Spectroscopic system with disposable calibration device

• US 5,792,049 A
• Filed: 08/06/1997
• Issued: 08/11/1998
• Est. Priority Date: 01/17/1996
• Status: Expired due to Term

• Current Assignee: Spectro Incorporated (Spectro Scientific, Inc.)
• Original Assignee: Spectro Incorporated (Spectro Scientific, Inc.)
• Inventors: Eppstein, Jonathan A., Ignotz, Keith D., Samuels, Mark A., Newman, Gregory J.
• Primary Examiner(s): MANUEL, GEORGE C
• Application Number:
  US08/906,969
• Time in Patent Office: 370 Days
• Field of Search: 128/660.06, 128/660.07, 128/632, 128/633, 128/664, 128/665, 178/18, 250/491.1, 73/620, 73/621, 367/140, 378/18, 378/207, 355/20, 355/81, 356/243, 356/244, 600/442, 600/443, 600/306, 600/309, 600/310, 600/473, 600/476
• US Class Current: 600/306
• CPC Class Codes: A61B 2560/0233 Optical standards
• CPC Class Codes: A61B 5/0059 using light, e.g. diagnosis by transillumination, diascopy, fluorescence A61B5/0093, A61B5/1455, A61B5/02416 and A61B5/0261 take precedence
• CPC Class Codes: A61B 5/0071 by measuring fluorescence emission
• CPC Class Codes: A61B 5/0075 by spectroscopy, i.e. measuring spectra, e.g. Raman spectroscopy, infrared absorption spectroscopy A61B5/0071 takes precedence
• CPC Class Codes: A61B 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• CPC Class Codes: A61B 5/1455 using optical sensors, e.g. spectral photometrical oximeters
• CPC Class Codes: A61B 5/14556 by fluorescence A61B5/14555 takes precedence
• CPC Class Codes: A61B 5/1495 Calibrating or testing of in-vivo probes
• CPC Class Codes: G01J 5/02 Constructional details
• CPC Class Codes: G01J 5/021 Probe covers for thermometers, e.g. tympanic thermometers; Containers for probe covers; Disposable probes
• CPC Class Codes: G01J 5/04 Casings
• CPC Class Codes: G01J 5/048 Protective parts
• CPC Class Codes: G01J 5/53 Reference sources, e.g. standard lamps; Black bodies
• CPC Class Codes: G01N 21/278 Constitution of standards

Abstract

A disposable calibration device is used to calibrate a spectroscopic measurement system which transmits radiation to a material or tissue in order to effect measurements such as bilirubin measurements. The disposable calibration device includes a structure with a window through which radiation can be transmitted, as well as a removable calibration target arranged on the window and capable of returning a portion of the radiation for calibrating the spectrometer system. The removable calibration target can be peeled of the window to allow a measurement to be made on the material or tissue. Once a measurement is complete, the disposable calibration device can be discarded and a new calibration device can be inserted on the spectroscopic system.

Claims

1. A spectrometer system, comprising:

a spectrometer instrument which transmits radiation to a material or tissue in order to effect measurements;

a calibration device holder on the spectrometer instrument;

a calibration device which can be attached to said calibration device holder, said calibration device comprising;

a structure including an opening through which the radiation can be transmitted; and

a removable calibration target arranged on said opening, said removable calibration target for returning a portion of said radiation for calibrating the spectrometer instrument, wherein the removable calibration target is to be removed from said opening while said structure remains attached to said calibration device holder to allow a measurement to be made on the material or tissue.

2. The spectrometer system as claimed in claim 1, further comprising a window arranged at said opening.

3. The spectrometer system as claimed in claim 2, wherein said removable calibration target includes a tear tab which can be gripped to remove said removable calibration target from said window.

4. The spectrometer system as claimed in claim 2, wherein said structure and said window comprises a barrier between the material or tissue and the spectrometer system.

5. The spectrometer system as claimed in claim 2, wherein said structure and said window comprise an infection shield between the material or tissue and the spectrometer system.

6. The spectrometer system as claimed in claim 2, further comprising a tab attached to said calibration target, wherein said calibration target comprises a perforation which causes said calibration target to become mechanically altered when said calibration target is pulled away from said window using said tab.

