WO2008130689A1 - Device and method for treating chronic wounds - Google Patents

Abstract

An extracorporeal device for the treatment of a body wound includes a treatment head adapated to be secured to a patient's body in an area of the wound. The treatment head includes a chamber with at least one pressure input to receive and apply to the wound a sequence of hyperbaric and hypobaric pressures, and an irrigating mechanism to receive an irrigating fluid and apply the irrigating fluid to the wound. The treatment head also includes a drainage output. A control system is arranged to apply the sequence of hyperbaric and hypobaric pressures to the at least one input of the treatment head, to regulate the application of the irrigating flud input to the irrigating mechanism and to control the drainage output to drain irrigating fluid and wound debris from the treatment head.

Description

DEVICE AND METHOD FOR TREATING CHRONIC WOUNDS

FIELD OF THE INVENTION

[001] The present invention generally relates to the field of medical treatment devices, more specifically to the field of a device and method for promoting healing and possibly preventing necrosis of human chronic wounds.

BACKGROUND OF THE INVENTION

[002] Chronic wounds are a major health challenge especially patients with venous insufficiency, diabetes and arterial disease. Such wound can lead to limb amputation. While underlying causes of chronic wounds vary from patient to patient, they tend to occur in patients with conditions associated with poor blood circulation such as diabetes, or for other reasons related to a patient's condition.

[003] Traditional standard therapy includes gentle wound wash and local antibiotic treatment with or without bandages. At the initial stages a more vigorous wash or surgical debridment may be performed to wash all debris, when the healing process takes place (granulation tissue) a more gentle wash is to be performed.

[004] Other methods utilize high oxygen in a high pressure treatment applied via a hyperbaric chamber that includes inserting the patient or a patient's limb into a pressurized oxygen chamber. Oxygen applied directly to the base of an open wound at pressure slightly above atmospheric e.g. 1.03 atmospheres (22 mm Hg or 0.4 psi.) shows healing effects. A disposable hyperbaric oxygen dressing adapted to treatment of body sores on the skin of the patient may also be employed. A recently introduced technique of Topical Negative Pressure therapy (TNP) can be also used. TNP applies a controlled negative pressure to the surface of a wound and has potential advantages for wound treatment and management.

[005] U.S. Patent No. 4,474,571 discloses a portable topical hyperbaric chamber assembly for covering a surface portion of a patient's body for treatment with pressurized oxygen. The assembly comprises a circular base with a plurality of support and positioning rods extending downwardly from the peripheral portion of the base. A resilient circular gasket, open at its top and bottom, is fitted into the circular area defined by the rods depending from the base so that its top engages the bottom surface of the base for sealing purposes and the bottom engages the skin of the patient for sealing. This assembly can not adjust nor control the flow of the pressurized oxygen.

[006] U.S. Patent No. 4,969,881 discloses disposable hyperbaric oxygen dressing adapted to treatment of a body sore on the skin of a patient. A thin flexible oxygen impermeable plastic film has upper and lower surfaces. A rigid flat open cell plastic member is oxygen permeable. The member has a central opening, a flat upper surface and a flat lower surface. The upper member surface is sealed to the lower surface of the film, the film-member seal being oxygen impermeable. A first self-adhesive layer is secured to the lower surface of the member. A second layer of release paper is removably secured to the first layer. The first layer, after the second layer has been removed, is adapted to be removably sealed in an oxygen impermeable manner to the skin of the patient with the sore being disposed in the opening. An oxygen feed tube extends through the member into the central opening. The tube is oxygen impermeable and sealed to the member. The tube-member seal is also oxygen impermeable. This assembly has the disadvantage of not stimulating the wound, with the result that blood is not stimulated to flow into the wound or sore.

[007] U.S. Patent No. 5,478,310 discloses a disposable hyperbaric oxygen chamber including a polyethylene bag which is substantially the length of a patient's leg. The bag is placed around the entire leg and thigh with the excess bag at the top thereof being folded over the thigh in order to fit snugly thereon without compression. This configuration is intended to stimulate growth of new blood vessels, but does not use the pressurized oxygen for stimulating the wound or stimulate blood flow into the wound.

