Oximetry using light wavelengths to avoid surgical dyes

An oximeter device comprising:

• a sensor head of the oximeter device comprising source structures and detector structures, wherein the source and detector structures of sensor head are used to measure oxygen saturation of a tissue, comprising:
• a first source structure located on a first line of the sensor head, wherein the first source structure comprises a first source capable of emitting at least a first wavelength of light longer than about 730 nanometers;
• a second source structure located on the first line, wherein the second source structure comprises a second source capable of emitting at least a second wavelength of light longer than about 730 nanometers;
• a first detector structure of the detector structures, wherein a first distance is from the first detector structure to the first source structure, a second distance is from the first detector structure to the second source structure, the first distance is greater than the second distance, and the first detector structure is located on a second line of the sensor head, perpendicular to the first line;
• a second detector structure of the detector structures, wherein a third distance is from the second detector structure to the first source structure, a fourth distance is from the second detector structure to the second source structure, the fourth distance is greater than the third distance, the second detector structure is located on a third line of the sensor head, perpendicular to the first line and parallel to the second line, the second and third lines are between the first and second source structures, and the first and second detector structures are arranged symmetrically about a point on the first line;
• a third detector structure of the detector structures, wherein a fifth distance is from the third detector structure to the first source structure, a sixth distance is from the third detector structure to the second source structure, the fifth distance is different from the first distance and the second distance, and the sixth distance is different from the first distance and the second distance;
• and
• a fourth detector structure of the detector structures, wherein the first, second, third, and fourth detector structures are not on the first line, a seventh distance is from the fourth detector structure to the first source structure, an eighth distance is from the fourth detector structure to the second source structure, the seventh distance is different from the first, second, and fifth distances, and the eighth distance is different from the first, second, and sixth distances,
• wherein a method of using the oximeter device comprises
• receiving digital reflectance data for reflected light received by at least two of the detector structures,
• calculating absorption coefficients using the digital reflectance data,
• solving a set of reflection coefficient equations for the tissue to be measured using the absorption coefficients to determine concentration values of at least oxygenated hemoglobin and deoxygenated hemoglobin, and
• determining an oxygen saturation value for the tissue to be measured using the concentration values of oxygenated hemoglobin and deoxygenated hemoglobin.