Abstract:
@ A pulse oximeter is disclosed of the type wherein light of two different wavelengths is passed through human or animal body tissue, such as a finger, an ear, the nasal septum or the scalp, so as to be modulated by the pulsatile component of arterial blood therein, and thereby allowing indication of oxygen saturation. The level of incident light is continually adjusted for optimal detection of the pulsatile component, while permitting accommodation to variable attenuations due to skin color, flesh thickness and other invariants. At significant slope reversal of the pulsatile component to negative (indicating a wave maximum), wave form analysis of blood flow occurs. A quotient of the pulsatile component of light transmission over the constant component of light transmission is measured for each of two wave lengths by direct digital tracking. The respective quotients are thereafter converted to a ratio, which ratio may be thereafter fitted to a curve of independently derived of oxygen saturation. Calibration is disclosed by solving four unknowns at at least four differing saturations. An output of pulse rate, pulse flow and oxygen saturation is given. An incident light source duty cycle is chosen to be at least 1 in 4 so that noise, inevitably present in the signal, may be substantially eliminated and filtered. Provision is made for a local battery-driven low power consumption instrument capable of being substantially independent of ambient light noise.
Abstract:
A fetal pulse oximetry probe (200) has clusters of light-transmissive bumps (100, 300) over the light source (110) and the light detector (120) on the surface of the probe. The probe is usually attached to the fetus's head. The clusters part the fetal hair and penetrate other light-attenuating organic materials on the head. The clusters thus transmit a more intense light signal. To reduce the amount of the signal shunting between them, the clusters also may be separated by additional opaque (light-shielding) bumps (190).
Abstract:
A CO₂ monitor which has a reusable portion and a disposable portion is disclosed. The disposable portion includes an airway sensor (4) for connecting between a ventilator output and an endotracheal tube. The airway sensor has ports (16,18) on opposite sides. In one port (16) a disposable infrared light source (20) is inserted with wire contacts extending to the exterior of the airway sensor body. The reusable portion is a detector module (6) which includes a detector (24) and an amplifier. The detector module attaches to the airway sensor so that the detector is disposed in the second port (18) and so that contacts in the detector module communicate with the wire contacts of the light source. The detector module may be removed from the airway sensor without removing the light source from the airway sensor.
Abstract:
Système de télémétrie ou de réseau (10) permettant à des services virtuels au niveau de la couche d'application ou de présentation de communiquer avec d'autres services virtuels, indépendamment des interconnexions physiques. Chaque message, appelé colis, comprend des informations devant être transmises en même temps qu'un en-tête d'adresse virtuel. Le colis est transmis à une passerelle (12, 26) qui l'introduit sans modification dans un paquet comprenant des données d'adresse destinées aux couches allant des couches physiques jusqu'aux couches sessions dans l'en-tête du paquet. Le paquet est alors transmis à un autre noeud de réseau (62, 64, 66, 68, 70, 72) qui reçoit et livre le colis, sans modification, au service virtuel destinataire adressé. Un certain nombre de colis provenant des mêmes services virtuels, ou de services virtuels différents, peuvent être groupés en un seul paquet (712) afin d'être transmis à partir de la passerelle, lorsqu'il s'agit de colis qui sont tous destinés à des services virtuels dans le même noeud destinataire. Une fois qu'une session est établie, par exemple entre une passerelle et un poste de travail, des services virtuels au niveau du noeud de passerelle et du poste de travail peuvent communiquer les uns avec les autres sans nécessiter un temps système d'en-tête excessif pour chaque transmission.
Abstract:
A fetal pulse oximetry probe (200) has clusters of light-transmissive bumps (100, 300) over the light source (110) and the light detector (120) on the surface of the probe. The probe is usually attached to the fetus's head. The clusters part the fetal hair and penetrate other light-attenuating organic materials on the head. The clusters thus transmit a more intense light signal. To reduce the amount of the signal shunting between them, the clusters also may be separated by additional opaque (light-shielding) bumps (190).
Abstract:
A pulse oximeter sensor that is designed to surround an appendage of the patient, such as a finger, toe or foot is disclosed. The sensor has a reusable member (14) which preferably includes a photodetector (24). A disposable, flexible member (12) preferably contains the photoemitter (22) and can be wrapped around the patient's appendage to secure it to the appendage and the reusable member. When secured, the photoemitter and photodetector end up on opposite sides of the appendage. The disposable member (12) connects to the reusable member (14) to establish electrical contact. The reusable member (14) is connected to a cable (26) which can be plugged into a sensor monitoring system.