7. The spectrometer system as claimed in claim 2, further comprising a first tab and a second tab, wherein said calibration target comprises a perforation which divides said calibration target into first and second regions and said first and second tabs are attached to said first and second regions, respectively.

8. The spectrometer system as claimed in claim 2, further comprising a landing attachment, said landing attachment comprising an extension of said window.

9. The spectrometer system as claimed in claim 1, wherein said removable calibration target includes a tear tab which can be gripped to remove said removable calibration target from said opening.

10. The spectrometer system as claimed in claim 1, wherein said structure is shaped to provide separation between the material or tissue and the spectrometer system.

11. The spectrometer system as claimed in claim 1, wherein said spectrometer instrument comprises:

an optical unit for outputting output radiation and for receiving received radiation and detecting said received radiation as spectral return information; and

a processor coupled to said optical unit for receiving and processing said spectral return information.

12. The spectrometer system as claimed in claim 11, wherein said optical unit comprises an optical source for outputting said output radiation, and a detector array for detecting said received radiation and outputting said spectral return information.

13. The spectrometer system as claimed in claim 12, wherein said optical unit further comprises a grating for diffracting said return radiation according to wavelengths therein toward said detector array.

14. The spectrometer system as claimed in claim 1, wherein said structure of said calibration device is readily removable from said spectrometer system.

15. The spectrometer system as claimed in claim 1, further comprising a landing attachment attached to said structure.

16. The spectrometer system as claimed in claim 15, wherein said landing attachment further comprises a landing annulus.

17. The spectrometer system as claimed in claim 1, wherein said structure comprises a ridge arranged along said opening said ridge maintaining said removable calibration target at the opening of said structure.

18. A spectrometer system, comprising:

a spectrometer instrument which transmits radiation to a material or tissue in order to effect measurements;

a calibration device holder on said spectrometer instrument;

a calibration device which can be attached to said calibration device holder, said calibration device comprising;

a structure through which the radiation can be transmitted; and

a removable calibration target arranged about said structure and capable of returning a portion of said radiation for calibrating the spectrometer instrument, wherein the removable calibration target is to be removed from said structure while said structure remains attached to said calibration device holder to allow a measurement to be made on the material or tissue.

19. A spectrometer system, comprising:

a housing including a calibration device holder;

a spectrometer instrument arranged in said housing, said spectrometer instrument transmitting radiation through said calibration device holder to a material or tissue in order to effect measurements; and

a calibration device which can be attached to said calibration device holder, said calibration device comprising;

a structure including a window through which the radiation can be transmitted and

a removable calibration target arranged on said window and capable of returning a portion of said radiation for calibrating the spectrometer instrument, wherein the removable calibration target is to be removed from said window while the structure remains attached to the calibration device holder to allow a measurement to be made on the material or tissue.

20. A method for calibrating a spectrometer system that outputs radiation from an output end, comprising the steps of:

placing a calibration device over the output end of the spectrometer system, wherein the calibration device has a removable calibration target;

activating the spectrometer system to perform a calibration measurement wherein radiation is reflected from the calibration target back toward the output end of the spectrometer system and wherein the reflected radiation is received by the output end of the spectrometer system; and

removing the removable calibration target from the calibration device.

21. The method as claimed in claim 20, wherein said removing step comprises removing the removable calibration target from the calibration device while leaving a window attached to the spectrometer system, and said radiation is output through the window.

22. The method as claimed in claim 20, further comprising the step of calculating calibration information based on the calibration measurement.

23. A method for transcutaneous determination of bilirubin concentration in tissue, comprising the steps of:

performing a calibration measurement on a calibration target and storing resulting calibration data;

illuminating said tissue with light;

detecting a frequency spectrum of light scattered from said tissue;

calculating, from a first portion of said spectrum, a first parameter indicative of a maturity of said tissue;

calculating, from a second portion of said spectrum, a second parameter indicative of an amount of melanin in said tissue;

calculating, from a third portion of said spectrum, a third parameter indicative of a blood content of said tissue;

calculating, from a fourth portion of said spectrum, a fourth parameter indicative of an uncorrected bilirubin concentration in said tissue;

calculating a corrected bilirubin concentration in said tissue as a function of said first, second, third, and fourth parameter;

adjusting said corrected bilirubin concentration using said resulting calibration data to yield a calibrated and corrected bilirubin concentration, whereby said calibrated and corrected bilirubin concentration may compensate for any or all of the following;

unit to unit and time varying changes in source luminosity, delivery optics, collection optics, detection sensitivity, electronic drift, and environmental conditions such as temperature and humidity.

