Wound treatment apparatus

A control unit is adapted for use with a vacuum wound bandage. The control unit has a canister to collect waste material from the vacuum wound bandage, a fluid source to irrigate the wound, and a door to at least partially cover the fluid source.

TECHNICAL FIELD

The present disclosure relates to wound treatment apparatus for use with vacuum bandages of the type that dispenses fluid to a wound and draws fluid away from the wound.

BACKGROUND AND SUMMARY

Medical professionals, such as nurses and doctors, routinely treat patients having surface wounds of varying size, shape, and severity. It is known that controlling the topical atmosphere adjacent a wound can enhance the healing process. For example, by applying medicinal agents or even water over a wound, dirt and bacteria are either killed or washed away, thereby promoting healing. In addition, applying a negative pressure or vacuum to a wound draws out exudate, which might contain dirt and bacteria, from the wound to further promote healing.

Conventional treatment of a surface wound involves placement of a packing or dressing material, such as cotton, gauze, or other bandage-like material directly in contact with the patient's wound. Often there is a need to change the dressing material frequently because it becomes saturated with exudate discharged from the wound. Some dressings include an apparatus attached thereto for applying a vacuum through the bandage to the wound to draw exudate and promote healing.

According to the present disclosure, a control unit is adapted for use with a vacuum wound bandage. The control unit comprises a control module to provide a negative pressure through the vacuum wound bandage and a canister having an interior region to collect waste material from the vacuum wound bandage and a latch to couple the canister to the control module. The latch extends through the interior region. Illustratively, the latch is operable to move the canister into sealing engagement with the control module. Further illustratively, the canister has a sleeve positioned within the interior region, and a portion of the latch is positioned within the sleeve.

According to another aspect of the disclosure, the control unit comprises a vacuum source to provide a desired negative pressure through the vacuum wound bandage to treat the wound, a pressure sensor, and a canister. The canister has a chamber to collect waste material from the vacuum bandage, an inlet port to introduce waste material from the vacuum bandage into the chamber, an outlet port to communicate with the chamber and the vacuum source, and a pressure port to communicate with the chamber and the pressure sensor. The pressure port is positioned to allow the pressure sensor to sense the pressure within the chamber when the waste material within the chamber at least partially occludes the outlet port so as to prohibit the vacuum source from providing the desired negative pressure within the chamber.

According to another aspect of the disclosure, the control unit comprises a fluid source to irrigate the wound, a housing carrying the vacuum source and the fluid source, and a door movable relative to the housing between an opened position uncovering the fluid source and a closed position at least partially covering the fluid source. The control unit further comprises a latch coupled to the door for movement relative to the door between a latched position blocking movement of the door from its closed position to its opened position and a release position allowing the door to move between its closed position and its opened position. According to another aspect of the disclosure, the door has a mount supporting the fluid source.

Additional features and advantages of the apparatus will become apparent to those skilled in the art upon consideration of the following detailed descriptions exemplifying the best mode of carrying out the apparatus as presently perceived.

Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates several embodiments of the apparatus, and such exemplification is not to be construed as limiting the scope of this disclosure in any manner.

DETAILED DESCRIPTION OF THE DRAWINGS

An embodiment of wound treatment apparatus2is shown inFIG. 1. Wound treatment apparatus2comprises a central unit housing4, having wound treatment systems6,8appended to each side of housing4. A user interface10is shown positioned between each treatment system6,8. Central unit housing4is configured to be a portable unit allowing a caregiver to move housing4to wherever the patient is located and to close proximity to the wound or wounds. Housing4is shown having a handle portion12to assist the caregiver in moving housing4.FIG. 1also shows wound treatment system6coupled to a bandage14attached to a patient's leg16. Dispensing and evacuating tubes18,20are coupled to both bandage14and system6. Specifically, dispensing tube18is coupled to a luer-lok port22extending from syringe24. Syringe24is filled with a fluid, typically saline, that empties through tube18and into bandage14, and ultimately onto a wound300positioned under bandage14. (See alsoFIG. 9.) After contacting wound300, the fluid and exudate from wound300are drawn from bandage14through evacuating tube20and into a waste canister26where it is collected. It is contemplated that the canister26can be discarded when filled and replaced with a new canister26.

Apparatus2comprises a second system8on the opposite side of housing4from system6. This configuration allows two wounds to be treated simultaneously with separate bandages, yet, under the control of a single housing4. Second bandage15, as part of system8, is coupled to dispensing and evacuating tubes28,30, respectively, to perform the same functions as described for system6. (SeeFIG. 2.) User interface10is provided to allow the caregiver to control either or both systems6,8, to dispense fluid from either or both syringes24,224, and to evacuate from either or both bandages14,15. It is contemplated that each wound treatment system6,8will work independent of each other, thus, allowing the caregiver flexibility to apply an appropriate and, yet, possibly different level of treatment to each wound.

The arrangement of systems6,8relative to user interface10on housing4allows convenient interaction between systems6,8and the caregiver. For example, syringes24,224are conveniently positioned on opposite sides of user interface10. Each syringe is partially covered by doors32,33on the front of housing4. Each door32,33swings outwardly about hinges34,36, allowing syringes24,224to be removed and replaced. Similarly, waste canisters26,27are each positioned in a cavity9provided on each side of housing4. (SeeFIG. 7.) Each canister26,27includes a grip portion40for convenient removal and replacement. Canisters26,27are illustratively secured into each cavity by a friction fit. (SeeFIG. 6.) It is appreciated, however, that syringes24,224can be secured to other locations on housing4.

