Cancellation of light shunting

• US 8,923,944 B2
• Filed: 08/20/2012
• Issued: 12/30/2014
• Est. Priority Date: 03/09/2007
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Covidien LP (Medtronic Plc)
• Inventors: Petersen, Ethan
• Primary Examiner(s): Winakur, Eric
• Assistant Examiner(s): Liu, Chu Chuan (JJ)
• Application Number:
  US13/589,642
• Publication Number:
  US 20120316410A1
• Time in Patent Office: 862 Days
• Field of Search: 600/310, 600/322, 600/323, 600/331, 600/336, 600/340, 600/473, 600/476, 356/41
• US Class Current: 600/331
• CPC Class Codes: A61B 2560/0233 Optical standards
• CPC Class Codes: A61B 2562/085 combined with means for recording calibration data
• CPC Class Codes: A61B 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/1495 Calibrating or testing of in-vivo probes
• CPC Class Codes: A61B 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: A61B 5/7225 Details of analog processing, e.g. isolation amplifier, gain or sensitivity adjustment, filtering, baseline or drift compensation A61B5/30, A61B5/316 take precedence; transformers for specific applications H01F38/00; amplifiers H03F
• CPC Class Codes: A61B 5/7278 Artificial waveform generation or derivation, e.g. synthesising signals from measured signals A61B5/327 takes precedence
• CPC Class Codes: A61B 5/742 using visual displays A61B5/339 takes precedence
• CPC Class Codes: A61B 90/90 Identification means for patients or instruments, e.g. tags
• CPC Class Codes: A61B 90/98 using electromagnetic means, e.g. transponders
• CPC Class Codes: G01D 18/008 with calibration coefficients stored in memory
• CPC Class Codes: G01D 5/30 the beams of light being detected by photocells
• CPC Class Codes: Y10T 29/49002 Electrical device making

Abstract

There is provided a system and method for canceling shunted light. The method includes transmitting electromagnetic radiation at tissue of interest and generating a signal representative of detected electromagnetic radiation. A portion of the generated signal representing shunted light is canceled from the generated signal and the remaining portion of the generated signal is used to compute physiological parameters.

Claims

1. A system for non-invasively determining physiological parameters, the system comprising:

a sensor configuration configured to obtain measurements of a tissue of interest;

a monitor coupled to the sensor and comprising a controller and a memory, wherein the controller is configured to;

receive the measurements;

retrieve from the memory a first value and a second value, the first value representing an amount of light emitted from emitters in the sensor and the second value representing an attenuation coefficient of everything other than the tissue of interest, wherein the attenuation coefficient of everything other than the tissue of interest relates at least in part to light shunting through the sensor;

determine a third value using the measurements provided to the controller and the first and second values, the third value representing an attenuation coefficient for the tissue of interest; and

determine a physiological parameter based at least in part on the third value.

2. The system of claim 1 wherein the memory is associated with the sensor or on a connector coupled to the sensor.

3. The system of claim 1 wherein the memory is associated with the monitor.

4. The system of claim 1 wherein the monitor is configured to receive coded values from the sensor and correlate the coded values with first and second values.

5. The system of claim 1 wherein the monitor is configured to recognize the sensor and retrieve the first and second values associated with the sensor.

6. The system of claim 1 wherein the monitor is configured to receive information from the sensor related to sensor identification to recognize the sensor.

7. The system of claim 1 wherein determining the physiological parameter based at least in part on the third value comprises using the equation