Fresenius Medical Care Holdings, Inc.

Hema Metrics, Inc.

Efi Electronics Corporation

Efi Corporation

Fresenius Medical Holdings, Inc.

Perry N Law

Louis Leegrande Barrett

David W Peterson

Matthew A Stowell

Douglas L Cox

David R Miller

David Allen Bell

Chris Chau

Christopher Yim Chau

Kristian Allen Sammann

Carl M Rasmussen

Ronald S Glaittli

Jorge Perez

Louis Lee Barrett

N Diane Hudkins

Bemjamin D Jensen

Howard C Cooper

Linear blood flow chamber

Blood flow line

Embodiments of the disclosure provide a method for determining beginning blood volume of a patient during dialysis (e.g., hemodialysis). Ultrafiltration rates are determined at different time stamps during dialysis by obtaining a blood flowrate measurement and hematocrit measurements at input port and output port of a dialyzer connected to the patient. The flowrate and hematocrit measurements are used to determine fluid removed from the patient during dialysis. The ultrafiltration rates and fluid removed from the patient are used to determine the beginning blood volume of the patient.

Determination of patient blood volume at start of a dialysis treatment

Systems and sensor clip assemblies for optically monitoring blood flowing through a blood chamber are provided. A sensor clip assembly includes emitters and photodetectors positioned on opposing arms, a signal conditioning circuit for conditioning raw analog signals generated by the photodetectors while the sensor clip assembly is fastened to a blood chamber, and an analog-to-digital converter for converting the conditioned analog signals to raw digital data. The sensor clip assembly may include a microcontroller for calculating parameters of blood flowing through the blood chamber such as hematocrit, oxygen saturation, and change in blood volume from the raw digital data. The sensor clip assembly is in communication with a networked computer, and the networked computer is in communication with a remote computer configured to provide a user interface for monitoring and/or controlling the sensor clip assembly.

Controlling data output of a sensor clip assembly for an optical monitoring system

Remote interfacing with a sensor clip assembly for an optical monitoring system

Systems and sensor clip assemblies for optically monitoring blood flowing through a blood chamber are provided. A sensor clip assembly includes emitters and photodetectors positioned on opposing arms, a signal conditioning circuit for conditioning raw analog signals generated by the photodetectors while the sensor clip assembly is fastened to a blood chamber, and an analog-to-digital converter for converting the conditioned analog signals to raw digital data. The sensor clip assembly may output the raw digital data to an external device and receive synchronized control signals from the external device, or the sensor clip assembly may include a microcontroller for performing calculations on the raw digital data and providing synchronized control signals internally. Parameters of blood flowing through the blood chamber such as hematocrit, oxygen saturation, and change in blood volume may be calculated from the raw digital data derived from the raw analog signals generated by the photodetectors.

Sensor clip assembly for an optical monitoring system

An optical blood monitoring system and corresponding method avoid the need to obtain a precise intensity value of the light impinging upon the measured blood layer during the analysis. The system is operated to determine at least two optical measurements through blood layers of different thickness but otherwise substantially identical systems. Due to the equivalence of the systems, the two measurements can be compared so that the bulk extinction coefficient of the blood can be calculated based only on the known blood layer thicknesses and the two measurements. Reliable measurements of various blood parameters can thereby be determined without certain calibration steps.

Self calibrating blood chamber

Blood flow chamber with directional arrow

Blood flow chamber

An optical blood monitoring system for blocking unwanted light from reaching sensors in a sensor clip assembly fastened to a blood chamber connected in an extracorporeal blood treatment system. The blood chamber has an internal flow cavity for communicating the extracorporeal blood flow and viewing windows to enable the sensor clip assembly to illuminate the blood with light as the blood flows through the blood chamber in order to monitor characteristics of the blood. The sensor clip assembly includes opposing heads with LED emitters and photodetectors. In one embodiment, lenses in the heads are surrounded by shrouds extending from the lenses so that when the sensor clip assembly is fastened to the blood chamber the shrouds block unwanted light from reaching the photodetectors. Either alternatively or as a complement to the shrouds, the blood chamber includes an opaque portion or a portion colored to attenuate particular wavelengths of light to further enhance the overall ability of the blood chamber and sensor clip assembly to block unwanted light from reaching the photodetectors.

Shrouded sensor clip assembly and blood chamber for an optical blood monitoring system

An extracorporeal blood chamber for an optical blood monitoring system includes an opaque chamber body in order to prevent inaccuracies when measuring oxygen saturation levels due to light ducting, which can occur at low oxygen saturation levels and low hematocrit levels. In one embodiment, the blood chamber need not include a moat as is present in conventional blood chambers.

Blood chamber for an optical blood monitoring system

A sensor clip assembly for an optical blood monitoring system includes a circuit board with a microprocessor that is programmed with a ratiometric model to calculate hematocrit and/or oxygen saturation levels of a patient.

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Centerville, UT, United States of America

Perry N Law