STEM Website 2025-2026

Carpal Tunnel Syndrome (CTS) is a pathologic, usually progressive, process due to compression of the median nerve in the carpal tunnel, often due to excessive wrist motion. CTS affects 6.7% of employed adults in the US, with major socioeconomic consequences for prolonged work absence and reduced earnings. Present methods to address CTS symptoms are reactive, utilizing either various braces to hold the wrist in a neutral position or surgical solutions. The aim of this project is to develop a wearable active ergonomic system, named Ventrilo-Wrist, aimed at preventing the occurrence of CTS. The system is comprised of two inertial measurement units, one located on the forearm and the other on the hand, which calculate wrist angles of flexion, extension, and deviation with high accuracy. A risk-scoring algorithm identifies risky wrist deviations, sending a warning signal to the user upon exceeding critical risk levels or offering corrective actions to ensure proper wrist angles. Experimental validation included an average absolute error of less than 0.4 degrees, good correlation with ground-truth data (r > 0.999), and good actuation. The functional test also showed reduced risk of unsafe angles, as well as typing inaccuracy. Ventrilo-Wrist, by blending biomechanics, embedded systems engineering, and statistical validation, realizes a prevention-based approach to CTS, shifting the paradigm from post-injury rehabilitation to long-term ergonomic habit development.

There is no accurate, low-cost wearable device capable of continuously monitoring wrist posture and detecting hazardous deviations and repetitive strain patterns in real time to proactively prevent the onset of Carpal Tunnel Syndrome.

Design, build, and validate a dual-IMU wearable wrist brace that measures wrist kinematics with high precision, computes real-time biomechanical risk, and delivers corrective feedback to reduce exposure to CTS-inducing postures.

Carpal Tunnel Syndrome, or CTS, is the most common compressive neuropathy of the upper extremity, and it results from chronic compression of the median nerve within the carpal tunnel (Aboonq, 2015). The carpal tunnel is a rigid osteofibrous canal formed by the carpal bones and transverse carpal ligament, containing nine flexor tendons and the median nerve (Aboonq, 2015). Because the tunnel has a fixed volume, small increases in tissue swelling or mechanical load significantly elevate intracarpal pressure (Aboonq, 2015). Normal pressure ranges from 2–10 mmHg, but wrist flexion and extension can increase it to approximately 30 mmHg and damage intraneural microcirculation and disrupt the blood-nerve barrier (Aboonq, 2015). Sustained compression leads to ischemia, inflammation, demyelination, and progressive nerve degeneration (Aboonq, 2015). Repetitive wrist deviation and vibration exposure also damage the subsynovial connective tissue, reducing tendon glide efficiency and further increasing pressure inside the tunnel (Werthel et al., 2014). These biomechanical stressors create a self-perpetuating cycle of inflammation and structural degeneration (Werthel et al., 2014). CTS is also highly prevalent in the working population. According to the National Health Interview Survey, 6.7% of employed US adults aged 18-64 report CTS, with a 12-month prevalence of 3.1%, which translates to approximately 4.8 million persons in 2010 (Luckhaupt et al., 2013; Centers for Disease Control and Prevention [CDC], 2010). There was significantly higher prevalence among women (5.4%) compared to men (1.9%) and increased age-specific prevalence (Luckhaupt et al., 2013). Occupational factors were strongly associated with risk, particularly in occupations and industries categorized as manufacturing and administrative work involving repetitive motion. The economic burden is substantial, with workers with CTS missing a median of 138 workdays and may lose approximately $31,000 in earnings per decade. Total case costs range from $85,000 to $110,000. These data underscore the need for preventative ergonomic strategies rather than reactive treatment.. The current interventions that are being used are mainly symptomatic. The passive brace, such as the Manu® Soft Hand Brace, alters carpal tunnel geometry. It has been proven to reduce symptoms over the short term (Manente et al., 2013). So, soft or rigid splints increase the pain scores. The problem with this is that it’s not addressing the long-term biomechanical issues. Surgery, when performed, is effective, though it has its own set of complications. However, it neither alters occupational biomechanics. (Aboonq, 2015). Recent wearable technologies attempt to monitor wrist posture. Flex-sensor-based systems provide simple curvature detection but lack multi-axis precision and are prone to nonlinear drift (Agarwal, 2019). IMU-based systems enable three-dimensional kinematic reconstruction and have been validated for occupational posture assessment (Umar et al., 2019; Shawn, 2019a). Ayrapetyan et al. (2021) developed an overuse warning glove integrating IMUs and EMG to trigger alerts; however, limitations included signal instability and limited personalization. Additionally, many monitoring systems provide feedback without validated high-precision angle tracking or active correction mechanisms (Piper, 2017).

The experimental procedure in Ventrilo-Wrist was designed for wrist-angle measurement accuracy, real-time biomechanical risk modeling, and assessment of functional performance during bracing. The system was implemented by using an ESP32 dual-core microcontroller and two MPU6050 6-DOF IMUs attached on the dorsal forearm and dorsal hand to calculate the relative orientation of the wrist. Sensors were sampled at 500 Hz and processed using a Madgwick sensor fusion algorithm to perform estimates of flexion, extension, radial, and ulnar deviation angles relative to a calibrated neutral reference posture. Static validation involved having the forearm fixed on a table with the wrist at controlled angles of 30°, 45°, and 60° across all motion planes. Synchronized video recordings were performed to extract protractor-based ground-truth measurements using manual digitization via paired statistical comparison. Dynamic validation had thirty standardized throwing trials with the forearm fixed at a pivot point and peak wrist angles from IMU data aligned against video timestamps to assess accuracy in high-velocity conditions. A three-zone biomechanical risk model was also employed, where posture severity and repetition exposure were quantified, and actuation due to violation of thresholds was reliably triggered through vibration warnings and/or servo motors for corrective action, while reliability and latency were measured for repeated actuations. Finally, functional ergonomic testing involved thirty trials of typing while wearing a brace on and off, where words per minute, accuracy, and risk exposure were used to assess performance compromises. Various statistical tests were also employed, including Pearson correlation, RMSE, agreement tests using Bland–Altman, repeated-measures ANOVA, equivalence tests, and nonparametric tests, where α = 0.05 was chosen for all tests.