American Optical Corporation

Mks Instruments, Inc.

Clinical Data, Inc.

Christopher C Day

Jerry D Haney

William D Jansen

Robert A McEachern

Robert Lee Cannon

Stephen A Schneeberger

A fluid flow control apparatus including a fluid flow control valve, a fluid flow sensor, and a fluid flow control circuit receiving a signal from the fluid flow sensor and outputting a signal to the fluid flow control valve. The fluid flow control circuit including an actual control circuit which outputs a signal related to the comparison of an actual flow signal and a desired flow signal, a desired flow comparator circuit which outputs a signal based on the comparison of the desired flow signal with a desired flow threshold signal, and a summing circuit which receives the outputs and provides a control signal based on these outputs.

Flow controller

Signals subject to amplitude variations, such as physiological signals, are detected when the amplitude thereof exceeds a threshold level, where the threshold level is made adaptive to both the amplitude and the rate of the signals so as to desensitize the detection process for artifacts, which occur sporadically, and to avoid the need for automatic gain control of the signals prior to detection.

Adaptive signal detection system especially for physiological signals

In apparatus such as a defibrillator having a CRT display of an ECG wave, and an alternative display of the firing time of the defibrillator pulse in relation to the ECG wave, the inclusion of method and apparatus for orienting the waveform to a synchronization indicator. In the preferred form, the display is a single, non-fade stationary complex of the ECG wave starting prior to the occurrence of the oriented 'P' wave. The display is timed through combination of clocking pulses responsive to a wave detection apparatus and a recirculating memory which establishes an orienting marker. The clock pulsing includes a predetermined delay to initiation of display from the data recirculating memory such that the data display is coordinated in time to a fixed reference.

Method and apparatus for orienting the display of information from a

Improved method and apparatus for identifying and quantizing a substantially periodic, steeply rising wavefront of a signal in the possible presence of low amplitude interference. A time derivative of at least the steep wavefront is obtained. The derivative is then integrated over a predetermined interval in each of successive repetitions of the steep wavefront, the interval being that during which the derivative exceeds a reference level. A threshold value is established, preferably dynamically, to verify or validate that when the derivative exceeds the reference level it indeed represents the steeply rising wavefront. The integrated derivative is recognized as the quantized value of the steeply rising wavefront only if such verification occurs. The invention is suited to oscillometric determination of systolic pressure in a patient, where measurement of signal amplitude is preferably achieved by integrating the time derivative of the systolic rise wavefront.

Systolic pressure determining apparatus and process using integration to

A system for the cyclical time-compression of a signal waveform, particularly applicable to displays. Continuous input data is temporarily stored, as in a recirculating memory, during the trace and retrace phases (B & A) of a processing or display operation. The stored data is subsequently read out in time-compressed form during the trace phase (B) of the cycle. The average rate at which data is read out of storage is faster than the average rate at which it is entered, the ratio of average readout rate to average entry rate being the compression ratio of the system and corresponding herein with the ratio of a full display sweep cycle to the trace portion of that cycle such that the initial waveform, time-compressed, is displayed in its entirety. In an illustrated embodiment, the data is entered into a recirculating memory at a rate resulting in apparent precession of the data in memory. When the memory is 'full', data is read out at a rate, here syncopated, which on average is faster than the rate at which it enters. In this embodiment, the time-compression ratio is essentially n+1/n, where n is an integer representative of the length of the trace phase of a trace-retrace display cycle. The data samples read out of memory at a syncopated rate are retimed to avoid distortion in the output waveform.

Growing community of inventors

Newtonville, MA, United States of America

Christopher C Day