Abstract: A system includes a garment and a sensor module. The garment includes an engagement feature. The garment is configured to encompass a first location on a body. The engagement feature is positioned in fixed alignment with the garment. The sensor module includes a sensor housing and includes a sensor having an electrical node. The sensor is configured to provide an electrical output on the node. The housing has a complementary feature. The complementary feature is configured to couple and decouple with the engagement feature. The electrical output is based on a measure of a physiological parameter associated with the body and is based on site information corresponding to the engagement feature.

Abstract: An oximeter can include a sensor and a processor. The processor can access signal information corresponding to a test signal. The signal information can correspond to a characteristic. The characteristic can be determined using at least one of an AC component and a DC component. The processor can compare the characteristic and a reference value. The processor can adjust the signal, based on the comparison, to set a relationship between the characteristic and the reference value.

Abstract: A method includes affixing a co-planar sensor on a surface, using a processor, and providing an output. The method includes affixing a co-planar sensor on a surface at a first tissue site. The sensor has a force transducer disposed at an aperture of a rigid guard member. The guard member and the transducer are in co-planar alignment. The transducer is configured to provide an electrical signal corresponding to an internal pressure at the first tissue site. The method includes using the processor to compare the internal pressure with a reference value. Based on the comparison, the method includes providing an output corresponding to compartment syndrome at the first tissue site.

Abstract: A device includes a digit probe, a plurality of optical elements, a processor, and a communication module. The digit probe has an interior surface and has an exterior surface. The interior surface is configured to engage a digit and the exterior surface is configured to engage a tissue site associated with the digit. The plurality of optical elements is coupled to at least one of the interior surface and the exterior surface. The plurality of optical elements includes at least one emitter and includes at least one detector. The processor is coupled to the plurality of optical elements. The processor is configured to generate a measure of arterial oxygenation corresponding to the digit and configured to generate a measure of regional oxygenation corresponding to the tissue site. The communication module is coupled to the processor. The communication module is configured to communicate the measure of arterial oxygenation and regional oxygenation with a remote device.

Abstract: A device includes a housing, an emitter, a detector, and a processor. The housing has a body contact surface. The emitter is coupled to the housing and has an emission surface and has an electrical terminal. The emission surface is configured to emit light proximate the body contact surface in response to a signal applied to the electrical terminal. The detector is coupled to the housing. The detector has a sense surface and an output terminal. The detector is configured to provide an output signal on the output terminal in response to light detected at the sensor surface. The processor is configured to implement an algorithm to determine a tissue site based on the emitted light and based on the detected light.

Abstract: A device includes a housing, an emitter, a detector, and a processor. The housing has a body contact surface configured for affixation to a tissue site of a body. The emitter is coupled to the housing and has an emission surface and an electrical terminal. The emission surface is configured to emit light proximate the body contact surface in response to a signal applied to the electrical terminal. The detector is coupled to the housing. The detector has a sense surface and an output terminal. The detector is configured to provide an output signal on the output terminal in response to light detected at the sensor surface. The processor is coupled to the electrical terminal and coupled to the output terminal. The processor is configured to implement an algorithm to monitor for an interruption between the body contact surface and the body and configured to generate an interrupt signal corresponding to the monitoring.

Abstract: A device includes a digit probe, a plurality of optical elements, a processor, and a communication module. The digit probe has an interior surface and has an exterior surface. The interior surface is configured to engage a digit and the exterior surface is configured to engage a tissue site associated with the digit. The plurality of optical elements is coupled to at least one of the interior surface and the exterior surface. The plurality of optical elements includes at least one emitter and includes at least one detector. The processor is coupled to the plurality of optical elements. The processor is configured to generate a measure of arterial oxygenation corresponding to the digit and configured to generate a measure of regional oxygenation corresponding to the tissue site. The communication module is coupled to the processor. The communication module is configured to communicate the measure of arterial oxygenation and regional oxygenation with a remote device.

Abstract: Systems, devices, and methods for measuring one or more parameters at a tissue site of a patient are disclosed. The system can include a sensor that can be configured to measure a first physiological parameter. The physiological parameter can be associated with oxygenation of arterial blood. A second physiological parameter can be associated with respiration of the patient. The system can include a processor that can be configured to use the first and second physiological parameters to determine a waveform associated with the oxygenation of the arterial blood, and the processor can be configured to compensate for a signal artifact associated with motion of the tissue site.

Abstract: A device includes a digit probe, a plurality of optical elements, a processor, and a communication module. The digit probe has an interior surface and has an exterior surface. The interior surface is configured to engage a digit and the exterior surface is configured to engage a tissue site associated with the digit. The plurality of optical elements is coupled to at least one of the interior surface and the exterior surface, The plurality of optical elements includes at least one emitter and includes at least one detector. The processor is coupled to the plurality of optical elements. The processor is configured to generate a measure of arterial oxygenation corresponding to the digit and configured to generate a measure of regional oxygenation corresponding to the tissue site. The communication module is coupled to the processor. The communication module is configured to communicate the measure of arterial oxygenation and regional oxygenation with a remote device.

Abstract: A method includes emitting optical energy, detecting a feature, emitting optical energy, and determining a physiological parameter. The method includes emitting optical energy having spectral content in a first range. The first range includes green light or infrared light. The optical energy is directed at tissue using a wearable module. The method includes detecting a feature in a photoplethysmogram signal. The feature has spectral content corresponding to optical energy in the first range. In response to detecting the feature, the method includes emitting optical energy having spectral content in a second range. The second range is different from the first range. The method includes determining a physiological parameter using the optical energy in the second range.

