Abstract: A patient's general state of anesthesia is displayed as a Cartesian plot of two vital signs: heart rate and blood pressure, in a window on a monitor. The heart rate is plotted on the x-axis while blood pressure is plotted on the y-axis. An anesthetist selects minimum and maximum values for each vital sign which are appropriate for the patient. These limits denote a desired zone which is indicated on the display. As the heart rate and the blood pressure are monitored, the general state is shown as an indicator on the plot as a multi-variable function of the two vital signs. When the indicator is within the desired zone, the two vital signs are in an acceptable range. When the indicator is outside of the desired zone, a visual or audible alarm indicates potential patient distress.

Abstract: A System for Collecting Weakly Scattered Electromagnetic Radiation is disclosed. The present invention overcomes problems suffered by previous collection systems by providing a reliable and efficient device for intensifying and collecting the scattered radiation generated by laser induced scattering. The present invention employs a laser source which illuminates an unknown gas contained by a long hollow tube having a highly reflective sheathing. The illuminating electromagnetic radiation from the laser is directed along the entire length of the tube and collides with the molecules of the unknown gas in the tube. The collisions cause the emission of weakly scattered electromagnetic radiation that is shifted in reference to the illuminating radiation. The sheathing is sufficiently reflective of the scattered radiation to substantially contain it. An exit is coupled to the long hollow tube in such a way that the scattered radiation may pass from the reflective sheathing and be collected for analysis.

Abstract: Method and apparatus for determining the composition and concentration of gases present in a patient's airway by measurement of the spectrum of Raman scattered light from these gases. The efficiency is improved by collecting Raman scattered light generated outside the collection region. The gases present are assumed to be drawn from a predetermined set of gases with known Raman scattering spectra, and the concentrations are determined by solution of a matrix equation Ac=b, where the c vector components are the unknown concentrations and the b vector components are determined from measurements of the Raman scattering intensifies in a plurality of wavelength or wavenumber intervals. The linear system of equations represented by the matrix equation may be overdetermined and may require solution by non-conventional methods, such as singular value decomposition.

Abstract: A method for field calibrating a system adapted for spectrographic analysis of gaseous substances. The method uses an easily available gas, for example ambient air, thereby providing for field calibration of the system without the inconvenience of using a purified noble gas and a pre-measured calibration gas mixture. During calibration, spectrograms from the easily available gas are generated by the system at various number density levels of the gas. Information from the spectrograms is then used in setting an operating parameter of the system.

Abstract: A Dual-Finger Vital Signs Monitor is disclosed. The present invention overcomes problems suffered by previous patient monitors by providing a simultaneous and continuous measurement of three primary vital signs: ECG and heart rate, blood pressure, and blood oxygen saturation. The invention employs a pair of finger cuffs that each include an electro-cardiographic electrode, a first LED and detector pair for blood pressure measurement, and a second LED and detector pair for blood oxygenation measurement. The electrodes are connected to a voltmeter which displays an electrocardiogram. The first LED and detector in each cuff function as a finger-photoplethysmographic pressure sensor. A pair of gas lines connect each finger cuff to a pair of pressure controllers, which each include a fluid reservoir. One of the servos is linked to a blood pressure meter. The second LED and detector pair in each cuff are each connected to a pair of oximeters. All the sensors operate independently.

Abstract: An apparatus and method are disclosed for an IV pump which can act also as a passive infusion controller. The apparatus has a disposable flow chamber with two pumping subchambers connected by a first collapsible passageway. A pump drive is used to operate the pumping subchambers and includes a first control valve for depressing the first collapsible passageway to control flow between the subchambers and an outlet control valve for depressing an outlet collapsible passageway to control flow of infusate out of the flow chamber. The flow chamber has a base surface and first and second caps, each cap being spaced apart from the base surface and having means for attachment to one of two moveable connector rods. The caps each act as one side of the first and second pumping subchambers, respectively, the base surface being the other side. A flexible wall is connected to the base surface and to each of the caps providing the subchamber volumes therebetween.

Abstract: An apparatus and method are disclosed for an IV pump which can act also as a passive infusion controller. The apparatus has a disposable flow chamber with two pumping subchambers connected by a first collapsible passageway. A pump drive is used to operate the pumping subchambers and includes a first control valve for depressing the first collapsible passageway to control flow between the subchambers and an outlet control valve for depressing an outlet collapsible passageway to control flow of infusate out of the flow chamber. The flow chamber has a base surface and first and second caps, each cap being spaced apart from the base surface and having means for attachment to one of two moveable connector rods. The caps each act as one side of the first and second pumping subchambers, respectively, the base surface being the other side. A flexible wall is connected to the base surface and to each of the caps providing the subchamber volumes therebetween.