Mechanical properties of mammalian single smooth muscle cells. I. A low cost large range microforce transducer.

A transducer has been developed for measuring the minute forces generated during isometric contractions (1.0-10.0 microN) of single smooth muscle cells from the pig urinary bladder and the human uterus. In addition to its high sensitivity, resolution and stability (100 mV microN-1, and less than 0.1 microN and less than 2.0 microN h-1), the transducer features a very wide range (100-140 microN) with good linearity, enabling measurement of contractions as well as passive force-length characteristics within one uninterrupted measurement session. Since the transducer features an independent and interchangeable force to displacement conversion system, different force ranges can be realized by inserting force conversion systems with different compliances.