Abstract: Systems and methods for measuring a physiological parameter of tissue in a patient are provided herein. In a first example, a method of measuring a physiological parameter of blood in a patient is provided. The method includes emitting at least two optical signals for propagation through tissue of the patient, detecting the optical signals after propagation, identifying propagation pathlengths of the optical signals, and identifying detected intensities of the optical signals. The method also includes processing at least the propagation pathlengths to scale the detected intensities for determination of a value of the physiological parameter.

Abstract: Systems and methods for determining physiological parameters of a subject using a sensor array. In an embodiment, a sensor array may contain sensor elements for determining multiple physiological parameters. A combination of sensor elements and the physiological parameters determined may be selected based on signals obtained from the sensor elements of the sensor array. A sensor array may be connected to a monitoring device that may select an optimal sensor element or combination of sensor elements and one or more physiological parameters to be determined. The monitoring device may then determine physiological parameters using the selected combination of sensor elements and display information associated with the parameters on a monitor for use, for example, in monitoring a medical patient.

Abstract: An indicator dilution system includes a catheter configured to deliver an indicator to a patient, an injection device configured to deliver the indicator to the catheter, and a connector coupling the injection device to the catheter. The system also includes one or more sensors configured to acquire measurements from components of the system, which may be used to determine the start and end time of the injection of the indicator to the patient. For example, the one or more sensors may be configured to acquire signals relating to a state of the connector, which may be used to determine whether the connector is in an open state to enable flow of the indicator or in a closed state to reduce flow of the indicator.

Abstract: A photoacoustic sensor system includes a photoacoustic sensor assembly having a light emitting component configured to emit one or more wavelengths of light into a region of a patient's tissue and an acoustic detector configured to detect acoustic energy generated within the region of the patient's tissue in response to the emitted light. The photoacoustic sensor assembly is configured to generate a signal that enables a monitor to determine a potion of the sensor assembly relative to the patient's tissue.

Abstract: The present disclosure describes systems and methods that use spatial modulation to focus continuous wave light into a localized region of interest such as an individual blood vessel. In certain embodiments, intensity modulation techniques, such as linear frequency modulation, are used in conjunction with spatial modulation to achieve more precise measurements through otherwise scattering medium. The focused beam of continuous wave light is capable of penetrating several centimeters of tissue to deliver measurements and images associated with individual blood vessels and other discrete vascular components.

Abstract: A patient monitoring system may provide photoacoustic sensing based on an indicator dilution to determine one or more physiological parameters of a subject. The system may detect an acoustic pressure signal, which may include one or more thermo-dilution responses, one or more hemo-dilution responses, or a combination thereof, using one or more sensor units. The system may use multiple light sources and/or detectors to diagnose and/or improve signal to noise ratio, distinguish between arterial and venous signals, prevent under-sampling, and separate the effects of hemo-dilution and thermo-dilution.

Abstract: According to various embodiments, a tracheal tube may employ optical sensing techniques for determining a distance between the inserted tube and an anatomical structure, such as a carina. The distance information may provide an indication as to whether or not the tracheal tube is properly placed within the trachea. The optical techniques may include backscattered intensity measurements.

Abstract: A physiological monitoring system may use photoacoustic sensing to determine one or more physiological parameters of a subject. The photoacoustic system may use two light sources (e.g., a high power pulsed laser diode and a continuous wave laser diode) to generate acoustic pressure signals in a subject. One or more light sources (e.g., the high powered pulsed laser diode) may provide a high signal-to-noise ratio. The high signal-to-noise ratio signals may provide high sensitivity for physiological measurements (e.g., cardiac output and temperature measurements). The photoacoustic system may use high powered light sources in combination with other light sources to improve physiological measurements.

Abstract: According to various embodiments, a tracheal tube may employ optical sensing techniques for determining an orientation of the inserted tube in a subject. The orientation information may provide an indication as to whether or not the tracheal tube is properly placed within the trachea. The optical techniques may include interferometry.

Abstract: According to various embodiments, methods and systems for determining pressure in the lungs may employ intracuff pressure measurements. The intracuff pressure measurements may calibrated or adjusted based on a set of calibration coefficients or a set of calibration curves, which may reflect patient parameters and cuff/tube geometry factors. The resulting calibration may be used to determine a more accurate estimate of lung pressure, which in turn may be used to control a ventilator and provide breathing assistance to a patient. Also provided are tracheal tubes with couplers or other memory devices for storing calibration information. Such tubes may allow calibration at the level of an individual tracheal tube to account for changes in tube geometry and individual patient factors.

