Abstract: A photoplethysmography (PPG) device includes an equipment module which includes a photodetector and first and second light emitting diodes (LED's) adapted to emit light of first and second wavelengths, respectively. The PPG device also includes a mask covering the patient facing extremity of the equipment module so that when the device is applied to a patient the mask is situated between the patient and the patient facing extremity. A processor is adapted to control drive current and/or operating time of the second LED to achieve an elevated localized body tissue temperature of a patient to which the PPG device is applied.

Abstract: A monitoring device configured to be attached to a subject includes a photoplethysmography (PPG) sensor configured to measure physiological information from the subject, a blood flow stimulator, and a processor configured to process signals from the PPG sensor to determine a signal-to-noise level of the signals. In response to a signal-to-noise level determination, the processor is configured to instruct the blood flow stimulator to increase blood perfusion at a location where the PPG sensor is attached to the subject. The signal-to-noise level determination may be a determination that the signal-to-noise level is below a threshold level. The blood flow stimulator may be a heating element or light source configured to heat the location of the subject.

Abstract: The invention provides a body-worn patch sensor for simultaneously measuring a blood pressure (BP), pulse oximetry (SpO2), and other vital signs and hemodynamic parameters from a patient. The patch sensor features a sensing portion having a flexible housing that is worn entirely on the patient's chest and encloses a battery, wireless transmitter, and all the sensor's sensing and electronic components. It measures electrocardiogram (ECG), impedance plethysmogram (IPG), photoplethysmogram (PPG), and phonocardiogram (PCG) waveforms, and collectively processes these to determine the vital signs and hemodynamic parameters. The sensor that measures PPG waveforms also includes a heating element to increase perfusion of tissue on the chest.

Abstract: A sensor system for measuring blood perfusion, blood temperature, and thermal resistance using heat transfer and temperature measurements. The system uses a heat flux sensor, temperature sensor and electric resistance heater with a data analysis device using measurements before, during and after the thermal event provided by the heater.

Abstract: The present invention provides a personal hand-held monitor (PHHM) comprising a signal acquisition device for acquiring signals which can be used to derive a measurement of a parameter related to the health of the user, wherein the signal acquisition device comprises a blood photosensor having one or more photo-emitters for transmitting light to a body part of a user, one or more photo-detectors for detecting light transmitted through or scattered by the body part and two or more optical cells, at least one of which contains an analyte to be detected or which mimics the absorption spectrum of the analyte, through which the light that has been or will be transmitted through or scattered by the body part passes before it reaches the photo-detector(s).

Abstract: Disclosed herein is a physiological measurement system that can automatically adjust the number of wavelengths used based on the quality of a sensor signal that is reflective of an optical radiation detected at a sensor after tissue attenuation. The signal quality is examined to determine if it is sufficient to support the use of a full set of wavelengths. If it is determined to be insufficient to support the full set, a reduced number of wavelengths is used.

Abstract: Embodiments of the present disclosure relate to techniques for controlling the temperature of light sources within physiological sensors in order to regulate the wavelengths emitted by the light sources. The sensors may include a temperature control element that is designed to provide heating and/or cooling to the light sources. The sensors also may include a temperature sensor designed to detect the temperature of the light sources. Based on the detected temperature, a controller can vary the amount of heating and/or cooling provided by the temperature control element to maintain the temperature of the light sources at a desired temperature or within a desired temperature range.

Abstract: An ultrasonic diagnostic apparatus is provided for displaying a color map on which a difference in blood flow dynamics is reflected. Setting a test subject who is administered a contrast agent is assumed as an imaging target, and a probe transmits and receives ultrasonic waves to and from the target for contrast imaging. Image data is constructed based on signals received by the probe and a time-intensity curve is generated from intensity values of the image data. According to the time-intensity curve, a value of a predetermined parameter is calculated for producing a distribution image of blood flow dynamics. The distribution image (color map) of the blood flow dynamics is produced from the parameter value. The color map is a two-dimensional or a three-dimensional image being color-coded according to the parameter value.

Abstract: An optical sensor unit (10) for measuring a concentration of a gas is provided, comprising at least one sensing layer (122) adapted to be irradiated with a predetermined radiation; at least one gas-permeable layer (121) adjacent to one side of the at least one sensing layer (122) and adapted to pass gas which concentration is to be measured through the gas-permeable layer (121) towards the sensing layer (122); a removable protective layer (150) covering at least the gas-permeable layer (121) and adapted to be removed before use of the optical sensor unit (10), wherein the optical sensor unit (10) is adapted to measure an optical response of the at least one sensing layer (122), which optical response depends on the concentration of the gas.