The portability of apparatus2allows a caregiver to position it near the patient in preparation for treatment wherever the patient is located. To prepare apparatus2for treatment, the caregiver secures syringes24,224, which contain fluid, to apparatus2in a manner described in greater detail below. The caregiver then couples tube18to port22and bandage14, and tube20to bandage14and waste canister26, for treatment of one wound. The caregiver then couples tube28to port222and bandage15, and tube21to bandage15and waste canister27, for treatment of a second wound. (See alsoFIG. 2.) The caregiver, through the use of user interface10can treat the patient by selectively irrigating the wounds with fluid and drawing exudate and the fluid from the wounds.

A diagram depicting how wound apparatus2operates is shown inFIG. 2. A controller50is provided in housing4and is an electronic control unit that controls apparatus2. Controller50receives user input from and provides feedback to user interface10through lines52,54, respectively. It is contemplated that controller50will process information from both systems6,8, and provide appropriate and independent input to each system. Controller50also monitors the status of all various sensors, and provides input for the valves and motors, as discussed in further detail herein. Illustratively, user interface10is composed of a conventional graphic liquid crystal display (LCD) and a membrane switch panel.

A power supply56provides power to controller50and all the attendant systems in housing4. Power supply56can be a conventional external wall socket supply (not shown), or be a battery pack supply (also not shown), or even be variations of both (e.g., a wall socket supply with a battery pack supply). Illustratively, power supply56is a medical grade power supply providing an output of about 65-watts and a voltage of about 12VDC. It is contemplated that the power supply can be configured for 120V/60 Hz or 220-240V/50 Hz depending on whether housing4is used in America or Europe. Illustratively, the battery power provides the device with power to operate for about 60 minutes without connection to an external power source. It is further contemplated that the batteries can be rechargeable, and store energy when the device is connected to an external wall socket.

An attitude sensor58is provided in communication with controller50through line60. Attitude sensor58is, illustratively, a tilt switch which provides feedback to controller50. If the switch is, illustratively, in the closed position, controller50will continue to operate, but if the switch opens, controller will shut systems6,8down. For example, sensor58disables systems6,8if housing4tilts at or greater than a predetermined amount, such as 45° from vertical in any direction.

It is contemplated that controller50, user interface10, power supply56, and attitude sensor58are all common to and all operate with both systems6,8. Each system6,8further comprises fluid dispensing and vacuum evacuating sub-systems62,64and66,68. Fluid dispensing sub-system62comprises a syringe24having a plunger70. (See alsoFIG. 4.) Syringe24is, illustratively, a standard 60-ml medical syringe utilizing a luer-lok port22. Plunger70is a conventional plunger that extends into syringe24to dispense fluid through luer-lok port22. A syringe drive motor72is, illustratively, a 12VDC brushless electric motor or stepper motor configured to provide rotational energy to a syringe drive74. (SeeFIG. 4.) When a signal is sent from controller50along line76to syringe drive motor72, motor22applies torque and angular velocity to syringe drive74which is, illustratively, a power screw322. (See alsoFIG. 4.) Power screw322translates rotational movement of the syringe drive motor72into translational movement. The drive has a guide80to limit a plunger interface78to motion along one axis. In the illustrated embodiment, syringe drive72provides about 5.25 inches (13.3 cm) of travel of plunger interface78, indicated by reference numeral82, to evacuate the fluid contained in syringe24. (See alsoFIG. 4.) Furthermore, syringe drive motor72and syringe drive74, as a system, provide about 27 pounds of linear force at a velocity of 1.45 inches (3.7 cm) per second to the plunger interface78. The resulting force created by the fluid exiting syringe24creates, illustratively, 4-PSIG to 6-PSIG positive pressure at wound300.

A syringe home sensor84receives information from plunger interface78, and provides feedback to controller50when syringe capture mechanism88reaches its home position79. A syringe full travel sensor86determines when syringe24is fully evacuated by sensing when plunger interface78has reached fill travel. After sensor86has been activated, controller50resets plunger interface78to home position79once syringe24is removed.

Syringe capture mechanism88holds syringe24in place when the caregiver places syringe24in apparatus2. (See alsoFIG. 4.) Capture mechanism88is also configured to allow the caregiver to release syringe24from apparatus2when it is empty. Capture mechanism88further includes a syringe sensor90that provides feedback to controller50through line92when syringe24is properly held in capture mechanism88. Controller50prevents system6from operating if sensor90does not detect syringe50being properly held in capture mechanism88.

Connectors94,96are provided at opposed ends of dispensing tube18. Either one or both connectors94,96, when closed, block flow from syringe24to bandage14. Such connectors94,96allow the patient to be disconnected from apparatus2without having to remove bandage14or even shut apparatus2down.

A manual port98is also attached to dispensing tube18by an auxiliary tube100. Port98permits the caregiver to attach a dispensing container to the system to manually dispense fluid into bandage14. It is appreciated, however, that port98is configured to be closed while no syringe is attached to maintain a closed system.

