title: High-speed ultrasensitive instrumentation for myofibril mechanics measurements.
abstract: A novel instrument for measuring the mechanics of a single myofibril is described. The principle of the transducer operation is to attach a myofibril to a very fine wire suspended in a magnetic field. Feedback circuits pass current through the wire to maintain the length constant when the myofibril contracts. The wire position is measured optoelectronically at a resolution below 1 A. The myofibril measurement system consists of two independent transducers and is capable of resolving tension down to 0.5 ng/square root Hz and controlling the myofibril length with a 10-microseconds rise time. Optical and electronic designs of the system and calibration and adjustment procedures are described. Experimental chamber design, a flow controller, and an environmental noise cancellation scheme are also discussed.
mesh_terms: D001696:Biomechanical Phenomena; D002138:Calibration; D008280:Magnetics; D009119:Muscle Contraction; D009210:Myofibrils / Q000502:physiology*; D055095:Optics and Photonics; D012518:Sarcomeres / Q000502:physiology; D012996:Solutions; D013048:Specimen Handling; D014159:Transducers
chemical_list: D012996:Solutions