Real-time tracking of cerebral hemodynamic response (rtchr) of a subject based on hemodynamic parameters

Abstract

A system for measuring pain of a person, the system for use with the tissue of the person. Various sensors and detectors on the tissue provide signals to a controller for determining and indicating a pain level of the person.

What is claimed is: 
     
         1 . A system for providing an indication of pain of a person such as measuring pain or a surrogate of pain symptoms of a person, said system for use with the tissue of the person, said system comprising:
 A light source adapted for illuminating the tissue of the person;   An optical sensor adapted for sensing light emitted or reflected by the tissue of the person, said optical sensor generating a light signal indicative of a light parameter of the sensed light;   A surface electrode adapted for sensing an electrical parameter of the tissue of the person, said surface electrode generating an electrode signal indicative of an electrical parameter of the sensed electrical parameter;   A temperature sensor adapted for sensing a temperature of the tissue of the person, said temperature sensor generating a temperature signal indicative of the sensed temperature;   One or more circuits adapted for receiving the light signal, the electrode signal, and the temperature signal and providing corresponding signals;   A controller adapted for receiving and processing the corresponding signals and adapted for providing a pain indication signal which is a function of the corresponding signals;   An indicator adapted to be responsive to the controller for providing an indication which is indicative of the pain indication signal; and   A power supply for supplying power to the system.   
     
     
         2 . The system of  claim 1  further comprising a motion sensor adapted for sensing a motion of the person, said motion sensor generating a motion signal indicative of the sensed motion; and wherein the controller is adapted for receiving and processing the motion signal and is adapted providing the pain indication signal as a function of the motion signal and as a function of the corresponding signals. 
     
     
         3 . The system of  claim 2  wherein the motion sensor comprises at least one of:
 an accelerometer; 
 a GPS sensor; and 
 a gyroscope. 
 
     
     
         4 . The system of  claim 1  wherein the light source comprises at least one of:
 A light source emitting light having a frequency in the range of near infrared wavelengths (e.g., about 10 14  Hz; about 1000 nm in wavelength); 
 An LED; 
 An LED emitting visible light; and 
 An LED emitting light having a frequency in the range of infrared wavelengths (e.g., between 10 11  to 10 15  Hz; between 1000 nm to 1 cm in wavelength). 
 
     
     
         5 . The system of  claim 1  wherein the optical sensor comprises at least one of:
 A photodetector; and 
 A light sensitive element. 
 
     
     
         6 . The system of  claim 1  wherein the light parameters comprises at least one of:
 Light intensity; 
 Light frequency; 
 Light wavelength; and 
 A light emitting pattern (chirp pattern). 
 
     
     
         7 . The system of  claim 1  wherein the surface electrode comprises at least one of:
 an electrode; and 
 Conductive elements adapted to contact the tissue. 
 
     
     
         8 . The system of  claim 1  wherein the electrical parameters comprises at least one of:
 Voltage; 
 Current; 
 Resistance; 
 Capacitance; 
 Inductance; 
 Impedance; and 
 Charge. 
 
     
     
         9 . The system of  claim 1  wherein the temperature sensor comprises at least one of:
 A resistive temperature sensitive element; 
 A bi-metallic element; and 
 A MEMS temperature sensor. 
 
     
     
         10 . The system of  claim 1  wherein the one or more circuits comprise:
 An analog to digital circuit; 
 A signal conditioning circuit; 
 A filtering circuit; and 
 Hardware and drivers for optical transceivers in both normal and chirp modulation modes. 
 
     
     
         11 . The system of  claim 1  wherein the light source, the optical sensor, the surface electrode, the temperature sensor and the one or more circuits comprise one unitary, integrated component and the controller is a separate, unitary, integrated component and further comprising a wireless link between the controller and the one or more circuits. 
     
     
         12 . The system of  claim 1  wherein the light source, the optical sensor, the surface electrode, the temperature sensor, the one or more circuits, the power supply and the controller comprise one unitary, integrated component. 
     
     
         13 . The system of  claim 1  wherein the indicator comprises at least one of:
 One or more LEDs; 
 An LCD device; 
 A screen; and 
 A set of LEDs operating in visible wavelength as indicators of hemodynamic change rate and/or pain level. 
 