Abstract: A device for hypothermic perfusion of a cardiac organ comprising a first sealed tank able to contain a physiological liquid, a second sealed tank communicating, in a sealed manner, with an internal volume of the first tank via a nozzle, a device for refrigerating the first tank and keeping the first tank at a substantially constant temperature and a device for intermittently pressurizing the internal volume of the first tank. The first tank communicates with the pressurizing device by way of a conduit connecting an interior of the first tank to the pressurizing device to permit pressurization of the internal volume of the first tank, and of the physiological liquid inside the first tank, in order to perform perfusion of the organ. The second tank comprises a safety element formed by an overflow outlet duct which communicates with the first tank and includes a non-return valve.

Abstract: A biological signal measuring system includes: a light emitter emitting a first light beam and a second light beam; a light receiver outputting first and second signals in accordance with light intensities of the first and second light beams that have been passed through or reflected from a living tissue of a subject; a first calculating section acquiring a light attenuation of the first light beam based on the first signal and a light attenuation of the second light beam based on the second signal; a second calculating section acquiring a blood-derived light attenuation based on the light attenuation of the first and second light beams; a third calculating section acquiring information relating to a blood oxygen saturation based on a change amount of the blood-derived light attenuation associated with pressurization of the living tissue; and an outputting section outputting the acquired information.

Abstract: A method for classifying tissue as normal or abnormal tissue includes obtaining segmented reconstructed volumetric image data for predetermined tissue of interest, generating a 2D voxel representation of the segmented reconstructed volumetric image data, and classifying voxels of the segmented reconstructed volumetric image data as corresponding to abnormal and normal tissue based on the 2D voxel representation.

Abstract: A near-infrared spectrophotometric system (e.g., a cerebral oximeter) includes a sensor portion and a monitor portion. The monitor portion includes a processor that runs an algorithm which utilizes the amount of detected light to determine the value of the oxygen concentration (e.g., the absolute level of oxygen concentration). The monitor portion also includes a visual display that displays the determined oxygen concentration values in various formats. The monitor portion may also include an audible device (e.g., a speaker), that provides audible indications of the determined oxygen concentration values. Various visual indicators may include, for example, color-coded graphs of the determined oxygenation values to alert the system user, for example, whether one hemisphere of the brain, or one or more regions of the brain, is in danger of adverse and potentially permanent damage. Also, data may be pre-processed by selecting the most clinically concerning sensor value (e.g.

Abstract: An optical sensor for a medical device includes a fixed lens spacing between emit and receive modules to achieve target sensor sensitivity, while varying other sensor parameters in order to increase signal amplitude without increasing power demand. An optical sensor connected to a housing of a medical device includes a circuit board, an opto-electronic component, a wall, a lens, and a ferrule. The circuit board is arranged within the housing. The opto-electronic component is mounted on a surface of the circuit board. The wall protrudes from the surface of the circuit board and surrounds the opto-electronic component. The lens is offset from the surface of the circuit board. The ferrule is connected to the housing, the lens and the wall. An inner surface of the wall mates with an outer surface of the ferrule.

Abstract: A medical device for monitoring a patient condition includes a first combination of a light source and a light detector to emit light into a volume of tissue, detect light scattered by the volume of tissue, and provide a first output signal corresponding to an intensity of the detected light. A control module is coupled to the light source to control the light source to emit light at least four spaced-apart light wavelengths, and a monitoring module is coupled to the light detector to receive the output signal, compute a measure of tissue oxygenation in response to the light detector output signal, and detect tissue hypoxia using the measure of tissue oxygenation.

Abstract: A stretchable electronic circuit that includes a stretchable base substrate having a plurality of stretchable conductors formed onto a surface thereof, with both the stretchable base substrate and conductors being bendable together about two orthogonal axes. The stretchable circuit also includes a stretchable sensor layer attached to the base substrate with a cavity formed therein which has a contact point exposing one of the plurality of stretchable conductors. The stretchable electronic circuit further includes a surface mount device (SMD) package with a conductor contact protrusion installed into the cavity, and wherein a substantially constant electrical connection is established between the conductor contact protrusion and the stretchable conductor at the contact point by tensile forces interacting between the stretchable base substrate and the stretchable sensor layer.

