Compression device for the limb

Abstract

The invention provides a compression device for the limb of a mobile patient. The device includes an inflatable sleeve adapted to surround the limb; a conduit attached to the sleeve for delivering fluid to the sleeve; and a portable, wearable controller attached to the conduit that generates and controls the flow of fluid in the device.

Claims

1. A compression device for the limb of a mobile patient comprising: an inflatable sleeve adapted to surround the limb; a conduit attached to said sleeve for delivering fluid to said sleeve; and a portable, wearable controller attached to said conduit that generates and controls the flow of fluid in the device, the controller comprising a microprocessor control system and a pump, wherein the device is configured to provide compression to the limb using the inflatable sleeve and configured to provide a patient controlled silent mode, wherein the device applies compression with the pump disabled when in the silent mode and the device does not operate the pump to compensate for a pressure fall after a period of time when in the silent mode, and wherein the patient can switch the device out of silent mode and reactivate the pump.

2. The compression device as claimed in claim 1, wherein said sleeve includes one or more individually inflatable cells.

3. The compression device as claimed in claim 1, wherein said sleeve includes a leg cuff and a foot cuff.

4. The compression device as claimed in claim 3, wherein said leg cuff includes at least three cells.

5. The compression device as claimed in claim 1, wherein said controller is battery operated.

6. The compression device as claimed in claim 2, wherein each cell is monitored by a sensor.

7. The compression device as claimed in claim 4, wherein said cells include a gaiter cell, adapted to wrap around the lower limb in the region closest to the ankle, a mid-calf cell, adapted to wrap around the lower limb above the region occupied by the gaiter cell and an upper cell adapted to wrap around the lower limb in the region between the mid-calf cell and the knee.

8. The compression device as claimed in claim 4, wherein said cells are pressurized to the same or different predetermined pressures.

9. A compression device for the limb of a mobile patient comprising: an inflatable sleeve adapted to surround the limb; a conduit coupled to said sleeve for delivering fluid to said sleeve; and a portable, wearable controller coupled to said conduit that generates and controls the flow of fluid, the controller comprising a microprocessor control system and a pump, wherein the controller is configured to allow a patient to selectively operate the device in dynamic compression in which the pressure is monitored during use to provide the dynamic compression and maintain a preset compression profile on the limb and operate the device in a silent mode, wherein the device applies compression with the pump disabled when in the silent mode and the device does not operate the pump to compensate for a pressure fall after a period of time when in the silent mode.

10. The compression device as claimed in claim 9, wherein the device is configured to allow the patient to switch the device out of silent mode and reactivate the pump.

11. The compression device as claimed in claim 9, wherein said sleeve includes one or more individually inflatable cells.

12. The compression device as claimed in claim 9, wherein said sleeve includes a leg cuff and a foot cuff.

13. The compression device as claimed in claim 9, wherein said controller is battery operated.

14. The compression device as claimed in claim 11, wherein each cell is monitored by a sensor.

15. A compression device for the limb of a mobile patient comprising: an inflatable sleeve adapted to surround the limb; a conduit coupled to said sleeve for delivering fluid to said sleeve; and a portable, wearable controller coupled to said conduit that generates and controls the flow of fluid, the controller comprising a microprocessor control system and a pump, wherein the device is configured to provide compression to the limb using the inflatable sleeve and the device is configured to provide a patient controlled silent mode, wherein the pump is disabled and all valves are kept closed when in the silent mode.

16. The compression device as claimed in claim 15, wherein the controller is configured to allow a patient to selectively operate the device in dynamic compression in which the pressure is monitored during use to provide the dynamic compression and maintain a preset compression profile on the limb or operate the device in the silent mode in which the device applies compression but if the pressure falls after a period of time the device does not operate the pump to compensate.

17. The compression device as claimed in claim 15, wherein said sleeve includes one or more individually inflatable cells.

18. The compression device as claimed in claim 15, wherein said sleeve includes a leg cuff and a foot cuff.

19. The compression device as claimed in claim 15, wherein said controller is battery operated.

20. The compression device as claimed in claim 15, wherein each cell is monitored by a sensor.

Description

(1) Preferred embodiments of the invention will now be described with reference to the accompanying drawings in which:

(2) FIG. 1 is a perspective view of the sleeve of the device on the limb and the controller,

(3) FIG. 2 is a perspective view of the sleeve of the device off the limb and opened up and

(4) FIG. 3 is a perspective view of the sleeve and controller of a second embodiment of the device on the limb.

