Design Team Members: Soniya Patel, Leena Motwani, Amanie Ismail

Supervisor:Professor Dan Stashuk

Background

The Wireless Myoelectric Sensor (WMS) is a proposed solution to the problem of transmitting a muscle electromyographic (EMG) signal wirelessly between two points. The resolution to this dilemma will have a wide variety of applications in the biomedical industries. There will be many uses in the kinesiological, clinical and rehabilitative markets. A wireless EMG transmitter will aid in kinesiology research, and in clinical cases will allow for the patient to have a greater range of motion as they will not be relegated to the length of a wire. There are many rehabilitative applications as well such as use in prostheses, communication and muscle movement detection.

With the new age of wireless technology it is greatly desirable to upgrade the biomedical industry as well. The WMS will be able to interface with any type of electrode to detect the EMG signal, and after amplifying the EMG signal, it will be transmitted wirelessly to a receiver up to 20 m away. The goal is to make the total system completely wireless while still maintaining signal integrity.

Project description

The purpose of this project is to develop a wireless myoelectric sensor (WMS) that will take an EMG signal and transmit it wirelessly to a receiver. The circuitry associated with acquiring the EMG signal will be able to connect to any type of electrode to allow for optimal usage of the product. The WMS will consist primarily of three components: circuitry that will acquire EMG signals through an electrode, a transmitter to send the signal and a receiver to accept the signal. The figure below illustrates this sequence in more detail.

overview diagram of the entire system

The inputs to the surface electrodes will be in the range of 0.1 - 5 mV with a frequency between 10 and 400 Hz. Due to the very small input values, it will be necessary for the integrated circuit to amplify the signal by a gain of 1000.

Design methodology

For this project, a top down design methodology has been adopted. The top down design methodology starts with the definition of the problem at a conceptual level as described above. The problem at hand has been broken down into two major components the mobile station and the base station. The mobile station has been further broken down into two sub-components the integrated (analogue) circuit and wireless communication.

The basic components include the electrodes, instrumentation amplifier, transmitter, receiver and the power supply. Once the component selection and testing phase is completed the analogue and wireless aspects will be integrated together. This will be our initial prototype and the whole system will be rigorously tested from the collection of the EMG signal to the wireless transmission of the signal to the base station. Through testing certain areas of the circuit may need to be redesigned due to compatibility issues. This iterative design technique will result in an optimum solution. Subsequently, this solution will be built as a more streamlined model to meet the listed specifications using a printed circuit board.

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Sponsor: For providing us with the original idea and support