Abstract: Systems and methods are provided for spectrophometric measurement of a physiological property of a patient. For example, an embodiment of a patient monitoring system may include a monitor operatively coupled to a spectrophotometric sensor, which may include an emitter configured to transmit light into tissue of the patient and a detector configured to receive the light from the tissue. The emitter may use a photonic crystal light emitting diode to generate the light.

Abstract: Various methods and systems for photoacoustic patient monitoring are provided. A photoacoustic system includes a light emitting component that emits one or more wavelengths of light into an interrogation region of a patient and an acoustic detector that detects acoustic energy generated by the interrogation region of the patient in response to the emitted light. The system also includes an optical detector that detects the emitted light and provides a signal that is used as an input to remove noise from the signal generated by the acoustic detector.

Abstract: Various methods and systems for photoacoustic patient monitoring are provided. A photoacoustic system includes a light emitting component that emits one or more wavelengths of light into an interrogation region of a patient and an acoustic detector that detects acoustic energy generated by the interrogation region of the patient in response to the emitted light. The system may be implemented to receive photoacoustic waves from a local vein and artery and determine hemodynamic parameters based on a summed indicator dilution curve representative of both arterial and venous indicator dilution.

Abstract: Various methods and systems for photoacoustic patient monitoring are provided. A photoacoustic system includes a light emitting component that emits one or more wavelengths of light into an interrogation region of a patient and an acoustic detector that detects acoustic energy generated by the interrogation region of the patient in response to the emitted light. A reflective coating is disposed on the light emitting component, the acoustic detector, the patient, or a combination thereof to direct the emitted light toward the interrogation region of the patient.

Abstract: According to various embodiments, a tracheal tube may employ optical sensing techniques for determining a distance between the inserted tube and an anatomical structure, such as a carina. The distance information may provide an indication as to whether or not the tracheal tube is properly placed within the trachea. The optical techniques may include time of flight techniques.

Abstract: Multi-wavelength photon density wave medical systems, methods, and devices are provided. In one embodiment, a multi-wavelength system may include a sensor, a sensor cable, and a patient monitor. The sensor may have an emitter output and a detector input configured to pass a multi-wavelength photon density wave input signal into a patient and receive a resulting multi-wavelength photon density wave output signal. The sensor cable may couple to the sensor using two optical cables for transmitting and receiving the multi-wavelength photon density wave signals. The patient monitor may couple to the sensor cable and generate several time-division multiplexed single-wavelength input signals by modulating one or more light sources at a frequency sufficient to produce resolvable photon density waves.

Abstract: The present disclosure describes techniques that may provide more accurate estimates of arterial oxygen saturation using pulse oximetry by switching between a wavelength spectrum of at least a first and a second light source so that the arterial oxygen saturation estimates at low (e.g., in the range below 75%), medium (e.g., greater than or equal to 75% and less than or equal to 84%), and high (e.g., greater than 84% range) arterial oxygen saturation values are more accurately calculated. In one embodiment, light emitted from a near 660 nm and a near 900 nm emitter pair may be used when the arterial oxygen saturation range is high. In another embodiment, light emitted from a near 730 nm and a near 900 nm emitter pair may be used when the arterial oxygen saturation range is low. In yet another embodiment, light emitted from both a near 660 nm-900 nm emitter pair and light emitted from a near 730 nm-900 nm emitter pair may be used when the arterial oxygen saturation range is in the middle range.

Abstract: Embodiments of the present disclosure relate to a system and method for determining a physiologic parameter of a patient. Specifically, embodiments provided herein include methods and systems for non-invasive determination of blood pressure. Information from a photoplethysmography sensor may be used to determine a systolic pressure, which in turn may be used to control a deflation pattern of a blood pressure cuff.

Abstract: A system for measuring a physiological parameter of blood in a patient is presented. The system includes a transmission module configured to emit a plurality of photon density waves into tissue of the patient from a plurality of modulated light sources. The system also includes a receiver module configured to detect characteristics of the plurality of photon density waves. The system also includes a processing module configured to identify characteristics of a pulsatile perturbation of the tissue based on the characteristics of the plurality of photon density waves, and identify a value of the physiological parameter based on at least the characteristics of the pulsatile perturbation of the tissue and the characteristics of the plurality of photon density waves.

Abstract: According to various embodiments, methods and systems for determining pressure in the lungs may employ intracuff pressure measurements. The intracuff pressure measurements may calibrated or adjusted based on a set of calibration coefficients or a set of calibration curves, which may reflect patient parameters and cuff/tube geometry factors. The resulting calibration may be used to determine a more accurate estimate of lung pressure, which in turn may be used to control a ventilator and provide breathing assistance to a patient. Also provided are tracheal tubes with couplers or other memory devices for storing calibration information. Such tubes may allow calibration at the level of an individual tracheal tube to account for changes in tube geometry and individual patient factors.