Robust calibration and self-correction for tissue oximetry probe

A method comprising:

• providing a tissue oximeter comprising a sensor head and a nonvolatile memory,
• wherein the sensor head comprises a plurality of sources and a plurality of detectors, the sources are arranged along a line, and a first distance is between a first one of the sources and a second one of the sources that are farthest apart,
• there are an equal number of detectors on either side of the line, and a position of a detector on a first side of the line will have point symmetry with another detector on a second side of the line about a selected point on the line,
• a second distance is between a first one of the detectors and a second one of the detectors that are nearest,
• the first distance is greater than the second distance, and
• each detector above the line has a third distance from each source that is different from every other detector above the line;
• emitting light from a first source of a plurality of sources of the tissue oximetry device into a tissue phantom, wherein the emitted light is reflected by the tissue phantom;
• detecting the reflected light from the tissue phantom using the plurality of detectors of the tissue oximetry device;
• generating a set of detector responses by the plurality of detectors based on detecting the light emitted from the light source;
• comparing the set of detector responses to a previously determined reflectance curve for the tissue phantom;
• generating a set of calibration functions based on the comparison of the set of detector responses to the previously determined reflectance curve,
• wherein each calibration function in the set of calibration functions is associated with a different pair of a source of the plurality of sources and each detector above the line, each different pair having a different source-to-detector separation distance;
• and
• storing the set of calibration functions in the nonvolatile memory of the tissue oximetry device.

A method comprising:

• providing a tissue oximeter comprising a sensor head and a memory,
• wherein the sensor head comprises a plurality of sources and a plurality of detectors, the sources are arranged along a line,
• there are an equal number of detectors on either side of the line, the detectors are not positioned on the line, and a position of a detector on a first side of the line will have point symmetry with another detector on a second side of the line about a selected point on the line, and
• each detector above the line has a first distance from each source that is different from every other detector above the line;
• emitting light from a first source of a plurality of sources of the tissue oximetry device into a tissue phantom, wherein the emitted light is infrared light and reflected by the tissue phantom;
• detecting the reflected light from the tissue phantom using the plurality of detectors of the tissue oximetry device;
• generating a set of detector responses by the plurality of detectors based on detecting the light emitted from the light source;
• comparing the set of detector responses to a previously determined reflectance curve for the tissue phantom;
• generating a set of calibration functions based on the comparison of the set of detector responses to the previously determined reflectance curve,
• wherein each calibration function in the set of calibration functions is associated with a different pair of a source of the plurality of sources and each detector above the line, each different pair having a different source-to-detector separation distance;
• and
• storing the set of calibration functions in the memory of the tissue oximetry device.

A method comprising:

• providing a tissue oximeter comprising a sensor head and a memory,
• wherein the sensor head comprises a plurality of sources and a plurality of detectors, the sources are arranged along a line, the detectors are not located on the line, and a first distance is between a first one of the sources and a second one of the sources that are farthest apart,
• there are an equal number of detectors on either side of the line, a position of a detector on a first side of the line will have point symmetry with another detector on a second side of the line about a selected point on the line, and the plurality of detectors comprises four detectors above the line and four detectors below the line,
• a second distance is between a first one of the detectors and a second one of the detectors that are nearest,
• the first distance is greater than the second distance, and
• each detector above the line has a third distance from each source that is different from every other detector above the line;
• emitting light from a first source of a plurality of sources of the tissue oximetry device into a tissue phantom, wherein the emitted light is reflected by the tissue phantom;
• detecting the reflected light from the tissue phantom using the plurality of detectors of the tissue oximetry device;
• generating a set of detector responses by the plurality of detectors based on detecting the light emitted from the light source;
• comparing the set of detector responses to a previously determined reflectance curve for the tissue phantom;
• generating a set of calibration functions based on the comparison of the set of detector responses to the previously determined reflectance curve,
• wherein each calibration function in the set of calibration functions is associated with a different pair of a source of the plurality of sources and each detector above the line, each different pair having a different source-to-detector separation distance;
• and
• storing the set of calibration functions in the memory of the tissue oximetry device.

A method comprising:

• providing a tissue oximeter comprising a sensor head and a memory,
• wherein the sensor head comprises a plurality of sources and a plurality of detectors, the sources are arranged along a line, the detectors are not located on the line, and a first distance is between a first one of the sources and a second one of the sources that are farthest apart,
• a second distance is between a first one of the detectors and a second one of the detectors that are nearest,
• the first distance is greater than the second distance,
• there are an equal number of detectors on either side of the line, and a position of a detector on a first side of the line will have point symmetry with another detector on a second side of the line about a selected point on the line, and
• each detector above the line has a third distance from each source that is different from every other detector above the line;
• emitting light from a first source of a plurality of sources of the tissue oximetry device into a first tissue phantom, wherein the emitted light is reflected by the first tissue phantom;
• detecting the reflected light from the first tissue phantom using the plurality of detectors of the tissue oximetry device;
• generating a set of detector responses by the plurality of detectors based on detecting the light emitted from the light source;
• comparing the set of detector responses to a previously determined reflectance curve for the first tissue phantom;
• generating a first set of calibration functions based on the comparison of the set of detector responses to the previously determined reflectance curve,
• wherein each calibration function in the set of calibration functions is associated with a different pair of a source of the plurality of sources and each detector above the line, each different pair having a different source-to-detector separation distance;
• storing the set of calibration functions in the memory of the tissue oximetry device, wherein the tissue phantom is a first tissue phantom, and the method comprises repeating the emitting light, detecting the reflected light, generating a set of detector responses, comparing the set of detector responses, and generating a second set of calibration functions for a second tissue phantom, which is different from the first tissue phantom;
• storing the set of calibration functions for the second tissue phantom in the memory of the tissue oximetry device, wherein each different pair of one of the sources and one of the detectors has a first calibration function from the first set of calibration function stored in the memory and a second calibration function from the second set of calibration function stored in the memory;
• for each of the different pairs of the one of the sources and the one of the detectors, generating an average the first calibration function and the second calibration function;
• and
• storing the average for each of the different pairs of the one of the sources and the one of the detectors in the memory.

