Myocardial force measuring appts. - uses deflection of pin which flexes diaphragm, being insensitive to pressure

摘要

Measurement of myocardial force in given muscle fibre layers is performed with a tube (7) in which an internal pin (3) can be deflected relative to the tube through a lateral hole (8). Deflection of the pin is pref. measured by flexure of a diaphragm (5), so that pressure load have no effect. At the same time, temp. or the ECG can be measured by means of a thermistor or an ECG electrode mounted in a bore (6) in the pin. Flexure of the diaphragm is picked up with wire straing gauges (4) connected in the form of half-bridge and arranged so that S-shaped deflection of the diaphragm produces a signal. Diaphragm deflection which occurs under pressure load does not affect the half-bridge. Contraction forces can thus be measured without being affected by pressure.