BEfast
Bariatric Echo Focused Assessment with Sonography for Trauma
This educational device was designed as a Bioengineering Senior Design project at the University of Pittsburgh, Swanson School of Engineering. This course implements the medical device design lifecycle, from ideation to validation, over a two semester sequence course. The aim of this project is to develop an emergency medicine training tool to facilitate learning FAST (focused assessment with sonography for trauma) exam on bariatric patients.
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This course enabled me to learn...
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FDA Quality System Regulation (QSR) with Emphasis on Design Controls
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Risk Analysis (Fault Tree, Failure Modes & Effects Analysis)
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Forming a Comprehensive Design History File (DHF)
Project Overview
BEfast is a medical education simulation device. Beginning in the Fall 2021 semester, our team started the needs finding process through extensive outreach and ethnographic study with a variety of medical professionals, as well as patients, about the problems they face in their experience with the medical field. Initially, our team identified 35 unmet needs, which were then evaluated using ethnographic data to ultimately converge on a single project topic: training student physicians to perform the FAST exam on bariatric patients.
Personal Contribution
During our needs finding process, I worked with with physicians from the UPMC Emergency Medicine Department, as well as the MageeWomens Chronic Pelvic Pain and Endometriosis Center, administrators at WISER (Winter Institute of Simulation, Education and Research), and physical therapists at the UPMC Center for Assistive Technology (CAT) to identify unmet clinical needs.
After converging on our final project topic, we began specific ethnography pertaining to Emergency Medicine, Medical Education Simulation and ultrasound. I performed 5 ethnographic observations, ranging from participating in ultrasound classes at WISER to observing the use of emergency medicine training dummies.
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Once our team began prototyping, I assisted in the production of multiple small scale silicone models that were used for informal testing to inform our final design. Finally, I was individually responsible for two of our formal tests: Portability and Mechanical Loading
I performed...
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5 Ethnographic Observations (~10 hours)
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2 Design Reviews with Emergency Medicine Physicians (~4 hours)
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3 iterations of physical prototypes
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2 V&V test plans, protocols and reports
Our team's booth at the Swanson School of Engineering Spring 2022 Design Expo
A design review with Dr. Adam Tobias of the Emergency Medicine Department
Preparing a silicone mixture for a chest prototype, which contained a PLA 3D printed heart and polystyrene rib cage.
Project Background
The FAST exam (Focused Assessment with Sonography for Trauma) is a common diagnostic tool used by Emergency Medicine physicians when a patients arrives in the emergency room following an abdominal trauma. This involves a rapid evaluation of 4 key regions of the abdomen to identify free intraperitoneal or percardial fluids in the Right Upper Quadrant (A), Left Upper Quadrant (B), pelvic region (C), and subxiphoid view of the heart (D).
Currently, WISER uses the trainer (pictured on the left) to allow student physicians to practice ultrasound technique before performing on a live patient. Additionally, WISER offers courses where "patient volunteers" are used as ultrasound subjects.
However, both of these models for learning fall short in some ways. Using a volunteer patient only provides experience with identifying "normal" anatomy, whereas most individuals presenting in an emergency room will not have normal anatomy. The dummy trainer only demonstrates one body type, a physically fit male, yet ~42% of all adults in the US are considered "obese".
When evaluating obese patients, the excess adipose tissue poses a challenge when obtaining an ultrasound image, so additional force and alternative hand positioning must be used. Without practice on a variety of body types, emergency medicine students may not be fully proficient in real-life scenarios.
Ideation
Our team identified the unmet clinical need for a bariatric ultrasound model that could facilitate training for the cardiac subxiphiod view during a FAST exam.
Using anthropometric data, we produced this low-resolution foam-core model to roughly estimate the dimensions and volume of our design.
21"L 17"W 18"H
Prototyping
Top view of Eco-Flex cube chest model
Backside view of Eco-Flex Cube model before silicone filling
We produced two cube shaped models with a PLA 3D printed heart and polystyrene rib cage using two different silicone materials : Eco-Flex (pictured above) and Dragon Skin.
Through testing with a ultrasound machine, we determined that the image fidelity was preferable on the Dragon Skin model, while the texture and feel was preferable on the Eco-Flex model
Dr. Adam Tobias testing our models with an ultrasound machine
Scaled Prototype
We produced a miniature version of our propsed design (11"L 7.5"W 3"H) with a modeling clay heart and polystyrene rib caged embedded in it.
This model allowed us to further refine our materials selection and freeze our design.
Polystyrene, heat formed rib cage
Modeling clay miniature heart
Design Freeze
Our final production equivalent device is composed of 13 liters of Ecoflex 30 silicone, a ballistics gel heart and a polystyrene ribcage.
V & V Testing
Screen capture from ultrasound on the BEfast
Verification: Mechanical Loading
I developed the plan, protocol and report for this verification test. It required 4 test technicians who applied 25 cycles of the specified load to the surface of the BEfast. After each technician completed 25 cycles, I inspected the trainer for detectable damage according to a predetermined data sheet.
Acceptance Criteria: the BEfast is able withstand 100 cycles of 7 PSI applied over the estimated area of an ultrasound probe (2 in2) without detectable damage
Status: Failed
Validation: Portability
I developed the plan, protocol and report for this validation test. It required 10 test technicians who transported the BEfast from one specified surface to another and then evaluated the difficulty of this task based on a predetermined data sheet.
Acceptance Criteria: the level of difficulty for “Picking Up from Storage”, “Carrying” and “Returning to storage” should average a Difficulty score of < 3
Status: Passed
Our team received 2nd place in the Swanson School of Engineering Spring 2022 Design Expo for the Bioengineering Department
