ASSESSING CIRCULATORY FAILURE

• US 20150359440A1
• Filed: 01/28/2014
• Published: 12/17/2015
• Est. Priority Date: 01/28/2013
• Status: Active Grant

• Current Assignee: Oslo Universitetssykehus Hf
• Original Assignee: Oslo Universitetssykehus Hf
• Inventors: Kvernebo, Knut
• Granted Patent: US 10,987,011 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61B 2503/045 Newborns, e.g. premature baby monitoring
• CPC Class Codes: A61B 2505/03 Intensive care
• CPC Class Codes: A61B 2576/00 Medical imaging apparatus involving image processing or analysis A61B1/00009, A61B6/52 and A61B8/52 take precedence; image processing per se G06T; details of algorithms for analysing medical images G06T7/0012
• CPC Class Codes: A61B 3/13 Ophthalmic microscopes
• 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 5/0077 Devices for viewing the surface of the body, e.g. camera, magnifying lens
• CPC Class Codes: A61B 5/02007 Evaluating blood vessel condition, e.g. elasticity, compliance
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/0261 using optical means, e.g. infrared light
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/14558 by polarisation
• CPC Class Codes: A61B 5/1464 specially adapted for foetal tissue
• CPC Class Codes: A61B 5/445 Evaluating skin irritation or skin trauma, e.g. rash, eczema, wound, bed sore
• CPC Class Codes: A61B 5/4848 Monitoring or testing the effects of treatment, e.g. of medication
• CPC Class Codes: A61B 5/489 Blood vessels

Abstract

The present invention relates to a method of identifying or monitoring circulatory failure in a subject, which method comprises assessing the subject'"'"'s microcirculation in respect of the following parameters: (a) functional capillary density (FCD); (b) heterogeneity of the FCD; (c) capillary flow velocity; (d) heterogeneity of capillary flow velocity; (e) oxygen saturation of microvascular erythrocytes (SmvO₂); and (f) heterogeneity of SmvO₂; wherein parameters (a) to (d) are assessed visually by microscopy and parameters (e) and (f) are assessed by diffuse reflectance spectroscopy (DRS); well as apparatus and software designed for performance of such a method.

Claims

1. A method of identifying or monitoring circulatory failure in a subject, which method comprises assessing the subject'"'"'s microcirculation in respect of the following parameters:

(a) functional capillary density (FCD);

(b) heterogeneity of the FCD;

(c) capillary flow velocity;

(d) heterogeneity of capillary flow velocity;

(e) oxygen saturation of microvascular erythrocytes (SmvO₂); and

(f) heterogeneity of SmvO₂;

wherein parameters (a) to (d) are assessed visually by microscopy and parameters (e) and (f) are assessed by diffuse reflectance spectroscopy (DRS).

2. The method of claim 1, wherein the microcirculation of the skin, conjunctiva or oral mucosa is assessed.

3. The method of claim 1, wherein the microcirculation of the skin is assessed.

4. The method claim 1, wherein the assessment comprises use of a video light microscope, orthogonal polarization spectral (OPS) imaging or sidestream dark field (SDF) imaging and/or images obtained therefrom.

5. The method of claim 1, wherein the microscope uses unpolarised light.

6. The method of claim 1, wherein one or more of parameters (a) to (d) are assessed using computer assisted video microscopy (CAVM), images obtained therefrom, or a combination thereof.

7. The method of claim 1, wherein the method further comprises comparison of the results of the assessment with reference values.

9. The method of claim 1, wherein clinically relevant information about a subject with or suspected of having circulatory failure is provided.

10. The method of claim 1, further comprising measurement of oxygen extraction by the microvasculature.

11. The method of claim 9, wherein the method is employed to assess the effectiveness of a therapeutic intervention on the subject.

