Abstract:
A pulse oximeter which determines multiple heart rates, and selects between them based on the metrics of only one of the heart rate calculations. A primary heart rate calculation method is selected, and is used unless its metrics indicate questionable accuracy, in which case an alternative rate calculation is available and is used instead.
Abstract:
A pulse oximeter method and apparatus which provides (1) a notch filter (46) at a distance between a modulation frequency and a common multiple of commonly used power line frequencies (50, 60, 100 and 120) and also (2) a demodulation frequency greater than a highest pulse rate of a person and lower than any harmonic of 50, 60, 100 or 120 Hz, to filter ambient light interference, while choosing an optimum demodulation frequency that avoids interference from the notch filter or from harmonics of the line interference. Also, ambient light for any low frequency interference, such as power line interference, is measured both before and after each of the light emitter wavelengths and the average of the ambient light is then subtracted from the detected signal.
Abstract:
A pulse oximeter with drive lines for driving red and IR LEDs, and a drive circuit for driving those drive lines. A processor controls the drive circuit using a red zero output line and an IR zero output line directly connected between the processor and the drive circuit. This allows a control signal to directly control the turning off of either the red or IR drive transistors to prevent forward current flow through the red and IR LEDs by overriding the ongoing programmable logic state machine control of the drive transistors. The effects of crosstalk and capacitive coupling are reduced as a result.
Abstract:
An oximeter uses a sigma-delta modulator and a multi-bit ADC with PWM feedback enabling high precision multi-bit conversion. Demodulation is done in software, thus requiring only a single hardware path for both red and IR. Multiple capacitors are switched into the integrator in the sigma-delta modulator, with different capacitors for red, IR and dark signals, thus enabling the use of the single hardware path. A switching circuit at the input of the sigma-delta modulator acts as a sample and hold, controlled by the PWM feedback.
Abstract:
A method for use and an improved oximeter sensor substrate that is conforming to the shape of the patient's forehead. In one embodiment, the present invention is an oximeter sensor, having a substrate with a shape similar to a shape of at least a portion of a patient's forehead and including a section adapted to substantially fit over a portion of a forehead of a patient; an emitter disposed on the substrate at a position located on the section; and a detector disposed on the substrate at a distance from the emitter. In one embodiment, the substrate includes a hat that holds the emitter and the detector in a spaced-part manner against the patient's forehead.
Abstract:
A headband (102) with a tension indicator (110) having an elastic segment (102) sized to fit around a wearer's head; and a non-elastic segment (104) being smaller than and attached with the elastic segment (102). The non-elastic segment (104) is sized to span a portion of the elastic segment (102) when the elastic segment is stretched, and the non-elastic segment (104) is larger than the portion of the elastic segment (102) it spans when the elastic segment (102) is not stretched. The non-elastic segment (104) is attached with the elastic segment in such a manner that the non-elastic segment (104) projects out from the surface of the elastic portion when the headband is not sufficiently tight, thus creating a loop (110) which provides a visual indication that the headband needs re-tightening.
Abstract:
The compression molded aircraft personal service unit and integrated oxygen module housings (22) are formed by compression molding of a sheet or bulk molding material. The integrated oxygen module (20) can be mounted separately in the aircraft, or can be contained in the personal service unit, and includes a container housing (22) having a multiple release main door (30), an oxygen generation cartridge (26) removably disposed in the container housing (22), and an inner mask packing door (122) between the main door (30) and the oxygen masks (28) for aiding in the packing of the oxygen masks (28) in the container (22). In one embodiment, an external test lever is mounted on the main door, and in an alternative embodiment an auxiliary test deployment tool is insertable through an aperture in the main door for retaining the main door (30) in a partially opened test position.
Abstract:
The compression molded aircraft personal service unit and integrated oxygen dispensing system module housings (22) are formed by compression molding of a sheet molding material. The integrated oxygen dispensing system module can be mounted separately in the aircraft, or can be contained in the personal service unit, and includes an oxygen dispensing system module container housing (22) having a multiple release main door (30), an oxygen generator (26) removably disposed in the oxygen dispensing system module container housing (22), and one or more oxygen masks (28). In one embodiment, an external test lever is mounted on the main door (30), and in an alternative embodiment an internal test mechanism is provided that is operated by a test tool insertable through an aperture in the main door. An improved latch testing system and related capability is also provided.
Abstract:
An oximeter sensor formed with a housing made of a relatively rigid material into which the oximeter electrical components can be mounted is provided. An overmolded material, of lesser rigidity, is injection-molded over the housing to complete the sensor. In one embodiment the housing is made of plastic, such as polypropylene, and the overmolded material is an injection-molded thermal plastic elastomer, such as Santoprene