Negative pressure device
A method and apparatus are disclosed for providing negative pressure at a wound site. The apparatus includes a negative pressure reservoir and a reservoir valve for selectively connecting the reservoir to a wound chamber at a wound site. In particular, but not exclusively, the present invention relates to an apparatus including a source of negative pressure which acts as a negative pressure reservoir to continually or repeatedly “top up” an applied negative pressure so that negative pressure applied at a wound site can be maintained within desired limits for a relatively long period of time.
1. An apparatus for providing negative pressure at a wound site, comprising:
a first negative pressure reservoir configured to supply negative pressure at a first negative pressure level;
a conduit configured to be in fluid communication with the first negative pressure reservoir and further configured to supply the negative pressure from the first negative pressure reservoir to the wound site;
a first valve configured to be in fluid communication with the conduit and the first negative pressure reservoir, the first valve further configured to control delivery of the negative pressure supplied from the first negative pressure reservoir to the wound site by:
opening to increase level of negative pressure at the wound site;
closing in response to a pressure difference between the wound site and
the first negative pressure reservoir;
a second negative pressure reservoir configured to supply negative pressure at a second negative pressure level, wherein the second negative pressure reservoir is configured to be in fluid communication with the first negative pressure reservoir;
a second valve configured to be in fluid communication with the first and second negative pressure reservoirs, the second valve further configured to control delivery of the negative pressure supplied by the second negative pressure reservoir to the first negative pressure reservoir by:
opening to allow negative pressure stored in the second negative pressure reservoir to be supplied to the first negative pressure reservoir in response to the negative pressure in the first negative pressure reservoir depleting, and
closing in response to the negative pressure in the first negative pressure reservoir reaching a desired negative pressure level,
wherein the second valve is configured to open and close in response to a pressure difference between the first and second negative pressure reservoirs.
2. The apparatus of claim 1 , further comprising a third valve configured to permit a level of negative pressure in the second negative pressure reservoir to be increased.
3. The apparatus of claim 2 , further comprising an additional negative pressure source configured to supply negative pressure to the second negative pressure reservoir.
4. The apparatus of claim 3 , wherein the additional negative pressure source comprises a pump.
5. The apparatus of claim 1 , wherein said first negative pressure reservoir is enclosed in a rigid housing.
6. The apparatus of claim 1 , wherein the first negative pressure reservoir is enclosed in a first rigid housing and the second negative pressure reservoir is enclosed in a second rigid housing.
7. The apparatus of claim 1 , wherein a pressure at the wound site is configured to be maintained at less than about 200 mm Hg below atmospheric pressure.
8. The apparatus of claim 1 , wherein a pressure at the wound site is configured to be maintained at about 125 mm Hg below atmospheric pressure.
9. The apparatus of claim 1 , wherein a pressure in the first negative pressure reservoir is configured to be maintained at greater than about 500 mm Hg below atmospheric pressure.
10. The apparatus of claim 1 , wherein a level of negative pressure in the second negative pressure reservoir is configured to be more negative than a level of negative pressure in the first negative pressure reservoir.
11. The apparatus of claim 1 , wherein the first negative pressure reservoir is configured to expand so as to increase a volume of the first negative pressure reservoir when a level of negative pressure in the first negative pressure reservoir diminishes.
12. A method of providing negative pressure at a wound site comprising:
supplying, via a conduit and a first valve, negative pressure from a first negative pressure reservoir to the wound site;
in response to a pressure at the wound site becoming less negative:
opening the first valve to supply negative pressure from the first negative pressure reservoir to the wound site; and
closing the first valve in response to a pressure difference between the wound site and the first negative pressure reservoir; and
in response to a negative pressure in the first negative pressure reservoir becoming less negative:
opening a second valve to allow negative pressure stored in a second negative pressure reservoir to be supplied to the first negative pressure reservoir, and
closing the second valve in response to a pressure difference between the first and second negative pressure reservoirs reaching a desired pressure difference.
13. The method of claim 12 , further comprising selectively supplying, via a third valve, negative pressure from an additional negative pressure source to the second negative pressure reservoir.
14. The method of claim 13 , wherein the additional negative pressure source comprises a pump.
15. The method of claim 12 , wherein supplying negative pressure from the first negative pressure reservoir to the wound site comprises supplying negative pressure less than about 200 mm Hg below atmospheric pressure.
16. The method of claim 12 , wherein supplying negative pressure from the first negative pressure reservoir to the wound site comprises supplying negative pressure less than about 125 mm Hg below atmospheric pressure.
17. The method of claim 12 , wherein supplying negative pressure from the first negative pressure reservoir to the wound site comprises supplying negative pressure less than about 500 mm Hg below atmospheric pressure.
18. The method of claim 12 , wherein the negative pressure stored in the second negative pressure reservoir is more negative than the negative pressure stored in the first negative pressure reservoir.
19. The method of claim 12 , wherein the first negative pressure reservoir expands so as to increase a volume of the first negative pressure reservoir in response to the negative pressure in the first negative pressure reservoir decreasing.
20. The method of claim 12 , further comprising maintaining pressure at the wound site substantially within a desired negative pressure range by repeatedly opening and closing the first valve.
21. The apparatus of claim 1 , wherein the first valve is further configured to be repeatedly opened and closed to maintain pressure at the wound site substantially within a desired negative pressure range.
22. The apparatus of claim 1 , wherein the first negative pressure reservoir is at least partially filled with an elastic filler and an absorber gel.
23. The method of claim 12 , wherein the first negative pressure reservoir is at least partially filled with an elastic filler and an absorber gel.
24. An apparatus for providing negative pressure at a wound site, comprising:
a first negative pressure reservoir configured to supply negative pressure at a first negative pressure level, the first negative pressure reservoir at least partially filled with an elastic filler and an absorber gel;
a conduit configured to be in fluid communication with the first negative pressure reservoir and further configured to supply the negative pressure from the first negative pressure reservoir to the wound site;
a first valve configured to be in fluid communication with the conduit and the first negative pressure reservoir, the first valve further configured to control delivery of the negative pressure supplied from the first negative pressure reservoir to the wound site by:
opening to increase level of negative pressure at the wound site;
closing in response to a pressure difference between the wound site and
the first negative pressure reservoir;
a second negative pressure reservoir configured to supply negative pressure at a second negative pressure level, wherein the second negative pressure reservoir is configured to be in fluid communication with the first negative pressure reservoir;
a second valve configured to be in fluid communication with the first and second negative pressure reservoirs, the second valve further configured to control delivery of the negative pressure supplied by the second negative pressure reservoir to the first negative pressure reservoir by:
opening to allow negative pressure stored in the second negative pressure reservoir to be supplied to the first negative pressure reservoir in response to the negative pressure in the first negative pressure reservoir depleting, and
closing in response to the negative pressure in the first negative pressure reservoir reaching a desired negative pressure level;
wherein the second valve is configured to open and close in response to a pressure difference between the first and second negative pressure reservoirs.