University of Michigan

Other

Nephros Therapeutics, Inc.

William F Weitzel

Jonathan M Rubin

Matthew N O'Donnell

H David Humes

Deborah A Buffington

Kang Kim

Emil Presley Paganini

Angela J Funke

Joseph M Messana

Grant H Kruger

Mainak Mitra

Robert Brook

Congxian Jia

Theodore J Kolias

Hua Xie

Brian Thelen

Xunchang Chen

Leo Koziol

An ultrasound imaging system uses a magnetic linear motor driven ultrasound scanner, with accurate track and hold operation and/or other motion feedback, to scan a two dimensional or three dimensional area of a sample. The scanner is implemented in a low-power and low-bandwidth handheld device and is connected with a remote image processing system that receives raw data and performs full ultrasound image analysis and creation, allowing the handheld to be used for scanning, pre-processing, and display.

Linear magnetic drive transducer for ultrasound imaging

An optimized elastic modulus reconstruction procedure can estimate the nonlinear elastic properties of vascular wall from intramural strain and pulse wave velocity (PWV) measurements. A noninvasive free-hand ultrasound scanning procedure is used to apply external force, comparable to the force in measuring a subject's blood pressure, to achieve higher strains by equalizing the internal arterial baseline pressure. PWV is estimated at the same location where intramural strain is measured. The reconstructed elastic modulus is optimized and the arterial elastic modulus can be determined and monitored using a simple dual elastic modulus reconstruction procedure.

Measurement of tissue elastic modulus

Methods and systems for measuring mechanical property of a vascular wall and a method and system for determining health of a vascular structure are provided wherein local deformation of a vessel wall resulting from physiologic pressures with altered transmural forces is measured. A non-invasive free-hand ultrasound scanning-procedure was performed to apply external force, comparable to the force generated in measuring a subject's blood pressure, to achieve higher strains by equalizing the internal arterial baseline pressure. When the applied pressure matched the internal baseline diastolic pressure, strain and strain rate increased by a factor of 10 over a cardiac cycle. Radial arterial strain was assessed in the vessel wall over the entire deformation procedure using a phase-sensitive, two-dimensional speckle-tracking algorithm. An elastic modulus reconstruction procedure was developed to estimate the non-linear elastic properties of the vascular wall.

Methods and systems for measuring mechanical property of a vascular wall and method and system for determining health of a vascular structure

A circuit for extracorporeal treatment of a body fluid, the circuit including in serial fluidic communication an inlet for receiving the body fluid from a patient, a first pump, a first treatment device for processing the body fluid, a second pump, an outlet for returning processed body fluid to the patient; and a shunt. The shunt is upstream from the first pump and downstream from the second pump.

Extracorporeal fluid circuit and related methods

A system and method are provided for determining the performance of a vessel, such as a hemodialysis access, which communicates blood between two locations of a patient. A conduit, such as an external dialysis circuit or an intravascular catheter, is provided in fluid communication with the vessel, and has a diversion point for diverting blood from the vessel into the conduit. The system further includes means for determining a flow rate of the diverted blood through the conduit. A first sensor in communication with the vessel generates at least one signal that is a function of a blood flow rate in the vessel downstream from the diversion point, wherein the downstream flow rate depends on the determined conduit flow rate and the performance of the vessel can be determined based on the signal. In addition, a processor can be provided in communication with the first sensor for determining a flow rate in the vessel upstream from the diversion point from the signal and the conduit flow rate. In a preferred embodiment, the first sensor is an ultrasonic sensor, and the at least one signal represents a time-averaged mean Doppler velocity of blood flow. Still further, additional sensors may be employed to provide a measure of the upstream flow rate as well as the conduit flow rate.

System for determining blood flow rate in a vessel using diverted flow measurements

System and method for determining blood flow rate in a vessel

A system and method are provided for determining the flow rate of blood in a vessel, such as a hemodialysis access. The system includes a conduit, such as an external dialysis circuit or an intravascular catheter, in communication with the blood in the vessel and having a diversion point for diverting the blood from the vessel into the conduit. As such, the vessel has a flow rate (Q,) upstream from the diversion point and a flow rate (Q,) downstream from the diversion point. A pump is connected to the conduit for diverting the blood into the conduit using a pump flow rate. An ultrasonic sensor is provided in communication with the blood in the vessel downstream from the diversion point. The ultrasonic sensor senses the downstream flow rate (Q,) and generates at least two downstream Doppler frequency signals including a first downstream Doppler frequency signal when the pump has a first pump flow rate and a second downstream Doppler frequency signal when the pump has a second pump flow rate. A processor connected to the ultrasonic sensor and the pump then determines the upstream flow rate (Q,) when the pump has a selected pump flow rate from the first and second downstream Doppler frequency signals and the selected pump flow rate.

System and method for determining the flow rate of blood in a vessel using doppler frequency signals

Growing community of inventors

Ypsilanti, MI, United States of America

William F Weitzel