Negative pressure device
A method and apparatus are disclosed for providing negative pressure at a wound site. The apparatus includes a suction pump for generating negative pressure, a negative pressure reservoir, a valve element arranged to selectively provide a fluid communication path between the reservoir and the wound site while a negative pressure in the negative pressure reservoir is greater than a threshold negative pressure, to thereby provide a desired negative pressure at the wound site, and wherein in response to a pressure in the negative pressure reservoir decreasing to the threshold negative pressure, the suction pump is operable to re-establish an initial negative pressure in the negative pressure reservoir.
1. A vacuum pressure regulator valve produced by a process comprising:
compressing first and second opposing sidewalls of a first portion of a tube toward one another in a direction transverse to a longitudinal axis of the tube to move the first and second opposing sidewalls into a deformed configuration;
heating the first portion to a deforming temperature while maintaining the first portion of the tube in the deformed configuration;
maintaining the first portion of the tube in the deformed configuration at the deforming temperature for a duration of time; and
cooling the first portion of the tube to a setting temperature after the duration of time has elapsed,
wherein the first portion of the tube includes a deformed section in which the first and second opposing sidewalls are closer to one another than in another section of the first portion, the deformed section facilitating transitioning between collapse and expansion of the deformed section, and
wherein the deformed section of the first portion of the tube is configured to:
collapse as a result of the first and second opposing sidewalls coming into contact and block flow through the tube responsive to an internal pressure within the tube being reduced compared to an ambient atmospheric pressure outside the tube, the internal pressure within the tube being reduced as a result of negative pressure being applied to the tube, and
expand as a result of the first and second opposing sidewalls coming apart and permit flow of negative pressure from a negative pressure reservoir through the tube responsive to the internal pressure approaching the ambient atmospheric pressure.
2. The vacuum pressure regulator valve of claim 1 , wherein the duration of time is at least 3 seconds.
3. The vacuum pressure regulator valve of claim 1 , wherein the first portion of the tube is maintained in the deformed configuration during said cooling.
4. The vacuum pressure regulator valve of claim 1 , wherein the process further comprises:
rotating the tube a half turn along a long axis of the tube from a first circumferential position to a second circumferential position; and
compressing again the first portion of the tube.
5. The vacuum pressure regulator valve of claim 1 , wherein the process further comprises:
compressing a second portion of the tube, wherein the second portion is adjacent to the first portion.
6. The vacuum pressure regulator valve of claim 5 , wherein the process further comprises:
compressing a third portion of the tube, wherein the first portion of the tube is disposed longitudinally between to the second portion of the tube and the third portion of the tube.
7. The vacuum pressure regulator valve of claim 1 , wherein the tube is made of a transparent thermoplastic elastomer tubing.
8. The vacuum pressure regulator valve of claim 1 , wherein the deforming temperature is between 90° C. and 110° C.
9. The vacuum pressure regulator valve of claim 1 , wherein compressing the first and second opposing sidewalls of the first portion of the tube comprises applying a deforming pressure of 3 Bars to the first portion of the tube.
10. The vacuum pressure regulator valve of claim 1 , wherein the setting temperature is 80° C.
11. The vacuum pressure regulator valve of claim 1 , wherein the process further comprises:
connecting an inlet at a first end of the tube and an outlet at a second end of the tube opposite the first end, the inlet maintaining the first and second opposing sidewalls open at the first end and the outlet maintaining the first and second opposing sidewalls open at the second end.
12. The vacuum pressure regulator valve of claim 1 , wherein the deformed section of the first portion is configured to expand responsive to a pressure differential created by the internal pressure that is negative acting on inner surfaces of the first and second opposing sidewalls and the ambient atmospheric pressure acting on external surfaces of the first and second opposing sidewalls.
13. The vacuum pressure regulator valve of claim 1 , wherein the process further comprises forming an inlet opening by inserting a portion of an inlet into a first end of the tube and forming an outlet opening by inserting a portion of an outlet into a second end of the tube opposite the first end, wherein the portion of the inlet inserted into the first end of the tube maintains first and second opposing sidewalls in an open configuration at the first end of the tube, and wherein the portion of the outlet inserted at the second end of the tube maintains the first and second opposing sidewalls in an open configuration at the second end of the tube.