Abstract: This invention encompasses a standard for determining glycosylated hemoglobin comprising a mixture of hemoglobin or methemoglobin and about 1% to 25% of the N-[5-nitrotropon-2-yl] hemoglobin or methemoglobin derivative wherein the allosteric binding site is blocked.

Abstract: In an optical system including a light source and a photodetector, a circuit and method for compensating for degradation of the optical system which may include deterioration in the intensity of the light source, caused by a variety of factors such as dirt, aging of the light source, etc., or dirt on the photodetector. The intensity of the light from the light source as received by the photodetector is repeatedly measured and an average value determined which accurately indicates the intensity of the light received. Subsequent use of the optical system includes comparison to the most recent average value of light received by the photodetector. Hence the present system eliminates the need for repeated calibration of the optical system by providing the same effect as though the system were being repeatedly and automatically calibrated to account for system degradation.

Abstract: Electrochemical process and apparatus to control the chemical state of a material, that is, to cause said material to retain desired characteristics in an environment that normally would cause a change in those characteristics or to cause a material that has deteriorated from a desired chemical state to revert to the desired state.

Abstract: A system for continuously monitoring and/or controlling blood hematocrit levels is disclosed. The system includes a photometric hematocrit sensor which is coupled to a linear response meter, and in one embodiment a separate sensor is coupled to a three-way solenoid valve. The sensor is responsive to the hemoglobin density in the optical path. The valve system automatically causes diversion of solution having a degree of hematocrit dilution below a set minimum. The sensor is independent of the amount of oxy-hemoglobin (HbO.sub.2) and reduced hemoglobin (HHb) and the system allows for instantaneous detection of improper hematocrit levels and obviates the need for time-consuming and unreliable centrifugal micro-hematocrit tests.

Abstract: A housing contains a light source, a monochromator, a photosensitive unit and an oscilloscope-type display. A flexible bundle of fiber-optic elements extends from within the housing out, and is provided at its outer end with a spacing ring. The spacing ring is placed against a skin surface, holding the ends of the fiber-optical bundle properly spaced and oriented relative to the skin surface. At the other end of the bundle, the bundle is subdivided into one branch which receives light from the source, and another branch which emits light refleced from the skin surface into the monochromator. The monochromator projects the spectrum of the skin-reflected light onto the photosensitive unit. The output signal of the photosensitive unit, in a sequential and periodic manner, contains information concerning successive spectral components of the skin-reflected light. The sweep of the display is synchronized with this periodic sequence, so as to display a spectral analysis of the skin-reflected light.

Abstract: An account is given of a test vessel, more specially for use in a photometer. The vessel has inwardly running wall parts forming hollows and at the edges of these hollows there are outwardly running hollow processes for taking up capillary tubes used in conditioning a liquid in the vessel for a measuring operation.

Abstract: Light of two different wavelengths is passed through or reflected from a member of the body so as to be modulated by the pulsatile blood flow therein. The amplitudes of the alternating current components of the logarithms of the respective light modulations are compared by taking their molecular extinction coefficients into account so as to yield the degree of oxygen saturation. By adding a third wavelength of light, the percentage of other absorbers in the blood stream such as a dye or carboxyhemoglobin can be measured. Fixed absorbers reduce the amount of light that passes through or is reflected from the body member by a constant amount and so have no effect on the amplitudes of the alternating current components that are used in making the measurements.

Abstract: A device permitting the rapid and direct determination of red cell percentages in centrifuged blood samples comprised of a scale optically variable in length in combination with an adjustable holder for the blood containing capillary tube.

Abstract: Method and automatic, electronic apparatus for detecting carriers of thalassaemia, especially beta thalassaemia minor, which involve measuring the mean corpuscular volume (MCV) and the mean corpuscular hemoglobin (MCH) of a blood sample from the subject. A descriminant preferably defined as the product (MCV).sup.2 MCH, the thalassaemia index is obtained and compared with a predetermined thalassaemia index threshold value.

