Wound Ventilation System

• US 20110034861A1
• Filed: 08/07/2009
• Published: 02/10/2011
• Est. Priority Date: 08/07/2009
• Status: Active Grant

• Current Assignee: Acute Ideas, Inc.
• Original Assignee: Acute Ideas, Inc.
• Inventors: Schaefer, Joseph H.
• Granted Patent: US 8,758,291 B2
• Time in Patent Office: Days
• US Class Current: 604/23
• CPC Class Codes: A61M 1/94 with gas supply means
• CPC Class Codes: A61M 1/964 having venting means on or near the dressing
• CPC Class Codes: A61M 2202/0007 introduced into the body
• CPC Class Codes: A61M 2202/0208 Oxygen
• CPC Class Codes: A61M 2205/18 with alarm
• CPC Class Codes: A61M 2205/3331 Pressure; Flow
• CPC Class Codes: A61M 2205/3368 Temperature
• CPC Class Codes: A61M 2205/362 by gas flow
• CPC Class Codes: A61M 2205/3653 by Joule effect, i.e. electric resistance
• CPC Class Codes: A61M 35/30 Gas therapy for therapeutic treatment of the skin

Abstract

A wound treatment apparatus that ventilates a wound dressing with warm humidified oxygen and/or air at a very low flow rate while under a sub-atmospheric pressure. A controlled flow of filtered air and/or oxygen is selected or blended under atmospheric pressure. This gas is pulled by a downstream vacuum source through a flow limiting device and exits at a sub-atmospheric pressure equal to the vacuum source. The gas flow is then humidified and heated to prescribed conditions before entering a substantially airtight negative pressure type wound dressing which is adapted for ventilation with an added inlet connection. This conditioned gas ventilates and nourishes the wound environment exiting the dressing outlet, through a fluid trap, to the vacuum source.

Claims

1. A wound ventilation system comprising:

a wound dressing having an inlet and outlet, said wound dressing forming a substantially airtight cover over a wound;

a gas supply in fluid communication with said inlet supplying a gas to said inlet;

a gas flow controller controlling the flow of gas from said gas supply into said inlet;

a humidifier humidifying said gas entering said inlet;

a heater located prior to an exit of said humidifier;

a re-heater located after said exit of said humidifier to minimize any condensate that may be formed; and

a vacuum source in fluid communication with said outlet, said outlet drawing said gas through said inlet over the wound covered by said wound dressing, and out of said outlet.

2. The ventilation system of claim 1 in which a temperature controller includes a sensor that senses wet bulb temperature at an outlet of said humidifier, wherein said temperature controller controls the humidification of said gas by said humidifier.

3. The ventilation system of claim 2 in which the humidifier saturates the gas to 100% relative humidity at the sensor location, making the distinction between wet bulb and dry bulb temperature irrelevant, and enabling the temperature controller to sense an accurate dry bulb temperature, while assuming wet bulb, at the humidifier'"'"'s outlet for controlling the humidifier.

4. The ventilation system of claim 1 in which a temperature controller senses dry bulb temperature at the wound dressing inlet for controlling the re-heater.

5. The ventilation system of claim 2 in which a specified relative humidity is maintained by using its relationship to the settings of the wet bulb temperature and a dry bulb temperature.

6. The ventilation system of claim 1 in which said humidifier provides a relative humidity above 100% to flush the wound with warm condensate.

7. The ventilation system of claim 1 in which a high temperature safety controller senses temperature at the wound dressing inlet, and upon sensing a temperature above a predetermined level, provides an alarm and turns off all sources of heat.

8. The ventilation system of claim 1 including a vacuum pressure switch that provides a signal to turn off all sources of heat upon sensing a loss of vacuum in the ventilation system.

9. The ventilation system of claim 1 including a humidity sensor that senses relative humidity downstream of the humidifier, wherein upon sensing a humidity condition below a predetermined level activates an alarm.

10. The ventilation system of claim 1 in which said gas passes through a bacteria filter prior to entering said inlet.

11. The ventilation system of claim 1 in which the gas flow controller is selected from the group consisting of a filtered orifice flow restrictor, a needle valve, and a porous material having flow rate characteristics.

12. The ventilation system of claim 1 in which said gas supply includes an oxygen supply provided by at least one of a regulated and flow limited source from a compressed oxygen bottle and a regulated and flow limited source of wall outlet oxygen.

13. The ventilation system of claim 1 in which the humidifier uses sterile water.

14. The ventilation system of claim 1 including a programmable timer/display unit capable of recording total accumulated runtime of the ventilation system.

15. The ventilation system of claim 1, in which said gas is at least one of air and O₂.

16. The ventilation system of claim 1, in which said gas flow controller, humidifier, heater, and re-heater are integrated into a single wound vacuum therapy unit.

17. The ventilation system of claim 15, further comprising a mixture plenum in which a controlled flow of oxygen and a free flow of air are mixed under atmospheric pressure and wherein the mixture plenum is located before the gas flow controller.