Abstract: A device for sensing and/or measuring fluid pressure which includes a pressure-sensing tube elongating as a function of fluid pressure therein, a non-expanding member connected to the tube and extending in generally parallel relation thereto and terminating short of a free distal end of the tube, and an electric resistance strain gage connected to and spanning the distance between the distal end of the tube and the adjacent end of the non-expanding member, the combination functioning to provide a mechanically amplified motion at the strain gage with excellent lineal signal to pressure response.

Abstract: A construction having utility as a replacement for one or both chambers of a human heart, constituting a pump which operates in accordance with solenoid principles. A hollow and firm cylindrical member of non-magnetic material has an inlet port and an outlet port at each end. A check valve is associated with each of the ports, so that blood may be both admitted and expelled from each end of the cylinder. A ball which is responsive to a magnetic field rolls or floats within the cylinder. A magnetic field, typically obtained from passing current through an electrical coil, is alternately established at one end of the cylinder and then the other end, whereby the ball will oscillate to and fro--pushing blood ahead of it. Clearance between the ball and the inside wall of the cylinder insures at least some reverse flow of blood, cleaning the ball with each stroke. Electrical circuitry is provided to adjust at least one of the electrical pulse parameters, including frequency, amplitude and duty cycle.