Tourniquet for magnetic resonance angiography, and method of using same

• US 20060167492A1
• Filed: 01/13/2006
• Published: 07/27/2006
• Est. Priority Date: 01/24/2005
• Status: Active Grant

• Current Assignee: Martin R. Prince
• Original Assignee: Martin R. Prince
• Inventors: Prince, Martin R.
• Granted Patent: US 8,190,236 B2
• Time in Patent Office: Days
• US Class Current: 606/203
• CPC Class Codes: A61B 17/1322 comprising a flexible encircling member A61B17/135 takes precedence
• CPC Class Codes: A61B 17/135 inflatable for measuring blood pressure A61B5/022; inflatable pressure pads A61F5/34
• CPC Class Codes: A61B 17/1355 Automated control means therefor
• CPC Class Codes: A61B 2090/374 NMR or MRI
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: A61B 5/702 Posture restraints

Abstract

There are many inventions described herein as well as many aspects and embodiments of those inventions. A thigh compression device and technique to control, time, delay and/or prevent excessive early venous enhancement relative to arterial enhancement and thereby improve and/or enhance MRA images, including peripheral MRA images. In one embodiment, the present invention uses a curved strip of material which is longer on the superior edge and shorter along the inferior edge. When wrapped around the conical or conal-like shape of the thigh of a subject (for example, a human), the thigh compression device more uniformly conforms to and/or fits around the thigh, providing more even/uniform compression as well as reducing, minimizing and/or eliminating significant movement of the thigh compression device towards the knees of the subject. Notably, a snug fit on the thighs may also enable the thigh compression device to be inflated with less fluid (for example, air) which is faster and less cumbersome for the operator.

Claims

1. A thigh compression device for use with magnetic resonance imaging equipment, the thigh compression device comprising:

a bladder pouch having a curved rectangular-like shape wherein the pouch includes first side that is longer than an opposing second side;

an inflatable bladder, adapted to be inflated by a fluid, disposed within the bladder pouch;

extension tubing coupled to the inflatable bladder; and

an attachment mechanism to secure the bladder pouch and the inflatable bladder to a thigh of a human, wherein when the thigh compression device is affixed on the thigh of the human using the attachment mechanism, the bladder pouch and the inflatable bladder conform to the conical shape of the thigh.

2. The thigh compression device of claim 1 wherein the length of the first side of the bladder pouch is greater than about 20 inches and less than about 50 inches.

3. The thigh compression device of claim 1 wherein the bladder pouch includes third and fourth sides having a substantially equal length.

4. The thigh compression device of claim 2 wherein the length of the third and fourth sides of the bladder pouch is greater than about 4 inches and less than about 12 inches.

5. The thigh compression device of claim 1 wherein the bladder pouch includes a radius of curvature between 2 and 20 feet.

6. The thigh compression device of claim 1 wherein the inflatable bladder is inflatable with a gas or liquid to a pressure of greater than about 40 mm Hg.

7. The thigh compression device of claim 6 further including an inflation device, coupled to the extension tubing, to inflate the inflatable bladder.

8. The thigh compression device of claim 1 further including a pressure gauge, coupled to the extension tubing or inflatable bladder, to provide information which is representative of the pressure of the fluid in the inflatable bladder.

9. A thigh compression system for use with magnetic resonance imaging equipment, the thigh compression system comprises:

a first thigh compression device comprising;

a bladder pouch having a curved rectangular-like shape wherein the pouch includes first side that is longer than an opposing second side;

an inflatable bladder, adapted to be inflated by a fluid, disposed within the bladder pouch;

extension tubing coupled to the inflatable bladder;

an attachment mechanism to secure the bladder pouch and the inflatable bladder to a right thigh of a human, wherein when the thigh compression device is affixed on the right thigh of the human using the attachment mechanism, the bladder pouch and the inflatable bladder conform to the conical shape of the right thigh; and

a second thigh compression device comprising;

a bladder pouch having a curved rectangular-like shape wherein the pouch includes first side that is longer than an opposing second side;

an inflatable bladder, adapted to be inflated by a fluid, disposed within the bladder pouch;

extension tubing coupled to the inflatable bladder;

an attachment mechanism to secure the bladder pouch and the inflatable bladder of the second thigh compression device to a left thigh of a human, wherein when the thigh compression device is affixed on the left thigh of the human using the attachment mechanism, the bladder pouch and the inflatable bladder conform to the conical shape of the left thigh; and

an inflation device, coupled to the extension tubing of the first and second thigh compression devices, to simultaneously inflate the inflatable bladder of each of the first and second thigh compression devices.

