Patent ID: 7559894

Claim:
A blood monitoring device comprising: an intravascular catheter terminating in a tip; a transducer configured to transmit an ultrasound signal, wherein the transducer is disposed in the intravascular catheter; a reflector disposed in the tip of the intravascular catheter and spaced apart a fixed distance from the transducer, wherein the transducer is configured to detect at least a portion of the ultrasound signal that is reflected from the reflector; an analysis device configured to continuously estimate at least one of a real-time hematocrit value and a real-time hemoglobin value based on a transit time of the ultrasound signal between the transducer and the reflector; wherein the analysis device includes an attenuation adjustment module configured to measure attenuation of the ultrasound signal, wherein the analysis device is configured to adjust at least one of the estimated real-time hematocrit value and the estimated real-time hemoglobin value based on attenuation of the ultrasound signal measured by the attenuation adjustment module; and wherein the analysis device includes a backscatter adjustment module configured to measure backscatter of the ultrasound signal, wherein the analysis device is configured to adjust at least one of the estimated real-time hematocrit value and the real-time hemoglobin value based on backscatter measured by the backscatter adjustment module.