Master's Thesis: Designing for Interactions Between Patients and Medical Devices

Project Type: Master's Thesis  //  Fall 2014 - Spring 2015

Program: Master of Design, Interaction Design  //  Carnegie Mellon University School of Design

Faculty Advisor: Professor Wayne Chung

For my Master's thesis at CMU, I explored interactions between patients and life-sustaining medical devices. My aim was to learn how the design of these devices could be enhanced to deliver a better experience and provide a better quality of life for patients. I designed a concept for a wearable dialysis dashboard, which would help patients to feel more in control of both their physical bodies and their lives.

To view the full text of my thesis, click here.

1. Project Definition and Scope

DESIGN RESEARCH METHODS: Territory Map, Stakeholder Map, Literature Review

The purpose of this research was to explore the interactions between patients and life-saving medical devices, to understand how the design of these machines can be enhanced to promote wellness and provide a better quality of life. Life-saving medical devices such as dialysis machines, artificial hearts (LVAD’s), and artificial lung machines (ECMO) are amazing pieces of technology that perform the incredible function of sustaining and extending life. However, aside from meeting the patient’s medical needs, it is also important to consider how interactions with these devices impact a patient’s psychological well-being and overall quality of life.

Types of medical devices in scope. 

Types of medical devices in scope. 

Types of Devices in Scope

I limited my scope to focus on medical devices that are life-sustaining, mechanically complex, and have the potential (now or in the future) to be used in the home.

  • Life-Sustaining: Life-sustaining devices place patients in the vulnerable position of depending on a machine to survive.
  • Mechanically Complex: Mechanically complex devices require the patients to form sophisticated mental models in order to understand how they work. These devices may also require a higher level of interaction and maintenance.
  • Used in the Home: Devices that have the potential to be used at home must be integrated into patients’ everyday lives. If the patient is also the device operator, they must be trained and must bear the responsibility for their own treatment.

The three main devices that meet these criteria are dialysis, LVAD’s (artificial hearts), and ECMO (artificial lung). Out of those three, I have chosen to focus on dialysis as my main case study.


Why Dialysis?

In addition the criteria listed above, dialysis is an ideal device to focus on because of several unique characteristics:

  • Environments: Dialysis machines may be used in a variety of environments, including hospitals, clinics, or homes. This creates many possible contexts of use.

  • Users: Dialysis machines may be operated by nurses, technicians, patients, or spouses / care partners. The wide variety of users introduces a wide range of possible interactions.

  • Time: Patients are on these devices for treatment sessions lasting typically 4+ hours per session, 3+ times per week, for years or decades at a time. Therefore, they play a very prominent role in patients’ lives.

  • Components: The mechanical complexity of dialysis machines means that they incorporate many elements (components and systems) common to a variety of other devices. They include pumps, IV tubing, needles, tubing with visible blood, filters, a screen-based interface, etc.

Stakeholder Map

For dialysis patients, there are a variety of stakeholders involved in their lives and in their care: family and friends, medical professionals, and other professionals such as social workers and dietitians. This may vary depending on where the patient is in their treatment journey, as well as which modality of treatment (home vs. clinic) they choose.

2. Exploratory Research

DESIGN RESEARCH METHODS: Case Studies, In-Depth Interviews, Affinity Clustering, Rose Bud Thorn, Personas, Concept Mapping, User Experience Journey Map

I interviewed a total of 18 people and asked them in-depth questions about their experiences, how they perceive and interact with the device, impacts on their lifestyle, and opportunities for improvement. I also read dialysis case studies including personal first-hand accounts from patients, caregivers, and medical professionals. 

Synthesis: Affinity Diagramming


Throughout the course of my research, I identified two categories of patient personas:

  • Passengers: Preferred having their dialysis treatments done in a clinic so they could relax and feel cared for. They tended to be more trusting of their care team, and felt relieved that the professionals bore the responsibility for managing their treatment. 
  • Drivers: Had a stronger need to feel in control over their dialysis machines and their treatment. They were more likely to second guess their healthcare team or ask for further explanations. These patients tended to feel happier and more in control when they were able to be trained and equipped to administer their own treatments at home. 
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Either of these personality types could cope successfully or unsuccessfully with being on dialysis. Passengers who coped best tended to be the outgoing, extroverted “squeaky wheels” who didn’t mind asking the dialysis nurses and technicians for exactly what they needed. The passengers who didn’t cope well tended to feel that they didn’t have a voice or the courage to speak up, and as a result they felt helpless over their situation and slipped into a silent depression. The drivers coped best when they were able to achieve independence by doing dialysis at home. Drivers who were unable to do home dialysis - either because they didn’t have a caregiver, due to other disabilities, or because of temporary complications - tended to be the most upset and distressed. 



