Somanetics Corporation

Energy Conversion Devices, Inc.

Wayne P Messing

Gary D Lewis

Peter H Klose

Stanford R Ovshinsky

Oleg Gonopolskiy

Richard S Scheuing

Melville C Stewart, Ii

A spectrophotometric instrument for conducting in vivo patient examinations has a sensor which is applied to the patient target area, e.g. the forehead, which includes a source for emitting electromagnetic energy e.g. selected wavelengths in the near infrared range, such that the energy passes through the underlying tissue and is emitted at other locations spaced from the point of entry. The sensor also includes detectors for receiving the resulting light energy at two or more such other locations and sending corresponding signals to a processor for analysis, by which characteristics of the tissue transmissed by the examination wavelengths may be determined. Processing of such signals includes the contrasting of detected intensity levels corresponding to a reference wavelength received at one detection location with intensity signals representative of an investigative wavelength also received at such location to determine a first resultant signal, repeating the process for the same wavelengths at another detection location, to thus determine another resultant signal, and the contrasting of such two resultant signals. In a particular application, the instrument is used to determine regional cerebral blood oxygenation by processing the detection signals to obtain a first resultant having a value proportional to the ratio of deoxygenated hemoglobin with respect to oxygenated hemoglobin and then using the value of such resultant to compute a further resultant having a value proportional to the ratio of oxygenated hemoglobin with respect to the sum of oxygenated hemoglobin and deoxygenated hemoglobin.

Optical cerebral oximeter

A method of conducting clinical examination procedures by use of electrically actuated spectrometric apparatus, of the type which uses a sensor that is placed in contact with the patient to transmit and receive electromagnetic energy of selected wavelengths for non-invasive in vivo examination of a selected area on the body, in which a conductive member is placed in contact with the patient near or at the location of the sensor and connected to the signal-processing circuitry of the processor for the spectrometric signals in a manner such that the examination signals have significantly less noise content than would otherwise be true. In so doing, the signal-processing circuitry is isolated from the power supply circuitry, and the sensor and conductive member are preferably coupled to the processor by use of an isolation preamplifier, such that the signal-processing ground potential reference is maintained separate and distinct from the power supply ground. The specially-grounded conductive member that is placed in contact with the patient is preferably made part of the sensor itself, as by using a conductive material on at least part of the sensor surface that is placed in contact with the patient, and such a conductive surface element may comprise a flexible outer coating or layer of a compliant sensor which is conformable to the shape of the patient extremity to which it is applied. In this manner, the surface potential of the patient at the location of the sensor may be equalized with that of the signal-processing circuitry ground potential to substantially reduce signal noise content, and ambient sources of electrical noise may be effectively shielded as well.

Method for improving signal-to-noise in clinical spectrometric procedures

A specially grounded sensor for improving signal-to-noise ratios in clinical spectrometric procedures includes a sensor body carrying electrically actuated spectrometric signal-producing and receiving components, e.g., electro-optical components, for transmittal and reception of particular examination energy wavelengths, in which the sensor body has an electrically conductive portion or element associated therewith for contacting the patient. This electrically conductive, member is coupled to the signal ground potential of associated signal-processing apparatus to thereby equalize the electrical potential of the patient surface area to which the sensor is applied with the aforementioned signal ground potential. Preferably, an isolation preamplifier is utilized between the sensor and a microprocessor wherein the examination signals are analyzed, to provide the aforementioned signal ground, but in any event this signal ground is maintained separate from and preferably isolated from the primary ground conductor and potential of the processor and/or of the driver circuitry which provides excitation for the electro-optical components. In a particular preferred embodiment, conductive shielding is used in the sensor for reducing electrical noise from ambient sources, and the aforementioned conductive sensor member is electrically connected to such shielding, for improved results. Also, in a preferred embodiment, this shielding substantially encloses an inner portion of the sensor carrying the electro-optical components, in particular, the light-detector, except for openings in the shielding of a size and shape to fit relatively closely around the detector and thereby provide maximal shielding effects for the detector and their associated electrical conductors.

Specially grounded sensor for clinical spectrophotometric procedures

A sensor for use in medical patient examination and monitoring by spectrophotometric apparatus, including a main body having a soft, resilient outer cover on at least one side for conformably contacting a selected area on the patient, in particular the forehead, also having and an electro-optical light source and a plurality of electro-optical light detectors spaced from the source and from one another, and exposed to the selected site on the patient by light-transmissive passages extending through the resilient cover, in which the resilient cover is formed of a thin, softly compressible member of light-absorbing and moisture-transmissible material, preferably of resilient cellular polymeric foam.

Patient sensor for optical cerebral oximeter and the like

A data storage and retrieval system is provided utilizing digital or analog data input signals to energize one or more data recording heads which can produce a selection of sizes of alpha-numeric, pictorial or digital coded images on a recording medium. Where alpha-numeric or pictorial images are produced, the images are both human and machine readable. Such alpha-numeric or pictorial images can be sequentially or simultaneously selectively produced full sized and/or reduced substantially in size to form at least 24:1 or greater size reductions of these images on the same or different recording media. Thus, for example, X-ray pictures or letters and the like can be simultaneously produced in reduced form on a microfilm recording medium for record storage purposes and full sized simultaneously on a recording medium for direct examination and delivery to third parties. The reduced data is directly human readable by projecting light preferably through the recording medium and magnifying and projecting the image on a screen. Alternatively, the data is machine readable as by scanning small segments of the image with a capacitance or resistance responsive or photo-electric display device, to develop electrical signals which can operate conventional display readout devices. The microfilm recording and electrical readout operations most advantageously are achieved by supporting the recording head or readout unit on a carrier which moves across the recorded area of the recording medium in a line-by-line scanning operation, carried out so rapidly that a complete page of information can be recorded upon the recording medium or read therefrom in at most a manner of a few seconds or less.

Data storage and retrieval system

A data storage and retrieval system is provided utilizing digital or analog data input signals to energize one or more data recording heads which can produce a selection of sizes of alpha-numeric, pictorial or digital coded images on a recording medium. Where alpha-numeric or pictorial images are produced, the images are both human and machine readable. Such alpha-numeric or pictorial images can be sequentially or simultaneously selectively produced full sized and/or reduced substantially in size to form at least 24:1 or greater size reductions of these images on the same or different recording media. Thus, for example, X-ray pictures or letters and the like can be simultaneously produced in reduced form on a microfilm recording medium for record storage purposes and full sized simultaneously on a recording medium for direct examination and delivery to third parties. The reduced data is directly human readable by projecting light preferably through the recording medium and magnifying and projecting the image on a screen. Alternatively, the data is machine readable as by scanning small segments of the image with a capacitance or resistance responsive or photo-electric display device, to develop electrical signals which can operate conventional display readout devices. The microfilm recording and electrical readout operations most advantageously are achieved by supporting the recording head or readout unit on a carrier which moves across the recorded area of the recording medium in a line-by-line scanning operation, carried out so rapidly that a complete page of information can be recorded upon the recording medium or read therefrom in at most a manner of a few seconds or less. In the most commercially significant form of the invention, each data recording head capable of producing the reduced images is a Joule heat-producing device comprising one or more uniquely small current-carrying, heat-producing points each having dimensions preferably no greater than about 14 micron and less desirably no greater than about 20 micron. The heat-producing points are spaced about a distance no greater than about the aforesaid dimensions.

Growing community of inventors

Troy, MI, United States of America

Wayne P Messing