No abstract

IN 1911 Professor J. B erg on ie of Bordeaux constructed an instrument by which powerful rhythmic contractions of human muscles can be induced -electrically with a minimum of unpleasant sensations (1). Bergonie6 utilises a special induction coil, invented by himself. The primary current is interrupted about 30 times per second. The secondary coil is connected with an automatic commutator which closes the circuit for i second, opens it for i, reverses and closes it again for J second and so on. The muscles of the subject are therefore tetanised twice every second for about i second each time, and the tetanising currents are continually reversed. In the secondarv circuit a set of rheostats are provided with a total resistance which can be regulated from 10,000 ohms to 0. The current is then distributed to a number of electrodes; 4 of these are large metal plates fixed symmetrically in the seat and back of an easy chair while the rest (5 or 7) are flexible metal plates as large as convenient, which can be put on to the calves, thighs, stomach and arms of the subject. For each electrode a special rheostat is provided, the resistance of which can be varied from 2000 ohms to 0. The metal plates are never placed directly in contact with the body, but the current is transmitted through several layers of cloth thoroughly moistened in warm water or saline. As the current enters through very large surfaces cutaneous sensations can be almost completely avoided, and by suitable connections of the single electrodes and regulation of the resistance in series with each electrode a large number of powerful muscles can be uniformly and strongly stimulated. In order to increase the muscular work and diminish the violent* movements, which would otherwise result, the body is loaded with bags of sand the total weight of which can be brought up to 100 kg. By each contraction the whole of this weight

No abstract

No abstract

No abstract