CA2652466A1

CA2652466A1 - Process and device for application of active substances to a wound surface

Info

Publication number: CA2652466A1
Application number: CA002652466A
Authority: CA
Inventors: Wilhelm Fleischmann
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-07-17
Filing date: 2007-07-17
Publication date: 2008-01-24
Also published as: JP2010501203A; EP2040656A2; AU2007274731A1; WO2008010094A3; WO2008010094A2; US7938790B2; US7759538B2; US20070021698A1; US20100249732A1; ZA200900521B

Abstract

For application of active substances to a wound surface a porous padding (12) is provided upon the wound (10), which is sealingly covered over with a foil (14). A fluid active substance is introduced into the padding (12) via a supply line (22) and is then suctioned out of the padding (12) via a removal line (26). Closure mechanisms (32, 34) control the introduction of the active substance and the suctioning off of the active substance in the manner, that the active substance after being introduced remains for a predetermined dwell time in the padding (12), before it is suctioned off. After the suctioning off the vacuum in the padding (12) is maintained for a certain time period, before renewed introduction of the active substance. The opening of the closure mechanisms (32, 34) are temporally controlled to occur slowly.

Description

Title: Process and aevice for Application of Autiv+a Substances to a Wound Surface acscrintiorti of InvCrtticn Technical Field The irtventinn concerns aprocess and a device for applicaticn of active aubstances to a wound surface.
'10 Background Art For the medicinal local treatment of wounds there have until now been en7pioyed Salves, solutions or solid medicament camiers. such as resorbable ooIlagen, antibiotic soaked bone cement or impregnated wound coverings. .In particular in deep wounds there exists the diificulty, that salves are not employable, and $olutians are soaked up by bandage materials and frequently do not come into sufficient contact with the inner wound surface, in order that its therapeutic. effect unfolds. In the implantation of faraign body madicinal carriers, such as bone cement or rasnrbable materials, there occurs a ios$ of o'ffec:riveness by dissipation or dilution with wound secretion. Besides this only a faw medicines are available, which exhibit a Eocal sustained effect over a Isang period of time. In the tissue, under certain conditions, a damaging or injurious reaction to the foreign body can rasult. Decomposable medicine carriers can, in their dauumpositiQn, lead to undesirable side effects.
Fr4m DE 40 12 232 Al there is disclosed a RedQn-bandaga or, as the case may be, inatallation-bandage for the treatment of superficial and deep problerttiatic wounds, in particular with infections, in which the wound is covered by a thin semi-permeable fcil. A supply line and a removal line are provided iun.der the foil in tha wc}und area. Active substance$ can be applied to the wound surface under the foil via the supply lirte by means of a syringa.

After the desired application perind the active substances can, in certain uase$
together with the wound secretion, be suctioned out via the mrnovsl line by means of a vacuum sQuroa. The supply line is providod with a self-acting ulosing safety valve, which is opened by the intresduceci syringe for introduction of the fluid active r,ubstanues. Likewise there is provided on the removal line a closure or blockage mechanism, which closes off the output side during the application period of the active substan;.e.

In this known installation bandage the active substances are applied ciireotly upon the wound surface and suctianed off trom the wound surfam. The active substance can thus only be applied in imprecise doses and in particular in the case of large wound surface areas an even effect upon the entire surface is difficult to achieve. A long time continuous effect can net realized.

1.5 From U.S. 4,3$2,441 it is known, for treatment of wound surfaces, to lay a padding or dressing made of a porous material upon the wound surface and to sealingly cover thi$. The active substance to be applied is continuously oo nveyed through the padding, for which -a fluid supply oonnection and a tluid removal connection communicate with the padding. The capillary effect of the porous padding optimizes the distribution of the $upplied active substance over the entirety of the surface of the padding in contact with the wound surface.

The porous padding is substantially fonn-stable and also the sealing cover is preferably furm-stable. The fluid active substance is conveyed through the padding in a continuous stream, whereby a stream distribution results, in Which the fluid active substance flows essentially along the area between the fluid supply connection and fluid rernoval eenrter-tion, while the edge areas of the padding are barely perfused. Thus, ir, these adge area$ the ackive suhstances are only exchanged in small amounts and, further, in the edge areas accumulations of wound secretion are only insufficiently rernnved.

Beyond this the relatively form stable padding dc,es not lie in all areas equally against the wound surface, so that also hereby an even application of the active substance and. an even removal of the wmund secretion is compromised. AContir,uc-us effect is not envisioned or intended.
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Disclosure of Invention The invention is concerned with the task, of providing a process and device fQr fapplication of active substances to a wound surface, which guarantees a high effectiveness of the applied at;tive substance over the entire wound surFaca, makes possibla,an optimal dosing of the active suf3stanm, and enhances the wound healing process.

