Patient isolation in multichannel bioelectric recordings by digital transmission through a single optical fiber

A design for patient isolation in 64-channel electrocardiogram (ECG) recordings is presented. Small dimensions of the isolated section and the use of an optical fiber as the only connection between the isolated section and the grounded section of the measurement system ensured a minimal capacitance between the patient and the environment. The consistent low-power design of the isolated section resulted in a power consumption of 210 mW, which allowed a 10 h continuous operating time of the battery-powered isolated section. The system handles 64 signals with a dynamic range of 75 dB. Analog-to-digital conversion is performed in the isolated section with a sample rate of 1 kHz/channel. The receiver interfaces to a commercially available DMA board for a standard personal computer.