A multi-dermatome computer-controlled electrical perceptual threshold test: system development for standardized quantitative sensory assessment

Abstract Background Electrical perceptual threshold (EPT) testing is a quantitative sensory assessment used to evaluate the level and severity of sensory impairment after spinal cord injury (SCI). However, conventional EPT procedures may involve variability in stimulus delivery, examiner-dependent response logging, and manual workflow requirements. These limitations reduce reproducibility and hinder broader clinical adoption. This study aimed to develop a multi-dermatome computer-controlled electrical perceptual threshold (multi-dermatome CCEPT) system for standardized sensory assessment. Results The multi-dermatome CCEPT system was designed to deliver a standardized stimulation protocol in randomized order across 28 dermatomes bilaterally. It programmatically controlled pulse width, pulse count, current amplitude, and current-step size, while synchronizing participant responses, examiner verification, and digital data logging. The system and selected protocol parameters were evaluated in five non-disabled participants as part of an engineering design and protocol-selection study. A preliminary electrode comparison showed no significant difference in EPT min between the two electrode types. Pulse count and current-step size influenced measured thresholds: three pulses per step produced significantly lower EPT min values than one pulse per step, while 0.1 mA increments produced significantly lower EPT min values than 0.2 mA increments. Three pulses per step and a 0.2 mA current increment were selected for subsequent testing based on the observed EPT min responses together with practical protocol considerations. A representative bilateral dermatomal profile showed generally lower thresholds in cervical and thoracic dermatomes and higher thresholds in lumbosacral dermatomes, consistent with previously reported rostrocaudal EPT patterns. Conclusion This study demonstrates the technical feasibility of an integrated multi-dermatome CCEPT research prototype for standardized EPT testing. The system combines computer-controlled stimulus delivery, automated channel routing, synchronized response capture, and structured digital data acquisition within a single workflow. Further studies using the finalized protocol are required to establish test–retest reliability, healthy dermatomal reference profiles, and clinical feasibility and validity in individuals living with SCI.