A method comprising:

• providing a tissue oximeter comprising a sensor head and a memory,
• wherein the sensor head comprises a plurality of sources and a plurality of detectors, the sources are arranged along a line,
• there are an equal number of detectors on either side of the line, and a position of a detector on a first side of the line will have point symmetry with another detector on a second side of the line about a selected point on the line, and
• each detector above the line has a distance from each source that is different from every other detector above the line;
• emitting light from a first source of a plurality of sources of the tissue oximetry device into a first tissue phantom, wherein the emitted light is reflected by the first tissue phantom;
• detecting the reflected light from the tissue phantom using the plurality of detectors of the tissue oximetry device;
• from the electrical signals, generating a set of detector responses by the plurality of detectors based on detecting the light emitted from the light source;
• comparing the set of detector responses to a previously determined reflectance curve for the first tissue phantom;
• generating a first set of calibration functions based on the comparison of the set of detector responses to the previously determined reflectance curve,
• wherein each calibration function in the set of calibration functions is associated with a different pair of a source of the plurality of sources and each detector above the line, each different pair having a different source-to-detector separation distance;
• storing the set of calibration functions in the memory of the tissue oximetry device;
• repeating the emitting light, detecting the reflected light, generating a set of detector responses, comparing the set of detector responses, and generating a second set of calibration functions for a second tissue phantom, which is different from the first tissue phantom;
• storing the set of calibration functions for the second tissue phantom in the memory of the tissue oximetry device, wherein each different pair of one of the sources and one of the detectors has a first calibration function from the first set of calibration function stored in the memory and a second calibration function from the second set of calibration function stored in the memory;
• for each of the different pairs of the one of the sources and the one of the detectors, generating an average the first calibration function and the second calibration function;
• and
• storing the average for each of the different pairs of the one of the sources and the one of the detectors in the memory.

A method comprising:

• providing a tissue oximeter comprising a sensor head and a memory,
• wherein the sensor head comprises a plurality of sources and a plurality of detectors, the sources are arranged along a line,
• there are an equal number of detectors on either side of the line, and a position of a detector on a first side of the line will have point symmetry with another detector on a second side of the line about a selected point on the line, and
• each detector above the line has a distance from each source that is different from every other detector above the line;
• emitting light from a first source of a plurality of sources of the tissue oximetry device into a first tissue phantom, wherein the emitted light is reflected by the tissue phantom comprises
• emitting light from the first source at a first wavelength into a first tissue phantom,
• emitting light from the first source at a second wavelength into the first tissue phantom,
• emitting light from the first source at a third first wavelength into the first tissue phantom, and
• emitting light from the first source at a fourth first wavelength into the first tissue phantom, wherein the first, second, third, and fourth wavelengths are different from each other;
• detecting the reflected light from the first tissue phantom using the plurality of detectors of the tissue oximetry device;
• generating a set of detector responses by the plurality of detectors based on detecting the light emitted from the first source and reflected from the first tissue phantom;
• comparing the set of detector responses to a previously determined reflectance curve for the first tissue phantom;
• generating a first set of calibration functions based on the comparison of the set of detector responses to the previously determined reflectance curve,
• wherein each calibration function in the first set of calibration functions is associated with a different pair of a source of the plurality of sources and each detector above the line, each different pair having a different source-to-detector separation distance;
• and
• storing the first set of calibration functions in the memory of the tissue oximetry device
• emitting light from the first source into a second tissue phantom comprising:
• emitting light from the first source at a first wavelength into a second tissue phantom,
• emitting light from the first source at a second wavelength into the second tissue phantom,
• emitting light from the first source at a third wavelength into the second tissue phantom, and
• emitting light from the first source at a fourth wavelength into the second tissue phantom, wherein the first, second, third, and fourth wavelengths are different from each other;
• detecting the reflected light from the second tissue phantom using the plurality of detectors of the tissue oximetry device;
• generating a set of detector responses by the plurality of detectors based on detecting the light emitted from the first source and reflected from the second tissue phantom;
• comparing the set of detector responses to a previously determined reflectance curve for the second tissue phantom;
• generating a second set of calibration functions based on the comparison of the set of detector responses to the previously determined reflectance curve,
• wherein each calibration function in the second set of calibration functions is associated with a different pair of a source of the plurality of sources;
• and
• storing the second set of calibration functions in the memory of the tissue oximetry device:
• if one of the calibration functions from the first set of calibration functions for a given pair of a source and a detector is greater than a threshold value, then averaging the one of the calibration function with one of the calibration function from the second set of calibrations function for the pair of the source and the detector and storing an average value for the average in the memory.