10. The thigh compression system of claim 9 wherein the length of the first side of the bladder pouch of each of the first and second thigh compression devices is greater than about 20 inches and less than about 50 inches.

11. The thigh compression system of claim 9 wherein each bladder pouch of each of the first and second thigh compression devices includes third and fourth sides and wherein the length of the third and fourth sides of the bladder pouch is greater than about 4 inches and less than about 12 inches.

12. The thigh compression system of claim 9 wherein the bladder pouch of each of the first and second thigh compression devices includes a radius of curvature between 2 and 20 feet.

13. The thigh compression system of claim 9 wherein the inflatable bladder of each of the first and second thigh compression devices is inflatable with a gas or liquid to a pressure of greater than about 40 mm Hg.

14. The thigh compression system of claim 9 further including a pressure gauge, coupled to the inflation device, to provide information which is representative of the pressure of the fluid in the inflatable bladder of each of the first and second thigh compression devices.

15. A thigh compression system for use with magnetic resonance imaging equipment, the thigh compression system comprising:

a thigh compression device including;

first and second layers of flexible material welded together to form an air tight bladder wherein the bladder has a curved rectangular-like shape including a first side that is longer than an opposing second side, and wherein the bladder is inflatable by a fluid;

multiple welds within the bladder which restrict the amount that the bladder expands when inflated;

extension tubing coupled to the bladder; and

an inflation device, coupled to the extension tubing of the thigh compression device, to inflate the inflatable bladder.

16. The thigh compression system of claim 15 wherein the length of a first side of the thigh compression device is greater than about 20 inches and less than about 50 inches.

17. The thigh compression system of claim 15 wherein the bladder of the thigh compression device includes a radius of curvature between 2 and 20 feet.

18. The thigh compression system of claim 15 further including a pressure monitoring device to provide data which is representative of the pressure of fluid within the bladder.

19. The thigh compression system of claim 15 further including:

a first material having hooks, attached to a first portion of the first layer of the flexible material;

a second material having loops, attached to a second portion of the first layer of the flexible material; and

wherein thigh compression device is secured to a leg of a patient by engaging the first and second materials.

20. The thigh compression system of claim 19 wherein the first material or the second material is laminated to the corresponding portion of the first layer of the flexible material.

21. The thigh compression system of claim 15 wherein a plurality of the multiple welds are round and spaced 1 to 2 inches apart.

22. The thigh compression system of claim 21 wherein the plurality of the multiple welds is greater than 30 welds.

23. The thigh compression system of claim 15 wherein a plurality of the multiple welds restrict expansion of the bladder.

24. The thigh compression system of claim 15 wherein radius of curvature of bladder is between 2 and 20 feet.

25. The thigh compression system of claim 15 wherein the inflation device includes a regulator which controls the pressure of a pressurized air or oxygen source.

26. The thigh compression system of claim 25 wherein the regulator includes a diaphragm having at least 1 inch in diameter.

27. The thigh compression system of claim 15 further including a quick release connector to provide rapid deflation of the air tight bladder.

28. The thigh compression system of claim 15 wherein the thigh compression device being inflated to about 50 mmHg reduces the venous flow from the leg and suppresses enhancement of veins on peripheral MR Angiography.

29. A method of reducing venous enhancement on peripheral magnetic resonance imaging comprising:

uniformly compressing the thigh of the patient with a curved compression device that snuggly fits the conical shape of the thigh of a human and is inflated without substantially displacing the leg or putting the leg into an unstable position;

obtaining a first 3D gradient echo MR image;

injecting a contrast agent into an arm vein;

obtaining a second 3D gradient echo MR image using the same imaging parameters for obtaining a first 3D gradient echo MR image; and

creating a final image by subtracting the first 3D gradient echo MR image from the second 3D gradient echo MR image.