(5) In FIG. 1 the compression device of the invention is shown on the leg of a patient in a standing position. The device comprises a sleeve 2 having a leg cuff 4 connected to a foot cuff 6. The sleeve 2 is connected to a controller 8 by a conduit 10. The controller is a small, hand held unit that is attached to the sleeve or to the waistband of the patient's trousers or skirt. The controller is battery powered and rechargeable so that it can be recharged on the base unit 12. The device also comprises a sock 14 worn between the patient's leg and the sleeve 2. The sock is present to absorb any moisture from the patient's leg but does not apply compression. The sleeve 2 has an inner 16 and an outer 18 surface composed of a durable flexible material that can be sponged clean and is divided into a plurality of cells 20 best seen in FIG. 2.

(6) FIG. 3 shows an alternative embodiment of the device of the invention where the leg cuff and foot cuff comprise cells with an anatomical shape 22. Each cell is provided with a sensor located centrally in each cell but on the inside of the sleeve between the sleeve and the leg. In FIG. 3 the sleeve is marked on the outside at a position corresponding to the position of the sensor in the inside of the sleeve at 24. The foot cuff in either embodiment may have a sensor located in a position corresponding to the instep of the foot.

(7) FIG. 3 shows the cell structure of the device with a foot cell around the foot, a gaiter cell located closest to the ankle, a mid-calf cell located above the gaiter cell and an upper cell located between the mid-calf cell and the knee.

(8) As can be seen in both embodiments of the device, the patient puts the sleeve on by wrapping the leg cuff and the foot cuff around the leg or foot and securing them at the front of the limb where it is most bony. In this way pressure is applied by the sleeve where it is most needed, i.e. not on the bony areas of the limb but over the muscles.

(9) The invention will now be illustrated by the following non-limiting examples.

EXAMPLE 1

(10) A four cell device similar to that shown in FIG. 3 was used to apply controlled compression to the foot and calf areas of the lower leg. Patients were recruited to test the device on the basis that they had superficial venous insufficiency that had been present for six weeks or longer.

(11) The device was evaluated by measuring the time in seconds for the veins to refill to a level resulting in 90% of a pre-exercise venous pressure (RT90) with and without the device. The pressure was measured in the saphenous vein at the ankle using an Elcat Vasoquant VQ4000 while compression was applied to different regions of the lower leg. In each cycle of the experiment a different compression profile was set up and the pressure measured while the subject bent the knee with heels on the floor 20 times in 40 seconds. This action pumps blood from the veins reducing the venous pressure. The final venous pressure after the last knee bend is the ambulatory venous pressure (AVP). The patient then stood still and the blood flowed back into the legs. The time taken for the venous pressure to reach 90% of the resting level was recorded (RT90).

(12) The RT90 result from a healthy control subject with no compression from the device was 28 seconds. The AVP for this person was 24 mm Hg. The RT90 for a patient with superficial venous insufficiency with no compression from the device was 10.5 seconds. The AVP for this patient was 26 mm Hg. The device to be successful must increase the RT90 of a patient towards that of a healthy control subject. For instance in this case increase the RT90 from 10.5 towards 28 seconds. Compression was applied to the patient with 12 mm Hg in the foot cell, 48 mm Hg in the gaiter and mid-calf cells and 12 mm Hg in the upper cell. The RT90 for this patient increased to 27.5 seconds (very close to the level of a healthy control) and the AVP decreased to 21.5 mm Hg.

(13) In the study, the device was effective in increasing RT90 or reducing AVP at this level of compression in 54% of patients. The device could be effective in higher numbers of patients at higher levels of compression.

EXAMPLE 2

(14) In the experiment of Example 1 it was found that in patients that responded, the gaiter cell had the strongest effect on RT90. This proves that pressure in the gaiter cell reduces reflux. It was also found that the gaiter cell caused the greatest reduction in skin pressure during the knee bends possibly indicating that this cell has the strongest effect on oedema reduction. It was also found that this cell provides resistance to the lower part of the calf muscle, improving pumping efficiency.

EXAMPLE 3

(15) In the experiment of Example 1 it was found that in patients that responded, the mid-calf cell had the second strongest effect on RT90 proving that pressure in this region reduces reflux. It was also found that this cell provides resistance to the calf muscle improving pumping efficiency.

EXAMPLE 4

(16) In the experiment of Example 1 it was found that in patients that responded, the upper cell increases RT90 but only when the gaiter cell is pressurised. The resistance provided by this cell reduces when the venous pressure peaks. However as the calf muscle pump relaxes, it is believed that this cell reduces reflux by constricting the vein.

EXAMPLE 5

(17) In the experiment of Example 1, it was found that the foot cell increases RT90 but only when the gaiter cell is pressurised.

(18) Although the present invention has been shown and described with respect to several preferred embodiments thereof, various changes, omissions and additions to the form and detail thereof, may be made therein, without departing from the spirit and scope of the invention.