The syringe and drive are illustrated as one approach for providing a fluid source and a drive for irrigating a wound bed. It will be appreciated that containers other than syringes may be operated by a drive to expel irrigation fluid toward a wound surface. For example, any type of container of fluid may be squeezed or reduced in volume by a drive mechanism to expel fluid. Also, as discussed in connection withFIG. 8, a container may be held at an elevated position to provide head pressure for irrigation fluid.

Connectors104,106, similar to connectors94,96, are provided at opposed ends of evacuating tube20. Either one or both connectors104,106, when closed, block flow from bandage14to waste canister26. Such connectors104,106also allow the patient to be disconnected from apparatus2without having to remove bandage14or having to shut down apparatus2.

Waste canister sensors116,118are engaged when waste container26is properly seated in apparatus2. This prevents apparatus2from operating without canister26seated properly in apparatus2. As depicted inFIG. 2, both sensors116,118provide feedback to controller50through lines120,122, confirming to the caregiver that canister26is seated properly in apparatus2.

In the illustrated embodiment, waste canister26is a disposable unit that “snaps into” side portion38of housing4. (See alsoFIGS. 1 and 6.) Illustratively, canister26includes a window (not shown) to allow monitoring of the fluids. Illustratively, the fluid capacity of canister26is about 500-ml.

The illustrated embodiment of waste canister26further includes a hydrophobic filter108that is in communication with both evacuating tube20and vacuum pump110. (See alsoFIG. 6.) Such filter108is configured to allow air, but not liquid, to pass. Accordingly, as fluid is drawn into canister26, fluid is deposited into waste canister26while the vacuum continues through filter108and pump110. Illustratively, filter108is a 1.0-micron hydrophobic filter fixed into rear wall407of canister26. (SeeFIG. 6.) Hydrophobic filter108also serves as a canister full mechanism114or valve that shuts off the vacuum supply to the canister26when the fluid level exceeds the “full” level420. Because hydrophobic filter108prevents fluid from passing, once fluid covers filter108, vacuum is prevented from passing as well. The absence of any vacuum in the system will cause the system to shut down.

Vacuum pump110creates the negative pressure that is present through canister26. For monitoring and controlling such negative pressure, the vacuum is present through several devices, including a vacuum pressure transducer124. Transducer124is coupled to line128, extending from canister26. (SeeFIG. 5.) Transducer124measures the negative pressure that is present through canister26. Transducer124then provides feedback to controller50through line128. Controller50monitors the negative pressure by comparing the measured value from transducer124with the caregiver-defined value entered into controller50through user interface10.

A proportional valve130is connected to line126, through which the negative pressure is present, and which comprises a flow orifice132. (See alsoFIG. 5.) Flow orifice132selectively dilates or constricts, thereby controlling the negative pressure level through sub-system66. Specifically, controller50provides a signal input to proportional valve130based on the level of the vacuum pressure determined from feedback of transducer124and comparing that level to the caregiver-defined level. Orifice132then dilates or constricts, as necessary, to produce the appropriate level of negative pressure. Illustratively, proportional valve130is fully constricted or closed when receiving no signal from controller50, and dilates or opens to allow an illustrative maximum of two liters per minute at 250-mmHg (4.83-PSIG) vacuum when the proper signal from controller50is applied.

A vacuum regulator134is provided in line126between proportional valve130and pump.110as a mechanical limit control for pump110. Regulator134mechanically establishes a maximum level of negative pressure that is present in the system. Thus, vacuum pump110will not physically be able to draw a vacuum from bandage14beyond the maximum pressure. Illustratively, such maximum negative pressure or vacuum is 250-mmHg (4.83-PSIG). In addition, when proportional valve130, pursuant to a signal from controller50, creates a negative pressure less than the maximum negative pressure level, a port136, coupled to regulator134, opens so that pump110can draw more air to maintain a sufficient flow through pump110, to prevent it from becoming damaged. A first air filter137is illustratively associated with port136, between port136and pump110, to filter particulates from the air prior to reaching pump110. illustratively, filter137is constructed of glass microfibers with a filtration rating of 25 microns. A second filter139is associated with pump110and an outlet141. Filter139serves as an exhaust muffler for the air evacuated from pump110.

Vacuum pump110is, illustratively, a diaphragm-type compressor that flows about two liters per minute at 250-mmHg (4.83-PSIG) vacuum. Illustratively, vacuum pump110is mounted on the end of a single 12VDC brushless motor138to drive the pump. It is appreciated, however, that pump110can be of any other configuration, and mounted in any manner, so long as it draws a desired negative pressure through system6. It is also contemplated that a vacuum pump external to the housing4may be a part of the control system. For example, most medical facilities have vacuum ports near where patients are treated, each of which is served by a system vacuum (suction) pump. It is contemplated, therefore, that the pump110in the housing4may be an appropriate fitting which is, in turn, connected to a facility vacuum pump to provide a vacuum source to the control system.

It is contemplated that port136, filters137,139, electric motor138, vacuum pump110, and vacuum regulator134are all housed in a sound chamber140. Illustratively, the interior of sound chamber140is lined with a damping foil like the 3M Company's damping foil number 2552, for example. Sound chamber140dampens vibration energy produced by these components, as well as assists in dissipating heat they generated.