Abstract: Process and apparatus to control the chemical state of a material. Bulk control of the chemical state of such material which permits maintenance of chemicals including enzymes by both restoration and stabilization. Optical and electrical power sources act in the presence of chemical mediators to control the rate of charge transfer to substances including metals contained in proteins, for example. Controlled charge transfer to the proteins enables construction of devices including small molecule detectors, e.g., electrically restored ferrous deoxyhemoglobin in a discrete component electrooptical circuit to monitor, for example, oxygen and carbon monoxide partial pressures. Restoration of chemical activity in molecules which have deteriorated enables construction of chemical reactors composed of stabilized catalysts and enzymes, e.g., restored functional nitrogenase in solar energy conversion devices which evolve molecular hydrogen or in chemical reactors which convert molecular nitrogen into ammonia.

Abstract: Method and apparatus for the simultaneous automatic analysis and sequential displaying in digital form of a plurality of parameters of whole or hemolyzed blood samples, such as total hemoglobin, percent oxyhemoglobin, percent carboxyhemoglobin, percent methemoglobin (in each case percent meaning percentage of total hemoglobin) and oxygen content. The apparatus is an electro-optical instrument including a servo-controlled spectral line source, such as a hollow cathode lamp, a laser etc., a ratiometric logarithmic amplifier of minimized dynamic range, a fluid-flow system of improved design that combine to measure the absorbances of blood samples at a plurality of wavelengths defined and generated by the spectral line source, to calculate the above parameters based on the absorbances by the use of a micro-computer and associated circuitry absorbances, to display automatically and digitally one of the parameters, and then to display digitally seriatim the remaining parameters responsive to operator intervention.

Abstract: A test device and method are provided for determining the hemoglobin content of blood. The test device comprises a substantially opaque light reflecting matrix having a refractive index significantly different from the refractive index of blood. In use, a test sample of blood is contacted with the matrix of said test device and the light reflectance therefrom is measured as an indication of the quantitative amount of hemoglobin present in said sample.

Abstract: A method and apparatus for the determination of blood cell osmotic fragility, wherein a solution of salt, such as sodium chloride, with an osmotic gradient decreasing with time is passed through a coiled capillary tube, positioned with its axis vertical so that the flow through the turns of the tube is substantially horizontal, and the flow follows Poiseuille's parabolic flow pattern. The blood sample is inserted in the coiled tube and, because of the flow pattern, the salt solution travels through the capillary tube much faster than the erythrocytes, so that the erythrocytes are exposed to gradually decreasing osmolarity for hemolysis. Optical monitoring is carried out as the hemoglobin is rapidly removed from the flowing stream. Optical density is recorded against time, employing a 547 nm monitoring beam, thus providing a hemolysis curve.

Abstract: A fully automatic system is disclosed for determining the seven blood parameters, red blood counts (RBC), hematocrit (HCT), white blood counts (WBC), mean corpuscular hemoglobin (MCH), mean corpuscular volume (MCV) and mean corpuscular hemoglobin concentration (MCHC). The blood sample collected is divided into two solutions, one for use in red blood counts and subjected to the colorimetric analysis for HGB determination and the other for use in white cell counts. A portion of the RBC solution is subjected to the double blood dilution and it enters a red cell counting portion. The peak value of electrical pulses supplied by said counting portion is indicative of the hematocrit. These data are used by preset arithmetic circuits to determine MCH, MCV and MCHC. White blood corpuscles are counted by a counting means of the same structure as that of the red cell counting portion.

Abstract: This specification describes a new analyzer for the determination of total hemoglobin; percent oxyhemoglobin, deoxyhemoglobin, methmoglobin, sulfhemoglobin; and oxygen capacity in a micro sample (5 to 10 .mu.l) of hole human blood. The essential components of the analyzer are (1) a cuvette in which simultaneous measurements of PO.sub.2 (by an oxygen electrode) and absorbance (by a dual wavelength optical system) are made, (2) an automatic pump system for filling and emptying the cuvette, (3) an equilibrating tonometer to equilibrate the reagent with air or another gas phase, (4) electronic circuits for the measurement of light intensity and oxygen pressure, (5) an analogue computer, and (6) a printer. Other essential parts of the invention are (a) original procedures and (b) ad hoc developed physico-chemical equations.

