Abstract: A system and method for lysing of whole blood for CO-Ox measurement uses a lysing chamber for acoustic lysing of whole blood in a module in which the lysing chamber is separate from a CO-Ox measurement chamber. The disclosed acoustic lysing system and method avoids the expense and complexity of chemical lysing methods and allows the whole blood sample to be lysed while under continuous flow through the lysing chamber. The acoustic lysing chamber is provided upstream from a CO-Ox measurement chamber. The separation of the lysing chamber from the Co-Ox measurement chamber provides freedom to arrange and orient various optical components and/or other CO-Ox measuring components around the CO-Ox measurement chamber. The decoupling of the lysing chamber from the CO-Ox measurement chamber allows for more efficient design of the ultrasonic lysing transducer and CO-Ox measurement optics.

Abstract: A fluid aspiration probe apparatus for automatic fluid testing equipment includes a pair of electrodes mounted on a distal probe tip. The electrodes are coupled to an impedance measurement apparatus via conductive pathways along the probe. The impedance measurements and probe tip height are monitored as the probe tip is lowered into a fluid sample. Boundaries between layers of fluid in the container are detected by recognizing sudden changes in the impedance measurements and heights of the boundaries are determined by tracking the position of probe tip when the sudden changes of impedance occur.

Abstract: The invention relates to a method of performing an optical or electrical measurement in a sample of a disperse fluid, the sample comprising particles and a fluid. The method comprises the steps of: a) positioning the sample in a microfluidic cavity having a resonance frequency, b) subjecting the sample, in the cavity, to an acoustic standing wave configured for causing the particles to congregate in at least one first region of the cavity, thereby causing the fluid to occupy at least one second region of the cavity, wherein the frequency of the acoustic standing wave is varied between a frequency below the resonance frequency and a frequency above the resonance frequency, and c) performing an optical or electrical measurement in the fluid in at least one of the at least one second region of the cavity. Varying the frequency ensures reproducible results. The invention also relates to a system therefore and a method and system for measuring hematocrit.

Abstract: An apparatus for measuring hemolysis in a cartridge based automated blood analyzer is described. The apparatus allows hemolysis testing to be performed on a sample which is presented as a whole blood sample for other testing by the cartridge based automated blood analyzer. A disposable module is configured for optically analyzing one or more plasma analytes in a flow cell while red blood cells are acoustically separated from plasma in the flow cell.

Abstract: An apparatus for measuring hemolysis in a cartridge based automated blood analyzer is described. The apparatus allows hemolysis testing to be performed on a sample which is presented as a whole blood sample for other testing by the cartridge based automated blood analyzer. A disposable module is configured for optically analyzing one or more plasma analytes in a flow cell while red blood cells are acoustically separated from plasma in the flow cell.

Abstract: This invention relates to an optical system and method for performing turbidity assay, e.g. coagulation of blood or plasma, comprising a standard optical reference, a sample handling structure, a light source and an optical detection unit. The standard optical reference, such as a fluorophore-doped glass, provides constant optical signal under controlled optical conditions. The sample handling structure, such as a microfluidic system with reaction chamber, can be placed beneath or above the standard optical reference. During operation, the coagulating plasma/blood changes its optical absorbance and reflection properties, which results in changes in optical signal that reaches the optical reading unit. The variation of the optical signal, such as fluorescence signal indicates the kinetics of the turbidity varying process, such as plasma/blood coagulation process.

Abstract: The invention relates to a method of performing an optical or electrical measurement in a sample of a disperse fluid, the sample comprising particles and a fluid. The method comprises the steps of: a) positioning the sample in a microfluidic cavity having a resonance frequency, b) subjecting the sample, in the cavity, to an acoustic standing wave configured for causing the particles to congregate in at least one first region of the cavity, thereby causing the fluid to occupy at least one second region of the cavity, wherein the frequency of the acoustic standing wave is varied between a frequency below the resonance frequency and a frequency above the resonance frequency, and c) performing an optical or electrical measurement in the fluid in at least one of the at least one second region of the cavity. Varying the frequency ensures reproducible results. The invention also relates to a system therefore and a method and system for measuring hematocrit.