As previously indicated, it is contemplated that controller50, user interface10, power supply56, and attitude sensor58are common to, and operate with, both fluid dispensing and vacuum evacuating sub-systems62,64and66,68. Providing a second independently operable set of sub-systems64,68allows the caregiver to treat two wounds using a single apparatus2. Accordingly, second fluid dispensing and evacuating sub-systems64,68also shown inFIG. 2, comprise identical components as discussed regarding sub-systems62,66and are labeled in a corresponding manner. For example, syringe motor drive72in sub-system62is identified as syringe motor drive172in sub-system64, and a vacuum pump110in sub-system66is identified as vacuum pump210in sub-system68.

A schematic diagram of a portion of wound treatment apparatus2is shown inFIG. 3. Each system6and8is configured to operate in the same manner. Specifically,FIG. 3depicts the operation of system6. Movement of plunger70into syringe24causes fluid stored in syringe24to exit into tube18and into bandage314where it drains through orifices302onto wound300. Vacuum110applies a negative pressure through waste canister26and bandage314. Fluid and exudate are then drawn from wound300out through tube20and into canister26. The hydrophobic filter108, discussed in connection withFIG. 2, allows the vacuum to pass through waste canister26, yet, prevents any of the fluid from escaping, and depositing the fluid into pump110.

The mechanism for moving plunger70into syringe24, part of fluid dispensing sub-system62, is shown in cross-sectional form inFIG. 4. The illustrated embodiment includes sub-system62positioned within housing4. Specifically, a bracket frame310serves as the skeletal structure for sub-system62. Bracket310includes a base portion312with an upwardly extending structural member314appending from one end thereof. A support portion316extends outwardly from member314, and is superposed above base portion312. Extending from support portion316is syringe bracket318. Syringe capture mechanism88is formed in bracket318, and is configured to receive syringe24, as previously discussed. Bracket318and capture mechanism88are configured to suspend syringe24with luer-lok port22directed upwardly. It is contemplated that capture mechanism88secures syringe24to bracket318by other means, including being friction-fitted, or secured with clips or bolts. To move plunger70, syringe drive74and plunger interface78are coupled to frame310. Plunger interface78captures plunger70and provides upward linear motion to evacuate syringe24. Interface78provides a release mechanism for plunger70to remove syringe24at any position in the stroke.

Syringe drive74comprises syringe drive motor72and power screw322. Power screw322is disposed through an aperture324in support portion316, and is rotatably coupled to motor72. It is appreciated that motor72can be a stepper or electric motor, for example. The lower end326of power screw322is positioned within a bearing cavity328within which power screw322rotates. Spaced in parallel to power screw322is guide80. Guide80is received in an aperture330, also disposed in support portion316at its upper end332, and is received in cavity334at its lower end336. Plunger interface78is configured to receive cap338of plunger70, and is coupled to a dual coupler340. Dual coupler340comprises two blocks342,344, each having bores346,348disposed, respectively, there through. In the illustrated embodiment, bore346has a smooth surface and is configured to receive guide80. In contrast, bore348has a threaded surface and is configured to cooperate with threads on power screw322. Coupler340is movable upwardly and downwardly in directions350,352. A hatched outline version of coupling340, indicated by reference numeral354, is shown depicting plunger interface78and plunger70moving upwardly in direction350. As shown inFIG. 4, as plunger70is moved upwardly, head356is also moved upwardly, reducing the available space in syringe24, thus, displacing any fluid in syringe24out of luer-lock port22, thereby dispensing the fluid into tube18and into bandage14. The movement of cap356is depicted by the position of cap356in hatched lines moved to an upper position indicated by reference numeral358.

A cross-sectional view of waste canister26located in cavity9on side38of housing4is shown inFIG. 6. Tube20is connected to a check-valve assembly400coupled to recess402disposed in the front wall405of canister26. Check valve400is configured to allow fluid and exudate from bandage14to enter canister26and deposit in holding space404within canister26, yet prevent any fluid already in space404from exiting through valve400. Check valve400, thus prevents fluid from escaping when tube20is disengaged from valve400. In addition, canister26can be discarded without any fluid escaping. Hydrophobic filter108is located on the rear wall407of canister26. A liquid solidifier29is provided in space404to decease the fluidity of the exudate. This is a safety measure to lessen the chance of splashing or run-off if canister26(or27) is opened or broken.

Filter108in canister26is shown having an inlet410provided in space404and an outlet412coupled to a connector416with a barrier of hydrophobic material414provided there between. As previously discussed, the hydrophobic material allows the vacuum to pass through inlet410and outlet412, yet prevents any fluid from passing. Similar to check valve400, hydrophobic filter108too prevents any fluid from escaping even when canister26is removed from housing4. Outlet412of filter108is in communication with connector416. Connector416is configured to receive and seal outlet412when canister is positioned in cavity9. Connector416is in communication with line126and ultimately with pump110.

In the illustrated embodiment, hydrophobic filter108serves as both the canister full mechanism114that shuts off the vacuum supply to the canister26when the fluid level exceeds the “full” level as indicated by reference numeral420. When the fluid level is below inlet410, as indicated by reference numeral422, fluid continues to enter space404through valve400. When the fluid level420is above inlet410, the fluid is acting as an air block. Fluid cannot pass through filter108, but because the fluid level is above inlet410, air cannot pass through either. This causes a dramatic pressure drop (vacuum increase) through line126. Vacuum pressure transducer124is coupled to line126measuring the negative pressure passing through canister26, as previously discussed. If such a dramatic pressure drop occurs, transducer124will provide such data to controller50through line128. Controller50will then know to shut the system down until the full canister is replaced with either an empty or only a partially full canister.

