US20050070771A1 - Sample adapter - Google Patents

Sample adapter Download PDF

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Publication number
US20050070771A1
US20050070771A1 US10/900,062 US90006204A US2005070771A1 US 20050070771 A1 US20050070771 A1 US 20050070771A1 US 90006204 A US90006204 A US 90006204A US 2005070771 A1 US2005070771 A1 US 2005070771A1
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United States
Prior art keywords
analyte
sample
noninvasive
patient
detection unit
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Abandoned
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US10/900,062
Inventor
Peter Rule
James Braig
Philip Hartstein
Jennifer Gable
Original Assignee
Peter Rule
Braig James R.
Hartstein Philip C.
Gable Jennifer H.
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Publication date
Priority to US31308201P priority Critical
Priority to US10/015,932 priority patent/US6678542B2/en
Priority to US10/219,996 priority patent/US6771993B2/en
Application filed by Peter Rule, Braig James R., Hartstein Philip C., Gable Jennifer H. filed Critical Peter Rule
Priority to US10/900,062 priority patent/US20050070771A1/en
Publication of US20050070771A1 publication Critical patent/US20050070771A1/en
Abandoned legal-status Critical Current

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    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00Detecting, measuring or recording for diagnostic purposes; Identification of persons
    • A61B5/145Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissue
    • A61B5/1495Calibrating or testing of in-vivo probes
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00Detecting, measuring or recording for diagnostic purposes; Identification of persons
    • A61B5/145Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissue
    • A61B5/14532Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissue for measuring glucose, e.g. by tissue impedance measurement
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00Detecting, measuring or recording for diagnostic purposes; Identification of persons
    • A61B5/145Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissue
    • A61B5/1455Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissue using optical sensors, e.g. spectral photometrical oximeters
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00Detecting, measuring or recording for diagnostic purposes; Identification of persons
    • A61B5/145Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissue
    • A61B5/1491Heated applicators

Abstract

An adapter presents a sample of bodily fluid, such as whole blood, including an analyte to an analyzer window of a non-invasive monitor. The adapter comprises a base material that comprises a first side and a second side. The adapter also comprises a sample accommodating volume extending between an opening in the second side of the base material and an opening in the first side of the base material.

