Abstract: Spectrometric methodology for non-invasively obtaining optical spectra from heterogeneous material for the identification and quantification of constituent compounds. There is provided a transient or steady state subsurface thermal gradient spectroscopic methodology for obtaining in vivo optical spectra relating to the concentration of n analytes at depths to around 330 microns in human tissue, and for determining that concentration from the spectra. The methodology is employable on a wide variety of spectrometric devices, and enables: a real time determination of both surface and reference intensities; a fast, efficient calibration of the spectrometric device; and results in the provision of an analytical parameter which avoids the measurement of the optical path length to enable the extremely accurate calculation of a ratio of concentrations of n analytes in the system under analysis.

Abstract: A noninvasive infrared spectrometer which includes an infrared detector system for measuring the intensity, wavelength, and time varying nature of infrared energy emanating from deep layers within a body. Before detection, the energy emanating from deep within the body passes through layers of that body in the presence of a natural or induced thermal gradient. The measured infrared energy is processed into an absorption spectra and then into a concentration of at least one constituent of the body which concentration may be strongly dependent on the depth into the body. In one embodiment the temperature gradient is induced by chilling the surface of the body to provide a clearer indication of the infrared absorption levels of the deeper constituents. Other embodiments describe the sequential or simultaneous heating and cooling of the heterogenous body to induce and capture the transient infrared absorption spectral information.

Abstract: An side stream infrared gas analyzer for detecting the concentration of a gaseous component of a substantially gaseous flow stream such as the expired air of a patient under anesthesia. The infrared gas analyzer comprises an infrared energy detector, a sample cell, and an infrared energy source which are designed to be small and to consume relatively little electrical power. The infrared energy detector converts the received incident radiation into at least one electrical signal representative of the received incident radiation and is preferably mounted directly onto a printed circuit board containing signal processing circuitry which processes the electrical detection signals provided by the infrared energy detector. The infrared energy detector also has a first infrared transmissive window on a detection side thereof through which the incident radiation passes for detection.

Abstract: Spectrometric methodology for non-invasively obtaining optical spectra from heterogeneous material for the identification and quantification of constituent compounds. There is provided a transient or steady state subsurface thermal gradient spectroscopic methodology for obtaining in vivo optical spectra relating to the concentration of .eta. analytes at depths to around 330 microns in human tissue, and for determining that concentration from the spectra. The methodology is employable on a wide variety of spectrometric devices, and enables: a real time determination of both surface and reference intensities; a fast, efficient calibration of the spectrometric device; and results in the provision of an analytical parameter which avoids the measurement of the optical path length to enable the extremely accurate calculation of a ratio of concentrations of .eta. analytes in the system under analysis.

Abstract: A tool for nondestructive interrogation of the tissue including a light source emitter and detector which may be mounted directly on the surgical tool in a tissue contacting surface for interrogation or mounted remotely and guided to the surgical field with fiber optic cables. The light source may be broadband and wavelength differentiation can be accomplished at the detector via filters or gratings, or using time, frequency, or space resolved methods. Alternatively, n discrete monochromatic light sources may be provided which are subsequently multiplexed into a single detector by time or by frequency multiplexing. The optical sensing elements can be built into a surgical tool end effector tip such as a tissue grasping tool which has cooperating jaws (bivalve or multi-element).

Abstract: A tool for nondestructive interrogation of the tissue including a light source emitter and detector which may be mounted directly on the surgical tool in a tissue contacting surface for interrogation or mounted remotely and guided to the surgical field with fiber optic cables. The light source may be broadband and wavelength differentiation can be accomplished at the detector via filters or gratings, or using time, frequency, or space resolved methods. Alternatively, n discrete monochromatic light sources may be provided which are subsequently multiplexed into a single detector by time or by frequency multiplexing. The optical sensing elements can be built into a surgical tool end effector tip such as a tissue grasping tool which has cooperating jaws (bivalve or multi-element).