     
     
         14 . The system of  claim 1  wherein the controller comprises a processor having a memory device storing computer executable instructions which estimate hemodynamic parameters and wherein the processor is adapted to execute the instructions. 
     
     
         15 . The system of  claim 14  wherein the hemodynamic parameters comprise at least one of the following:
 hemoglobin oxygenation; 
 hemoglobin deoxygenation; 
 heart rate; 
 respiration rate; 
 forehead and/or body temperature; and 
 forehead and/or body impedance. 
 
     
     
         16 . The system of  claim 1  wherein the controller comprises a processor having a memory device storing computer executable instructions wherein the processor processes the received, corresponding signals according to at least one of the following: instructions for an algorithm to compute the pain indication signal based on hemodynamic parameters and hemodynamic response to external and/or internal stimulus in real-time or near real-time; instructions for comparing the signals to a reference (history of hemodynamic parameters and hemodynamic response; and instructions for scaling the hemodynamic response to the range of [0, 10]. 
     
     
         17 . (canceled) 
     
     
         18 . (canceled) 
     
     
         19 . The system of  claim 16  wherein at least one of the following:
 the instructions for the algorithm executed by the processor comprises instructions for fusing over a preset time interval a plurality of samples of a magnitude of the light signal LS, the electrode signal ES and the temperature signal TS, adjusted by preset weights a, b, and c, to compute a pain indicative signal PS corresponding to a fused signal according to the following: Fused Signal=Σ(a*LS+b*ES+c*TS); and 
 the instructions for the algorithm executed by the processor comprises instructions for using over a preset time interval a plurality of samples of a magnitude of a light pain signal LPS indicative of a pain level, an electrode pain signal EPS indicative of a pain level, and a temperature pain signal TPS indicative of a pain level, adjusted by preset weights a, b, and c, to compute an estimated pain indicative signal PS corresponding to a fused signal according to the following: Fused Signal=Σ(a*LPS+b*EPS+c*TPS). 
 
     
     
         20 . The system of  claim 16  wherein the instructions for the algorithm executed by the processor comprises instructions for summing over a preset time interval of a plurality of samples of a magnitude of the light signal LS, the electrode signal ES and the temperature signal TS, wherein each sample is compared to a preset range and the magnitude of the signals is adjusted according to a relationship between each signal and the preset range. 
     
     
         21 . The system of  claim 1  further comprising instructions for inputting personal input into the controller by an input device such as a keypad or keyboard, said personal input including conditions and/or environments of the person and wherein the pain indication signal is coordinated with the personal input whereby improved person pain management is provided. 
     
     
         22 . The system of  claim 16  wherein the personal input includes a level of consciousness indicator, such as:
 0 Awake; 
 2 Light/Moderate Sedation; 
 4 General Anesthesia; 
 6 Deep Hypnotic State; 
 8 Burst Suppression; and 
 10 Fully unconscious. 
 
     
     
         23 . The system of  claim 1  the controller processes at least one of the corresponding signals according to chirp based optical modulation. 
     
     
         24 . The system of  claim 1  wherein the optical sensor comprises a blood oxygenation sensor for sensing a blood oxygenation of the person and wherein the chirp based optical modulation by the processor comprises measuring the light signal in different wavelengths as indicative of blood oxygenation. 
     
     
         25 . The system of  claim 1  wherein the chirp based optical modulation comprises varying a carrier frequency in optical modulation over time to mimic hemodynamic response in different wavelengths over time to detect hemodynamic response recursively over time in a serial (recursive) approach. 
     
     
         26 . The system of  claim 1  wherein the controller calculates respirations and heart rate by evaluating different frequency components in raw sensor data from the optical sensor. 
     
     
         27 . The system of  claim 1  wherein a respiratory signal is a frequency component of the raw data [2-5 Hz] which can be extracted using a band pass frequency with cut off [2-5 Hz], and wherein the processor evaluates frequency components of 5-100 Hz to get heart rate. 
     