Another illustrative embodiment of a wound treatment apparatus is shown inFIG. 8and is indicated by reference numeral3. Apparatus3operates in a similar manner as apparatus2, with the exception of the use of two “intravenous-style” fluid bags510,512suspended above housing4to dispense the fluid. In this illustrated embodiment, posts514,516with hooks518,520extend upwardly of apparatus3from behind doors32,33. It will be appreciated that the posts514,516may be extensible to elevate the bags510,512to selected heights to provide selected pressures for irrigation. A dispensing tube18extends from each bag510,512at one end and couples to each bandage. Gravity assists in moving fluid through tubes18and into the bandages. A tube clip522is coupled to each tube18and configured to pinch and close tube allowing the caregiver to selectively prevent fluid from dispensing into bandages.

Illustrative vacuum bandage314ofFIG. 3is designed to provide a protective environment around wound300. Illustratively, such bandages last for up to 7 days without having to be replaced. Bandage314includes rinse and drain orifices (not shown) within the body of bandage314that communicate with tubes18,20, respectively. Such orifices are illustratively 0.030-inch (0.08 cm) diameter and/or 0.040-inch (0.10 cm) diameter. Vacuum evacuating sub-system66cooperates with bandage314, similar to bandage14, to draw the fluid and exudate from the surface of wound300, and collect same into waste canister26.

Examples of bandages14and15are shown in U.S. patent application Ser. No. 09/725,352, entitled VACUUM THERAPY AND CLEANSING DRESSING FOR WOUNDS, filed on Nov. 29, 2000, and assigned to the same Assignee or Affiliated Assignee as the present disclosure, and the complete disclosure of which is hereby expressly incorporated by reference. It is further contemplated that other bandages may be used with this control system, including bandages having separate irrigation and vacuum ports. Examples of such bandages are shown in U.S. patent application Ser. No. 09/369,113, entitled WOUND TREATMENT APPARATUS, filed on Aug. 5, 1999, and assigned to the same Assignee or Affiliated Assignee as the present disclosure, and the complete disclosure of which is hereby expressly incorporated by reference. The complete disclosure of U.S. patent application Ser. No. 10/144,504, entitled VACUUM THERAPY AND CLEANSING DRESSING FOR WOUNDS and filed on May 13, 2002, is hereby expressly incorporated by reference.

A side diagrammatic view of bandage14along with a portion of system6is shown inFIG. 9. (See alsoFIG. 1.) Bandage14is of an illustrative type for use with apparatus2. (Note that the bandage is not drawn to scale.) As previously discussed, bandage14is a vacuum bandage. Bandage14comprises a cover film602, illustratively a flexible cover, that seals wound300about its outer perimeter. It is contemplated, however, that film602can be made from an occlusive or semi-occlusive material that allows water vapor to permeate there through, but otherwise protects wound300from the outside environment. A bandage member604is placed adjacent wound300and is configured to irrigate wound300. In the illustrated embodiment, bandage member604comprises upper channels606and lower channels608, each provided on opposite sides610,612, respectively, of bandage member604. Each of the upper channels606is generally congruent with one of the lower channels608. Channels606and608are in communication with each other via apertures614. As shown in the illustrated embodiment, side612of bandage member604faces wound300, and side610faces a porous packing618. Packing618provided under film602to assist in providing a space616to facilitate the negative pressure. Packing618is typically a gauze material. It will be appreciated, however, that, for some wound care applications, the packing618will not be used with member604under the film602.

Illustratively, the caregiver may activate system6, by means previously described, to draw exudate from wound300through channels606,608and apertures614of bandage member604, packing618and film602, through splitter tube620connected to evacuating tube20, and deposit in canister26. The negative pressure applied to wound300created by pump110can be applied for a period of time as determined by the caregiver. After a period of drawing, the caregiver may deactivate the negative pressure. The caregiver may begin irrigating wound300by releasing fluid from syringe24, through tube18, into splitter tube620, through film602and packing618, and into bandage member604. The fluid will travel through channels606deposit in apertures614and irrigate wound300by traveling through channels608. Illustratively, the fluid will continue to irrigate wound300until space616can no longer receive any more fluid. The fluid is held in space616for a period of time as determined by the caregiver. After that period, pump110is reactivated and the fluid and exudate from wound300is evacuated from bandage14and into canister26by the manner previously described. This process is repeated as many times as necessary as determined by the caregiver.

In one embodiment, user interface10comprises a momentary switch (not shown) that selectively operates the aforementioned process. For example, the switch may be configured such that when the caregiver depresses and holds the switch, the fluid will dispense from syringe24into bandage14. When the caregiver releases the switch the fluid will stop dispensing and pump110will activate and begin drawing the fluid and exudate. It is contemplated that the switch may be configured to delay between the vacuuming and dispensing for a period of time that is definable by the caregiver. It is also contemplated that all of the aforementioned descriptions as applied to system6are applicable to system8.

The apparatus2is a portable, easy to use topical system that is intended to provide a protective/occlusive environment with features to facilitate the administering of standard wound care. The apparatus2provides for the care of two independently controlled wounds. The apparatus2provides negative pressure to the wound bed, and the caregiver can set the level of negative pressure. Illustratively, the negative pressure is variable from 25-mmHg to 175-mmHg at increments of 10-mmHg. The caregiver can choose between continuous, intermittent (profile), and no negative pressure modes. It will be appreciated that the apparatus2may be set up to provide various levels of vacuum at various times. The apparatus may be provided with the ability to pause negative pressure therapy for set durations of time. The system may be set up to provide audible alarms to remind the caregiver to reset or start a new cycle of vacuum therapy.