Abstract: A tool for nonactive interrogation of the tissue including a light source emitter and detector which may be mounted directly on the surgical tool in a tissue contacting surface for interrogation or mounted remotely and guided to the surgical field with fiber optic cables. The light source may be broadband and wavelength differentiation can be accomplished at the detector via filters or gratings, or using time, frequency, or space resolved methods. Alternatively, n discrete monochromatic light sources may be provided which are subsequently multiplexed into a single detector by time or by frequency multiplexing. The optical sensing elements can be built into a surgical tool end effector tip such as a tissue grasping tool which has cooperating jaws (bivalve or multi-element).

Abstract: A tool for nondestructive interrogation of the tissue including a light source emitter and detector which may be mounted directly on the surgical tool in a tissue contacting surface for interrogation or mounted remotely and guided to the surgical field with fiber optic cables. The light source may be broadband and wavelength differentiation can be accomplished at the detector via filters or gratings, or using time, frequency, or space resolved methods. Alternatively, n discrete monochromatic light sources may be provided which are subsequently multiplexed into a single detector by time or by frequency multiplexing. The optical sensing elements can be built into a surgical tool end effector tip such as a tissue grasping tool which has cooperating jaws (bivalve or multi-element).

Abstract: A class of novel surgical tools constructed from the surgical tools and a tissue state monitoring device to assess or image changes in the chemical or structural composition of tissue over time, which give feedback to surgeons during dynamic surgical interventions that change the character of tissue, such as tissue welding.

Abstract: This probe makes use of a simplified housing construction that significantly reduces the cost of the manufacture of the probe housing. The housing is implemented using two molded housing halves, which are pivotally connected together and which include an integral spring member. In addition, the housing includes a connector mounted thereon for enabling the probe to be disengaged from the cable and its associated connector that interconnects the probe with the medical monitoring equipment. As a further improvement, a notch is provided on the housing so that the conductors can be positioned to exit the probe in any direction to minimize the possibility of the conductors inadvertently pulling the probe loose from the patient's finger.

Abstract: A method and apparatus for monitoring glucose, ethyl alcohol and other blood constituents in a noninvasive manner. The measurements are made by monitoring infrared absorption of the desired blood constituent in the long infrared wavelength range where the blood constituent has a strong and distinguishable absorption spectrum. The long wavelength infrared energy emitted by the person as heat is monitored and the infrared absorption of particular constituents in the blood (such as glucose or blood alcohol) is measured at characteristic infrared absorption wavelengths for those constituents. The measurements are preferably synchronized with systole and diastole of the cardiac cycle so that the signal contribution caused by veins and tissues (which do not pulse) may be cancelled when a ratio of the detected signals is taken.

Abstract: A method and apparatus for monitoring glucose, ethyl alcohol and other blood constituents in a noninvasive manner. The measurements are made by monitoring infrared absorption of the desired blood constituent in the long infrared wavelength range where the blood constituent has a strong and distinguishable absorption spectrum. The long wavelength infrared energy emitted by the person as heat is monitored and the infrared absorption of particular constituents in the blood (such as glucose or blood alcohol) is measured at characteristic infrared absorption wavelengths for those constituents. The measurements are preferably synchronized with systole and diastole of the cardiac cycle so that the signal contribution caused by veins and tissues (which do not pulse) may be cancelled when a ratio of the detected signals is taken. The concentration of the blood constituents are then determined in accordance with a polynomial equation.

Abstract: A tissue penetrating apparatus including a surgical appliance having a sharp tip for penetrating tissue, a first optical element for emitting one or more selected monochromatic wavelengths of light, and a second optical element for sensing light corresponding to the one or more selected monochromatic wavelengths of light. The first and second optical elements are optical transmission fibers secured to the appliance proximate to the tip so that one fiber passes one or more monochromatic wavelengths of light into the tissue to be penetrated, and the other fiber passes the light sensed to a light detector. A control circuit is used to illuminate the one or more light sources to emit light out one of the first and second optical fibers, and to provide an electrical signal corresponding to the light sensed at the other of the first and second optical fibers. The electrical signal includes sensed light at each of the monochromatic wavelengths of light emitted, and sensed light in the absence of emitted light.

