ANGIOSOME-BASED PERFUSION MONITORING SYSTEM

• US 20140012108A1
• Filed: 06/27/2013
• Published: 01/09/2014
• Est. Priority Date: 07/06/2012
• Status: Active Grant

• Current Assignee: Covidien PLC (Medtronic Plc)
• Original Assignee: Covidien PLC (Medtronic Plc)
• Inventors: McPeak, Thomas
• Granted Patent: US 9,814,401 B2
• Time in Patent Office: Days
• US Class Current: 600/324
• CPC Class Codes: A61B 2562/17 Comprising radiolucent components
• 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 5/0295 using plethysmography, i.e. measuring the variations in the volume of a body part as modified by the circulation of blood therethrough, e.g. impedance plethysmography
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/7246 using correlation, e.g. template matching or determination of similarity
• CPC Class Codes: A61B 5/7282 Event detection, e.g. detecting unique waveforms indicative of a medical condition A61B5/4094, A61B5/4818, A61B5/349, A61B5/0823 take precedence

Abstract

A compression device includes at least one pressurizable bladder to substantially occlude blood flow into skin capillary beds adjacent to the at least one pressurizable bladder, and a plurality of perfusion sensors. In operation a first-angiosome sensor detects the perfusion parameter of a skin capillary bed in a first angiosome of the limb, and a second-angiosome sensor detects the perfusion parameter of a skin capillary bed in a second angiosome of the limb that is different from the first angiosome. A control circuit maps sensor signals from the first-angiosome sensor to the first angiosome or a first artery of the limb, and maps sensor signals from the second-angiosome sensor to the second angiosome or a second artery of the limb different from the first artery of the limb. For each perfusion sensor, the control circuit determines whether the received sensor signals are indicative of peripheral artery disease.

Claims

1. An angiosome-based perfusion monitoring system for peripheral artery disease, the monitoring system comprising:

a compression device sized and shaped for placement on a limb of a subject, the compression device including

at least one pressurizable bladder configured to exert a suitable compressive force on the limb of the subject when pressurized to substantially occlude blood flow into skin capillary beds adjacent to the at least one pressurizable bladder, and

a plurality of spaced apart perfusion sensors located generally adjacent the at least one pressurizable bladder, each perfusion sensor configured to detect a perfusion parameter of skin capillary beds adjacent the perfusion sensor for quantifying skin capillary bed perfusion and generate a signal indicative of the perfusion parameter,

wherein the perfusion sensors are located on the compression device such that in operation at least one sensor of the plurality of perfusion sensors is a first-angiosome sensor for detecting the perfusion parameter of a skin capillary bed in a first angiosome of the limb and at least one sensor of the plurality of perfusion sensors is a second-angiosome sensor for detecting the perfusion parameter of a skin capillary bed in a second angiosome of the limb that is different from the first angiosome.

2. The monitoring system of claim 1, wherein the first-angiosome sensor comprises a plurality of first-angiosome sensors, and wherein the second-angiosome sensor comprises a plurality of second-angiosome sensors.

3. The monitoring system of claim 2, wherein the first-angiosome sensors are arranged in a first row extending across the at least one pressurizable bladder, and wherein the second-angiosome sensors are arranged in a second row, different from the first row, extending across the at least one pressurizable bladder.

4. The monitoring system of claim 3, wherein the first and second rows are spaced apart along a length of the compression device.

5. The monitoring system of claim 2, wherein the first-angiosome sensors and the second-angiosome sensors are arranged in a same row extending across the at least one pressurizable bladder.

6. The monitoring system of claim 1, wherein the at least one pressurizable bladder comprises a plurality of bladders.

7. The monitoring system of claim 6, wherein the bladders are spaced apart along a length of the compression device, and wherein the compression device is sized and shaped for placement on a leg of the subject.

8. The monitoring system of claim 1, wherein the perfusion sensors comprise pulse oximetry sensors.

9. The monitoring system of claim 1, in combination with a control device, the control device comprising:

a source of pressurized fluid for introducing into the compression device that is placed on the limb of the subject; and

a control circuit configured to

pressurize the at least one bladder of the compression device when the compression device is placed on the limb of the subject to substantially occlude blood perfusion in skin capillary beds adjacent to the at least one bladder,

depressurize the at least one bladder at a controlled rate after pressurizing the bladder,

receive separate sensor signals from the plurality of perfusion sensors on the compression device during depressurization of the at least one bladder, wherein the sensor signals are indicative of perfusion parameters of skin capillary beds adjacent the perfusion sensors for quantifying skin capillary bed perfusion,

map sensor signals from the first-angiosome sensor to at least one of the first angiosome and a first artery of the limb,

map sensor signals from the second-angiosome sensor to at least one of the second angiosome and a second artery of the limb different from the first artery of the limb, and

determine, for each perfusion sensor, whether the received sensor signals are indicative of peripheral artery disease.