The saddest part of my research was that many patients I talked to readily admitted that at some point they had considered voluntarily discontinuing their treatment, which would mean letting themselves die. This is so ironic and disheartening, because dialysis technology is so successful in replicating the function of the human kidney, and yet the machine still imposes such a poor quality of life onto these patients that they feel their lives aren’t worth living. I gathered several key insights from my research:

  • Lifestyle Restrictions: The device indirectly imposes certain limitations on the patient’s physical abilities and lifestyle. Patients must drastically alter their diet to supplement their care, the treatment schedule is a huge burden on their time, and their reliance on this machine makes travel logistically difficult. These restrictions greatly reduce the level of freedom and control that patients have over their lives, often leading to depression.
  • Service Ecosystem:  The complexity of the device necessitates an entire service ecosystem of nurses, technicians, doctors, and educators who must take responsibility for operating the machine or managing the patient’s treatment parameters. The people in these roles interact closely and frequently with the patient, and have a substantial impact on the overall quality of their experience. Patients tended to report having positive experiences interacting with the nurses, but oftentimes their interactions with the underpaid and overworked technicians were of lesser quality.
  • Level of Independence:  Due to the complexity of the device, patients must either rely on others to receive treatment in a clinic, or they must meet numerous physical and logistical requirements in order to feasibly perform dialysis treatments at home. Even with home dialysis treatments, a fully-trained caregiver (usually a spouse) is required to be present at all times during treatments in case of emergency. In either arrangement, the patient is completely reliant on others, greatly limiting their independence and sense of autonomy.
  • Mastery & Knowledge: Surprisingly, instead of being frustrated by the steep learning curve required to operate home dialysis machines, patients actually viewed the process as a positive experience. The intensive six-week training process was one of the few times that they had one-on-one attention from a nurse. Learning about the equipment and their disease made them feel empowered, like they were finally taking control over their lives. Their mastery over this medical procedure, which is normally only performed by medical professionals, gave them a sense of pride.
  • Supplies & Maintenance: The supplies required to operate the machine impose a huge logistical burden on home dialysis patients who are already struggling with a severe illness. Some devices require 20 or more boxes of fluids and disposables to be delivered per week, then carried, stored, inventoried, and disposed of in one’s home. The supply inventory can take up an entire closet, or sometimes even the whole length of a wall in a spare bedroom. This makes travel especially difficult, because in additional to moving a bulky and heavy machine, supplies must be coordinated and delivered as well.
  • Future Outlook: All of these factors impact a patient’s overall outlook. However, there is a difference between devices intended for short, temporary use in emergency situations, versus devices that the patient will remain on permanently. It is easier for people to cope with various stressors if they know they will be cured, or if the situation is only temporary, although the experience stays with them if it was traumatic. But for dialysis patients who will be on the device for the rest of their lives, we must consider how the overall device experience impacts their quality of life and outlook on the future.

One key aspect of a dialysis patient's experience that makes it different from an LVAD or ECMO patient's experience is the chronic nature of their disease. LVAD and ECMO patients face acute emergency situations in the hospital where their lives are imminently in danger. While dialysis patients may face complications that may require hospitalization, the majority of their experience is dealing with chronic struggles either at home or at a clinic.

Dialysis Patient Experience Journey Map

Dialysis Patient Experience Journey Map

3. Generative Research and Concept Generation

DESIGN RESEARCH METHODS: Concept Mapping, User Experience Journey Map, Abstraction Laddering, Speed Dating

The insights I gained from my user interviews showed how the design of dialysis machines can impact a patient’s quality of life. In order to move forward with identifying a design solution, I first created a summary of user needs to be addressed:

  • Health: Dialysis patients want to optimize their physical health. They want effective dialysis treatments, and the ability to customize them to suit their individual needs.
  • Time: Dialysis patients have many demands placed upon their time. Long treatment sessions, travel time to and from appointments, and managing logistical tasks makes dialysis feel like a part-time job.
  • Mobility: Dialysis patients are restricted in their mobility. They can’t move their arm during treatments, they are confined to a chair, and on a larger scale they are limited in their ability to travel. 
  • Purpose: Dialysis must not interfere with one’s ability to find meaning and purpose in life. Patients want to spend quality time with family, and for some people, maintaining the ability to work is important.
  • Control: Dialysis patients want to be in control of their treatment and their lives, but their independence can feel limited due to their reliance on caregivers and their healthcare team. The ability to choose a treatment modality that suits their personality, as well as receiving dialysis education, can help them to regain a sense of control. 