Abstract: The pulse oximeter probe uses an inexpensive connector to electrically interconnect the sensor elements with the pulse oximeter. One segment of the probe connector contains a set of connector pins that are wired to the sensor elements. Another segment of the probe connector is equipped with a mating configuration of sockets which align with these pins. Three projections function to automatically align the connector pins with the connector sockets. Two of the projections engage a mating aperture in the other connector segment to fasten the two connector segments together, while a third projection aligns with an edge of the other connector segment to position the two connector segments.

Abstract: A method and infrared sensing device for determining the concentration of alveolar alcohol in a breath sample exhaled by a subject into an infrared sensing device. The presence of alcohol from the upper respiratory tract of the subject is detected by continuously monitoring alcohol and carbon dioxide, normalizing alcohol values with respect to carbon dioxide, calculating a difference between normalized alcohol concentration and carbon dioxide concentration over time, integrating (summing) the difference, and comparing the integrated difference with a threshold. This technique accurately and consistently detects the presence of mouth alcohol in the sample before the presence of carbon dioxide which originates in deep lung breath.

Abstract: A method and apparatus for monitoring glucose, ethyl alcohol and other blood constituents in a noninvasive manner. The measurements are made by monitoring infrared absorption of the desired blood constituent in the long infrared wavelength range where the blood constituent has a strong and distinguishable absorption spectrum. The long wavelength infrared energy is passed through a finger or other vascularized appendage and the measurement made. To prevent the high energy source from burning or causing patient discomfort, only short bursts or pulses of energy are sent through the finger with a very low duty cycle and low optical bandwidth. The bursts are further synchronized with systole and diastole of the cardiac cycle so that only two pulses are sent per heart beat, one during diastole and one during systole. The detection signals measured during application of these bursts of energy are then used to calculate the concentration of the blood constituents in accordance with a polynomial equation.

Abstract: An anesthetic agent analyzer having six or more independent analytical channels, where each channel comprises a first thermopile which receives incident infrared radiation and a second thermopile behind the first thermopile which is blocked from the incident infrared radiation and thus serves as a reference for detecting ambient temperature variations. The first and second thermopiles are connected in a "parallel opposed" fashion so that the effects of ambient temperature variations automatically cancel and the detectors may be readily configured in a detector package. The anesthetic agent analyzer of the invention is designed for use with a wideband infrared radiation source so that anesthetic agents having characteristic absorption bands in the far infrared wavelength range (6-15 microns) may be more readily detected and discriminated.

Abstract: An infrared gas analyzer implementing an optically stabilized detector in a sidestream configuration. In order to reduce the pneumatic sampling volume, an "optical funnel" or collimator is used to resize the optical aperture of a multi-channel optically stabilized detector without compromising signal strength. The smaller pneumatic volume is desirable in order to minimize the time required for a gas wavefront from the sample cell to traverse the optical aperture, thereby minimizing pneumatic response time. The geometry of the sample cell of the invention is also streamlined so that sharp corners or transitions which might induce turbulent gas flow are eliminated. The sample cell of the invention thus promotes smooth, laminar flow of aspirated respiratory gases through the optical aperture so as to preserve the temporal relationship of gas concentration wavefronts within the gas stream and to thereby allow the analyzer to exhibit a faster pneumatic response.

Abstract: Methods and apparatus for constructing optically stabilized, shutterless infrared capnographs are disclosed. The capnographs of the present invention provide the absolute concentration of the constituents of the respiratory airstream of a patient, without the thermal drift problems normally associated with thermopile detectors, thereby providing a device with a high degree of accuracy. The present invention eliminates the need for a mechanical shutter to modulate the incident infrared beam and the need for a modulated source, thereby increasing the reliability and response time of the devices disclosed. Capnographs which are substantially unaffected by changes in the ambient temperature at which they operate are provided by connecting pairs of optically filtered thermopiles in series and processing the resulting differential pair. In addition, techniques are provided for selecting overlapping optical filters for use with thermopiles with a minimum level of cross-talk.