Designing an Affordable Distal Radius Fracture Reduction Simulator for Medical Training; Lack of Diversity in Medical Devices and Simulators: A Sociotechnical Analysis

Despite their routine use in healthcare, medical devices and simulators often fail to serve all patients equally because they are primarily designed for white men. This idea was the driving force behind this Capstone project and STS (Science, Technology, and Society) research, which explored how medical devices are developed and constrained by institutional bias. The Capstone project focused on the design and development of an affordable and realistic wrist fracture reduction simulator. This was driven by the need to expand accessibility to a high-fidelity model representing one of the most common bone fractures. Meanwhile, the STS research investigated why medical devices and simulators fail to represent the majority of the patient population. The exclusion of important demographics such as gender, age, weight, and race is seen in a majority of devices on the market despite their benefits. The Capstone project provides tangible experience with how medical simulators are designed and developed, while the STS research explores the reasoning behind the normalization of non-representative models. These two projects work in tandem to reveal that non-diverse models are not a result of technical oversight, but rather a product of structural biases reinforced by a lack of regulation.

A Capstone team of eight members worked together to balance cost and realism when in the design of a wrist fracture reduction simulator. Essentially, this device allows medical students to practice “setting” broken wrists in a risk-free environment; specifically for a distal radius fracture. Distal radius fractures are one of the most common bone fractures, and current devices for this fracture are priced upwards of thousands of dollars. Additionally, models on the market reflect the anatomy of a fit, white male, poorly representing the wide variety of patients that undergo this wrist reduction procedure. The design approach heavily emphasized flexibility, accessibility, and 3D printing to reduce costs and allow for easy changes to designs. The development of an adjustable tension system, interchangeable components, and a silicone exterior were all subprojects that contributed to the final design. To verify the correct “feel” of the simulator (in function and physicality), the project heavily relied on iterative feedback from an orthopedic surgeon to refine its realism.

The final design of the wrist fracture reduction simulator nearly met all of the original specifications: realistic bone orientation and skin feel, accurate reduction forces (confirmed with expert feedback), two states of equilibrium (broken and “set”), adjustable tension representing tendons, ability for splinting, and total cost of under $150. The bones, base, hand, and silicone molds were developed using 3D printing; allowing the design to be scaled and easily recreated by others. The adjustable tension system was made by connecting elastic cords to guitar tuners, and the skin sleeve was made by pouring soft silicone into a mold. Finite element analysis (FEA), stress calculations, and testing were performed to confirm the strength of the design. The final prototype consisted of a silicone sleeve with plastic hand and bones within it, attached to a base that contains the tensioning system.

The STS research asked an important question: Why do medical devices and simulators fail to represent the majority of patients they aim to heal? Medical devices and simulators are designed using white male anatomy and medical data, which results in less effective devices for the majority of the population. An extreme example of this can be seen in the automobile industry, where women are more likely to suffer injuries or pass away in car accidents because the use of female crash test dummies aren’t required. In addition, the female dummy is so small that it also serves as a child dummy. Research was carried out in three phases. First, literature analysis was performed regarding the current state of medical devices and policies that regulate them. Next, original data was collected that outlined the demographic makeup of the top medical device company leadership teams. Finally, Actor-Network Theory was used to examine the impacts and relationships between key actors (company executives, regulations, and market dynamics) that contribute to the development of medical devices.

The research revealed that medical simulators overwhelmingly depict white male anatomy, and that diverse models are less detailed, more expensive, and less commonly available. A key finding regarding medical device policies reveals that diversity is not required in clinical trials, so devices can be sold on the market without testing on women and racial minorities. Another key finding was that the leadership demographics of the top 10 medical device companies reflect the lack of diversity in their products; all CEOs were male, and 80% were white. On average, executive boards were composed of 33% women, and 23% racial minorities. Combining these factors with a market structure that rewards mass-produced models; the exclusion of diverse features becomes systemic. Medical devices don’t require diversity in testing, company leaders create products that are familiar and profitable, and medical schools aren’t required to use diverse simulators. This cycle reinforces the presence of standardized models, and gives no incentive for change or improvement. This research concludes that regulatory bodies are the sole actor responsible for constraining this sociotechnical system.

School of Engineering and Applied Science

Bachelor of Science in Mechanical Engineering

Technical Advisor: Jason Forman

STS Advisor: Pedro Francisco

Technical Team Members: Natalie Bretton, Ryan DeLoach, Lauren Elliff, Brian Garmer, Greer Matthias, John Murphy, Ethan Norris