Speed Dating Design Concepts

I created an online speed dating survey to gather feedback from a variety of dialysis users. I reached out to patients who I had previously interviewed, as well as additional patients through social media platforms and support groups.

Concept #1: Putting control in your hands

In dialysis centers, oftentimes patients cannot physically see the screen on the dialysis machine, because it's facing away from them. In this concept, dialysis machines would come with a second portable screen, like an iPad or a tablet, that patients could view to see what's happening during their treatment. It could show how much time is remaining, how much fluid will be removed over the course of the treatment, as well as their personal treatment history - things like statistics and data trends over time. 

Concept #2: A personalized treatment roadmap

Medical charts don't always tell the whole story. They don't consider a patient's emotions, or other external factors impacting their quality of life. This roadmap would be a personalized story of one's dialysis history, treatment plan, and goals - created by the patient themselves. It would be more than just numbers and data. It would include past struggles, and any customizations they've made to their treatment regimen. It would also include goals, whether that's losing weight so they can get a transplant, or being able to travel so they can go on vacation or visit family. The roadmap could be something physical, on a piece of paper, or it could be digital, shared online.

Concept #3: A dialysis machine that takes care of itself

Dialysis machines should act like guests in your home. They shouldn't leave messes all over the place, and they shouldn't rely on you to take care of them. This concept would be a service that would be paired with home dialysis machines. The service would take care of ordering dialysis supplies, scheduling routine maintenance, and arranging transportation for the machine when you want to travel. This shifts the burden of responsibility off of the patient, so they can focus on taking care of themselves.

Strained Relationships

The most common theme throughout the survey responses was the strained relationships between patients and their healthcare team. Starting from the time the patient is faced with this devastating health crisis, they feel like their healthcare team is always telling them what to do (don’t eat this, come to this appointment, go to these treatment sessions). Patients lose many personal freedoms, including their time, their ability to freely travel, and potentially the ability to work. Along with the loss of so many freedoms and their loss of autonomy, receiving all those orders makes patients feel like they are always being bossed around. 

From the healthcare team’s point of view, they must frequently interact with patients who are depressed and angry, who take out their frustrations on whoever is around. Furthermore, they see the consequences of poor lifestyle and health decisions on a daily basis, so it frustrates and saddens them when patients don’t adhere to their diet restrictions or treatment plans. 

Finally, there is tension that develops around the machine itself. Since it’s such a complicated device that requires special training to operate, patients may not always understand what is happening or why the professionals are making certain decisions. This communication barrier, combined with other existing tensions, can lead to a breakdown of trust. 

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4. Prototyping and Evaluative Research

DESIGN RESEARCH METHODS: Interactive Prototype, Experience Prototyping, Survey

System Map & Opportunity

This system map describes the complex relationship between patients and their care team, and how tensions can build to manifest in the problems described above. The opportunity space is to shift this power imbalance by empowering patients be educated in their care, and take an active role in their treatment.

Design Solution

My design solution is a wearable dashboard displayed on an armband, that makes a patient’s data and status both visible and accessible to them during their treatment. On a subtler level, the armband also metaphorically communicates to the patient’s healthcare team that the patient is in control of their body. The goal of this solution is to empower patients to take an active role in their treatment, increasing their sense of control over their lives.

  • Visibility: Make data visible to patients by placing it where they can physically see it, and presenting it in a way that is intuitive.
  • Ownership: Give patients ownership of their data to make them active participants in their treatment.
  • Relationships: Improve relationships between patients and their health care team by metaphorically communicating that the patient is in charge of their body.
Dialysis armband illustration-03.png

The above visualization represents a flattened view of the armband interface. Click anywhere to start a "treatment session," then click to cycle through screen views. Use up and down arrow keys to rewind or fast forward the treatment session. (If the interactive prototype won't load in your browser, CLICK HERE to view in Open Processing).