The apparatus2is intended to provide an occlusive wound healing environment. The apparatus2provides an active therapy unit that delivers drainage and cleansing for aggressive wound healing. It is intended, for example, for use on all pressure ulcers (Stage II through Stage IV), surgical draining wounds and leg ulcers.

In the illustrated embodiment, as shown inFIGS. 7 and 10, for example, canister26is configured to be received in cavity9disposed in side38of housing4. As shown specifically inFIG. 10, cavity9comprises two pull recesses702,704. Such recesses702,704are concave-shaped portions formed adjacent to side38and to side walls706and708. Recesses702,704are provided to allow finger clearance when the caregiver grasps grip portions39,40of canister26to remove it from, or insert it into cavity9. (See alsoFIGS. 1,11and13.) Side walls706,710and bottom and top walls708,712define cavity9such that cavity9provides a relatively conforming receptacle for the canister26. The walls706,710and708,712conform to the size and shape of the panels714,716,718,720of canister26. (SeeFIGS. 12 and 13.) Outlet412of filter108mates with connector416to produce an air-tight seal between port412and connector416. It is further contemplated that other structures or configurations of outlet412and connector416can be used to ensure system6is a closed system when canister26is properly coupled to housing4. It is still further contemplated that the aforementioned descriptions of canister26of system6apply equally to canister27of system8.

Each of top and bottom panel718,720of canister26includes a boss722,724, respectively. Each boss722,724is configured to engage a sensor such as sensor116,118, respectively, as depicted inFIG. 2. This engagement provides a signal to controller50indicating that canister26is seated properly into cavity9and the vacuum therapy treatment may begin to be administered. It is contemplated that bosses722,724can be mechanical sensors, optical, capacitive or other similar type sensors.

Side panels714,716include buttons726,728to assist the caregiver in placing canister26in the proper location within cavity9. Illustratively, buttons726,728are small protrusions, each extending from a side panel. Each button726,728is configured to be received or “snapped” into corresponding dimples730,732, respectively, disposed in walls706,710, respectively. In the illustrated embodiment, the buttons extend from the widest point of side panels714,716of canister26.

Another wound treatment apparatus802is illustrated inFIG. 14. Apparatus802is similar in structure and function to apparatus2, except as otherwise noted, so that identical reference numbers refer to similar components. Apparatus802has a pair of vacuum wound bandages14, a pair of dispensing lines18, a pair of evacuating lines20, and a main control unit803adapted for use with bandages14and lines18,20. Bandages14, lines18,20, and control unit803cooperate to provide dual vacuum therapy systems806,808.

Control unit803has a control module810, a pair of fluid sources such as syringes24coupled to dispensing lines18to provide fluid for irrigation of the wounds, and a pair of disposable waste collection canisters826coupled to evacuating lines20to collect waste material such as exudate from the wounds and fluid from syringes24, as illustrated inFIG. 14. Each dispensing line18and evacuating line20is associated with one of bandages14. Each syringe24and canister826is provided for one of systems806,808. Control module810has a housing804. Syringes24are coupled to the front of housing804and canisters826are coupled to the sides of housing804, as discussed in more detail below. Housing804has a handle812at the top thereof for hand-carrying control unit803. A user interface10is centrally mounted to housing804between syringes24and canisters826to allow a caregiver to operate systems806,808.

Systems806,808are similar to one another in structure and function. Thus, the following description of system806applies also to system808.

Housing804has a door832to partially cover syringe24, as illustrated inFIG. 14. Door832is hinged to housing804by a pair of vertically-spaced hinges814positioned along a laterally outer side815of door832for movement of door832between opened and closed positions. A rear side816of door832has a plurality of vertically-spaced, horizontal mounts or grooves817(seeFIGS. 14 and 17) for receiving a flange818of syringe24. Housing804also has a plurality of corresponding vertically-spaced, horizontal mounts or grooves820(seeFIGS. 14 and 17) for receiving flange818. During installation of syringe24, an end of a plunger70of syringe24is placed on a vertically movable plunger interface78of a syringe drive mechanism, such as the one described above in connection with apparatus2, and flange818is inserted into one of grooves820. Door832is then closed causing one of grooves817to receive flange818so that syringe24is held in place by grooves817,820. Grooves817,820support syringe24in a vertical orientation.

A door latch822is coupled to a laterally inner side824of door832, as illustrated inFIGS. 14-16. Latch822is movable relative to door832between a latched position (FIG. 16) blocking movement of door832from its closed position to its opened position and a release position (FIGS. 14-15) allowing door832to move between its closed position and its opened position. Latch822has a fastener828, such as an arm or lug, and an actuator830to pivot fastener828into and out of a slot834of housing804between the latched and release positions. Actuator830has a stem836coupled to fastener828and a handle or door knob838coupled to stem836to rotate stem836and thus fastener828between the latched and release positions when a caregiver rotates handle838. Stem836extends through an aperture of door832. Handle838is coupled to one end of stem836in front of door832and fastener828is coupled to an opposite end of stem836behind door832.