     
         28 . The system of  claim 1  wherein the controller comprises a processor having a memory device storing computer executable instructions comprising machine learning techniques and wherein the processor is adapted to execute the instructions, wherein said machine learning techniques includes at least one of:
 Adaptive and non-adaptive noise cancellation of noise in the signals; 
 Signal Envelope Detection; 
 Low pass, band-pass, band-stop and high pass digital filters to extract different hemodynamic parameters from sensor data spectrum; and 
 supervised or unsupervised clustering including at least one of k-means, fuzzy c-means artificial neural networks, support vector machine, fuzzy systems to characterize hemodynamic response across different persons (persons) and across days (inter and intra subject variability characterization). 
 
     
     
         29 . The system of  claim 1  wherein the controller calibrates the system using a baseline wander correction algorithm based on at least one of adaptive or non-adaptive filtering. 
     
     
         30 . The system of  claim 1  further comprising providing data to the controller indicative of feedback from a person to train the controller or set a range. 
     
     
         31 . The system of  claim 30  wherein the data comprises subjective pain measurements from the person synchronized with pain indicator measurements by the system, wherein the subjective pain measurement comprise:
 0-1 No pain; 
 2-3 Mild pain; 
 4-5 Discomforting—moderate pain; 
 6-7 Distressing—severe pain; 
 8-9 Intense—very severe pain; 
 10 Unbearable pain. 
 
     
     
         32 . The system of  claim 1  wherein the controller synchronizes objective hemodynamic parameters of the sensor signals with subjective measurements provided by the person so that the sensor and person or a physician establish communication and coordination between the sensors and the person or physician. 
     
     
         33 . The system of  claim 1  at least one of the following:
 wherein the controller generates commands to which the person responds to at a particular point to define a baseline. 
 wherein the controller is responsive to a person or physician to trigger the hemodynamic monitor to make measurements and define a baseline. 
 wherein a person indicates his/her pain status among environmental parameters to train the device for threshold definition. 
 wherein the device communicates with the persons regarding its pain status in order to define a baseline and threshold for device training and personalization. 
 
     
     
         34 . The system of  claim 1  wherein said system is configured to be implantable within a person. 
     
     
         35 . The system of  claim 1  said system is configured to measure at least one of the following:
 pain associated with an addiction; 
 predict rising pain levels; 
 track uterus-related pain or uterus contractions; 
 epidural pain management; 
 post-childbirth pain management; 
 teething or other child-related pain; 
 post-surgery pain; 
 pain medication drug discovery; and 
 neurological disorders. 
 
     
     
         36 . The system of  claim 1  for use in combination with a PCA (patent controlled analgesia) infusion pump for controlling the delivery of medication to treat pain. 
     
     
         37 . The system of  claim 1  wherein the controller includes telemetry circuitry to communicate information indicative of the pain indicative signal to another device. 
     
     
         38 . A method for providing an indication of pain of a person such as measuring pain or a surrogate of pain symptoms of a person, said method comprising:
 illuminating the tissue of the person;   sensing light emitted or reflected by the tissue of the person;   generating a light signal indicative of a light parameter of the sensed light;   sensing an electrical parameter of the tissue of the person;   generating an electrode signal indicative of an electrical parameter of the sensed electrical parameter;   sensing a temperature of the tissue of the person;   generating a temperature signal indicative of the sensed temperature;   processing the light signal, the electrode signal and the temperature signal and providing a pain indication signal which is a function of the processed signals; and   providing an indication which is indicative of the pain indication signal.   
     
     
         39 . A system for cerebral monitoring of a person, said system for use with the tissue of the person, said system comprising:
 A light source adapted for illuminating the tissue of the person;   A optical sensor adapted for sensing light emitted or reflected by the tissue of the person, said optical sensor generating a light signal indicative of a light parameter of the sensed light;   A surface electrode adapted for sensing an electrical parameter of the tissue of the person, said surface electrode generating an electrode signal indicative of an electrical parameter of the sensed electrical parameter;   A temperature sensor adapted for sensing a temperature of the tissue of the person, said temperature sensor generating a temperature signal indicative of the sensed temperature;   One or more circuits adapted for receiving the light signal, the electrode signal, and the temperature signal and providing corresponding signals;   A controller adapted for receiving and processing the corresponding signals and adapted for providing a cerebral monitoring signal which is a function of the corresponding signals;   An indicator adapted to be responsive to the controller for providing an indication which is indicative of the cerebral monitoring; and   A power supply for supplying power to the system.