a balanced position right in front of the connection areas. 42 Figure 9-5 The placement of connections are investigated. Illustration 9-3 Figure 8-3 Filled packages. 9.2 Attachment Figure 9-6 The package has graphic circles indicating where to press in order to attach the concentrate package to the machine. The pictures above illustrate ideas for how the package could be attached to the machine, e.g. by snap buttons that will grab around the connection or fastened by rotating a handle. Different shapes of handles where drawn in the purpose of finding out the best grip and the most communicative shape that tells the user how it is aimed to be handled, e.g. by rotation or by pushing. Some disadvantages of this concept were identified such as high precision needed, rotation of wrist, and transversal forces on the machine that could cause movement of the machine. 43 Figure 9-7 The package is attached to the right side of the dialysis machine. Figure 9-8 Connection of the concentrate package on the dialysis machine. Figure 9-9 Another attachment principle, where the package is attached by rotating a handle 90 degrees, screw to fasten. Experimentation with physical sketch models lead thereafter to a new idea of how the package can be attached to the machine. The package was rotated 90 degrees and the connections where places at the longer edge instead. A new direction of the package concept was found which provides advantages for the user in form of less precision needed to attach the package, no rotation in wrist needed, better grip and less force needed to attach the package to the machine. Figure 9-10 Attachment of concentrate. The package willfall into the machine. The new concept idea of the concentrate package has a track along the longest edge, so that the user can attach the package to the machine by pushing the package down in a holding device. The rail is pulled down in a track of the holding device so that the package will fall into its correct position. Position the package in the track and pull it down in the holder with support from the weight of the package. Then yo