Description

    RELATED APPLICATIONS
  • This application is a continuation-in-part of U.S. application Ser. No. 10/015,932, filed Nov. 2, 2001, entitled CALIBRATOR, and also claims the benefit of U.S. Provisional Patent Application No. 60/313,082, filed Aug. 16, 2001, entitled ANALYTE MEASUREMENT ERROR CORRECTION METHOD AND DEVICE, the entire contents of both of which are hereby incorporated by reference.
  • BACKGROUND OF THE INVENTION
  • 1. Field of the Invention
  • This invention relates generally to determining analyte concentrations within living tissue.
  • 2. Description of the Related Art
  • Millions of diabetics are forced to draw blood on a daily basis to determine their blood glucose levels. A search for a non-invasive methodology to accurately determine blood glucose levels has been substantially expanded in order to alleviate the discomfort of these individuals.
  • SUMMARY OF THE INVENTION
  • A significant advance in the state of the art of non-invasive blood glucose analysis has been realized by an apparatus taught in U.S. Pat. No. 6,198,949, titled SOLID-STATE NON-INVASIVE INFRARED ABSORPTION SPECTROMETER FOR THE GENERATION AND CAPTURE OF THERMAL GRADIENT SPECTRA FROM LIVING TISSUE, issued Mar. 6, 2001; and by methodology taught in U.S. Pat. No. 6,161,028, titled METHOD FOR DETERMINING ANALYTE CONCENTRATION USING PERIODIC TEMPERATURE MODULATION AND PHASE DETECTION, issued Dec. 12, 2000; and in the Assignee's U.S. patent application Ser. No. 09/538,164, titled METHOD AND APPARATUS FOR DETERMINING ANALYTE CONCENTRATION USING PHASE AND MAGNITUDE DETECTION OF A RADIATION TRANSFER FUNCTION. Additional information relating to calibration of such non-invasive blood analysis is taught in U.S. Pat. No. 6,049,081, titled SUBSURFACE THERMAL GRADIENT SPECTROMETRY, issued Apr. 11, 2000; and by U.S. Pat. No. 6,196,046 B1, titled DEVICES AND METHODS FOR CALIBRATION OF A THERMAL GRADIENT SPECTROMETER, issued Mar. 6, 2001. The entire disclosure of all of the above mentioned patents and patent applications are hereby incorporated by reference herein and made a part of this specification.
  • U.S. Pat. No. 6,198,949 discloses a spectrometer for non-invasive measurement of thermal gradient spectra from living tissue. The spectrometer includes an infrared transmissive thermal mass, referred to as a thermal mass window, for inducing a transient temperature gradient in the tissue by means of conductive heat transfer with the tissue, and a cooling system in operative combination with the thermal mass for the cooling thereof. Also provided is an infrared sensor for detecting infrared emissions from the tissue as the transient temperature gradient progresses into the tissue, and for providing output signals proportional to the detected infrared emissions. A data capture system is provided for sampling the output signals received from the infrared sensor as the transient temperature gradient progresses into to the tissue. The transient thermal gradients arising due to the intermittent heating and cooling of the patient's skin generate thermal spectra which yield very good measurements of the patient's blood glucose levels.
  • Although the apparatus taught in the above-mentioned U.S. Pat. No. 6,198,949 has led to a significant advance in the state of the art of non-invasive blood glucose analysis, one possible source of error in such analysis arises due to physiological variation across the patient population. This variation, as well as other factors, can introduce systematic error into the measurements being performed.
  • In one embodiment, there is provided an adapter for presenting a sample of body fluid including an analyte to a window of a noninvasive analyte detection system. The adapter comprises a base material comprising a first side and a second side, and a sample accommodating volume extending between an opening in the second side of the base material and an opening in the first side of the base material.
  • In another embodiment, there is provided an adapter for presenting a sample of whole blood including an analyte to a window of a noninvasive analyte detection system. The adapter comprises a base material comprising a first side and a second side, and an optically transparent layer comprising a first side and a second side. The second side of the optically transparent layer is positioned proximate the first side of the base material. The adapter further comprises a sample accommodating volume extending between the second side of the optically transparent layer and an opening in the second side of the base material.
  • In another embodiment, there is provided an adapter for presenting a sample of whole blood including an analyte to a window of a noninvasive analyte detection system. The adapter comprises a base material comprising a first side having a first opening and a second side having a second opening, and a sample accommodating volume formed in the base material and extending between the first opening and the second opening.
  • In another embodiment, there is provided a method for calibrating a noninvasive detection unit including a window. The method comprises withdrawing a sample of bodily fluid from a patient, positioning the sample over the window, analyzing the sample with the noninvasive detection unit and generating an invasive-measurement output representing the concentration of an analyte. The method further comprises placing the window in contact with the skin of the patient, analyzing the patient's tissue with the noninvasive detection unit and generating a noninvasive-measurement output representing the concentration of the analyte. The method further comprises comparing the invasive-measurement output and the noninvasive-measurement output to estimate an error, and correcting the noninvasive-measurement output based on the error.
