Apparatus and method for non-invasive measurement of a substance within a body

• US 8,611,975 B2
• Filed: 10/28/2009
• Issued: 12/17/2013
• Est. Priority Date: 10/28/2009
• Status: Active Grant

• Current Assignee: GlucoVista, Inc.
• Original Assignee: Gluco Vista Incorporated
• Inventors: Gerlitz, Yonatan
• Primary Examiner(s): Laballe, Clayton E
• Assistant Examiner(s): PHAN, MINH Q
• Application Number:
  US12/607,903
• Publication Number:
  US 20110098542A1
• Time in Patent Office: 1,511 Days
• Field of Search: 600/310, 600/322, 600/340, 600/365, 356/215, 356/236, 250/228
• US Class Current: 600/310
• CPC Class Codes: A61B 2560/0252 using ambient temperature
• CPC Class Codes: A61B 5/0086 using infrared radiation
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: G01J 3/021 using plane or convex mirrors, parallel phase plates, or particular reflectors
• CPC Class Codes: G01J 3/0262 Constructional arrangements for removing stray light
• CPC Class Codes: G01J 3/0286 Constructional arrangements for compensating for fluctuations caused by temperature, humidity or pressure, or using cooling or temperature stabilization of parts of the device; Controlling the atmosphere inside a spectrometer, e.g. vacuum
• CPC Class Codes: G01J 3/28 Investigating the spectrum using colour filters G01J3/51
• CPC Class Codes: G01J 3/42 Absorption spectrometry; Double beam spectrometry; Flicker spectrometry; Reflection spectrometry beam switching arrangements G01J3/08
• CPC Class Codes: G01J 5/064 Ambient temperature sensor; Housing temperature sensor; Constructional details thereof
• CPC Class Codes: G01N 2021/3188 band-limited
• CPC Class Codes: G01N 21/314 with comparison of measurements at specific and non-specific wavelengths dual wavelength spectrometry G01J3/427
• CPC Class Codes: G01N 21/3581 using far infrared light; using Terahertz radiation

Abstract

A method and apparatus for the noninvasive detection of a concentration of a substance in a body, such as glucose in the human bloodstream is disclosed. The apparatus measures substance concentration by detecting radiation in the far infrared range emitted by the body using an infrared detected in combination with a set of adequate filters. In order to achieve the accuracy required, the radiation values detected by the detector are corrected for the emissions of the system components. The temperature of each system component including the detector temperature and an ambient temperate is determined using temperature sensors attached to the various system components. These temperatures are correlated with a set of predetermined calibration parameters to correct the detector readings.

Claims

1. Apparatus for non-invasive measurement of a substance within a body, the apparatus comprising:

a detector for sensing radiation emitted or remitted from a body;

optics configured to focus the radiation on a sensitive area of the detector;

a baffle attached to and in thermal contact with the detector, the baffle being disposed to at least partially surround a detector sensitive area and configured to minimize the incidence of stray radiation on the detector sensitive area,

wherein an interior surface of the baffle opposite the detector has a high reflectivity and low emissivity, the interior surface of the baffle being formed to minimize the incidence of radiation reflection or multi-reflection on the detector sensitive area, and

wherein the interior surface of the baffle constitutes a portion of a sphere surrounding the detector, a portion of the baffle above and opposite the sensitive area of the detector having an opening allowing the radiation to reach the sensitive area of the detector.

2. The apparatus of claim 1, further comprising one or more temperature sensors attached to one or more of a plurality of elements of the optics and to the detector, the one or more temperature sensors being configured to measure the temperature of the one or more elements of the optics and the temperature of the detector.

3. The apparatus of claim 2, wherein the temperature of the one or more of the plurality of optics elements and the temperature of the detector are matched with a set of predetermined compensation parameters stored in a look-up table for compensating for an effect on the non-invasive measurement of the temperature of each of the one or more of the plurality of optics elements and the detector, an ambient temperature and a temperature measured at a surface of the body.

4. The apparatus of claim 1, wherein an exterior surface of the baffle being coated with a suitable black coating for absorbing stray radiation.