A method and an apparatus to analyze two measured signals that are modeled as containing desired and undesired portions such as noise, FM and AM modulation. Coefficients relate the two signals according to a model defined in accordance with the present invention. In one embodiment, a transformation is used to evaluate a ratio of the two measured signals in order to find appropriate coefficients. The measured signals are then fed into a signal scrubber which uses the coefficients to remove the unwanted portions. The signal scrubbing is performed in either the time domain or in the frequency domain. The method and apparatus are particularly advantageous to blood oximetry and pulserate measurements. In another embodiment, an estimate of the pulserate is obtained by applying a set of rules to a spectral transform of the scrubbed signal. In another embodiment, an estimate of the pulserate is obtained by transforming the scrubbed signal from a first spectral domain into a second spectral domain. The pulserate is found by identifying the largest spectral peak in the second spectral domain.

Signal processing apparatus and method

A heart monitoring system for a person includes one or more wireless nodes; and a wearable appliance in communication with the one or more wireless nodes, the appliance monitoring vital signs.

Health monitoring appliance

A health care monitoring system for a person includes one or more wireless nodes forming a wireless mesh network; a wearable appliance having a sound transducer coupled to the wireless transceiver; and a heart attack or stroke attack sensor coupled to the wireless mesh network to communicate patient data over the wireless mesh network to detect a heart attack or a stroke attack.

Mesh network stroke monitoring appliance

A medical system includes a network; one or more medical data collection appliances coupled to the network, each appliance transmitting data conforming to an interoperable format; and a server coupled to the network to store data for each individual in accordance with the interoperable format.

Systems and methods for providing interoperability among healthcare devices

An intelligent, rule-based processor provides a pulse indicator designating the occurrence of each pulse in a pulse oximeter-derived photo-plethysmograph waveform. When there is relatively no distortion corrupting the plethysmograph signal, the processor analyzes the shape of the pulses in the waveform to determine where in the waveform to generate the pulse indication. When distortion is present, looser waveform criteria are used to determine if pulses are present. If pulses are present, the pulse indication is based upon an averaged pulse rate. If no pulses are present, no indication occurs. The pulse indicator provides a trigger and amplitude output. The trigger output is used to initiate an audible tone 'beep' or a visual pulse indication on a display, such as a vertical spike on a horizontal trace or a corresponding indication on a bar display. The amplitude output is used to indicate data integrity and corresponding confidence in the computed values of saturation and pulse rate. The amplitude output can vary a characteristic of the pulse indicator, such as beep volume or frequency or the height of the visual display spike. The visual pulse indicator is supplemented by a signal quality alert. Combined with several indicators of signal quality, the alert is used to initiate a warning when data confidence is very low. The alert may be in the form of a message generated on the pulse oximeter display to warn that the accuracy of saturation and pulse rate measurements may be compromised. A confidence-based alarm utilizes signal quality measures to reduce the probability of false alarms when data confidence is low and to reduce the probability of missed events when data confidence is high.

Pulse oximetry data confidence indicator

The piezoelectric sound monitor comprises a piezoelectric membrane including an inner face, an outer face, and first and second peripheral portions. The piezoelectric sound monitor further comprises a piezoelectric membrane support structure including an outer face, two first mutually facing membrane-clamping walls, a first electrically conductive area, two second mutually facing membrane-clamping walls, and a second electrically conductive area. The inner face of the piezoelectric membrane is applied to the outer face of the support structure. The first peripheral portion of the piezoelectric membrane is clamped between the two first walls, and the first electrically conductive area is located on one of the two first walls for electrically contacting the inner face of the piezoelectric membrane. The second peripheral portion of the piezoelectric membrane is clamped between the two second walls, and the second electrically conductive area is located on one of the two second walls for electrically contacting the outer face of the piezoelectric membrane.

Piezoelectric biological sound monitor with printed circuit board

A tension-adjusting mechanism for the elongated earpieces of a stethoscope comprises a neckpiece and, for each earpiece, a pivot mechanism portion between the proximal end of the earpiece and the neckpiece, a spring mechanism portion between the proximal end of the earpiece and the neckpiece, and a tension-adjusting mechanism portion between the spring member and the neckpiece. For each earpiece, the pivot mechanism portion defines a pivot axis about which the earpiece pivots, and the spring mechanism portion comprises a resilient blade deforming upon spreading apart of the earpieces. This deformation produces a tension on the earpieces opposing to further spreading apart thereof. The tension-adjusting mechanism portion defines a plurality of interchangeable point of contacts with the resilient blades, which contact points having different positions relative to the neckpiece.

Larrimore A. S. Adams

Papers

Piezoelectric biological sound monitor with printed circuit board

Tension-adjustable mechanism for stethoscope earpieces

Piezoelektrisk biologisk lydmonitor med kretskort.