Canister826is coupled to vacuum bandage14and other components of apparatus802, as illustrated, for example, inFIG. 27. Evacuating line20is coupled to vacuum bandage14and an inlet port850of canister826to introduce waste material into an interior region or chamber866of canister826through inlet port850. A pressure sensor124is coupled to an upper pressure port852of canister826via a fluid line854(seeFIGS. 19 and 27) to sense the pressure in region866. Pressure sensor124sends a signal indicative of the sensed pressure to a controller850, which is common to both systems806,808, via an electrical line856(seeFIG. 27). A proportional valve130(seeFIGS. 19 and 27) is coupled to a lower outlet port857of canister826via a fluid line858(seeFIGS. 19 and 27). A pressure regulator134(seeFIGS. 19 and 27) is coupled to proportional valve130and a vacuum source110(seeFIGS. 19 and 27) via fluid lines860and862, respectively (seeFIG. 27). Vacuum source110provides a negative or vacuum pressure within bandage14through lines862,860,858,20and regulator134, valve130, and canister826to suction waste material into canister826.

Vacuum source110continues to operate even if, for example, blockage occurs somewhere upstream from vacuum source110. If the blockage becomes too great, vacuum source110could experience too great a load, or vacuum pressure. Pressure regulator134is provided to establish a maximum load that vacuum source110can experience. Pressure regulator134allows air to be suctioned into line862when this maximum load is reached to protect vacuum source110.

A filter864is positioned in interior region866, as shown inFIGS. 20,23, and27. Filter864covers pressure port852and outlet port857to prevent waste material from entering lines856,858and possibly damaging pressure sensor124, proportional valve130, pressure regulator134, or vacuum source110. Filter864is, for example, a 1.0 micron teflon hydrophobic filter.

Controller850, pressure sensor124, and proportional valve130cooperate to provide feedback control of the vacuum pressure provided to bandage14. Controller850operates proportional valve130via electrical line864in response to the pressure sensed by pressure sensor124to provide a desired negative pressure in interior region866. A caregiver provides the desired negative pressure to controller850through user interface10. If, for example, pressure sensor124senses a pressure in canister826that is more negative than the desired negative pressure (which includes a suitable tolerance range), controller850will cause valve130to move closer toward its fully closed position so that interior region866experiences less of the suction from vacuum source110and the pressure in canister826rises to approach the desired negative pressure. On the other hand, if pressure sensor124sense a pressure in canister826that is more positive than the desired negative pressure, controller850will cause valve130to move closer to its fully opened position so that interior region866experiences more of the suction from vacuum source110and the pressure in canister826lowers to approach the desired negative pressure.

Based on readings from pressure sensor124, controller850is able to detect when the waste material in canister826has reached a fill limit, which occurs when the waste material at least partially occludes outlet port857. As outlet port857becomes occluded due to the wetting of filter864, the negative pressure established by vacuum source110becomes blocked from interior region866. The pressure sensed by sensor124then begins to rise (i.e., become less negative) above the desired negative pressure, especially if bandage14has a vent in communication with atmosphere, and air enters interior region866through bandage14, line20, and inlet port850. In some embodiments, air enters interior region866through a bleed port (not shown) formed in housing884at an elevation higher than outlet port857instead of through the bandage vent or in addition to the bandage vent. In response to the pressure rise, controller850moves proportional valve130toward its fully opened position to try to lower the sensed pressure to the desired negative pressure. If vacuum source110is able to lower the sensed pressure to the desired negative pressure, the waste material fill limit has not been reached. If the sensed pressure remains above the desired negative pressure, controller850opens proportional valve130further and compares the sensed pressure to the desired negative pressure.

Controller850determines that the waste material in canister826has reached its fill limit when proportional valve130has been fully opened but the sensed pressure remains above the desired negative pressure. This occurs because the waste material has occluded outlet port857enough to prevent vacuum source110from being able to lower the sensed pressure to the desired negative pressure. Pressure sensor124, however, is still able to sense the pressure within interior region866through pressure port852because pressure port852is positioned at an elevation higher than outlet port857. Controller850then activates an alarm868via an electrical line870to alert a caregiver that canister826is full and needs to be changed.

Housing804contains components of control unit803, as illustrated inFIG. 19. Housing804has two receptacles840, one receptacle840on each side of housing804; and each receptacle840is configured to receive a respective canister826therein. Housing804also has a removable vertical rear wall842(seeFIG. 18). Behind rear wall842is a chamber871(seeFIG. 19). Each receptacle840extends toward a center of chamber871from a side wall of housing804. A printed circuit board (PCB)872is mounted to a rear surface of a front wall873of housing804within chamber871. Pressure sensors124and controller850are mounted to PCB872within chamber871. Valves130, pressure regulators134, vacuum sources110, and lines854,858are also positioned within chamber871.

A pair of mufflers874and a pair of muffler lines876are positioned within chamber871. Each muffler line876is coupled to one of mufflers874and one of vacuum sources110. Illustratively, each muffler874has three disk filters878in series to provide three chambers880having glass fiber material882therein to absorb sound energy. Adjacent filters878are coupled together by luer-lock mechanisms.

A battery954rests on a bottom wall956of housing804in chamber871, as illustrated inFIG. 19. A main power connection958is coupled to battery954and to PCB872. Battery954is illustratively a rechargeable nickel metal hydride battery that automatically recharges when main power connection958is coupled to an external electrical outlet (not shown) via a power cord (not shown), for example, and automatically provides electrical power to the electrical components of control unit803when battery954is charged and the power cord is disconnected from the external electrical outlet.

