Abstract: An apparatus and method to assess the compressibility, density, and hematocrit of blood including an optical ultrasound probe clipped onto tubing in which blood is flowing. The probe includes a combination of ultrasound transducers, a light emitting diode, and photodiodes. An indicator medium is injected into the bloodstream of the subject over one or more time points. Ultrasound waves are emitted by a transducer and received by another transducer, and a novel signal-processing unit and a computer with a novel computation scheme process the ultrasound signals to assess the phase shift of ultrasound as it transmitted across the blood stream.

Abstract: A density/solute monitor having at least one ultrasound probe, a signal processing unit, and a computing mechanism, and process for using the same, to measure phase shift between emitting and receiving ultrasound, sound velocity, compressibility, density, and solute concentration of fluid flowing through a fluid processing system. The ultrasound probe emits and receives ultrasound waves through the fluid and the signal-processing unit and computing mechanism process the ultrasound waves to determine phase and time shift. The computing mechanism converts phase shift to density, compressibility, and solute concentration measurements of the fluid. Calibrating fluids calibrate the detected phase shift in terms of sound velocity in the factory. Measurements provide information about passage of solutes and flow to achieve better solute collection efficiency, solution purity, and control of fluid processing systems.

Abstract: An apparatus and method to assess the compressibility, density, and hematocrit of blood including an optical ultrasound probe clipped onto tubing in which blood is flowing. The probe includes a combination of ultrasound transducers, a light emitting diode, and photodiodes. An indicator medium is injected into the bloodstream of the subject over one or more time points. Ultrasound waves are emitted by a transducer and received by another transducer, and a novel signal-processing unit and a computer with a novel computation scheme process the ultrasound signals to assess the phase shift of ultrasound as it transmitted across the blood stream. Based on the linear relationship between compressibility and density, changes in blood density are calculated from changes in phase shift. The optical part of the probe assesses the hematocrit of blood. Two fluid media are used to calibrate the probe on the relationship between phase shift and density in the factory.

Abstract: A density/solute monitor having at least one ultrasound probe, a signal processing unit, and a computing mechanism, and process for using the same, to measure phase shift between emitting and receiving ultrasound, sound velocity, compressibility, density, and solute concentration of fluid flowing through a fluid processing system. The ultrasound probe emits and receives ultrasound waves through the fluid and the signal-processing unit and computing mechanism process the ultrasound waves to determine phase and time shift. The computing mechanism converts phase shift to density, compressibility, and solute concentration measurements of the fluid. Calibrating fluids calibrate the detected phase shift in terms of sound velocity in the factory. Measurements provide information about passage of solutes and flow to achieve better solute collection efficiency, solution purity, and control of fluid processing systems.

Abstract: An apparatus and method to assess the compressibility of blood includes a combination of ultrasound transducers attached to tubing in which blood is flowing. An indicator medium is injected into the bloodstream of the subject over one or more time points and ultrasound waves are transmitted and monitored using transducers and phase lock amplifier to assess transmission time. Using a linear relationship between compressibility and density, changes in blood density are calculated from changes in transmission time to predict blood density changes and then the blood volume and microvascular pooling. This information allows prediction of complications that can occur during hemodialysis or because of post-traumatic fluid replacement and development of therapy to alleviate the complications.