Compressibility probe for monitoring blood volume changes

A process for monitoring changes in blood volume and microvascular pooling in animals, comprising:

• a diagnostic apparatus attached to said blood system for transmission and detection of ultrasound through blood flowing in the extracorporeal system;
• a signal processing system to determine the time shift between the emitting and receiving ultrasound for determination of blood parameters;
• a control unit linked to said diagnostic apparatus for detecting compressibility with high resolution, for assessing density change at the same temperature, for initiating and recording ultrasound waves, and for monitoring the characteristics of said modified blood;
• and
• a computer memory unit for determining blood volume and microvascular pooling from said compressibility and density change.

An apparatus for monitoring changes in blood volume and microvascular pooling in animals, comprising:

• an extracorporeal blood treatment device having a first branch, said first branch having a first end and a second end, said first end being connected by tubing to an arterial segment of the animal's blood system and said second end being connected to a filtration member;
• and a second branch, said second branch having a first end and a second end, said first end being connected by tubing to a venous segment of the animal's blood system and said second end being connected to said filtration member;
• a diagnostic apparatus attached to said animal's blood system for transmission and detection of ultrasound through blood flowing in said extracorporeal device;
• a signal processing system to determine the time shift between the emitting and receiving ultrasound for determination of blood parameters;
• an injection connection for infusing accurately a known amount of an indicator fluid to said animal's blood system downstream of said diagnostic apparatus;
• an indicator fluid infusion process to change the density of the animal's blood system as measured through said diagnostic apparatus;
• a control unit linked to said diagnostic apparatus for detecting compressibility with high resolution, for assessing density change at the same temperature, for initiating and recording ultrasound waves, and for monitoring the characteristics of said modified blood;
• and
• a computer memory unit for determining blood volume and microvascular pooling from said compressibility and density change.