Development of a Wearable Device to Manage Upper Extremity Lymphedema
Virginia Tech and Carilion Innovations Research
June 2021- Present
Project
Background
Funding provided by Carilion Innovation
Proof of Concept Program
Total Awarded: $20,000
The project first started as a summer internship but quickly evolved into something bigger. We were connected with Tara Newberry (Carilion Clinic Oncology Rehab Coordinator, COTA/L, CLT, OCC) who first proposed the idea of combining vibration and compression to alleviate lymphedema symptoms. After initial prototyping during the summer, we received confirmation and more funding from Carilion Innovations to continue our work.
During my final year of college, I led the team to continue our research and experimentation, further develop the device, and work towards commercialization.
Clinical Background Research
1.
Lymphedema affects 3 to 5 million Americans and approximately 140 to 200 million patients worldwide [1,2]
2.
The chronic, progressive condition is treatable, but not curable, leaving patients with debilitating symptoms that can significantly impair their quality of life [3].
3.
There is a gap in research, as well as technology, regarding the use of wearable technology to provide targeted lymphatic drainage to various parts of the body.
Current Treatment Methods
These are some of the most common ways that certified lymphedema therapists use to treat patients with lymphedema.
Manual Lymphatic Drainage
Patients typically undergo manual massage therapy from licensed lymphedema therapists to stimulate lymphatic drainage.
Handheld Vibration Tools
Although this might not be commonly used in the field, Tara Newberry has been using vibration tools for pointed stimulation, which is what inspired her to ask us to research more about the effects of vibratory stimulation on lymphatic drainage.
Compression Garments
Many patients wear compression garments daily in between their massage therapy treatments to help reduce swelling.
LIMITATIONS
- Must be completed by a licensed therapist, which increases patient dependence on ongoing treatment
LIMITATIONS
- Only provides stimulation in specific areas rather than whole limb vibration
- Handheld tools have not been officially proven/marketed for lymphedema treatment
LIMITATIONS
- Can be very painful and uncomfortable for patients
-Currently one of the few options for at-home use
- Restricts patient mobility
- Very expensive
Our Solution
A Wearable Device Combining
Vibration + Compression
Our device has embedded vibration motors in a compression sleeve, providing a customizable lymphatic drainage massage that can be used by patients at home.
Goals: To promote lymphatic drainage and to promote independence by creating a better at-home treatment option
Personal Contribution 1.0
Vibration Motor Analysis
Skills Used:
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Experimental design
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Statistical analysis
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Signal processing
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MATLAB
To characterize the motors and understand the ideal frequency for lymphatic drainage, I conducted several experiments to gather vibration data.
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My teammate created silicone blocks (formulated with a special formula to mimic human tissue) and I sewed mock compression sleeves to wrap around each block.
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I attached a vibration motor to one side of the block and an accelerometer to the opposite side. The same setup was recreated (right side of Figure 2) with a clinically used small vibration massager tool.
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Data was gathered from both setups and repeated with silicone blocks of varying sizes to mimic the various depths that the lymphatic vessels lie beneath the epidermis.
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I wrote a MATLAB script to signal process the data from the accelerometer and conduct a Fast Fourier Transform (FFT). The resulting data was used to statistically analyze the optimal vibration frequency comparable to the clinically used massage tool.
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Personal Contribution 2.0
Hardware Prototyping
Skills Used:
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Microcontroller prototyping
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Schematic design
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Sewing
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After the vibration motors were characterized through our benchtop experiments, I was able to build the circuit. I used an Adafruit Feather 32u4 Bluefruit LE® powered by a 3.7V lithium polymer battery that provided Bluetooth LE capabilities. Motors were driven by the TB6612 chipset with thermal shutdown protection as part of the Adafruit FeatherWing DC Motor Shield. The drivers were powered by a 6V UBEC (switch-mode DC-DC regulator) with an anti-short circuit and overheat functionality supplied by a 7.4V LiPo battery. The eccentric rotating mass (ERM) motor was a waterproof, 3V DC vibration motor (NFP-E1015) (Fig. 2).
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I sewed a compression sleeve with pockets to hold each motor embedded in a silicone pod (Fig 3.)
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I soldered the motors together in pairs for a total of 16 motors. The 8 pairs are strategically positioned on the arm to activate the posterior and anterior sections simultaneously. (Fig 5.)
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Fig. 1 Handsketches from my design notebook showing initial prototype ideas.
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Fig. 2 Circuit Diagram
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Fig. 3 Silicone pods designed and fabricated by Seth Jarvis and Laura Wenger. The purpose of the pods is to propogate the vibration and increase patient comfort
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Fig. 5 Anterior and posterior motor pods embedded into rough prototype
Fig. 4 Initial user testing with Tara Newberry (Occupational therapist and lymphedema specialist)
Personal Contribution 3.0
App Development
Skills Used:
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Microcontroller prototyping
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Bluetooth LE
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UART
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Arduino IDE
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MIT App Inventor
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I designed an Android app that controls the motors via Bluetooth LE.
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I worked with Tara Newberry (Occupational Therapist and lymphedema specialist) to understand how manual lymphatic massages feel, and simulated the massage using various vibration patterns and intensities.
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Focus was directed on creating an engineering interface that would properly control the motors. Future development will involve improving the UI/UX of the app.
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Fig 1. App GUI showing options for forearm, upper arm, and full arm vibration
Fig 2. Preliminary video showing the app functionality
Current Progress
Clinical Trials
We have submitted an IRB for a human subjects study targeted for Spring 2023.
Patent Pending
We have worked with Carilion Innovations and Virginia Tech to submit a PCT patent (PCT/US22/37612)
Further Testing
Further experimentation and testing will be required as we work towards commercializtion of our device.
Future Design Considerations
Lymphedema affects all parts of the body so we have designed various wearable garments with embedded motors to accommodate for this. Future testing will be needed to determine optimal vibration testing for more sensitive areas of the body.
Interested?
Read more about it!
Accepted paper (DMD2023-6551) for the Design of Medical Devices Conference 2023 to be published in the ASME Conference Proceedings
Accepted poster for 2022 Biomedical Engineering Society Annual Meeting, San Antonio, TX
Meet the Team
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Leah Thomas
VT BME '22
Laura Wenger
VT BME '23
Seth Jarvis
VT BME '23
Dr. Chris Arena, PhD
Co-PI; VT BEAM Faculty
Dr. Andre Muelenaer, MD
Co-PI; VT BEAM Faculty
Tara Newberry, COTA/L, CLT, OCC
Clinical Advisor
Citations:
[1] Foldi, Michael. Foldi's textbook of lymphology for physicians and lymphedema therapists. Mosby Elsevier, Missouri (2006).
[2] Cemal, Yeliz, Pusic, Andrea, and Mehrara, Babak. “Preventative measures for lymphedema: Separating fact from fiction.” Journal of the American College of Surgeons Vol. 213, No. 4 (2011): pp. 543–551. DOI 10.1016/j.jamcollsurg.2011.07.001
[3] Poage, Ellen, Singer, Marybeth, Armer, Jane, Poundall, Melanie, and Shellabarger, M. Jeanne. “Demystifying lymphedema: Development of the lymphedema putting evidence into Practice® Card.” Clinical Journal of Oncology Nursing Vol. 12 No. 6 (2008): pp. 951–964. DOI 10.1188/08.CJON.951-964