Nellcor Incorporated

Other

James E Corenman

Daniel S Goldberger

David E Goodman

James Roswell Braig

William New, Jr

Emil P Rojas

Edward M Richards

David A Gallup

Robert T Stone

Deborah A Briggs

Andras Boross

Kenneth R McCord

Willaim New, Jr

Mark Yelderman

James H Stone

A gas analyzer system and method for detecting and displaying information of gases in a respiratory gas stream, comprising an optical bench including a gas pathway for the flow of a gas stream through the optical bench, a flow shaping inlet at the entrance to the optical bench's gas pathway, two infrared detection channel assemblies for measuring the partial pressures of the gases in the respiratory gas stream, a pressure sensor for measuring the pressure within the gas pathway, a temperature sensor for measuring the temperature within the optical bench, and a flow rate sensor for measuring the gas flow rate through the gas pathway, circuitry for processing the detected partial pressures of the gases and the measured values for pressure, temperature, and flow rate, and for providing output signals indicative of processed measured values, the detected partial pressures of the gasses, and characterization information with respect to the optical bench components; analog input circuitry for processing the signals output from the optical bench for input to analog processing circuitry; analog processing circuitry for processing and correcting at least the detected partial pressures of the gases signals for collision broadening, temperature, pressure in the gas pathway, barometric pressure, cross-correction, and characterization of the optical bench components, and providing output signals indicative of the corrected partial pressures of the gases to display processing circuitry; display processing circuitry for processing the signals for display of at least the corrected partial pressure of one gas on a cathode ray tube.

Method for distinguishing respiratory events in a gas analyzer

A backflushing system for an inlet filter in an airway adapter in a gas flow sampling and analyzing system includes a back flush fluid supply conduit and sampling conduit connected to the airway adapter by a single coupling element. Flow of back flush fluid causes material blocking the filter to be washed away into the respiratory conduit for disposal. Flow of backflush fluid is restricted to one way flow through the backflush conduit by a disk shaped valve member mounted in the air way adapter.

Airway adapter with backflush tube

A method and apparatus for improving the calculation of oxygen saturation and other blood constituents by non-invasive pulse oximeters. The method and apparatus permit more accurate determination of blood flow by collecting time-measures of the absorption signal at two or more wavelengths and processing the collected time-measure to obtain composite pulsatile flow data from which artifacts have been filtered. The processing may occur in the time domain or in the frequency domain. In the preferred time domain embodiment, successive portions of periodic information are weighted and added together in synchrony to obtain the composite pulse information. In the preferred frequency domain embodiment, the time-measure in Fourier transformed into its spectral components to form the composite information. A new method and apparatus for correlating the heartbeat and optical pulse is provided whereby a product of the ECG R-wave and optical pulse signals corresponding to the same heartbeat is obtained, and one signal is time shifted relative to the other until a maximum waveform product corresponding to the heartbeat is determined.

Method and apparatus for detecting optical pulses

A method and apparatus for measuring and correlating a patient's heart activity with optical detection of the patient's blood flow. The method and apparatus permit more accurate determination of blood flow characteristics such as oxygen saturation and pulse rate. In a preferred embodiment, the heart activity is detected by monitoring the patient's EKG waveform, and the blood flow is detected by a non-invasive pulse oximeter. The occurrence of the R wave portion of the EKG signal is detected and the time delay by which an arterial pulse follows the R wave is determined to establish a time window in which an arterial is to be expected. The established time window provides the oximeter with a parameter enabling the oximeter to analyze the blood flow only when it is likely to present an arterial blood pulse for waveform analysis. The invention also includes adjusting the polarity of the detected EKG signal to have a preselected uniform upgoing or downgoing polarity.

A method and apparatus for improving the calculation of oxygen saturation and other blood constituents by non-invasive pulse oximeters. The method and apparatus permit more accurate determination of blood flow by collecting time-measures of the absorption signal at two or more wavelengths and processing the collected time-measure to obtain composite pulsatile flow data from which artifacts have been filtered. The processing may occur in the time domain or in the frequency domain. In the preferred time domain embodiment, successive portions of periodic information are weighted and added together in synchrony to obtain the composite pulse information. In the preferred frequency domain embodiment, the time-measure is Fourier transformed into its spectral components to form the composite information. A new method and apparatus for correlating the heartbeat and optical pulse is provided whereby a product of the ECG R-wave and optical pulse signals corresponding to the same heartbeat is obtained, and one signal is time shifted relative to the other until a maximum waveform product corresponding to the heartbeat is determined.

