Wearable Sensors for Biofeedback & Remote Monitoring - Rotator cuff tears are a common condition affecting approximately 25% of the population older than 60 years,
and rotator cuff repair is a standard surgical procedure with nearly 500,000 procedures performed annually. In
the United States alone the direct costs are over $7 billion per year. There is a relatively high rate of retears:
ranging from 10% to 78%. Healing of the repair cuff is a protracted process during which the repaired tendon
has to be unloaded by carefully restricting active muscle contraction. There is an inherent conflict in
immobilizing the shoulder to protect the repair and mobilizing the shoulder to prevent stiffness. Teaching the
patient passive exercises that do not activate contraction of the supraspinatus muscle is challenging and very
difficult to monitor. To address this unmet need, we have developed a wearable sensor that provides direct
real-time continuous biofeedback of muscle activity, joint angle, skin temperature, and swelling to enable
passive shoulder exercises while minimizing muscle contraction. To test and validate this device we propose
to the following Specific Aims.
Aim 1: Design, manufacture, and test a wearable device with surface EMG (sEMG), inertial
measurement unit (IMU), temperature, and bioimpedance sensors.
Aim 2: Measure accuracy of Active4D sEMG and IMUs relative to standard clinical measurements.
Active4D is a surgeon-driven company devoted to enhancing patient recovery from surgery by leveraging new
technology. Active4D’s unique wearable sensor provides continuous long-term sensor augmented
biofeedback to patients and enables remote patient monitoring for surgeons. The device measures seven
physiologic metrics in real time – muscle activation, joint range of motion, skin temperature, swelling, activity,
gait, and fall risk. Real time physiologic data will increase safety, improve outcomes, and enhance patient
experience while lowering the cost of rehabilitation and complications. Unique artificial intelligence driven
algorithms can decrease complications through predictive analytics which enable early detection and
intervention for high risk patients.
The specific innovation to the application of rotator cuff repair, is the instantaneous feedback of muscle
activity and motion which can accelerate recovery while reducing the risk of retears. At the successful
completion of Phase I, we plan to launch a clinical trial comparing the outcomes of rotator cuff repair in patients
guided by the A4D device in comparison to the current standard of postoperative rehabilitation.
Active4D is a small business with the objective of developing smart wearables, which integrate multiple
biological and environmental sensors, wireless communication, computer models, and data analysis for
providing feedback and remote monitoring, to enhance surgical rehabilitation and improved patient outcomes
in orthopaedics. Co-founders Drs. Hoenecke and D’Lima have extensive experience in shoulder surgery and
rehabilitation, multi-center clinical trials, and biomechanics research; and have successfully executed
challenging projects such as implantation of innovative electronic knee designs and development of new
shoulder implants. Dr. Hoenecke has over 30 years of experience in the practice of sports medicine with an
emphasis on shoulder repair and reconstruction. He provides care for elite athletes and is design surgeon for
two shoulder implants. Active4D has partnered with expert physical therapists and orthopedists to develop and
test our innovative technology.
