Force transducer for measurement of muscle contraction

Single channel force transducers, intended for measurement and evaluation c urves of preconditioned fibres in muscles contracting synergistically durin g direct or indirect electric stimulation of isolated muscle, were designed , developed and experimentally tested. The force transducers were made up o f a full Wheatstone bridge composed of four semiconductor strain gauges bon ded on a specially designed cantilever The transducers with a natural-frequ ency 350Hz and compliance of 0.25 mu m g(-1) represents a very linear depen dence of the output voltage upon the load giving a sensitivity for the tran sducers of 0.5 mVmN(-1) with a bridge excitation voltage of 5V. The nominal range of each transducer is 0-70 mN. The system is able to record even a c ontraction of only a few muscle fibres, both single twitches as well as sus tained tonic contractions.