Electrocardiogram-Synchronized Neuromuscular Electrical Stimulation

This study aims to propose a novel electrical stimulation device that integrates electrocardiogram (ECG) signals to synchronize electrical stimulation output, optimizing the combined effects of cardiac pumping and leg muscle contraction. Seven volunteers were recruited for the experiment, during which five stimulation modes were applied to the right gastrocnemius muscle: no stimulation, stimulation during cardiac systole, stimulation during cardiac diastole, constant 1Hz stimulation, and constant 2Hz stimulation. Peak blood flow velocity in the popliteal vein was measured using Doppler ultrasound to assess the blood flow acceleration effects under different stimulation modes. The results showed that diastolic stimulation nearly doubled the peak blood flow velocity compared to no stimulation, making it the most effective mode. Systolic stimulation increased the peak blood flow velocity by approximately 65%, comparable to constant 1Hz stimulation (also around 65% improvement), while constant 2Hz stimulation increased it by about 73%. Overall, all stimulation modes significantly enhanced peak blood flow velocity, with diastolic stimulation demonstrating the most substantial improvement, confirming the correlation between optimal stimulation timing and cardiac activity. This study provides new insights into the application of electrical stimulation for improving blood circulation, especially highlighting the potential of ECG-synchronized stimulation in optimizing venous blood flow. Future research will focus on validating the findings with larger sample sizes and integrating physiological feedback-based intelligent control technologies in clinical applications to further enhance the efficacy and precision of electrical stimulation.