Abstract: An accurate and reliable pneumotachometer with annular ring transducers for determining the velocity of a fluid flow is provided. A novel and accurate flow measurement system for measuring transit time of a fluid flow using chirp signals and a pneumotachometer with annular ring transducers is also disclosed.

Abstract: During sampling, a finite impulse response (FIR) filter separates a composite signal into two components, non-cardiac physiological phenomena and cardiac artifacts. The length of the filter window dynamically varies to produce an output signal in which the cardiac frequency and any associated harmonics are suppressed with a fixed delay. The FIR filter is applied to the patient signal and lags the patient signal by at least one interval between triggering events. When the present interval between triggering events passes by the filter window, the window length is gradually adjusted to have the same length as the next period such that the window length is centered between two adjacent triggering events. The difference between the present interval and the next interval is evenly distributed or subtracted across the filter window between centerings.

Abstract: During sampling, a finite impulse response (FIR) filter separates a composite signal into two components, non-cardiac physiological phenomena and cardiac artifacts. The length of the filter window dynamically varies to produce an output signal in which the cardiac frequency and any associated harmonics are suppressed. The FIR filter is applied to the patient signal and lags the patient signal by at least one interval between triggering events. When the present interval between triggering events passes by the filter window, the window length is gradually adjusted to have the same length as the next period such that the triggering events are synchronized with the endpoints of the filter window at the start of each interval. The difference between the present interval and the next interval is evenly distributed or subtracted across the filter window between synchronizations.

Abstract: A computer system comprises a computer, a monitor, a keyboard, a mouse, and an instrumentation system. The instrumentation system is coupled to a patient to gather data about a patient over time. The data is arranged in a flowsheet, only a portion of which can be displayed at one time. Indicators are used to indicate the presence of data off-display meeting a preselected criterion. This criterion can be the existence of a value entry or the existence of a value entry exceeding a threshold, for example. Upon activation of an indicator, the display scrolls to the next flowsheet neighborhood containing an entry meeting the criterion. In this way, a physician or other operator can navigate efficiently and rapidly through a large flowsheet. The invention allows an operator to skip large quantities of empty cells and uninteresting data when the flowsheet is sparsely filled.

Abstract: A delay circuit for providing signal delay within an acoustic imaging system is provided. Reflected acoustic signals are transformed into electrical signals and are used to reproduce images of objects. Delay lines along the electrical signal path are used to focus the images compensating for asynchronism of electrical signals caused by variations in the length of acoustic signal paths.

Abstract: An array of transducers is focussed by insertion of a means for providing a small variable delay between each transducer and a selected tap on a master delay line.