DEVELOPING A FUNCTIONAL ELECTROSTIMULATION SYSTEM USING AN ARDUINO MICROCONTROLLER

Abstract

The goal of this work is to study the operating principle of an electrical stimulator 
and develop its functional device. Determination of the amplified output current (or 
voltage) is one of the main tasks of the functional electrostimulation system. To solve this 
problem, a passive-invasive method is used using electrodes (Latin invasio - attack, 
invasion), while the electrodes are placed on the skin surface. The output cascade of 
electrostimulation is interconnected with the rest of the system nodes. Usually, the low
voltage signal generated by other stages is amplified in the output cascade. 
A comparative analysis of circuits with transformer and mirror connection of 
currents in the output cascade is carried out. The transformer solution has a number of 
disadvantages: the output signal is strictly limited in frequency band and the dimensions 
has large sizes. Unlike the transformer, the mirror transistor circuit has the ability to 
control and limit the power, which allows us to obtain a power value less than the specified 
one, in the event of a short circuit at the active point of the patient. In the case of using 
circuits with a mirror connection of currents, it is possible to simultaneously limit the 
distribution of power in the active points of the muscles.  
In addition, a program is developed for the electrostimulator using the Arduino Due 
microcontroller. The microcontroller uses a 32-bit SAM3X8E ARM Cortex-M3, unlike the 
Arduino MEGA and Uno, which use a 16-bit processor. 
A functional electrical stimulation device has been developed, allowing to 
simultaneously stimulate the affected nodes in several active points. Thus, we can provide 
the patient with universal, versatile stimulation or monitor the reactions of healthy and 
diseased areas. Experimental studies are conducted at the Institute of Radiophysics and 
Electronics of NAS, RA both on a healthy muscle, and by using an equivalent electrical 
circuit of the muscle.