[008] U.S. Patent No. 6,135,116 discloses a method and apparatus for providing concurrent applications of intermittent pneumatic compression therapy and vacuum assisted closure therapy. The apparatus comprises a wound dressing for introduction of a negative pressure into a wound on a patient's foot and a foot wrap for application of positive, compressive forces to substantially all of the patients foot. A suction pump having an associated vacuum sensor and first feedback mechanism supplies negative pressure to the wound dressing. A source of pressurized gas having an associated pressure transducer and second feedback mechanism supplies positive force to the foot wrap. At least one control system is operably associated with the suction pump. A source of pressurized gas, capable of being vented, is provided for controlling the negative and positive applications of pressure to the patient's foot. SUMMARY OF THE INVENTION

[009] It is an object of the present invention to provide a method and apparatus to automatically induce and reduce pressure on a body wound as well as automatically wash the wound with an irrigating fluid, such as saline and/or gentle soap and/or antibacterial, and/or any biological, chemical or a therapeutically effective agent or agents and/or dry cleaning air spray.

[0010] According to an embodiment of the invention, there is provided an extracorporeal device for the treatment of body wounds and tubular limbs adapted to emit a predetermined sequence of hyperbaric and/or hypobaric pressure thus facilitating blood flow along the limb while facilitating measurable oxygen flow, and irrigating the wound to remove wound debris.

[0011] According to a further embodiment of the invention there is provided an extracorporeal device for the treatment of a body wound, comprising: a treatment head adapted to be secured to a patient's body in an area of the wound, the treatment head including a chamber with at least one pressure input to receive and apply to the wound a sequence of hyperbaric and hypobaric pressures, the treatment head further including an irrigating mechanism to receive an irrigating fluid and apply the irrigating fluid to the wound; the treatment head further including a drainage output; and a control system arranged to apply the sequence of hyperbaric and hypobaric pressures to the at least one input of the treatment head, to regulate the application of the irrigating fluid input to the irrigating mechanism of the treatment head and to control the drainage output to drain irrigating fluid and wound debris from the treatment head.

[0012] According to yet another embodiment of the of the invention there is provided an extracorporeal device for the treatment of a body wound, comprising: a treatment head adapted to be secured to a patient's body in an area of the wound; a first pump having an input for being coupled to a source of oxygen enriched air and an output coupled to the treatment head; a second pump arranged to be coupled to a source of irrigation fluid and an output coupled to the treatment head; and a controller arranged to control the first pump to produce a pressure sequence applied to the treatment head, the pressure sequence including alternating hyperbaric air pressure enriched with oxygen and hypobaric air pressure, and to control the output of the second pump to selectively apply irrigation fluid to the treatment head to wash the wound. [0013] According to another aspect of the invention there is provided a method of treating a body wound, which in one embodiment comprises: securing a treatment head to an area of the wound so that the treatment head is sealed around the area of the wound; washing the wound with a fluid through the treatment head; and applying an alternating pressure sequence on the wound through the treatment head, the pressure sequence including periods of hyperbaric pressure enriched with oxygen alternating with periods of hypobaric pressure.

[0014] Other features, advantages and benefits of the invention will become apparent from the following detailed description of the invention.

BRIEF DESCRIPTION OF THE FIGURES

[0015] In order to understand the invention and to see how it may be implemented in practice, a plurality of embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

[0016] Fig. 1 schematically shows a block diagram of one embodiment of the device according to the present invention;

[0017] Fig. 2 illustrates a schematic of an embodiment implementing the principles of the invention.

[0018] Fig. 3 shows a flow diagram of a method according an embodiment of the invention.

[0019] Fig. 4A shows a side view of an embodiment A and cross-sections of embodiments B and C of treatment heads which can be used for implementing the invention.

[0020] Fig. 4B shows a cross-section of another embodiment of a treatment head according to the invention.