Abstract: An inventive method and system are provided for identifying a compatible photoplethysmographic sensor when interconnected to a given photoplethysmographic monitor. The method and system may further provide for the identification of which of a plurality of compatible sensors is interconnected to allow for selective calibration of the photoplethysmographic monitor. In this regard, the system and method may entail provision of a predetermined drive or test signal to a light source and/or identification element (i.e., sensor elements) of a photoplethysmographic sensor, and the obtainment of a corresponding output signal for use in sensor identification. In one approach, an output signal is obtained from at least one of three sensor elements each of which is interconnected between a different pair of sensor terminals which is a unique combination of two of four sensor terminals on the sensor.

Abstract: A system including an implantable neurostimulator device capable of modulating cerebral blood flow to treat epilepsy and other neurological disorders. In one embodiment, the system is capable of modulating cerebral blood flow (also referred to as cerebral perfusion) in response to measurements and other observed conditions. Perfusion may be increased or decreased by systems and methods according to the invention as clinically required.

Abstract: In general, the invention is directed toward an implantable medical device that includes a controller and a plurality of sensor modules. The controller may control the sensor modules to perform one or more sensor actions in order to facilitate a measurement. The sensor modules may store one or more operational parameters that control various aspects of the sensor actions performed by the sensor modules. The controller may automatically adjust one or more of the operational parameters based on results received from previous measurements in order to provide closed loop parameter adjustment of the operational parameters associated with the sensor modules. The controller may communicate with the sensor modules via a common bus. Example measurements include tissue perfusion measurements, blood oxygen sensing measurements, sonomicrometry measurements, and pressure measurements.

Abstract: A system including an implantable neurostimulator device capable of modulating cerebral blood flow to treat epilepsy and other neurological disorders. In one embodiment, the system is capable of modulating cerebral blood flow (also referred to as cerebral perfusion) in response to measurements and other observed conditions. Perfusion may be increased or decreased by systems and methods according to the invention as clinically required.

Abstract: A pulse oximetry sensor having a temperature indicator and a method of operating such a sensor to visually indicate to an operator the temperature of the sensor and hence a measure of the temperature of the tissue location to which the sensor is attached. In one embodiment, the temperature indicator is a color changing liquid crystal temperature monitor. The liquid crystal temperature monitor includes a number of segments, each of which is activateable within a predetermined temperature range to be monitored. In other embodiments of the present invention, the oximetry sensor includes an active regulated heating element to enhance blood perfusion within the tissue location being monitored. In either embodiment, the temperature indicator provides the operator with an effective way of monitoring the temperature of the sensor and the adjacent tissue location. In case of a heated sensor, the temperature indicator informs the operator that the warming function of the sensor is functioning correctly.

Abstract: A pulse oximetry sensor having a temperature indicator and a method of operating such a sensor to visually indicate to an operator the temperature of the sensor and hence a measure of the temperature of the tissue location to which the sensor is attached. In one embodiment, the temperature indicator is a color changing liquid crystal temperature monitor. The liquid crystal temperature monitor includes a number of segments, each of which is activateable within a predetermined temperature range to be monitored. In other embodiments of the present invention, the oximetry sensor includes an active regulated heating element to enhance blood perfusion within the tissue location being monitored. In either embodiment, the temperature indicator provides the operator with an effective way of monitoring the temperature of the sensor and the adjacent tissue location. In case of a heated sensor, the temperature indicator informs the operator that the warming function of the sensor is functioning correctly.

Abstract: A medical imaging system includes an imaging device for producing temporally spaced image representations, a memory for storing the image representations, and a processor. The processor aligns the image representations by iteratively deriving a transform between progressively smaller sub-sets of pixels in temporally adjacent images until the sub-sets converge, and, applies the transform to the temporally adjacent images. The processor further sorts selected pixels in a region of interest spatially within each of the image representations for further processing by classifying pixels in the images according to a characteristic indicative of an absorption rate of the contrast agent.

Abstract: An improved pulse oximeter provides for simultaneous, noninvasive oxygen status and photoplethysmograph measurements at both single and multiple sites. In particular, this multiple-site, multiple-parameter pulse oximeter, or “stereo pulse oximeter” simultaneously measures both arterial and venous oxygen saturation at any specific site and generates a corresponding plethysmograph waveform. A corresponding computation of arterial minus venous oxygen saturation is particularly advantageous for oxygen therapy management. An active pulse-inducing mechanism having a scattering-limited drive generates a consistent pulsatile venous signal utilized for the venous blood measurements. The stereo pulse oximeter also measures arterial oxygen saturation and plethysmograph shape parameters across multiple sites.

