Abstract: Disclosed is a valve replacement comprising a braided helical design that mimics the heart's natural movement. The braided wire frame of the disclosed valve replacement may be compressed to enable compact and secure delivery into the heart and convenient control during implantation as well as the expansion and retraction when implanted or removed/replaced, preferably entirely via a catheter. The valve replacement may comprise a one-piece system comprising an adapter body with engaging mechanisms that secure to the heart, and a valve assembly with leaflets positioned within the adapter body. The valve replacement may also comprise a two-piece system comprising an adapter body and valve assembly that are compatible with each other yet wherein the valve assembly may be removable from the adapter body such that both can be delivered together or separately and such that the adapter body may remain implanted while the valve assembly may be removed and replaced.

Abstract: A method and apparatus are disclosed for measuring the state of charge of a battery. The apparatus comprises threshold means for sensing reductions below a threshold level in the output terminal voltage of the battery and for producing a signal in response thereto and means for integrating said signal over a plurality of such reductions. The output of the integrating means is indicative of the state of charge of the battery. In a preferred embodiment the signal comprises a series of pulses whose number is proportional to the time that the terminal voltage is below the threshold value and the integrating means counts such pulses. Alternatively, a single pulse may be produced and counted for each time the output terminal voltage is reduced below the threshold level. In another embodiment, the signal from the threshold means is integrated directly to develop a representation of the state of charge of the battery. Circuits are also disclosed using a plurality of threshold means connected in series or in parallel.