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

Project Type: Master's Thesis at Carnegie Mellon University School of Design // Fall 2014 - Spring 2015

Faculty Advisor: Professor Wayne Chung

For my Master's thesis, I am exploring how patients perceive and interact with life-saving medical devices. Aside from performing the crucial function of supporting life, it is also important to consider how interactions with these devices impact a patient's psychological well-being and overall quality of life. I am focusing on dialysis as my main case study due to the wide range of challenges and design opportunities it poses, as well as its applicability to related devices such as heart pumps and artificial lung machines. My goal is to improve the dialysis patient experience through the interactions with the device itself.

This project is currently in progress, to be completed in May 2015. 

1. Project Definition and Scope

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

The purpose of this research is to explore the interactions between patients and life-saving medical devices, to understand how the design of these machines can be improved 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 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 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. 


When designing a medical device, there is a hierarchy of needs that must be addressed. First and foremost, the device must achieve its medical function of keeping the patient alive. Second, the device must be usable so that the medical professionals and/or the patients themselves can operate it without making mistakes. However, beyond that, in order to consider the greater implication of how living on this device will impact a patient’s psychological well-being, we need to step back and look at the greater context in which the device exists. 

  • Lifestyle: The device indirectly imposes certain limitations on the patient’s physical abilities and lifestyle. This can greatly reduce the level of freedom and control they have over their lives, which can be difficult to cope with.
  • Service:  An entire service ecosystem exists around the device, consisting of nurses, technicians, doctors, and educators. This indirectly impacts the types of interactions that patients will have with healthcare professionals, and the level of attention they will receive.
  • Independence:  The nature of the device and the treatment dictates whether it must be operated by medical professionals in a medical environment, or at home by the patient. Some devices can be operated at home but require the help of a secondary care partner. This impacts the level of independence that people have in their lives, which has a great effect on their psychological wellbeing and outlook. 
  • Supplies & Maintenance: The supplies required of the device and its ongoing maintenance can create an undue burden on people who are already struggling with a severe illness. Some devices (peritioneal dialysis) require over a dozen large boxes per week to be delivered, moved, stored, inventoried, and disposed of in one’s home. Other devices limit the patient’s ability to travel based on the locations where their device can be serviced, and the logistical challenge of moving supplies.
  • 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, vs. 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 reality that the device imposes impacts their long term outlook for 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.


User Experience Journey Map

As I was putting together my findings from my user interviews, I found that the most natural way to tell all of the experiences and stories was through a collective user experience journey map. This format helped to inspire one of my preliminary design concepts, described in the next section.

3. Generative Research and Concept Generation

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

Preliminary Design Concept

In order for designers to fully understand how a medical device may impact a patient's life, I am proposing a patient experience journey map that outlines various milestones in a patient's medical journey, as well as the emotional states that they face along the way. This particular map is specific to dialysis patients, however, the general idea can be applied to other devices such as LVADs and ECMO as well.

It is my hope that this map not only serves as a tool for medical device designers, but that it also facilitates discussion between the product designers, service providers, and the patients themselves about where the gaps are and where opportunities for improvement lay. I would also like to explore whether this tool could be useful for individual patients as a roadmap or discussion tool with their care team, to help them mentally prepare for life changes, anticipate issues, be aware of options, and talk about and track progress towards long term goals.

Dialysis Patient Experience Journey Map

Dialysis Patient Experience Journey Map

Midterm Poster Session

In December 2014, we had a midterm poster session to present our research findings and show our preliminary design concepts. If you'd like to see a full-sized version of my poster, click here to download the PDF file.

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 on the computer.

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.

Concept Feedback: Relationships are the bigger issue

I speed dated the various concepts with 22 users (mostly dialysis patients, some caregivers), and received an interesting mix of results. Home dialysis patients most preferred the third concept, because they felt that the management of incoming supplies was a part time job, which added no value to their care or sense of purpose. Dialysis patients who receive treatment in clinics most preferred the first concept, though many noted that they already ask their technicians to turn the machine towards them so they can see the screen. However, the concept appealed to them mainly for its potential to empower patients to be educated about dialysis and thereby better advocate for themselves. Most surprisingly, the second concept was highly favored by all in theory, for its potential to allow patients to be actively involved in their care, but most people felt that it would fail in its current state. The issue was not so much a lack of opportunity to communicate about goals and plans, as much as it was a perceived lack of sympathy from the care team. Patients felt that if their care team had this info they would either ignore it, or use it to patronize them. This tense relationship between patients and their care team was a common theme underlying many of the smaller issues that manifested as a result.

4. Prototyping and Evaluative Research

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.

Prototype Concept

A concept I'm exploring is a wearable dialysis screen for patients receiving care in clinics, which visualizes treatment status and parameters through an ambient, abstract visualization. On the surface, this concept creates a way for patients to understand and feel in control of what is happening to their bodies. On a deeper level, this visualization helps to encourage healthier relationships between patients and health care professionals through education, promoting active involvement in one’s care, shifting power and control to the patient, and personalized self-expression.

The dialysis display could be worn on customizable, personalized arm bands that coordinate with the patient’s personality and outfits. Over time, these arm bands could be collected and displayed as artifacts to symbolize their journey and progress over time. 

5. Reflection and Communication

(Coming soon!)