Patent ID: 7426407

Claim:
An apparatus for measuring total hemoglobin of whole blood, comprising: a catheter; a light source configured to emit light at multiple wavelengths; a transmit optical fiber positioned within the catheter, the transmit optical fiber having a proximal end configured to receive the light from the light source and a distal end configured to be in communication with whole blood; a receive optical fiber positioned within the catheter, the receive optical fiber having a proximal end and a distal end configured to receive reflected light from the whole blood; a detector positioned at the proximal end of the receive optical fiber, the detector configured to measure a change in light absorbance of the reflected light between multiple wavelengths; and a processing unit configured to measure total hemoglobin of the whole blood using the change in light absorbance of the reflected light between multiple wavelengths in proportion to a difference between the wavelengths.