An improved gas analyzer system (FIG. 1) and method of use for detecting and displaying the partial pressures of certain constituent gases in a respiratory gas stream, the system comprising an optical bench (111) through which a respiratory gas flows and in which measurements of the gas are taken; analog input circuits (122) for receiving signals output from the optical bench (111) through which a respiratory gas flows and in which measurements of the gas are taken; analog processing circuits (124) for processing signals output from the analog input circuits (122); display processing circuits (128) for processing the signals output from the analog processing circuits (124) and other system circuitry; pixel logic circuits/analog outputs (130) for processing signals output from the display processing circuitry (128) and providing analog output ports; a five button panel (148), an alarm/knob board (144), and a speaker driver (152) for operator interface and activation of audible and visual alarms; a CRT driver for driving a CRT; and a power supply (158) for powering the system.

Multichannel gas analyzer and method of use

A sensor for trans-illumination of a blood perfused portion of flesh to measure light extinction during trans-illumination is disclosed. The sensor is preferably mounted on a fingertip but any digit or blood perfused portion of flesh will work. The sensor includes a first end for disposition on one side of the trans-illuminated flesh and a second end for disposition on the opposite and opposed side of the trans-illuminated flesh. A light source is mounted to the first side and a photo-sensor is mounted to the second side. If an elongated flexible strip is used, it is provided with adhesive and is suitably windowed that light is allowed to take an optical path through the finger. If no flexible strip is used, the two ends are aligned and secured to the flesh such that the light emitted takes an optical path through the finger. When the adhesive fastener is used, the effect of the light source and photo-detector substrates being integrated into the adhesive fastener is that they become, in effect, a part of the skin. The resulting device is resistant to accidental removal and avoids constriction of blood vessels. Most importantly, the low mass of the sensor itself and its conformance to, so as to effectively become a part of, the skin, prevents relative motion between the light source and sensor and the perfused flesh. This eliminates the common interference associated with the operation of conventional plethysmographs and oximeters.

Sensor having cutaneous conformance

An improved gas analyzer system (FIG. 1) and method of use for detecting and displaying the constituent gases of a respiratory gas stream, the system comprising an optical bench (109) through which a respiratory gas flows and in which measurements of the gas are taken; analog input circuits (122) for receiving signals output from the optical bench (109); analog processing circuits (124) for processing signals output from the analog input circuits (122); display processing circuits (128) for processing the signals output from the analog processing circuits (124) and other system circuitry; pixel logic circuits/analog outputs (130) for processing signals output from the display processing circuitry (128) and providing analog output ports; a five button panel (148), an alarm-knob board (144), and a speaker driver (152) for operator interface and activation of audible and visual alarms; a CRT driver for driving the CRT; and a power supply (158) for powering the system.

A probe apparatus for use with an optical oximeter is disclosed. A pair of light emitting diodes emit light of known narrow wavelengths through an appendage of a patient onto a photosensor. A resistor of coded known resistance is used to enable the oximeter to calculate the co-efficient of extinction of the wavelengths of the LEDs. The resistor, LEDs and photosensor are mounted on self-attaching hook and eye tape for mounting the probe onto the appendage of the patient. The probe is detachably wired to the oximeter, rendering the probe completely disposable. The oximeter is programmed at the factory to calculate the co-efficients of extinction of any LEDs which may be encountered in a series of disposable probes. From the co-efficients of extinction, the pulse rate and degree of arterial oxygen saturation is computed and displayed by the oximeter.

Calibrated optical oximeter probe

A sensor for use with instruments that non-invasively measure blood constituents, particularly oxygen saturation of arterial blood from the patient's tissue. The sensor has two rigid housings adapted for arrangement in opposition and secured about a patient's tissue. Each housing has a deformable pad adapted for receiving, conforming to, and securely gripping the patient's tissue without significantly affecting arterial blood flow. In one embodiment, the housings are pivotally mounted and biased closed under tension, one pad contains a light source for illuminating the tissue in its tissue contacting surface, and the other pad contains the light detector for use in measuring the amount of light absorbed by the blood constituent. In a second embodiment one or the other pad contains both the light source and light detector. The detected light can then be correlated to the amount of blood constituent present in the blood.

Durable sensor for detecting optical pulses

A display monitor is disclosed for a pulse oximeter of the type wherein light of two different wavelengths is passed through body tissue, such as a finger, an ear or the scalp, so as to be modulated by the pulsatile component of arterial blood therein and thereby indicate oxygen saturation. A tonal signal is emitted having a pitch proportional to the ratio of oxygen saturation and a sequential repetition proportional to pulse. A visual cue consisting of an array of strobed light emitting diodes is flashed having a total light output proportional to the magnitude of the pulse and a sequential flashing rate proportional to pulse rate. A systematic rejection of extraneous or irregular detected data prevents undue sounding of alarms.

Growing community of inventors

Oakland, CA, United States of America

James E Corenman