Interactive Prototype and Ambient Data Visualization

The dialysis dashboard externalizes the patient’s current system state by using intuitive visualizations to make their information understandable. Four different screens show time, fluid volume, flow rate, and waste removal. The blue fluid height represents the volume of excess fluid remaining to be removed from the patient's bloodstream. The yellow particles represent urea waste products that are being removed through the dialysis treatment. Their flow rate and concentration will change as the treatment progresses. The goal of this visualization is to ambiently convey the progress and therapeutic nature of the treatment to the user.

Time Remaining:  One of the most frequent questions that dialysis patients ask during treatment is, “how much longer is this going to take?” This dashboard communicates not only the amount of time remaining, but also the variables it is dependent upon.

Time Remaining: One of the most frequent questions that dialysis patients ask during treatment is, “how much longer is this going to take?” This dashboard communicates not only the amount of time remaining, but also the variables it is dependent upon.

Flow Rate:  The faster the blood moves through the machine, the faster it will be cleaned. However, higher speeds (as represented by the movement of the particles) may cause the patient to experience painful cramping. This visualization shows flow rate settings throughout the course of the session, so the patient knows when to expect the higher flow rate stretches.

Flow Rate: The faster the blood moves through the machine, the faster it will be cleaned. However, higher speeds (as represented by the movement of the particles) may cause the patient to experience painful cramping. This visualization shows flow rate settings throughout the course of the session, so the patient knows when to expect the higher flow rate stretches.

Fluid Volume:  Dialysis treatment removes excess fluid that has accumulated in the body. The blue background area represents the volume of excess fluid remaining. The fluid level starts the top of the screen, and gradually drains to the bottom by the end of the session. 

Fluid Volume: Dialysis treatment removes excess fluid that has accumulated in the body. The blue background area represents the volume of excess fluid remaining. The fluid level starts the top of the screen, and gradually drains to the bottom by the end of the session. 

Waste Removal:  The key goal of dialysis treatment is to remove excess waste products that have built up in the body. The yellow particles represent the waste products in the bloodstream. These particles will gradually disappear throughout the course of the treatment session.

Waste Removal: The key goal of dialysis treatment is to remove excess waste products that have built up in the body. The yellow particles represent the waste products in the bloodstream. These particles will gradually disappear throughout the course of the treatment session.

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User Feedback

I distributed an online survey to dialysis patients via social media support groups in order to show them my design concept and gather their feedback. I received a total of 65 responses, which consisted of mostly positive reactions to the design, as well as some ideas for future improvement. The most common complaint about the design was the physical form. Patients were concerned about having to wear and be tethered to yet another device, and some people perceived it as something that would further restrict their movement.

Alternative Form Factors

At the end of the survey, I presented the two alternative designs (the phone app and watch concepts), and asked patients for their thoughts as well as which design they preferred. Although many people noted that the armband would be beneficial for people who don’t have smart phones or for elderly people who aren’t familiar with phone interfaces, the vast majority voted in favor of the app concept. Their main reason was that regardless of the cost of the device, they didn’t want to wear something else since they already felt like they were losing autonomy over their bodies. 16 people preferred the armband, 44 people preferred an app, and 5 preferred the watch design.

Alternative design concepts: mobile app vs. smart watch app

Alternative design concepts: mobile app vs. smart watch app

5. Reflection

The overarching goal of this project was to recognize the role of medical devices in creating interaction and quality of life challenges for patients through the nature of their design. 

Through my research, I found that the design of dialysis machines impacts a patient’s experience on several different levels. Physically, the large size of the machine and the presence of needles and visible blood can initially be intimidating and can incite fear in patients. Functionally, the complexity of the device necessitates that the patient either travels to designated clinics to receive care from trained professionals, or they must undergo a lengthy training process to administer their own treatment at home. Emotionally and psychologically, factors such as the nature of the treatment, the service ecosystem that exists around the device, and the lifestyle restrictions that the treatment regimen imposes have a profound impact on a patient’s quality of life. Overwhelmingly, all of these factors combined can make a patient feel out of control of not only their body, but also their life. 

My design solution serves as an example for how negative effects such as these can be mitigated through the design of the device itself. Although further iteration on the design would be required in order to address all of the patients’ needs, the approach demonstrates how devices can be designed to empower patients to feel in control during the treatment experience. 

This design approach would be applicable to a wide array of devices, beyond just dialysis. As heart pump and artificial lung technology advances to the point where more patients are living on these devices for extended periods of time, it will be equally important to address quality of life and patient autonomy issues for patients on those devices as well.