GB1502447A - Method and apparatus for deriving oxygen association curves - Google Patents

Abstract

1502447 Haemoglobin-oxygen association test apparatus BAXTER TRAVENOL LABORATORIES Inc 3 March 1975 [1 May 1974 9 Sept 1974] 8715/75 Heading G1B [Also in Division G2] An assembly for use in the photometric determination of oxygen association curves for, for example, haemoglobin comprises Fig. 1, chamber 26, means 12, 13 for transmitting a measuring light beam through the chamber, light transmitting support means 14 arranged to support a thin flat layer of sample material in the chamber in the optical path of the measuring light beam, a source of deoxygenating gas and controlled conduit means 31 connecting this source to the chamber, a source of oxygen and controlled conduit means 28 connecting the oxygen source to the chamber. Cell means 14 may comprise a body of transparent plastics material having in its upper face a shallow circular recess which communicates with the lower face through capillary conduits (17, 18) for inflow and outflow of sample, a blood sample for testing held in the recess being covered by a gas-permeable membrane. In alternative embodiments Fig. 5 the cell may comprise a stainless steel ring 15 which has an annular internal seat for a quartz window 51, the top face of the window being below the top plane of the ring to form the sample recess, gas-permeable membrane 20 being stretched over the recess, or Fig. 10 an annular opaque member 68 supporting a transparent glass disc 72, the blood sample lying on disc 72 beneath gas-permeable membrane disc 73. The assembly of Fig. 1 may also comprise oxygen electrode 36, fan 34, humidifying member 46, controlled heater 37, vent passage 41 and photo-multiplier tube 42. In operation, the sample is first treated with deoxygenating gas, then oxygen is fed to the chamber and readings of oxygen content (measured by electrode 36) and light absorption are correlated to produce the oxygen association curve for the sample. In an alternative assembly Fig. 7 (not shown) a side wall of the chamber has a large circular aperture and a retractable cover-plate (6') for the aperture, the cell being carried on a horizontal supporting arm connected to the inside of the cover-plate.