24. A method for transcutaneous determination of bilirubin concentration in tissue, comprising the steps of:

arranging a calibration device on a spectrometer system, wherein said calibration device comprises a calibration target;

performing a calibration measurement on a calibration target and storing resulting calibration data;

removing the calibration target from the calibration device;

illuminating said tissue with light;

detecting a frequency spectrum of light reflected from said tissue;

calculating, from a first portion of said spectrum, a first parameter indicative of a maturity of said tissue;

calculating, from a second portion of said spectrum, a second parameter indicative of an amount of melanin in said tissue;

calculating, from a third portion of said spectrum, a third parameter indicative of a blood content of said tissue;

calculating, from a fourth portion of said spectrum, a fourth parameter indicative of an uncorrected bilirubin concentration in said tissue;

calculating a calibrated and corrected bilirubin concentration in said tissue as a function of said first, second, third, and fourth parameter along with said resulting calibration data.

25. A spectrometer system, comprising:

a spectrometer instrument which transmits radiation from an output end to a material or tissue in order to effect measurements; and

a calibration device including a removable calibration target, said calibration device being removably arranged on the instrument to scatter said radiation as calibration radiation, wherein a portion of the calibration radiation returns to the output end of the instrument, and wherein said spectrometer instrument uses the returned portion of the calibration radiation to effect calibration, whereby said spectrometer can effect a subsequent calibrated measurement of the material upon removal of said removable calibration target.

26. The spectrometer system as claimed in claim 25, wherein said calibration device comprises a structure including an opening through which the radiation can be transmitted.

27. The spectrometer system as claimed in claim 26, wherein said calibration device further comprises a removable calibration target arranged on said opening which scatters said radiation as said calibration radiation.

28. The system of claim 26, wherein the structure of the calibration device remains attached to the instrument during a subsequent calibrated measurement.

29. A spectrometer system, comprising:

a spectrometer instrument which transmits light to a material or tissue in order to effect measurement;

a calibration device holder;

a calibration device which can be arranged in said calibration device holder, said calibration device comprising;

a structure including an opening, said opening having a window arranged thereat, wherein the light transmitted from the spectrometer instrument can pass through said window thereby illuminating the material or tissue, and said window allows the transmission of light scattered or reflected from the material or tissue illuminated; and

a removable calibration target arranged on said opening and capable of returning a portion of the light transmitted from the spectrometer instrument for calibrating the spectrometer instrument.

30. The spectrometer instrument as claimed in claim 29, wherein a frequency spectrum can be detected from the light scattered or reflected from the material or tissue.

31. A method for calibrating a spectrometer system that outputs radiation from an output end, comprising the steps of:

placing a calibration device on the output end of the spectrometer system, wherein the calibration device has a window and a removable calibration target arranged on said window;

activating the spectrometer system to perform a calibration measurement; and

removing the removable calibration target from the calibration device while leaving the window on the spectrometer system such that radiation passes through the window during subsequent measurements.

32. A spectrometer system, comprising:

a spectrometer instrument which transmits radiation to a material or tissue in order to effect measurements;

a calibration device holder;

a calibration device which can be arranged in said calibration device holder, said calibration device comprising;

a structure including an opening through which the radiation can be transmitted, and

a removable calibration target arranged on said opening, said removable calibration target including a user graspable tear tab for removing the calibration target from the opening, wherein the calibration target is to be removed from said opening to allow a measurement to be made on the material or tissue.

33. The system of claim 32, wherein said removable calibration target further comprises a perforation which causes the calibration target to become mechanically altered when the calibration target is removed from the window.

34. The system of claim 32, wherein the user graspable tear tab comprises a first tab and a second tab, wherein the perforation divides the calibration target into first and second regions, and wherein the first and second tabs are attached to the first and second regions, respectively.