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Biomedical subjects

G Bini

Publications and source records attributed to G Bini.

13 recordsLinked to original sources
PubMed1979

[Multielectronic computerized EMG: technical notes on the recording and parallel off-line elaboration].

A Multielectrodic EMG analysis program is developing. The purpose is to get as short as possible the main EMG parameters (amplitude, duration, frequency) of most motor units, and to reach an estimation of the anatomical extent of single units. According to the muscle extent a variable number of electrodes are inserted crosswise the fibers. EMG signals are simultaneously recorded on a multichannel AMPEX FR1300 and then off-line processed by a 21MX HP minicomputer connected with a 5Mbytes disc drive. Some technical problems had to be solved:channel amplification adjustment to avoid any difference among preamplifiers calibration and filtering, severe hum filtering of main power that is specially strong in nultielectrodic recording systems, the need of sampling at the same Nyquist time the signals of different channels. The computer is instructed to identify the "sinchronous" units i.e. the motor units recorded from more than one channel. These motor units are detected, counted and deleted from all the channels, except the one where they show the maximum amplitude. The percentage of these sinchronous units depends upon the interelectrodic distance and their anatomical area, thus it can support an evaluation of motor unit anatomical spread.

Computers↗
PubMed1977

Selective Activation of peripheral nerve fibre groups of different diameter by triangular shaped stimulus pulses.

1. The differential block of cutaneous nerve fibres has been achieved with a simple method of electrical stimulation, employing a single pair of active electrodes. 2. The method allows the selective activation of 95% of small myelinated (delta) axons, without activation of the larger (beta) ones; and activation of unmyelinated (C) fibres, without A fibre activation. Asynchronous firing of myelinated axons was absent in the majority of the experiments. 3. The method employs triangularly shaped electrical pulses, with a steep rise front and a slow exponential decay. The outward flow of current at the cathode fires conducted impulses in both larger and smaller axons, and the inward flow inactivates differentially the conduction in the smaller ones. 4. The differential effect of anodal currents rests upon the greater internal conductance and greater conduction velocity of larger fibres. 5. The method has the advantage over the conventional polarization block of simpler surgical preparation, longer nerve survival and minimal latency distortion. However, it cannot be applied in experiments requiring physiological stimulation of peripheral receptors.

Action Potentials↗
PubMedDate not supplied

[Validity of the V/Q index in the monitoring of critical patients].

The Authors have controlled the validity of VQI to quantify pulmonary shunt (Qs/Qt). The survey involved (group A) patients who had undergone major surgery and (group B) patients hospitalized in ICU for cardiorespiratory failure. Four subgroups were identified in both the groups according to different values of SaO2. A good correlation, already described by Räsänen, was comproved in the groups and subgroups. However a progressive reduction of the coefficient of correlation from the lower to the higher values of SaO2 was noted. Finally the differences observed between group A and group B, are supposed to be dependent on a greater variability of haemoglobin, in the surgical group, in relation to the time of evaluation.

Analysis of Variance↗