Abstract: A photometer for measuring the light permeability of a material for testing is made portable for hand-held operation outside a laboratory for measurements such as determining the proportion of hemoglobin in human blood. It includes a battery power supply that energizes a lamp, an opening for receiving a cuvet for a measurement, and a measuring circuit having a light-sensitive element. An indicator instrument in the measuring circuit indicates zero compensation, and a manually movable wedge filter is in the path of the light beam for adjusting the light passing through the cuvet. A manually operable element effects a zero compensation of the measuring circuit before a test is made, and a viewable scale on a setting member carrying the wedge filter directly displays a test result value from adjustment of the wedge filter during measurement of the material.

Abstract: An opto-electrical measuring apparatus for determining the hemoglobin content of an illuminated hemoglobin solution arranged in the path of light between a light source and a photoelectric transducer by evaluating the light absorption of the solution within a predetermined wavelength range. The spectral or spectrum properties of the light source, the transducer and other components arranged in the path of the light emanating from the light source are accommodated or matched to one another such that in the absence of the hemoglobin solution in the path of light an electrical magnitude generated in the photoelectric transducer possesses a spectral dependency which in the wavelength range of 540 to 560 nm constitutes a maximum value and to both sides of such range with a half-value width of at least 60 nm continually decreases to less than 20% of the maximum value at about 500 and 600 nm, respectively, and externally of these band limits asymptotically approaches the value null.

Abstract: The invention relates to a method and apparatus for measuring one or more data of blood samples, such as oxygen saturation, contents of hemoglobin, bicarbonate, sodium, potassium, etc. involving hemolyzation of the blood sample. The blood sample is passed into a conduit and hemolyzed therein by imparting ultra-sonic waves to all parts defining said conduits. Measurement is performed after and possibly also prior to hemolyzation. In its preferred embodiment the apparatus according to the invention comprises a computer for automatically controlling the operational sequence of the components of the apparatus and for receiving measuring signals from measuring devices of the apparatus and converting said signals into immediately understandable digital data.

Abstract: A device for use in producing a scanning beam of radiation comprises a rotor member carrying two optical wave guides arranged so as to direct light along the rotary axis of the rotor member, then radially outwardly to pass from one wave guide to the other, then radially inwardly and finally along the said rotary axis again.When the device is adapted for investigating liquid samples, a turntable, carrying a number of vials containing liquid samples at spaced locations around its periphery, is rotated in indexing fashion and, during each dwell period of the turntable, the rotor member is rotated so that the circularly scanning beam of light leaving the first mentioned wave guide scans each of the vials in turn at least once.

Abstract: In a system which automatically analyzes laboratory slides, the adjustable objective lens is automatically focused. A beam splitter splits light from the slide into two parts. One slide image is projected to an actual image plane where it is converted into electrical signals representing the optical characteristics of the slide. The other slide image is projected to a parfocal image plane at which two light sensing devices for the focusing system are positioned. One light sensing device is in front of the parfocal image plane and the other is behind the parfocal image plane. These light sensing devices produce electrical signals representing the position of the actual image plane with respect to the desired image plane. The electric signals are differentiated and then applied to a comparator which supplies pulses to a stepping motor which moves the objective lens.

Abstract: The photometer circuit is operative to receive and store a reference voltage which is generated in a photosensor by light which passes through a blank solution in a cuvette and is received at the photosensor. The photometer circuit includes reference voltage input control circuitry for placing the photometer circuit in a receiving and storage mode of operation for a predetermined period of time while the reference voltage is being generated in the photosensor. The photometer circuit includes a comparator having two inputs, a first electronic switch for coupling the output of the comparator to a voltage storage circuit and a second electronic switch for coupling the output of the voltage storage circuit to a voltage run-down circuit.