7 results about "Hematocrit levels" patented technology

Principals of refraction of a light ray are used to identify the location of an interface between two materials having different refractive indices. The interface may be an interface between a plasma layer and a red blood cell layer of a centrifuged container, for example. An array of light detector elements are arranged to receive light that has been refracted through different layers in a centrifuged sample. Elements of the light detector array are arranged at known locations relative to an emitter of the light so detection of light by one or more particular detector elements is indicative of the angle of refraction of the light. Vertical position of the sample is tracked and correlated with corresponding angles of refraction to determine the vertical position of the sample when a change in the angle of diffraction is detected.

Disclosed herein are embodiments of a method for calibrating a group of analyzer units, each analyzer unit of the group of analyzer units configured for determining an amount of an analyte in plasma of a whole-blood sample. The method comprises: providing a plurality of calibration whole-blood samples, the plurality of calibration whole-blood samples including calibration whole-blood samples having respective hematocrit levels, for each calibration whole-blood sample of the plurality of calibration whole-blood samples: measuring a hematocrit measurement value indicative of the hematocrit level of said calibration whole-blood sample, measuring a whole-blood measurement value indicative of an amount of the analyte in the calibration whole-blood sample using at least one calibration analyzer unit of said group of analyzer units, measuring a plasma measurement value indicative of an amount of the analyte in plasma of said calibration whole-blood sample, and computing a ratio between the whole-blood measurement value and the plasma measurement value; generating a nonlinear functional relationship between the computed ratios and the corresponding hematocrit measurement values by curve fitting of a nonlinear function parametrized by one or more calibration parameters, the curve fitting resulting in respective parameter values of the one or more calibration parameters; storing a representation of the fitted nonlinear function in each analyzer unit of the group of analyzer units to allow each analyzer unit of the group of analyzer units to compute a hematocrit correction factor.

Disclosed herein are systems and methods for determining a volume of plasma and / or a dilution factor of a volume of diluted plasma, prepared from a whole blood sample with an unknown hematocrit level after plasma separation, and determining a volume of diluted plasma after plasma separation from a diluted whole blood sample having an unknown hematocrit level that is equivalent to undiluted plasma in a said whole blood sample. Kits and software for implementing the systems and methods are also disclosed.

A device and a method of using the device for determining hematocrit in a whole blood sample. The device includes a first portion having an introducer, at least one fluid channel, a fluid actuator, and an analysis sensor and conductivity sensor disposed within the fluid channel. The second portion includes at least one well containing at least one material. The first portion and second portion are movable with respect to each other. The introducer is configured to transfer at least a portion of the material from the well in portion two into the fluid channel of portion one. The method includes measuring the resistance over substantially the entire portion of a whole blood sample and calculating an average hematocrit level of the whole blood sample based on the measured resistance.

An example medical system includes a hemodialysis device configured to receive blood from vasculature of a patient via an arterial line and to deliver blood to the vasculature of the patient via a venous line. The medical system includes a hematocrit sensor configured to generate a signal indicative of a hematocrit level of blood in at least one of the arterial line or the venous line. The medical system also includes processing circuitry configured to determine a change in blood volume of the patient over time based on the signal indicative of the hematocrit level, determine a threshold blood volume reduction over time for the patient, compare the change in the blood volume of the patient over time to the threshold blood volume reduction over time, and based on the comparison, generate an indication of vascular access recirculation.

An example medical system includes a hemodialysis device configured to receive blood from vasculature of a patient via an arterial line and to deliver blood to the vasculature of the patient via a venous line. The medical system includes a hematocrit sensor configured to generate a signal indicative of a hematocrit level of blood in at least one of the arterial line or the venous line. The medical system also includes processing circuitry configured to determine a change in blood volume of the patient over time based on the signal indicative of the hematocrit level, determine a threshold blood volume reduction over time for the patient, compare the change in the blood volume of the patient over time to the threshold blood volume reduction over time, and based on the comparison, generate an indication of vascular access recirculation.

The present invention relates to a device for determining the hematocrit level and / or the hemoglobin level of a liquid circulating in a tubular portion (2), comprising two transmitter-receiver assemblies (10; 20), each comprising a light source (11; 21) and a light sensor (12; 22), said light source and light sensor being intended to be arranged on either side of the tubular portion (2) at the circulation area of the liquid for carrying out transmission measurements; the light source (11; 21) of each of the two transmitter-receiver assemblies (10; 20) is configured to emit a light beam at an emission wavelength chosen to correspond to the isosbestic point of hemoglobin; each transmitter-receiver assembly (10; 20) further comprises a system (13; 23) for collimating the light beam emitted from the corresponding light source (11; 21) towards the corresponding light sensor (12; 22).