  • In another embodiment, there is provided a method for calibrating a noninvasive detection unit including a window. The method comprises determining whether there is a restricted period in effect, selecting an on-site or an alternative site measurement location based on whether a restricted period is in effect, and withdrawing an sample of bodily fluid from a patient at the selected measurement location, wherein the sample comprises at least one analyte. The method further comprises positioning the sample over the window, analyzing the analyte in the sample using the noninvasive detection unit and generating an invasive-measurement output representing a characteristic of the analyte. The method further comprises placing the window of the noninvasive detection unit in contact with the skin of the patient, analyzing the analyte in the tissue of the patient with the noninvasive detection unit, and generating a noninvasive-measurement output representing the characteristic of the analyte. The method further comprises comparing the invasive-measurement output and the noninvasive-measurement output to estimate an error, and correcting the noninvasive-measurement output based on the error.
  • All of these embodiments are intended to be within the scope of the invention herein disclosed. These and other embodiments of the present invention will become readily apparent to those skilled in the art from the following detailed description of the preferred embodiments having reference to the attached figures, the invention not being limited to any particular preferred embodiment(s) disclosed.
  • BRIEF DESCRIPTION OF THE DRAWINGS
  • Having thus summarized the general nature of the invention, certain preferred embodiments and modifications thereof will become apparent to those skilled in the art from the detailed description herein having reference to the figures that follow, of which:
  • FIG. 1 is a schematic view of a noninvasive optical detection system.
  • FIG. 2 is a perspective view of a window assembly for use with the noninvasive detection system.
  • FIG. 3 is an exploded schematic view of an alternative window assembly for use with the noninvasive detection system.
  • FIG. 4 is a plan view of the window assembly connected to a cooling system.
  • FIG. 5 is a plan view of the window assembly connected to a cold reservoir.
  • FIG. 6 is a cutaway view of a heat sink for use with the noninvasive detection system.
  • FIG. 6A is a cutaway perspective view of a lower portion of the noninvasive detection system of FIG. 1.
  • FIG. 7 is a schematic view of a control system for use with the noninvasive optical detection system.
  • FIG. 8 depicts a first methodology for determining the concentration of an analyte of interest.
  • FIG. 9 depicts a second methodology for determining the concentration of an analyte of interest.
  • FIG. 10 depicts a third methodology for determining the concentration of an analyte of interest.
  • FIG. 11 depicts a fourth methodology for determining the concentration of an analyte of interest.
  • FIG. 12 depicts a fifth methodology for determining the concentration of an analyte of interest.
  • FIG. 13 is a schematic view of a reagentless whole-blood detection system.
  • FIG. 14 is a perspective view of one embodiment of a cuvette for use with the reagentless whole-blood detection system.
  • FIG. 15 is a plan view of another embodiment of a cuvette for use with the reagentless whole-blood detection system.
  • FIG. 16 is a disassembled plan view of the cuvette shown in FIG. 15.
  • FIG. 16A is an exploded perspective view of the cuvette of FIG. 15.
  • FIG. 17 is a side view of the cuvette of FIG. 15.
  • FIG. 18 shows a pictorial representation of a monitor that includes a non-invasive detection unit and a traditional measurement system.
  • FIG. 19 shows a process flow for calibrating the monitor of FIG. 18.
  • FIG. 20 shows a variation of the process flow of FIG. 19 wherein a restricted period may be applied after the subject eats.
  • FIG. 21 shows a top view of a whole blood adapter.
  • FIG. 22 shows a cross-sectional view of the whole blood adapter of FIG. 21.
  • FIG. 23 shows a top view of a variation of the whole blood adapter.
  • FIG. 24 shows a cross-sectional view of the whole blood adapter of FIG. 23.
  • FIG. 25 shows a top view of another variation of the whole blood adapter.
  • FIG. 26 shows a cross-sectional view of the whole blood adapter of FIG. 25.
  • FIG. 27 shows a top view of another variation of the whole blood adapter.
  • FIG. 28 shows a cross-sectional view of the whole blood adapter of FIG. 27.
  • FIG. 29 shows a process flow for calibrating the non-invasive detection unit of FIG. 1.
  • FIG. 30 shows a variation of the process flow of FIG. 29 wherein a restricted period may be applied after the subject eats.
  • DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
  • Although certain preferred embodiments and examples are disclosed below, it will be understood by those skilled in the art that the invention extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses of the invention and obvious modifications and equivalents thereof. Thus, it is intended that the scope of the invention herein disclosed should not be limited by the particular disclosed embodiments described below.
  • I. Overview of Analyte Detection Systems
  • Disclosed herein are analyte detection systems, including a noninvasive system discussed largely in part A below and a whole-blood system discussed largely in part B below. Also disclosed are various methods, including methods for detecting the concentration of an analyte in a material sample. The noninvasive system/method and the whole-blood system/method are related in that the