Method and device for non-invasive regulation of temperature with radiation, especially laser radiation of biological tissue

• US 20030032949A1
• Filed: 07/24/2002
• Published: 02/13/2003
• Est. Priority Date: 07/24/2001
• Status: Active Grant

• Current Assignee: Medizinisches Laserzentraum Luebeck
• Original Assignee: Medizinisches Laserzentraum Luebeck
• Inventors: Schuele, George, Brinkmann, Ralf
• Granted Patent: US 6,830,567 B2
• Time in Patent Office: Days
• US Class Current: 606/4
• CPC Class Codes: A61B 2017/00084 Temperature
• CPC Class Codes: A61B 2017/00128 related to intensity or progress of surgical action
• CPC Class Codes: A61B 5/0095 by applying light and detecting acoustic waves, i.e. photoacoustic measurements
• CPC Class Codes: A61B 5/01 Measuring temperature of body parts ; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue clinical contact thermometers G01K13/20
• CPC Class Codes: A61F 2009/00844 Feedback systems
• CPC Class Codes: A61F 2009/00863 Retina
• CPC Class Codes: A61F 9/00727 Apparatus for retinal reattachment
• CPC Class Codes: A61F 9/008 using laser
• CPC Class Codes: A61F 9/00814 Laser features or special beam parameters therefor
• CPC Class Codes: A61F 9/00821 for coagulation
• CPC Class Codes: A61F 9/009 Auxiliary devices making contact with the eyeball and coupling in laser light, e.g. goniolenses apparatus for eye examination A61B3/0008

Abstract

A method and a system for the non-invasive temperature determination on biological tissue, particularly at the fundus of the eye, treated by a treatment radiation, particularly laser radiation, wherein, during the respective irradiation time, at essentially identical time intervals, additional radiation pulses of a shorter pulse duration and a lower energy are aimed at the treated biological tissue, the resulting tissue expansions and/or contractions being detected by a pressure measurement or optical measurement and, from the measuring signals, the absolute temperature values are determined and optionally the treatment radiation is controlled as a function thereof.

Claims

1. Method for the non-invasive determination of the temperature on biological tissue, particularly on the fundus of the eye, treated by means of a treatment radiation, particularly laser radiation, characterized in that

during the respective irradiation period by means of the treatment radiation, additional radiation pulses of a shorter pulse duration and a lower energy than during the treatment radiation are aimed at the treated biological tissue, or the treatment radiation is switched off for a short time and is switched back on again,

the resulting tissue expansions and/or contractions are detected by a measurement of the pressure or by an optical measurement, and

from the measuring signal, the temperature and/or the temperature rise is/are determined.

2. Method according to claim 1, characterized in that, during the optical measurement, the tissue expansion and/or contraction is detected by an interference measurement.

3. Method according to claim 1, characterized in that, during the pressure measurement, an electric pressure transient is formed for the analysis during the determination of the temperature.

4. Method according to one of claims 1 to 3, characterized in that the additional radiation pulses or the short-duration switch-off of the treatment radiation is/are provided at essentially the same time intervals.

5. Method according to one of claims 1 to 4, characterized in that the measuring signal formed when the treatment radiation is switched on is standardized to the normal body temperature of the irradiated biological tissue.

6. Method according to one of claims 1 to 5, characterized in that an additional radiation pulse is applied before or during the switch-on of the treatment radiation in order to standardize the measuring signal to the body temperature.

7. Method according to one of claims 1 to 6, characterized in that the treatment radiation is controlled as a function of the determined temperature.

17. Use of one of the methods according to one of claims 1 to 7 for determining the temperature at the fundus of the eye which is treated by the treatment radiation, particularly laser radiation.

8. System for the non-invasive determination of the temperature of biological tissue which is treated by means of a treatment radiation, particularly a laser radiation, with a defined treatment time, characterized by

a treatment radiation source (1) for generating the treatment radiation,

a control device (5) which controls the treatment radiation source (1) during the defined treatment time,

an irradiation lens system (2) by means of which the treatment radiation is aimed at the biological tissue,

an additional radiation source (3), particularly a laser radiation source, which, during the treatment time, can be coupled into the irradiation lens system (2) for supplying additional radiation pulses,

a detector (6;

7;

19) by means of which expansions and/or contractions caused by the radiation are acoustically and/or optically measured, and

an analyzing device (8) which has a calibration curve indicating the proportionality of the acoustically and/or optically detected measuring signals to the temperature and converts the measuring signal into a temperature value.

10. System according to claim 8, characterized in that the radiation pulses of the additional beam source (3) have a lower energy than the treatment radiation and the pulse duration is less than the respectively defined irradiation time.

11. System according to one of claims 8 to 10, characterized in that the pulse duration of the additional radiation pulses or the switch-off time of the treatment radiation is by a factor 102 and a higher factor smaller that the respective irradiation time.

12. System according to one of claims 8 to 11, characterized in that the pulse duration of the additional radiation pulses or the switch-off time of the treatment radiation is in the ns range.

13. System according to claim 8 or 11, characterized in that the analyzing device (8) is connected to the control device (5).

14. System according to one of claims 8 to 13, characterized in that the analyzing device (8) is connected to a temperature indicating device (11) which indicates the absolute temperature values.

15. System according to one of claims 8 to 14, characterized in that the detector (6;

7;

19) is constructed as a measuring converter which can be acoustically or optically coupled to the human eye.

16. System according to claim 15, characterized in that the detector (6;

7) can be coupled to the treated eye by means of a contact lens (17) which can be placed on the eye.

18. Use of a system according to one of claims 8 to 16 for determining the temperature at the fundus of the eye which is treated by the treatment radiation, particularly laser radiation.

9. System for the non-invasive temperature determination of biological tissue which is treated by means of a radiation, particularly a laser radiation with a defined treatment time, characterized by

a treatment radiation source (1) for generating the treatment radiation,

a control device (5) which controls the treatment radiation source (1) during the defined treatment time,

an irradiation lens system (2) by means of which the treatment radiation is aimed at the biological tissue,

an additional switching device (4) which, controlled by the control device (5) during the respectively defined irradiation time, switches the treatment radiation source (1) off for a short duration and switches it back on,

a detector (6;

7;

19) by means of which expansions and/or contractions caused by the radiation are acoustically and/or optically measured, and

an analyzing device (8) which has a calibration curve indicating the proportionality of the acoustically and/or optically detected measuring signals to the temperature and converts the measuring signal into a temperature value.