Compact electrotactile stimulation and EMG acquisition system with embedded blanking of stimulation artifacts We present a miniaturized closedloop system for myoelectric control and electrotactile feedback in upper limb prostheses. The system integrates an electrotactile stimulator, which allows synchronous and asynchronous distribution of stimulation pulses, and an acquisition system for the simultaneous recording of multichannel EMG. The stimulator generates biphasic, current controlled pulses (amplitude: 05 mA; duration: 50500 us; frequency: 1100 Hz), which are routed by a demultiplexing circuitry to any of the 16 output channels. The acquisition system can be configured to record 8 bipolar or 16 monopolar EMG channels with a sampling frequency in the range from 500 Hz to 2 kHz. Embedded firmware incorporates direct calculation of ARV or RMS in the defined time window, as well as direct blanking of recording channels for the duration of the stimulation pulse artifact. Based on initial tests in a simple experimental setup we can determine that the developed system and proposed blanking algorithm can be used to record EMG signals during simultaneous delivery of electrical stimulation in challenging conditions (e.g., close electrode placement, high stimulation intensity).

Multimodal Fusion Transcutaneous Electrical System for Haptic Feedback Haptic feedback is one of the important ways to sense surrounding environment. In terms of grasping objects, the haptic feedback assists in improving accuracy and assists man to recognize the shape of object. Thus, restoring haptic feedback of amputee is very meaningful and challengeable. In this paper we present a selfdeveloped transcutaneous electrical nerve stimulator which can stimulate neuromuscular by different waveform, frequency and voltage to generate haptic feedback for the amputee. The stimulator with multiple independent channels can generate up to 8 waveforms per electrode channel and can communicate any device by Bluetooth 4.0 using our custom communication protocol to improve the stimulator reliability. In order to choose the optimal stimulus waveform, frequency, current and location, the PC software have been designed to control the transcutaneous electrical nerve stimulator. We test the transcutaneous electrical nerve stimulator in human test. By questionnaire, pretest results showed that different stimulus location can evoke different figure movements, different stimulus waveforms can evoke different haptic sensation and the human have a same sense when stimulating in the same waveform.