Abstract: The present invention is an apparatus for detection of high-frequency heart sounds for diagnosing heart diseases. One embodiment utilizes an accelerometer-based detector that presents a light load to the chest, is sensitive to the desired high frequency range, and provides a quantitative measurement of the quality of the acquired signal. Two piezoelectric sensors are positioned so that they respond to the same mechanical energy and will produce identical electrical signals in the absence of noise. Through signal processing means the two signals can provide an estimate of the signal-to-noise ratio of the acquired signal. The two signals can also be combined to further improve the signal-to-noise ratio.

Abstract: The present invention is an apparatus for detection of high-frequency heart sounds for diagnosing heart diseases. One embodiment utilizes an accelerometer-based detector that presents a light load to the chest, is sensitive to the desired high frequency range, and provides a quantitative measurement of the quality of the acquired signal. Two pairs of flexible beams, each having piezoelectric transducers on the upper and lower surfaces are supported by a lightweight mechanical structure. The beams are center-loaded so that they respond to the same mechanical energy and will produce identical electrical signals in the absence of noise. Through additional signal processing means the two signals can provide an estimate of the signal-to-noise ratio of the acquired signal. The two signals can also be combined to further improve the signal-to-noise ratio. The invention is designed to be light weight, sensitive to higher frequencies, and to be relatively immune to noise.

Abstract: A system for storing and retrieving information-bearing units or modules, such as magnetic tape cassettes, including a fixed two-dimensional storage array, a fixed processing or play station for extracting information from the units, and a movable selection mechanism, having three degrees of freedom, for retrieving individual modules from the storage area, transferring them to the processing area and then returning them to the storage area after the information contained therein has been extracted. Additionally, the system includes means for automatically sequencing a series of units, as well as a preprocessing station for cueing up individual units for intra-unit accessing.