[0021] Fig. 5 is a cross section of another embodiment of a treatment head that can be used to implement the invention.

DETAILED DESCRIPTION [0022] In the detailed description below, the following definitions are applicable: [0023] The term "wound" refers hereinafter to any hit or damage of tissue caused by either an internal or external factor, and includes an ulcer, cut, bruise, incision, rift, rapture, burn or the like.

[0024] The term "necrosis" refers to accidental death of cells and living tissue.

[0025] The term 'pressure' refers hereinafter to materials forced or a flown or pushed towards or into or adjacent to an object. The term also refers to a flow of fluid such as air and/or oxygen and/or a saline composition which hits at least a portion of an object in such way that may cause stimulation or movement of at least a portion of that object. In some embodiments, the object is tissues of a wounded organ or limb which, cause stimulation and even simulates blood flowing in that limb. The pressure can either be perpendicular to the limb, or have a direction of 20°-90° from the surface of the limb or organ.

[0026] The term 'pressure sequence' refers hereinafter to more than one act of inducing pressure for a predetermined period of time. Each object to which the pressure sequence is applied has its own parameters selected, among other things, from duration, amplitude, frequency, temperature, time elapsing previous and/or after the pressure induction or any combination thereof. For example, for example one object may require a sequence of 2.5 seconds of 1.2 PSI induced on a limb, followed 5 seconds of a lower pressure.

[0027] The method of the invention may be carried out by an apparatus that automatically performs the following steps, not necessarily in the order listed:

[0028] 1. washing the wound with an irrigating fluid, such as saline, with or without gentle soap, and/or antibacterial, and/or any biological, chemical or a therapeutically effective agent or agents and/or dry cleaning air spray;

[0029] 2. applying to the wound a high pressure, known as hyperbaric pressure, above the ambient air pressure enriched with oxygen; and

[0030] 3. applying to the wound an alternating low pressure, known as vacuum or hypobaric pressure, that is lower than ambient air pressure.

[0031] The prolonged nature of wound treatment lends itself to the possibility of carrying out the steps of the invention by a portable device, which may be produced for home use at relatively affordable price.

[0032] Referring to Fig. 1, there is shown an embodiment of the invention in which a main chamber 1 is secured to a limb 5 of a body. A foam or air cushion (not shown) is located in the opening of the main chamber 1 and seals the area surrounding a wound on the limb 5. Chamber 1 is coupled to a source of fluid, for example saline or other irrigating fluid as mentioned above, under the control of a pump 3 to pump the fluid into chamber 1 to wash the wound under the automatic control of a computing device or controller 8. A pump 4 is then regulated by the computing device 8 to create a hyperbaric pressure in chamber 1, enriched with oxygen (O₂) from a pressurized source 2 of oxygen followed by a period of hypobaric pressure. Computing device 8 regulates air pressure in chamber 1 according to a predetermined pressure sequence of hyperbaric and hypobaric pressures as determined by a physician taking into account the particulars of the wound being treated.

[0033] The hyperbaric pressure may be held for a period of time, for example 0.1-30 seconds, and more preferably 2-10 seconds, after which oxygen flow from source 2 is stopped and the fluid is sucked by pump 3, and pump 4 is controlled to create hypobaric or low pressure in chamber 1. Low pressure is maintained in the main chamber 1 for 1-600 seconds, more preferably 10-15 seconds. After a predetermined period of time, the cycle starts again, under the automatic control of the controller 8.

[0034] The treatment head may be configured in dependence of a particular wound that is treated. For example, for a wound in the sole of the foot, the main chamber 1 may be located in the bottom or top of the treatment head that is provided with an appropriately positioned opening to fit around the wound. Fig. 4A shows three different embodiments for treatment heads. Embodiment A is for the thigh; embodiment B is for toes; and embodiment C is for the heal and/or ankle. Fig. 4B shows another embodiment D for the treatment head that may be used for the full foot. Figure 5 shows a treatment head 50 disposed for treating a wound 53 on an extremity of a person's body, such as a leg 51. The treatment head 50 is sealed to around wound 53 by a soft material 55, such as a foam or suitable elastomeric material. Treatment head 50 includes a main chamber 1 'provided with a spray head 57 that may be structured as a shower or sprinkler head to produce an irrigating pulsating spray to wash wound 53.