10. The monitoring system of claim 10, wherein each of the sensors is configured to send an identifier signal to the control device identifying the angiosome or location on the compression device corresponding to the sensor, wherein the control device is configured to receive each identifier signal and determine the location of the sensor based on the sensor identifier.

11. An angiosome-based perfusion monitoring system for peripheral artery disease, the monitoring system comprising:

a control device including;

a source of pressurized fluid for introducing into a compression device that is placed on a limb of a subject; and

a control circuit configured to

pressurize at least one bladder of a compression device when the compression device is placed on a limb of a subject to substantially occlude blood perfusion in skin capillary beds adjacent to the at least one bladder,

depressurize the at least one bladder at a controlled rate after pressurizing the bladder,

receive separate sensor signals from a plurality of perfusion sensors on the compression device during depressurization of the at least one bladder, wherein the sensor signals are indicative of perfusion parameters of skin capillary beds adjacent the perfusion sensors for quantifying skin capillary bed perfusion,

map sensor signals from a first sensor of the plurality of perfusion sensors to at least one of a first angiosome and a first artery of the limb,

map sensor signals from a second sensor of the plurality of perfusion sensors to at least one of a second angiosome and a second artery of the limb, wherein the second angisome and second artery are different from the first angiosome and the first artery, respectively, and

determine, for each perfusion sensor, whether the received sensor signals are indicative of peripheral artery disease.

12. The monitoring system of claim 11, wherein the control device is configured to determine at least one of:

adequate perfusion, no flow, baseline flow, skin perfusion pressure value, and return of microcirculation based on the received sensor signals.

13. The monitoring system of claim 12, wherein the control device is configured to determine skin perfusion pressure value based on the received sensor signals and compare the skin perfusion pressure value to a threshold value to determine whether the received sensor signals are indicative of peripheral artery disease.

14. The monitoring system of claim 12, wherein the control device is configured to determine the baseline flow and the return of microcirculation based on the received sensor signals and determine a time elapsed between the baseline flow and the return of microcirculation to determine whether the received sensor signals are indicative of peripheral artery disease.

15. The monitoring system of claim 11, wherein the control device comprises a user interface display, wherein the control circuit is configured to generate a graphical rendering of the limb and identify on the graphical rendering the location of the determined peripheral artery disease.

16. A method of monitoring for peripheral artery disease, the method comprising:

pressurizing a bladder of a compression device that is placed on a limb of a wearer so as to substantially occlude blood perfusion to skin capillary beds adjacent the bladder of the compression device;

depressurizing the bladder at a controlled rate after said pressurizing the bladder;

detecting, during said depressurizing the bladder and using a first perfusion sensor, a perfusion parameter of a skin capillary bed located in a first angiosome of the limb;

generating a first sensor signal indicative of the perfusion parameter detected by the first perfusion sensor;

detecting, during said depressurizing the bladder and using a second perfusion sensor, a perfusion parameter of a skin capillary bed located in a second angiosome of the limb that is different from the first angiosome of the limb;

generating a second sensor signal indicative of the perfusion parameter detected by the second perfusion sensor;

receiving, by a control circuit, the first and second sensor signals from at least one first perfusion sensor located generally adjacent the at least one pressurizable bladder;

mapping, by the control circuit, the first sensor signal to at least one of the first angiosome and a first artery associated with the first angiosome;

mapping, by the control circuit, the second sensor signal at least one of the second angiosome and a second artery associated with the second angiosome; and

determining, by the control circuit, whether the first and second sensor signals are indicative of peripheral artery disease.

17. The method of claim 16, further comprising determining, by the control circuit, at least one of:

adequate perfusion, no flow, baseline flow, skin perfusion pressure value, and return of microcirculation based on the received sensor signals.

18. The method of claim 17, further comprising determining, by the control circuit, skin perfusion pressure value based on the received sensor signals and comparing the skin perfusion pressure value to a threshold value to determine whether the received sensor signals are indicative of peripheral artery disease.

19. The method of claim 17, further comprising determining, by the control circuit, the baseline flow and the return of microcirculation based on the received sensor signals, and calculating, by the control circuit, a time elapsed between the baseline flow and the return of microcirculation for use in determining whether the received sensor signals are indicative of peripheral artery disease.

20. The method of claim 17, further comprising generating, by the control circuit, a graphical rendering of the limb, and identifying, by the control circuit, the location of the determined peripheral artery disease on the graphical rendering.