CONTACTLESS TEMPERATURE-BASED MONITORING OF A PATIENT

Abstract

According to the invention, a method for detecting at least one physiological signal (1) of a patient (7), wherein the method comprises the following method steps: monitoring at least a subsection (2) of a patient's surface (4) with a thermal camera (5) which generates consecutive video frames with multiple pixels (6) of the monitored subsection (2), wherein the subsection (2) of a patient's surface (4) includes at least a part of the mouth and/or nose area of the patient (7) as a region of interest (3); generating time-resolved temperature values of at least one pixel (8) of the region of interest (3); and generating a cardiac signal (9) as the physiological signal (1) based on the generated time-resolved temperature values. In this way, a possibility is provided for contactless tempera-ture-based monitoring of a patient in an easy and cost-efficient way.

Claims

1. A method for detecting at least one physiological signal of a patient, wherein the method comprises: monitoring at least a subsection of a patient's surface with a thermal camera which generates consecutive video frames with multiple pixels of the monitored subsection, wherein the subsection of a patient's surface includes at least a part of a humid portion of the surface, in particular the mouth and/or nose area of the patient as a region of interest; generating time-resolved temperature values of at least one pixel of the region of interest; and generating a cardiac signal as the physiological signal based on the generated time-resolved temperature values due to temperature changes due to breathing air flow.

2. The method of claim 1, wherein the camera detects the video frames in the wavelength region of 2 μm to 25 μm.

3. The method of claim 1, wherein the patient's nose and mouth are automatically detected as the region-of-interest from the video frames.

4. The method of claim 1, wherein the method further comprises; generating a respiration signal as an additional physiological signal based on the generated time-resolved temperature values.

5. The method of claim 1, wherein the method further comprises triggering and/or gating a scan acquisition based on the at least one physiological signal, wherein the scan acquisition is carried out during medical imaging examination with a medical imaging device and/or during medical therapy.

6. The method of claim 1, wherein the at least one pixel is from the pixels covering the patient's nostrils.

7. The method of claim 1, wherein in the step of generating time-resolved temperature values of at least one pixel of the region of interest one single pixel used.

8. A monitoring system for detecting at least one physiological signal of a patient wherein the monitoring system comprises a thermal camera which is adapted for monitoring at least a subsection of a patient's surface generating consecutive video frames with multiple pixels of the monitored subsection, wherein the subsection of the patient's surface includes at least a humid portion of the surface, in particular part of the mouth and/or nose area of the patient as a region of interest; and a signal processing unit which is adapted for generating time-resolved temperature values of at least one pixel of the region of interest and for generating a cardiac signal as the physiological signal based on the generated time-resolved temperature values due to temperature changed due to breathing air flow.

9. The monitoring system of claim 8, wherein the thermal camera is sensitive in an infrared wavelength range of 2 μm to 25 μm.

10. The monitoring system of claim 8, wherein the signal processing unit is provided with an automatic detection module to identify the patient's nose and mouth area from the video frames.

11. The monitoring system of claim 8, wherein the signal processing unit is adapted for generating a respiration signal based on the generated time-resolved temperature values as an additional physiological signal.

12. A non-transitory computer-readable medium, comprising instructions stored thereon, that when executed on a processor, induce a monitoring system with a thermal camera to perform the method according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter. Such an embodiment does not necessarily represent the full scope of the invention, however, and reference is made therefore to the claims and herein for interpreting the scope of the invention.

[0023] In the drawings:

[0024] FIG. 1 schematically depicts a scheme of a method according to a preferred embodiment of the invention;

[0025] FIG. 2 schematically depicts a second scheme of a method according to a preferred embodiment of the invention;

[0026] FIG. 3 schematically depicts a monitoring system according to a preferred embodiment of the invention; and

[0027] FIG. 4 schematically depicts a thermal camera and a ROI of a monitoring system according to a preferred embodiment of the invention.

