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AssigneeCalifornia Institute of Technology
InventorsCyril Feldstein, Gilbert W. Lewis, Virgil H. Culler
Estimating the term…
A myocardial transducer for simultaneously measuring force and displacement within a very small area of myocardium comprising an elongated body forked at one end to form an inverted Y-shaped beam, each branch of the beam constituting a low-compliant tine for penetrating the myocardium to a predetermined depth. Each tine has a transverse indentation formed around at least a part of it. When the tines are inserted into a heart, the surface membrane of the myocardium closes around the indentations to hold the tines in place. Bonded to one of the low-compliance tines is a small piezoresistive element for converting a force acting on the beam into an electrical signal. A third high-compliant tine of the transducer, which measures displacement of the myocardium in a direction in line with the two low-compliant tines, is of a length that just pierces the surface membrane. A small piezoresistive element is bonded to the third tine at its upper end where its bending is greatest. Displacement of the myocardium causes a deformation in curvature of the third tine, and the second small piezoresistive element bonded to the surface of its curved end converts its deformation into an electrical signal. A separate electrode placed on the epicardium and referenced to the transducer body provides an ECG signal simultaneously with force and displacement signals.
A transducer for use with instrumentation for simultaneously measuring muscle force and displacement comprising:
A myocaridal transducer for simultaneously sensing force and displacement within a very small area of myocardium comprising an elongated body forked at one end to form an inverted Y-shaped beam, each branch of the beam constituting a low-compliant tine for penetrating myocardium, a piezoresistive element bonded to one of the low-compliant tines for converting a force acting on the beam into an electrical signal, a third high-compliant tine connected to said body of the transducer for sensing displacement of the myocardium in a direction in line with the two low-compliant tines, said third tine extending from said body a length just sufficient for its free end to pierce the surface of said myocardium when the two low-compliant tines are inserted into the myocardium to a predetermined depth, a small piezoresistive element bonded to the third high-compliant tine at a location remote from its free end where its bending is greatest for converting displacement of the myocardium into an electrical signal.
Dependencies are inferred from the claim text.