Abstract: This invention relates to an optical system and method for performing turbidity assay, e.g. coagulation of blood or plasma, comprising a standard optical reference, a sample handling structure, a light source and an optical detection unit. The standard optical reference, such as a fluorophore-doped glass, provides constant optical signal under controlled optical conditions. The sample handling structure, such as a microfluidic system with reaction chamber, can be placed beneath or above the standard optical reference. During operation, the coagulating plasma/blood changes its optical absorbance and reflection properties, which results in changes in optical signal that reaches the optical reading unit. The variation of the optical signal, such as fluorescence signal indicates the kinetics of the turbidity varying process, such as plasma/blood coagulation process.

Abstract: Analyte content in a cell free portion of a body fluid, such as blood, is optically determined without centrifugation or other preliminary steps for separating the cell free portion from the body fluid. A channel is configured for containing a flowing sample of the body fluid along an optical boundary. The channel is configured so that a cell free layer of the fluid naturally forms along the boundary of the channel which coincides with the optical boundary. A light source is directed onto the optical boundary at an angle selected to generate total reflection from the boundary and to generate an evanescent field across the boundary in the cell free layer of fluid. A light detector is configured to detect absorption of the light in the evanescent field. The light source and light detector are matched to the wavelength range of an absorption peak of the analyte being detected.

Abstract: A system and method for lysing of whole blood for CO-Ox measurement uses a lysing chamber for acoustic lysing of whole blood in a module in which the lysing chamber is separate from a CO-Ox measurement chamber. The disclosed acoustic lysing system and method avoids the expense and complexity of chemical lysing methods and allows the whole blood sample to be lysed while under continuous flow through the lysing chamber. The acoustic lysing chamber is provided upstream from a CO-Ox measurement chamber. The separation of the lysing chamber from the Co-Ox measurement chamber provides freedom to arrange and orient various optical components and/or other CO-Ox measuring components around the CO-Ox measurement chamber. The decoupling of the lysing chamber from the CO-Ox measurement chamber allows for more efficient design of the ultrasonic lysing transducer and CO-Ox measurement optics.

Abstract: A fluid aspiration probe apparatus for automatic fluid testing equipment includes a pair of electrodes mounted on a distal probe tip. The electrodes are coupled to an impedance measurement apparatus via conductive pathways along the probe. The impedance measurements and probe tip height are monitored as the probe tip is lowered into a fluid sample. Boundaries between layers of fluid in the container are detected by recognizing sudden changes in the impedance measurements and heights of the boundaries are determined by tracking the position of probe tip when the sudden changes of impedance occur.

Abstract: An apparatus for measuring hemolysis in a cartridge based automated blood analyzer is described. The apparatus allows hemolysis testing to be performed on a sample which is presented as a whole blood sample for other testing by the cartridge based automated blood analyzer. A disposable module is configured for optically analyzing one or more plasma analytes in a flow cell while red blood cells are acoustically separated from plasma in the flow cell.

Abstract: A sample cell apparatus for use in spectroscopic determination of an analyte in a body fluid sample includes a first plate member and a second plate member made from an optically clear material. A channel extending into a surface of the first plate member and an opposing surface of the second plate member houses a floating seal, which surrounds a fluid sample chamber. The fluid chamber is closed to define a repeatable optical path-length therethrough by urging the first plate member against the second plate member without compressing the floating seal between the first plate member and the second plate member. The seal channel is vented to prevent fluid pressure from flexing the first plate member or the second plate member. An actuator having an extended foot portion extends over the fluid chamber to help prevent flexing of the first plate member or the second plate member.

Abstract: A sample cell apparatus for use in spectroscopic determination of an analyte in a body fluid sample includes a first plate member and a second plate member made from an optically clear material. A channel extending into a surface of the first plate member and an opposing surface of the second plate member houses a floating seal, which surrounds a fluid sample chamber. The fluid chamber is closed to define a repeatable optical path-length therethrough by urging the first plate member against the second plate member without compressing the floating seal between the first plate member and the second plate member. The seal channel is vented to prevent fluid pressure from flexing the first plate member or the second plate member. An actuator having an extended foot portion extends over the fluid chamber to help prevent flexing of the first plate member or the second plate member.

