Wireless sensor technology for collecting surface electromyography signals
This main purpose of the research was to develop and manufacture a prototype for a new Wireless Surface Electrode for acquiring surface Electromyography (sEMG) signals from the vastus lateralis muscle from the quadriceps of the knee in real-time.
Initially an extensive literature review was carried out which looked at literature either presented at recognised international conferences or published in journals. The literature review focused on papers from the year 2000 using two keywords, which were ‘Wireless’ and ‘Electromyography’. This showed that the majority of papers had been presented at conferences and published in their proceedings. The literature review showed that there were three main techniques used for wireless transmission with a large variation in the settings for the gain used, filtering and data acquisition of the sEMG signals.
For this research the overall design of the new Wireless Surface Electromyography (WsEMG) Electrodes consisted of two newly designed and developed components: (a) an Electrode Interface Node and (b) a Computer Interface Node.
The wireless link between the two nodes used a ZigBee protocol. The data acquisition was carried out using LabVIEW software to develop a new virtual instrument.
The electrode interface node used an integrated circuit chip from a family programme system on the chip (PSoC®). The PSOC® chip enable module configuration of the instrumentation amplifier, the low-pass filter, the analogue to digital convertor and it also required a universal asynchronous receiver/transmitter to interface to an XBee® transceiver module.
The computer interface node was developed to be a USB dongle to connect to a laptop computer. The USB dongle consisted of another XBee® transceiver module and a USB universal asynchronous receiver/transmitter.