Wound therapy system with proportional valve mechanism

1. A portable system for subatmospheric pressure therapy in connection with healing a wound, which comprises:

a wound dressing dimensioned for positioning relative to a wound bed of a subject to apply a subatmospheric pressure to the wound;

a subatmospheric pressure mechanism including:

a housing;

a vacuum source disposed in the housing and having an inlet port and an outlet port, the inlet port fluidly couplable to the wound dressing via a conduit;

a collection canister in fluid communication with the inlet port and the wound dressing via the conduit for collecting exudate removed from the wound bed;

a valve mechanism disposed relative to the vacuum source and fluidly coupled to the inlet and outlet ports via the conduit; and

an exhaust port in fluid communication with the wound dressing via the valve mechanism and with the outlet port of the vacuum source, the exhaust port configured to vent an air flow from at least one of the vacuum source and the wound dressing;

wherein the valve mechanism is adapted to move between an open position where the vacuum source is capable of drawing a vacuum in the collection canister through the inlet port via the conduit and an air flow from the outlet port is vented through the exhaust port, a proportional position where the outlet port is placed in fluid communication with the inlet port through the valve mechanism via the conduit such that an air flow exits from the outlet port and circulates through the valve mechanism and into the inlet port and an air flow from the wound dressing is vented through the exhaust port, and a closed position where an air flow from the outlet port circulates through the inlet port and fluid communication between the inlet port and the wound dressing is interrupted.

2. The portable system according to claim 1 , wherein the valve mechanism is adapted to move to the closed position in response to one of a clog, an air leak at the wound dressing, a tilting of the collection canister beyond a predetermined angle of orientation, and an inversion of the collection canister.

3. The portable system according to claim 2 , wherein the predetermined angle of orientation is relative to an upright position of the collection canister.

4. The portable system according to claim 1 , the subatmospheric pressure mechanism further comprising a control unit in communication with a pressure transducer adapted to detect a vacuum level at the collection canister, the control unit adapted to move the valve mechanism between the open, proportional, and closed positions in response to the vacuum level detected by the pressure transducer.

5. The portable system according to claim 4 , wherein the pressure transducer is adapted to generate an electrical signal which varies as a function of vacuum level at the collection canister.

6. The portable system according to claim 1 , wherein the vacuum source is adapted to run continuously.

7. A method of healing a wound using subatmospheric pressure therapy, the steps comprising:

positioning a wound dressing relative to a wound bed of a subject;

applying subatmospheric pressure to the wound bed via a subatmospheric pressure mechanism, the subatmospheric pressure mechanism comprising:

a housing;

a vacuum source disposed in the housing and having an inlet port and an outlet port, the inlet port fluidly coupled to the wound dressing via a conduit;

a collection canister in fluid communication with the inlet port and the wound dressing via the conduit for collecting exudate removed from the wound bed under influence of the vacuum source; and

a valve mechanism disposed relative to the vacuum source and fluidly coupled to the inlet and outlet ports via the conduit;

venting an air flow from at least one of the vacuum source and the wound dressing via an exhaust port in fluid communication with the wound dressing via the valve mechanism and with the outlet port of the vacuum source,

operating the vacuum source with the valve mechanism in an open position to vent an air flow from the outlet port through the exhaust port and achieve a reduced pressure state within the wound dressing at a desired vacuum level;

moving the valve mechanism to a proportional position upon achievement of the desired vacuum level to place the outlet port in fluid communication with the inlet port through the valve mechanism via the conduit; and

moving the valve mechanism to a closed position to interrupt fluid communication between the inlet port and the wound dressing and relieve vacuum pressure at the wound dressing if a higher than desired vacuum level is achieved;

wherein the step of moving the valve mechanism to the proportional position further comprises circulating an air flow from the outlet port through the valve mechanism and into the inlet port and venting an air flow from the wound dressing through the exhaust port; and

the step of moving the valve mechanism to the closed position further comprises circulating an air flow from the outlet port through the valve mechanism and into the inlet port to interrupt the influence of the vacuum source on the wound bed.

8. The method according to claim 7 , further comprising the steps of:

detecting a vacuum level at the collection canister; and

moving the valve mechanism between the open, proportional, and closed positions in response to the detected vacuum level.

9. The portable system according to claim 8 , further comprising the step of:

generating an electrical signal that varies as a function of the detected vacuum level.