A mounting bracket844is coupled to an outwardly facing surface of rear wall842, as illustrated inFIG. 18, to mount control unit803to a suitable control unit support (not shown). Bracket844has an envelope846to receive the support through a lower opening848. A horizontal upper wall849is coupled to the top of envelope846. Envelope846has internal tapered walls960extending from the bottom of envelope846to upper wall849. The control unit support wedges against tapered walls960when it is inserted within envelope846.

Canister826has a housing884providing interior region866to collect waste material therein and a latch886to couple housing884to housing804of control module810, as illustrated in FIGS.14and20-23. Canister826further has a cylindrical sleeve888carried by housing884and extending horizontally through interior region866. Ends of sleeve888are appended to respective outer and inner vertical walls891,899of housing884. Walls891,899are each formed with an aperture889that communicates with an interior region of sleeve888. Latch886extends through apertures889and sleeve888and engages a vertical back wall890of receptacle840, as described in more detail below.

Outer vertical wall891of housing884and sleeve888cooperate to provide a monolithic unit that is coupled, such as by RF or ultrasonic welding or adhesive, to a main portion892of housing884(seeFIGS. 20-23). An outer end portion893of sleeve888is formed monolithically with a recessed portion894of wall891. Wall891has a peripheral flange895that is coupled to a corresponding peripheral flange896of main portion892. An inner end portion897of sleeve888is coupled to a recessed portion898of inner vertical wall899of main portion892. Outer wall891has inlet port850formed integrally therewith or appended thereto. Inner wall899has upper pressure port852and lower outlet port857formed integrally therewith or appended thereto.

Latch886has a fastener910to couple to back wall890and an actuator912to rotate fastener910, as illustrated inFIGS. 21-23. Fastener910has a pair of bayonet-style canted lugs914coupled to an inner end portion916of a shaft918of actuator912. Lugs914are diametrically opposed to one another and extend somewhat circumferentially and axially on shaft918.

Actuator912further has a handle920coupled to an outer end portion922of shaft918, as illustrated inFIGS. 14,20,22and23. Handle has a disk924coupled to end portion922and a flange926coupled to and extending radially outwardly from disk924. Disk924and a portion of flange926are positioned within recessed portion894. Recessed portion894has a pair of stop edges952(seeFIG. 20) positioned to restrict rotation of flange926to about 90 degrees.

A retainer928(seeFIGS. 21-23) is mounted to shaft918between handle920and fastener910. Illustrative retainer928has a clip930, such as an e-clip, and a clip mount932. Clip mount932takes the form of a disk mounted to shaft918and has a circumferential groove934configured to receive clip930. Disk932has a diameter smaller than the inner diameter of sleeve888to facilitate insertion of fastener910through sleeve888during assembly of canister826. After insertion of fastener910through sleeve888, clip930is positioned in groove934to engage recessed portion898to prevent latch886from inadvertently withdrawing from sleeve888. An inner portion of disk932is received in one of apertures889and disk924is received in a space defined by an arcuate edge950(seeFIGS. 20,22, and23) of wall891to support latch886for rotation relative to housing884.

After latch886is coupled to housing884, canister826is ready to be installed within receptacle840. A caregiver places canister826within receptacle840(seeFIG. 22) and inserts leading edges of lugs914through an aperture938of back wall890shaped to receive lugs914(seeFIG. 24). The caregiver then rotates handle920, and thus lugs914, by hand, for example, approximately 90 degrees in a direction936(seeFIG. 25). This rotation causes lugs914to cam against inwardly facing thrust surfaces940of back wall890(seeFIG. 26) so that canister826moves toward back wall890and pressure port852and outlet port857are drawn into corresponding upper904and lower906sockets, respectively, of back wall890(seeFIGS. 22-23). Each port852,857has a nipple900that is inserted into the respective socket904,906and an O-ring902surrounding nipple900. When lugs914are rotated against surfaces940, nipples900are drawn into sockets904,906so that O-rings902sealingly engage tapered walls908of sockets904,906. Sockets904,906provide portions of lines854,858, respectively. A dome cover942is positioned on an inner surface of back wall890and over lugs914and inner end portion916of shaft918.

Canister826is removed from receptacle840and disposed of when canister826is fall of waste material. To do so, a caregiver removes line20from inlet port850, places a cap (not shown) on port850to prevent spillage, and rotates handle920in a reverse direction944to release lugs914from back wall890. The caregiver then pulls on side grips946(seeFIG. 14) of canister826to remove canister826from receptacle840. As canister826is removed from receptacle840, lugs914pass back through aperture938and pressure port852and outlet port857are withdrawn from upper and lower sockets904,906. Canister826can then be discarded and a new, empty canister826can be installed within receptacle840.

By having latch886included as part of canister826, which is disposed of after being filled with waste material, latch886is not used over and over again, thereby preventing lugs914from wearing down and degrading the sealed connection between ports852,857and sockets904,906.

Although the foregoing apparatus has been described, one skilled in the art can easily ascertain the essential characteristics of the apparatus, and various changes and modifications may be made to adapt the various uses and characteristics without departing from the spirit and scope of this disclosure, as described by the claims which follow.