Abstract: Analyte content in a cell free portion of a body fluid, such as blood, is optically determined without centrifugation or other preliminary steps for separating the cell free portion from the body fluid. A channel is configured for containing a flowing sample of the body fluid along an optical boundary. The channel is configured so that a cell free layer of the fluid naturally forms along the boundary of the channel which coincides with the optical boundary. A light source is directed onto the optical boundary at an angle selected to generate total reflection from the boundary and to generate an evanescent field across the boundary in the cell free layer of fluid. A light detector is configured to detect absorption of the light in the evanescent field. The light source and light detector are matched to the wavelength range of an absorption peak of the analyte being detected.

Abstract: A sample cell apparatus for use in spectroscopic determination of an analyte in a body fluid sample includes a first plate member made from an optically clear material and a second plate member made from an optically clear material and opposing the first plate member. A channel extending into a surface of the first plate member and an opposing surface of the second plate member houses a floating seal. The floating seal surrounds a fluid chamber that retains a sample of body fluid for optical measurement. The fluid chamber may be opened for flushing by separating the first plate member from the second plate member. During measurements the fluid chamber is closed to define a repeatable optical path-length therethrough by urging the first plate member against the second plate member without compressing the floating seal between the first plate member and the second plate member.

Abstract: A sample cell apparatus for use in spectroscopic determination of an analyte in a body fluid sample includes a first plate member and a second plate member made from an optically clear material. A channel extending into a surface of the first plate member and an opposing surface of the second plate member houses a floating seal, which surrounds a fluid sample chamber. The fluid chamber is closed to define a repeatable optical path-length therethrough by urging the first plate member against the second plate member without compressing the floating seal between the first plate member and the second plate member. The seal channel is vented to prevent fluid pressure from flexing the first plate member or the second plate member. An actuator having an extended foot portion extends over the fluid chamber to help prevent flexing of the first plate member or the second plate member.

Abstract: Analyte content in a cell free portion of a body fluid, such as blood, is optically determined without centrifugation or other preliminary steps for separating the cell free portion from the body fluid. A channel is configured for containing a flowing sample of the body fluid along an optical boundary. The channel is configured so that a cell free layer of the fluid naturally forms along the boundary of the channel which coincides with the optical boundary. A light source is directed onto the optical boundary at an angle selected to generate total reflection from the boundary and to generate an evanescent field across the boundary in the cell free layer of fluid. A light detector is configured to detect absorption of the light in the evanescent field. The light source and light detector are matched to the wavelength range of an absorption peak of the analyte being detected.

Abstract: A sample cell apparatus for use in spectroscopic determination of an analyte in a body fluid sample includes a first plate member made from an optically clear material and a second plate member made from an optically clear material and opposing the first plate member. A channel extending into a surface of the first plate member and an opposing surface of the second plate member houses a floating seal. The floating seal surrounds a fluid chamber that retains a sample of body fluid for optical measurement. The fluid chamber may be opened for flushing by separating the first plate member from the second plate member. During measurements the fluid chamber is closed to define a repeatable optical path-length therethrough by urging the first plate member against the second plate member without compressing the floating seal between the first plate member and the second plate member.

Abstract: A sample cell apparatus for use in spectroscopic determination of an analyte in a body fluid sample includes a first plate member made from an optically clear material and a second plate member made from an optically clear material and opposing the first plate member. A channel extending into a surface of the first plate member and an opposing surface of the second plate member houses a floating seal. The floating seal surrounds a fluid chamber that retains a sample of body fluid for optical measurement. The fluid chamber may be opened for flushing by separating the first plate member from the second plate member. During measurements the fluid chamber is closed to define a repeatable optical path-length therethrough by urging the first plate member against the second plate member without compressing the floating seal between the first plate member and the second plate member.