Electromagnetic noise superimposed on the electric power supply to electronic medical equipment.

The use of mobile medical electronic equipment driven at low electric power outputs has progressed rapidly in recent years. Voltage change and noise superimposed on the power supply could create obstacles to the operation of medical electronic equipment. We observed the quality of the power supply of medical electronic equipment in a university hospital, and found approximately 5% distortion on voltage. Possible causes of the distortion and factors involved in voltage/current distortion are discussed. Also shown are some points for avoiding power supply problems when using medical electronic equipment.