[0035] Reverting to Fig. 1, the oxygen source 2 may be a commercially available, high- pressure oxygen tank, or any other device that could be used for oxygen. Main chamber 1 may include provision for vigorous flow from the saline pump 3 to create a whirlpool like effect or gentle flow of irrigating fluid. The saline in the saline pump is disposable and should be replaced with each treatment. [0036] The wash or irrigating fluid may serve as a vehicle for delivery of ingredients aimed to heal or disinfect the wound. Local antiseptic, antibiotic, growth factors cytokines or the like may be added to improve or accelerate the healing process or improve bacterial/fungal/ viral control.

[0037] Referring now to Fig. 2, there is shown an embodiment in greater detail for implementing the principles of the invention. The illustrated system includes provisions to wash a wound, apply a vacuum and remove wound debris following the wash and to stimulate a strong blood flow by applying hypobaric (lower than atmospheric) pressure, followed by an increase of oxygen at a slightly higher than atmospheric pressure, i.e. hyperbaric pressure, around the wound. All the above phases, and not necessarily in the order described, are exerted on the wound via a treatment head that is configured as discussed above, in dependence on the location and wound size.

[0038] Fig. 2 shows a treatment head 10 sealed to a wound as discussed above and arranged with three continuously working pumps Pl, P2 and P3, eight controllable valves V-I to V-8 coupled to a controller 20 to deliver washing fluid to the wound and remove wound debris, while producing a pressure sequence in the treatment head 10. The pressure sequence comprises hyperbaric pressure enriched with oxygen alternating with hypobaric pressure. Pump Pl is employed to deliver the hyperbaric pressure enriched with oxygen from an oxygen tank 22 to the treatment head 10 via valves V-I and V-4, and to deliver the hypobaric pressure by opening valves V-3, V-5 and V-6. Pump P2 communicates with irrigation fluid in an irrigation fluid container 24, which may be heated by a heater 26, to deliver the heated irrigation fluid to the treatment head 10 via a valve V-2. The heating 26 in irrigation fluid container 24 assures the saline is at body temperature of 37⁰C. The heating system may have a temperature sensing device (not shown) connected to the controller 20 to sense and assure the proper temperature.

[0039] During periods that irrigation fluid is not delivered to the treatment head 10, valve V-2 is closed and valve V- 7 is opened to return the irrigation fluid back to the container 24. Pump P3 is employed to drain the irrigation fluid and wound waste from the treatment head 10 via a three way valve V-8 to a debris collection bottle 40 via a three way valve V-8 that has one input couple to air. The collection bottle 40 may have a level sensor (not shown) connected to the controller 20 to alarm the operator if the fluid level is too high so that the bottle can be removed and/or replaced. [0040] The pumps Pl to P3 are connected by a set of tubing in a known manner for delivery of the irrigation fluid, removal of the waste from the treatment head and delivery of the pressure sequence to the treatment head 10. A two-pump design is also conceivable whereby pump Pl can remove the debris and create the vacuum, if an air/liquid pump is used for pump Pl. Depending on the design, a smaller number of valves can achieve the same effect. The pumps may be of the rotary type. Alternatively, piston pumps may be used.

[0041] In operation, the treatment head 10 is secured to a patient's body. The controller 20 starts the pumps and goes through a fast system check, during which, among other things, the treatment head 10 is checked for leaks by a pressure sensor 28 between pump Pl and valve V-I and/or a vacuum sensor 30 between valves V-3 and V-5.

