A convertor to adapt general-purpose or obsolete oscilloscopes for biopotential measurements has been designed. This device consists of complete vertical and horizontal circuits to drive directly cathode-ray-tube delection plates. Vertical sensitivity ranges from 0·1 to 10 mV/cm and sweep speeds from 0·5 s/cm to 0·1 ms/cm. The linear-sweep sawtooth waveform is generated by an analogue integrator, which is reset by a vertical or external-input trigger signal. The circuits use low-cost operational amplifiers for design simplicity.
- differential amplifier
- sweep circuit