The Role of Daily Activity Living Entropy and Hurst Exponent as Dynamic Biomarkers in the Diagnosis and Personalized Rehabilitation of Carpal Tunnel Syndrome

Carpal Tunnel Syndrome (CTS) is the most common entrapment neuropathy, traditionally diagnosed via subjective clinical assessment and objective nerve conduction studies (NCS). This paper explores the utility of dynamic, non-invasive complexity metrics Sample Entropy (SampEn) and the Hurst Exponent (H) derived from continuous, wrist-worn accelerometry data collected during Daily Activity Living (DAL). We hypothesized that CTS affects the inherent fractal dynamics and complexity of wrist movement, providing quantifiable diagnostic biomarkers superior to traditional magnitude metrics. Data were collected from 30 diagnosed CTS patients and 30 matched healthy controls (HC) over seven days. Our analysis focused on classifying patient status based on the temporal structure of acceleration signals. While SampEn demonstrated significant diagnostic potential (78.3% classification accuracy), the Hurst Exponent, measuring the long-range dependence and fractality of movement patterns, proved overwhelmingly superior. The classification model using H achieved a robust accuracy of 95.2%, distinguishing CTS from HC with high precision. This finding highlights the critical sensitivity of fractal dynamics to early neuro-muscular impairment and positions the Hurst Exponent as a transformative, objective biomarker for non-invasive CTS diagnosis and personalized rehabilitation outcome monitoring.