[0042] Oxygen may be delivered to the treatment head 10, increasing the pressure from about 1.0 PSI to about 3 PSI and preferably up to a value of about 1.4 to 1.6 PSI. The flow is stopped and the controller 20 checks the reduction in pressure via the pressure manometer 28. Then a leakage test is performed for the low pressure by applying the vacuum to the treatment head and sensing the vacuum with vacuum sensor 30. An exemplary sequence of valve openings and closings to achieve the described operations is set forth in Table 1 below.

[0043] The controller 20 operates the sequence of valve openings and closings, according to the required length of time for each phase in the treatment. The controller 20 controls the illustrated eight valves, but can be programmed to control a smaller number of valves in a different design, to achieve a similar result as the sequence in Table 1. Controller 20 is used to measure and control the pressure and the vacuum. Controller 20 may have built in safety algorithms that will assure the pressure will not exceed, for example, 1.4 PSI within the range of 1.01 to 3 PSI, and that the vacuum will not be below, for example, -.0.7 PSI within the range of -0.01 to -3 PSI. In case an excessively high pressure is detected by pressure sensor 28 during a hyperbaric cycle, valve V-I will close and valves V-3 and V-5 will open to reduce the pressure. Alternatively, valve V-I may remain open, but valve V-6 may open to relieve the pressure. If the vacuum is greater then -0.7 PSI, valve V-3 will close, valve V-5 will open to air, valve V-I will open and Valve V-6 will open to Air. Alternatively, valve V-8 may open to air to relieve the vacuum. [0044] The irrigation fluid container 24 stores the irrigation fluid for the treatment that may be saline, but may also include medication as needed and decided by a treating physician's prescription.

[0045] The valves used may be solenoid operated valves and the commands to open and close the valves are controlled by the controller 20. In the illustrated embodiment, valves V- 5 and V-8 are three way valves that can let air into the tubing system according to sequence in the Table 1 below; the remaining valves are one way.

Table 1. O- Open, C- Closed, A- Open to Air

Valve #

[0046] Valves 5 and 8 are three way valves; when they are open to the air they close the other opening. Further, although valve V-6 is a one-way valve, it too is coupled to air via a filter 29. It should be apparent that because the pumps Pl to P3 run continuously, it is necessary that valves V-5, V-6 and V-8 be open to air during various ones of the listed actions. For example, valve V-8 must be open to air during all portions of the cycle except during the wash and suction action, during which the pump is coupled to the treatment head via valve V-8 to draw off irrigation fluid and wound debris. And, both valve V-5 and V-6 must be open to air during the wash and suction action so as not to strain continuously running pump P3, which creates neither high nor low pressure in the treatment head during such action.

[0047] Fig. 3 schematically illustrates the steps taken in one embodiment of the method according to the present invention. The first step 11 is washing the wound using a combination of saline and soap. In the next step 12, the high pressure is activated. At step 13 the high pressure is alternated with low pressure on the wound.

[0048] The low pressure may be in the range -O.Olto -3 PSI, and is preferably -0.1 to -1.0 PSI; the high pressure may be in the range 1.01-3.0 PSI, and is preferably between 1.05- 2.0 PSI.

[0049] The controller 20 may have an operator interface including one or more buttons, or a touch screen. In another embodiment, the device may be connected to a displays or the display may be incorporated in the device. The display may show data on the time elapsed since the start of pressure induction, the level of pressure, or any other parameter. The display may be digital, and may include one or more graphs. The device can also be attached to at least one sensor to provide an alert in case the level of any parameter exceeds a predetermined threshold.

[0050] The invention has been described in detail with respect to various embodiments, and it will now be apparent from the foregoing to those skilled in the art, that changes and modifications may be made without departing from the invention in its broader aspects, and the invention, therefore, as defined in the appended claims, is intended to cover all such changes and modifications that fall within the true spirit of the invention.

Claims

WHAT IS CLAIMED IS:

1. An extracorporeal device for the treatment of a body wound, comprising: a treatment head adapted to be secured to a patient's body in an area of the wound, the treatment head including a chamber with at least one pressure input to receive and apply to the wound a sequence of hyperbaric and hypobaric pressures, the treatment head further including an irrigating mechanism to receive an irrigating fluid and apply the irrigating fluid to the wound; the treatment head further including a drainage output; and a control system arranged to apply the sequence of hyperbaric and hypobaric pressures to the at least one input of the treatment head, to regulate the application of the irrigating fluid input to the irrigating mechanism of the treatment head and to control the drainage output to drain irrigating fluid and wound debris from the treatment head.