Abstract: A system includes a garment and a sensor module. The garment includes an engagement feature. The garment is configured to encompass a first location on a body. The engagement feature is positioned in fixed alignment with the garment. The sensor module includes a sensor housing and includes a sensor having an electrical node. The sensor is configured to provide an electrical output on the node. The housing has a complementary feature. The complementary feature is configured to couple and decouple with the engagement feature. The electrical output is based on a measure of a physiological parameter associated with the body and is based on site information corresponding to the engagement feature.

Abstract: A device includes a housing, an emitter, a detector, and a processor. The housing has a body contact surface. The emitter is coupled to the housing and has an emission surface and has an electrical terminal. The emission surface is configured to emit light proximate the body contact surface in response to a signal applied to the electrical terminal. The detector is coupled to the housing. The detector has a sense surface and an output terminal. The detector is configured to provide an output signal on the output terminal in response to light detected at the sensor surface. The processor is configured to implement an algorithm to determine a tissue site based on the emitted light and based on the detected light.

Abstract: A device includes a housing, an emitter, a detector, and a processor. The housing has a body contact surface configured for affixation to a tissue site of a body. The emitter is coupled to the housing and has an emission surface and an electrical terminal. The emission surface is configured to emit light proximate the body contact surface in response to a signal applied to the electrical terminal. The detector is coupled to the housing. The detector has a sense surface and an output terminal. The detector is configured to provide an output signal on the output terminal in response to light detected at the sensor surface. The processor is coupled to the electrical terminal and coupled to the output terminal. The processor is configured to implement an algorithm to monitor for an interruption between the body contact surface and the body and configured to generate an interrupt signal corresponding to the monitoring.

Abstract: A method includes affixing a co-planar sensor on a surface, using a processor, and providing an output. The method includes affixing a co-planar sensor on a surface at a first tissue site. The sensor has a force transducer disposed at an aperture of a rigid guard member. The guard member and the transducer are in co-planar alignment. The transducer is configured to provide an electrical signal corresponding to an internal pressure at the first tissue site. The method includes using the processor to compare the internal pressure with a reference value. Based on the comparison, the method includes providing an output corresponding to compartment syndrome at the first tissue site.

Abstract: A method, a system, or an apparatus for resuscitation can include a first sensor having a first output configured to provide a first sensor signal corresponding to optical attenuation of tissue at a site. The method, the system, or the apparatus can include a processor coupled to the first output. The processor can be configured to generate an output signal. The output signal can be determined based on a first parameter of the optical attenuation. The first parameter can correspond to blood circulation associated with externally applied stimulation of a cardiovascular organ. The method, the system, or the apparatus can include a system output coupled to the processor. The system output can be configured to provide a control signal determined using the output signal.

Abstract: A method of controlling a power factor correction (PFC) converter having a first PFC sub-circuit and a second PFC sub-circuit determines when to transition the PFC converter between an interleaved mode and a saving energy mode (SEM). The method includes generating an amplified error signal based on a monitored output voltage of the PFC converter. The second PFC sub-circuit is disabled in response to the amplified error signal being less than a first threshold value and enabled in response to the amplified error signal exceeding a second threshold value.

Abstract: A controller provides frequency compression for an interleaved power factor correction (PFC) converter that determines the ON and OFF times of each switch associated with the PFC converter to prevent operating frequencies in the audible range. The controller includes a first circuit for generating an ON time current source having a magnitude related to an amplified error signal and the monitored input voltage, and a second circuit for generating an OFF time current source having a magnitude related to the ON time current source, the monitored input voltage, and the monitored output voltage. Gate drive circuitry provides gate drives signals to the switches of the interleaved PFC converter at a frequency determined by magnitudes of the ON time current source and the OFF time current source.

Abstract: The present invention provides a method of controlling an interleaved power factor correction (PFC) circuit operating in a discontinuous conduction mode (DCM). The controller employs a normal mode of operation in which inductor currents in each PFC sub-circuit are estimated based on the monitored input voltage and monitored output voltage, and switching devices associated with each PFC sub-circuit are controlled to ensure DCM operation. As the input voltage increases, the OFF times of each PFC sub-circuit increase such that the inductor currents no longer overlap. In response, the controller activates a time-limiting mode (TLM) in which OFF time durations for each sub-circuit are based on the monitored sum of load currents as opposed to the monitored input voltage and monitored output voltage.

Abstract: A controller generates a drive signal for a converter circuit that includes an active component (i.e., transistor) that is selectively controlled to convert a rectified input to direct current (DC) output. The controller employs an outer feedback loop (based on monitored output voltage of the converter circuit), an inner feedback loop (based on monitored AC input current drawn by the converter circuit), and a pulse width modulator (PWM) to generate the drive signals necessary to generate the desired DC output voltage and to provide power factor correction to the converter circuit. In particular, the inner feedback loop includes an amplifier and a fault protection and clamp circuit. The amplifier has a first input connected to receive a feedback signal representing the monitored AC input current, a second input, and an output that provides a current feedback signal to the PWM.

Abstract: A current-mode under voltage lockout (UVLO) circuit provides an output signal that indicates to connected devices whether a connected power supply is sufficient (i.e., of sufficient strength and stability) based on a comparison of a current that is proportional to the power supply and a reference current. The current-based UVLO circuit employs a reference current generator that is capable of providing a stable reference current and a voltage-to-current converter that provides a current proportional to the power supply voltage. A comparator compares the reference current to the current proportional to the power supply voltage and determines based on the magnitudes of the two currents whether the power supply voltage is sufficient or ‘good’ and generates an output signal indicating the status of the power supply voltage.