Abstract: A method and apparatus for minimizing confounding effects in a noninvasive in-vivo spectral measurement caused by fluctuations in tissue state monitors a selected tissue state parameter spectroscopically and maintains the selected parameter within a target range, at which spectral effects attributable to the changes in the selected parameter are minimized. The invention includes both active and passive control. A preferred embodiment of the invention provides a method and apparatus for minimizing the confounding effects in near IR spectral measurements attributable to shifts in skin temperature at a tissue measurement site. Spectroscopic monitoring of skin temperature at the measurement site provides near-instantaneous temperature readings by eliminating thermal time constants. A thermistor positioned at the measurement site provides active control. The spectrometer and the temperature control device are incorporated into a single instrument for noninvasive measurement of blood glucose concentration.

Abstract: An optical system and method for transcranial in vivo examination of brain tissue includes a spectrophotometer coupled to an array of optical fibers and a processor. The array of optical fibers is constructed to transmit optical radiation of a visible to infra-red wavelength. The optical fibers have distal ends projected through the hair into contact with a surface of the scalp and arranged over a selected geometrical pattern. The spectrophotometer includes at least one light source constructed to emit optical radiation of the visible or infra-red wavelength and at least one light detector constructed to detect radiation that has migrated from a first of said distal ends within the brain tissue to a second of the distal ends. A sequencer is constructed to control introduction of radiation from a first distal end and constructed to control detection of radiation after arriving at a second distal end using a transmission/reception algorithm over the geometrical pattern.

Abstract: A method for determining the blood constituents of a patient comprising coupling an oximeter sensor arrangement to a tissue region of the patient; passing first and second lights through the patient's tissue region for a first period of time while the venous blood in the tissue region has a first volume and for a second period of time while the venous blood in the tissue region has a second volume, the first light being substantially in a red light range and the second light being substantially in an infrared light range; detecting a red light signal and an infrared light signal, the red and infrared signals having at least first and second frequencies; computing a first ratio of the red and infrared signals at the first frequency; computing a second ratio of the red and infrared signals at the second frequency; comparing the first and second ratios to determine a first blood constituent.

Abstract: A method and apparatus for both heating a patient's skin and for measuring the temperature using the same device, such as a thermistor. Thus, the thermistor generates controlled heat, and is not just used for sensing the temperature. In an oximetry sensor, the thermistor is located in the vicinity of the light emitter and photodetector to warm the optically-probed tissue region. As heat is dissipated, temperature changes are sensed as resistance changes according to Ohm's law. Active thermal regulation by varying the amount of thermistor current and power can safeguard against burning the tissue while maximizing perfusion.

Abstract: A method and apparatus for improving blood perfusion by both heating a patient's skin and providing emitters and a detector which are offset from each other. Since the emitters and detector are not directly opposite each other, the light is forced to pass through more blood perfused tissue (with blood perfusion enhanced by heating) to pass from the emitters to the detector. This causes the light emitted by the emitters to pass through more blood-perfused tissue to reach the detector than it would on the direct path through the appendage if the emitters and detector were opposite each other.

Abstract: A device and method for noninvasively quantifying important physiological parameters in blood. The device and method utilizes changes in molecular behavior induced by thermal energy of change to facilitate the measurement of the physiological parameters in blood. Oxygen saturation, partial pressure of oxygen, partial pressure of carbon dioxide, concentration of bicarbonate ion and total carbon dioxide, acid-base balance, base excess, hemoglobin level, hematocrit, oxyhemoglobin level, deoxyhemoglobin level, and oxygen content can all be determined quickly, easily, and continuously. There is no need for skin puncture or laboratory analysis.

Abstract: An improved method for optically measuring a characteristic of a patient's blood or tissue is provided which involves first passing an arterialization current (typically from about 1-10 mA AC or DC) through a relatively short tissue segment of a patient (up to about 12 inches) for a period of time sufficient to significantly increase blood flow, whereupon a transcutaneous optical measurement is made. The method is especially suited for pulse oximetry and permits more accurate readings owing to the increased amplitude of the detection signal. In another embodiment, a probe molecule composition may be initially applied to the patient's skin, and the arterialization current is used to rapidly and evenly diffuse the probe molecule into the tissue segment. An appropriate sensor can then be employed for detecting the probe molecule.