12. The method of claim 1, wherein the assessment of parameters (a) to (f) is performed off-line.

19. The method of claim 1, wherein the subject:

(i) is being considered for or undergoing intensive care therapy, such as extra-corporeal membrane oxygenation (ECMO) and/or extra-corporeal life support treatment (ECLS);

or

(ii) is suffering from pre-eclampsia;

or

(iii) is suffering from sepsis;

or

(iv) is suffering from chronic or acute heart failure;

or

(v) has a chronic skin wound;

or

(vi) is asphyxiated;

or

(vii) has acute or chronic respiratory failure;

or

(viii) has acute or chronic limb ischaemia;

(ix) has had an organ transplant;

(x) has erythromelalgia.

22. The method of claim 1, wherein the method is computer implemented.

26. The method of claim 10, further comprising measurement of oxygen extraction by heterogeneity of said extraction.

8. A method of making a prognosis for a subject with circulatory failure, the method comprising assessing the subject'"'"'s microcirculation in respect of the following parameters:

(a) functional capillary density (FCD);

(b) heterogeneity of the FCD;

(c) capillary flow velocity;

(d) heterogeneity of capillary flow velocity;

(e) oxygen saturation of microvascular erythrocytes (SmvO₂); and

(f) heterogeneity of SmvO₂;

wherein parameters (a) to (d) are assessed visually by microscopy and parameters (e) and (f) are assessed by diffuse reflectance spectroscopy (DRS).

20. The method of claim 8, further comprising measurement of oxygen extraction by the microvasculature.

21. The method of claim 8, wherein the assessment of parameters (a) to (f) is performed off-line.

23. The method of claim 8, wherein the method is computer implemented.

25. The method of claim 8, wherein the subject:

(i) is being considered for or undergoing intensive care therapy, such as extra-corporeal membrane oxygenation (ECMO) and/or extra-corporeal life support treatment (ECLS);

or

(ii) is suffering from pre-eclampsia;

or

(iii) is suffering from sepsis;

or

(iv) is suffering from chronic or acute heart failure;

or

(v) has a chronic skin wound;

or

(vi) is asphyxiated;

or

(vii) has acute or chronic respiratory failure;

or

(viii) has acute or chronic limb ischaemia;

(ix) has had an organ transplant;

(x) has erythromelalgia.

27. The method of claim 20, further comprising measurement of oxygen extraction by heterogeneity of said extraction.

13. Apparatus for assessing a subject'"'"'s microcirculation comprising a microscope, a spectrometer and a computer, whereby the computer is arranged to receive image(s) of the microcirculation obtained using the microscope and data relating to SmvO₂ from the spectrometer and, optionally, to process the image(s) and data to identify and/or determine characteristics/parameters associated with pathology, wherein the image(s) and data relate to the following parameters:

(a) functional capillary density (FCD);

(b) heterogeneity of the FCD;

(c) capillary flow velocity;

(d) heterogeneity of capillary flow velocity;

(e) oxygen saturation of microvascular erythrocytes (SmvO₂); and

(f) heterogeneity of SmvO₂.

15. The apparatus of claim 13, further comprising a means for outputting values corresponding to the parameters and/or a value based on them in combination, such as a weighted sum or average.

16. Software comprising instructions to cause a computer to carry out the image processing and/or output steps defined in claim 13.

14. Apparatus for assessing a subject'"'"'s microcirculation comprising a computer arranged to receive image(s) of the microcirculation of a neonate obtained using a microscope and data relating to SmvO₂ from a spectrometer and to process the image(s) and data to identify and/or determine characteristics/parameters associated with pathology, wherein the image(s) and data relate to the following parameters:

(a) functional capillary density (FCD);

(b) heterogeneity of the FCD;

(c) capillary flow velocity;

(d) heterogeneity of capillary flow velocity;

(e) oxygen saturation of microvascular erythrocytes (SmvO₂); and

(f) heterogeneity of SmvO₂.

24. The apparatus of claim 14, further comprising a means for outputting values corresponding to the parameters and/or a value based on them in combination, such as a weighted sum or average.

17. (canceled)

18. (canceled)