2. The device according to claim 1, wherein the control system includes a pump arrangement having an input for being coupled to a source of pressurized oxygen, a controllable valve arrangement coupling the pump arrangement to the treatment head, and a controller to control the valve arrangement to apply the pressure sequence to the treatment head, the pressure sequence including hyperbaric pressure enriched with oxygen from the source of pressurized oxygen and hypobaric pressure.

3. The device according to claim 2, wherein the pump arrangement has a further input for being coupled to the a source of irrigating fluid and the controller controls the controllable valve arrangement to apply the irrigating fluid to the irrigating mechanism in the treatment head.

4. The device according to claim 3, wherein the pump arrangement is coupled to the drainage output of the treatment head, and the controller controls the valve arrangement for draining the irrigating fluid and wound debris from the treatment head.

5. The device according to claim 3, wherein the pump arrangement includes a first pump arranged to generate the hypobaric pressure and the hyperbaric pressure enriched with oxygen applied to the treatment head, and a second pump to pump irrigating fluid to the irrigating mechanism in the treatment head.

6. The device according to claim 1, and further including a container to hold the irrigating fluid, the container including a heater to heat irrigating fluid in the container to approximately 37° C, the pump arrangement and valve arrangement being operative to deliver heated irrigating fluid to the treatment head under the control of the controller.

7. The device according to claim 4, wherein the controller is programmable to control actions including at least: the pressure and duration of the hyperbaric pressure enriched with oxygen applied to the treatment head, the pressure and duration of the hypobaric pressure applied to the treatment head, a quantity and duration of the irrigating fluid applied to the pressure head, the duration of the draining of the irrigating fluid and wound debris from the pressure head, and the sequencing of the foregoing actions.

8. A method of treating a body wound, comprising: securing a treatment head to an area of the wound so that the treatment head is sealed around the area of the wound; washing the wound with an irrigating fluid through the treatment head; and applying a pressure sequence on the wound through the treatment head, the pressure sequence including periods of hyperbaric pressure enriched with oxygen and periods of hypobaric pressure.

9. The method according to claim 8, and further including draining the irrigating fluid and wound debris from the treatment head.

10. The method of claim 8, wherein the applying of hypobaric pressure comprises applying substantially continuous hypobaric pressure.

1 1. The method of claim 8, wherein the applying of hypobaric pressure comprises applying intermittent hypobaric pressure.

12. The method of claim 8, and further including determining in advance according to a patient's condition the amount of pressure and the duration of the periods of hyperbaric and hypobaric pressure and programming a controller to automatically apply the pressure sequence.

13. The method of claim 8, wherein the washing and applying steps are manually controllable.

14. The method of claim 8, wherein the washing step includes applying an irrigating fluid that contains at least one of saline, soap, antiseptic, antibacterial or other therapeutically effective agent.

15. An extracorporeal device for the treatment of body wounds and tubular limbs adapted to emit a predetermined sequence of hyperbaric and/or hypobaric pressure thus facilitating blood flow along the limb while facilitating measurable oxygen flow, and irrigating the wound to remove wound debris.

16. An extracorporeal device for the treatment of a body wound, comprising: a treatment head adapted to be secured to a patient's body in an area of the wound; a first pump having an input for being coupled to a source of oxygen enriched air and an output coupled to the treatment head; a second pump arranged to be coupled to a source of irrigation fluid and an output coupled to the treatment head; and a controller arranged to control the first pump to produce a pressure sequence applied to the treatment head, the pressure sequence including alternating hyperbaric air pressure enriched with oxygen and hypobaric air pressure, and to control the output of the second pump to selectively apply irrigation fluid to the treatment head to wash the wound.