DETAILED DESCRIPTION OF EMBODIMENTS

[0028] FIG. 1 schematically depicts a scheme of a method according to a preferred embodiment of the invention. The first step S1 is to monitor at least a subsection 2 of a patient's surface 4 with a thermal camera 5. The thermal camera 5 generates consecutive video frames with multiple pixels 6 of the monitored subsection 2. In order to generate a physiological signal based on temperature changes due to breathing air flow, the subsection 2 of a patient's surface 4 includes at least a part of the mouth and/or nose area of the patient 7 as a region of interest 3. The second step S2 is to generate these time-resolved temperature values of at least one pixel 8 of the region of interest 3. The third step S3 is to generate a cardiac signal 9 as the physiological signal 1 based on the generated time-resolved temperature values. The generated cardiac signal 9 can be used for the fifth step S5 and/or for the sixth step S6. The fifth step S5 is to trigger and the sixth step S6 is to gate a scan acquisition based on the at least one physiological signal 1.

[0029] A scan acquisition is carried out during medical imaging examination with a medical imaging device 11 and/or during medical therapy. Hence, it is possible to reduce uncertainties because of heart motions during medical imaging examinations and/or during medical therapies. Some regions are moving during scan acquisition because of the beating heart. The image data acquisition may be gated in dependence on the cardiac signal 9, so that the cardiac motion can be traced on medical images. Another opportunity is to trigger the image data acquisition in dependence on the cardiac signal 9, so that the image data acquisition is triggered every time the heart is in the same position. In FIG. 1 the medical imaging device 11 is a MRI system, a CT or a linear accelerator.

[0030] FIG. 2 schematically depicts a second scheme of a method according to a preferred embodiment of the invention. After the second step S2, thus after generating time-resolved temperature values of at least one pixel 8 of the region of interest 3, it is not only possible to generate a cardiac signal, as it is described in the third step S3 in FIG. 1, it is also possible to generate a respiration signal 10 as an additional physiological signal 1 based on the generated time-resolved temperature values. Generating a respiration signal 10 is the fourth step S4. Based on the cardiac signal 9 and/or the respiration signal 10 the image data acquisition may be triggered S5 and/or gated S6.

[0031] FIG. 3 schematically depicts a monitoring system 14 according to a preferred embodiment of the invention. A situation during image data acquisition is shown. A patient 7 is lying on a patient table 16. The table is movable in all three dimensions so that the region of interest 3 may be positioned precisely. The region of interest 3 is a part of a subsection 2 of the patient 7 and includes the patient's nostrils 13. A thermal camera 5 is attached to the medical imaging device 11. In FIG. 3 the medical imaging device 11 is a MRI. The thermal camera 5 scans the patient's surface 4, especially the precisely positioned region of interest 3. The thermal camera 5 is adapted to generate time-resolved temperature-values that are processed by a signal processing unit 15. The signal processing unit 15 generates two physiological signals based on the time-resolved temperature-values: a cardiac signal 9 and a respiration signal 10 that are visualized.

[0032] FIG. 4 schematically depicts a thermal camera 5 and a region of interest 3 of a monitoring system according to a preferred embodiment of the invention. The thermal camera 5 scans the patient's surface 4 and generates consecutive video frames with multiple pixels 6 of the region of interest 3. For the sake of clarity, the patient's nostrils 13 are not shown in FIG. 4, but they are part of the region of interest 3. Time-resolved temperature values of at least one pixel 8 of the region of interest 3 are generated. Especially according to the invention, it is possible to generate time-resolved temperature values of at least one pixel 8 of the region of interest 3 with only one single pixel 12 used.

[0033] While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope. Further, for the sake of clearness, not all elements in the drawings may have been supplied with reference signs.

REFERENCE SYMBOL LIST

[0034]

TABLE-US-00001 monitoring a subsection S1 generating temperature values S2 generating a cardiac signal S3 generating respiration signal S4 triggering a scan acquisition S5 gating a scan acquisition S6 physiological signal  1 subsection  2 region of interest  3 patient's surface  4 thermal camera  5 multiple pixels  6 patient  7 pixel  8 cardiac signal  9 respiration signal 10 medical imaging device 11 one single pixel 12 nostrils 13 monitoring system 14 signal processing unit 15 patient table 16