Method and device for determining local distribution of a measuring parameter

• US 6,970,729 B2
• Filed: 11/30/2000
• Issued: 11/29/2005
• Est. Priority Date: 12/14/1999
• Status: Expired due to Fees

• Current Assignee: Perimed AB
• Original Assignee: Perimed AB
• Inventors: Hartmann, Paul
• Primary Examiner(s): Winakur, Eric F.
• Assistant Examiner(s): Kremer, Matthew
• Application Number:
  US10/149,383
• Publication Number:
  US 20030050543A1
• Time in Patent Office: 1,825 Days
• Field of Search: 600309-310, 600/322, 600/317
• US Class Current: 600/317
• CPC Class Codes: A61B 5/14542 for measuring blood gases A61B5/14551 takes precedence
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/14556 by fluorescence A61B5/14555 takes precedence
• CPC Class Codes: G01N 21/6408 with measurement of decay time, time resolved fluorescence

Abstract

A system and method for determining the local distribution of measurement variables being measured relative to or present in a predefined measurement area of a biological sample wherein in a first optical measuring process the local distribution of a first of the measurement variables is determined using a sensor film applied to the measurement area and including a luminescence indicator reacting to the first measurement variable by a change of luminescence decay time. The luminescence decay time or a quantity derived therefrom is recorded by an imaging technique as a function of the first measurement variable. In a second optical measuring process the local distribution of a second of the measurement variables is determined simultaneously or immediately following, using an imaging technique which is effective through the sensor film of the first optical measuring process.

Claims

1. Method for determining by imaging techniques the local distribution of first and second independent measurement variables measured relative to or present in a predefined measurement area of a biological sample comprising the steps of:

applying a single sensor film to the predefined measurement area of the biological sample, said single sensor film containing a luminescence indicator which reacts to said first independent measurement variable by a change in luminescence decay time,

directing first excitation radiation into said single sensor film to excite said luminescence indicator and cause said luminescence indicator to emit first measurement radiation,

detecting said first measurement radiation and determining therefrom local distribution of said first independent measurement variable in a first optical measuring process,

directing second excitation radiation into and through said single sensor film and into said biological sample to cause second measurement radiation to be emitted from said biological sample, and

detecting said second measurement radiation and determining therefrom local distribution of said second independent measurement variable in a second optical measuring process.

2. Method according to claim 1, wherein said biological sample is the epidermis or the surface of an organ.

3. Method according to claim 1, wherein said first measurement variable to be determined is one of the group consisting of the local distribution of oxygen concentration (tcPO₂), the local distribution of transcutaneous oxygen concentration and the local distribution of oxygen flow (O₂-flux) through an organ surface.

4. Method according to claim 3, wherein said organ surface is skin.

5. Method according to claim 1, wherein said first measurement variable determined is the local distribution of CO₂ concentration or the local distribution of CO₂ flow.

6. Method according to claim 1, wherein said first measurement variable determined is the local distribution of one of the group consisting of temperature, glucose concentration and an ionic concentration.

7. Method according to claim 6, wherein said ionic concentration is the pH level.

8. Method according to claim 1, wherein said second measuring process is a Laser Doppler imaging (LDI) process being used to determine a perfusion rate in said measurement area as said second measurement variable.

9. Method according to claim 1, wherein said second measuring process is a photometric or photographic method and said measurement area is recorded as an image in a predefined range of wavelengths.

10. Method according to claim 9, wherein autofluorescence in said measurement area is recorded as said image.

11. Method according to claim 9, wherein infrared radiation in said measurement area is recorded as said image.

12. Method according to claim 1, wherein said second measuring process is a profilometric method.

13. Method according to claim 12, wherein said profilometric method is an interferometric method.

14. Method according to claim 1, wherein said second measuring process is a visual inspection of said measurement area being assessed through said sensor film.

15. Method according to claim 1, wherein errors in measured results of said second optical measuring process, which are due to said sensor film, are corrected by a computing procedure or suitable calibrating parameters.