A Cost-Effective IoT-based Transcutaneous Electrical Nerve Stimulation (TENS): Proof-of-Concept Design and Evaluation

Transcutaneous electrical nerve stimulation (TENS) systems have been extensively used as a noninvasive and non-pharmaceutical approach for pain management and rehabilitation programs. Moreover, recent advances in telemedicine applications and the Internet of Things (IoT) have led to an increased interest in developing affordable systems that facilitate the remote monitoring of home-based therapeutic programs that help quantify usage and adherence, especially in clinical trials and research. Therefore, this study introduces the design and proof of concept validation of an IoT-enabled, cost-effective, single-channel TENS for remote monitoring of stimulation parameters. The presented prototype features programmable software that supports manipulating the stimulation parameters such as stimulation patterns, pulse width, and frequency. This flexibility can help researchers substantially investigate the effect of different stimulation parameters and develop subject-specific stimulation protocols. The IoT-based TENS system was built using commercial-grade electronic components controlled with open-source software. The system was validated for generating low- frequency (10 Hz) and high-frequency TENS stimulation (100 Hz). The developed system could produce constant biphasic pulses with an adjustable compliance voltage of 5-32 V. The stimulation current corresponding to the applied voltage was quantified across a resistive load of 1 k ohm, resulting in a stimulation current of approximately 4.88-28.79 mA. Furthermore, synchronizing the TENS system with an IoT platform provided the advantage of monitoring the usage and important stimulation parameters, which could greatly benefit healthcare providers. Hence, the proposed system discussed herein has the potential to be used in education, research, and clinics to investigate the effect of TENS devices in a variety of applications outside of the clinical setup.