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Biomedical subjects

A H Guerrero

Publications and source records attributed to A H Guerrero.

4 recordsLinked to original sources

Programmed stimulator for threshold of action potential.

A programmed digital stimulator is described, in which the pulse generator can be regulated in frequency and duration. The output pulses amplitude increases automatically by increments under 5% of the previous step, sequence which allows a much better approximation to the threshold value of action potential. A photographic camera is synchronized for recording. The power supplies, pulse duration generator, binary counter, converter, pulse control, and detector circuits are given in detail.

Action Potentials

Electronic system for the obtention of phase plane curves for action potentials.

This system is designed for the amplification of the bioelectrical signal, obtention of its derivative in respect to time, automatic brightness control for both beams of the oscilloscope, and stability. The system includes a central measuring section which is a modified Tektronix oscilloscope type 565. Automatic control of brightness as a function of sweeping speed allows photographic recordings.

Action Potentials

Automatic microelectrode compensator (AMC).

A solid-state system designed for compensation of asymmetry potentials between microelectrodes, for bioelectric measurements, is described. Advantages over the manual compensator are the following: synchronic compensation of electrodes, application to automatized systems against aging effects in electordes, high speed, and elimination of general muisances of manual circuits. Besides, the system allows to measure digitally the polarization difference and resting membrane potential with precision of +/- 1 mV.

Bioelectric Energy Sources