The basic idea of the invention is comprised therein. to lay a padding or bandage of an elastic camprasaibla porous material upon the wound surface and to cover the wound surface and the padding with a scaling layer or foil, which closes off the wound and the padding against the atmosphore. The supply line and the removal line are respectively provided with cc7ntrollable closure devices which at the appmpriate time are so controlled, that the introduction of the active substance and the auctioning off of the active substance and in cÃ:rtain cases the wound sacreticrn are separated from each other in time. Between the time interval in which the closure device of the supply line is opened and the activa substance is supplied, and the paint in time, in which the closure device of the removal line is opened in order to suctic-n out the autive substance and the wound secretion, there is programmed or provided an treatment dwell time interval, in which both closure devices are closed and the active.substance Statically has an effect upon the wound surface. After the suctioning off of the active substance and the wound secr+etion there is, besides this, a time interval programmed in which the closure mechanism of the supply side remains closed and a vacuum is maintained in the area of the wound. For this the closure mechanism of the sucti4ning side can remain opan, so that via the vacuum source a constant vacuum is maintainad in area of the wound and the wound secretion is suctioned off. The closure mechanism of the removal side can also be closed, so that the vacuum produced initially Can be maintained. It is also possible in this phase that the olosure mechanism of the removal side is temporarily controlled to be Qpert, in order that the vacuum is reestablished, in case this drops below a pre-determined value.

The dwell time intervaf, in which the padding is impregnated or soaked with the active substance and the active substance is applied with a continuous effect upon the wound surface, is selected corresprirtding to the nature of the active substar'tr:e, its dosing and the indications given by the condition of the wound surface. In the vacuum time interval, in which na aotive substance is applied and enly the wound se+cretiorr is auctinnad off, the bodily immunological repair and immune processes of the tissue can proceed unhindered, sn that the wound healing is optimized. Thus, active treatment phases and healing phases alternate temporally one after the another. In the treatment phase the wound systam is actively engaged by means of the activ,c substances, such as for example antibiatics or antiseptin$, in order to fight or combat infer-tions and the like. Since such active substances as a rule besides the desired main effect also have undesired side effects, the aetive substencAs; are suctionod off subsequent to the active treatment phase and with them the wound secretion, which contains the decomposition products produced during the active treatment phase with their, in certain cases, taxio agents. In the subsequent vacuum time interval the bQdVs Qwn immunological healing process can proGeed optimally, without being compromised by the undesired side eifects of the active substances and the decomposition products produced during the combating of the wound infection.

Preferably the closure mechanisms of the supply line and removal line are temporally so controlled, that the intrQduutian of the active substance begins slowly and with a minimal rrolurnetric stream. Thereby it is prevented, that wound pain is caused or increased by a too-sudden artd rapid intrcductinn of active substance. Likewise, the opening of the closure mechanism of the removal line is temporally controlled in such a manner, that the vacuum increases only graduafly. A too rapid, sudden vacuum leads likewise to 5 substantially wound pain.

The padding provided upon the wound surface is cortyprisad of an elastic compressible porous material, preferably a PVA-sponge (polyvinyl alcohol-sponge), wherein a flexible foil is employed for covering. If a vacuum is praduced in the foil-covered wound area, then the foil lies tightly upon the wound and compresses the padding. Thereby the padding lies over its entire surface equally tightly on the wound surface. This improves the suctioning off of the wound secretion during the vacuum time interval. Should the inlet opening be opened for introduction of the active substance, then the porous padding suctions the active substance in, whereby it expands on the basis of its efastic resilience. Therebyy it is achieved, that the padding evenly absorbs the active substance in the manner of a sponge_ The active substance is evenly distributed over the entire eurface of the padding and acts upon the entire wound surface in an even manner. This is improved thereby, that the padding in the vacuum phase liea tightly against the wound surface. The even distribution of the active substance over the entire surrace is not impeded or hindered during the active treatment phase, since .after the end of the introduction, during the active treatment time interval, a static condition exists, in which the intraductian and removal lines are closed.
Since the wound treatment can extend over a longer period of time, fbr example over several days, it can occur, that in particular during a I+cngof vacuum phase the pores of the padding slightly adhere or become glued together. Such adhesion increases the resistance against the introduction of active substance. Thereby the introduction of the active substance by gravity can be impeded. In such a case it is purposeful, at the beginning of fihe introduction of the active auh$tanue, to first rinse the porous padding clean.
For this, at the beginning of the. introdt,utiQn of the active substance, first a amall volume of a fluid active subatance is introduced under pressure, in order to rinse through the pores of the padding and to dissolve adhered areas. The intr,nduc#ion under pressure can advantageausly be achieved by a syringe, which is connected to the inlet. Via piston pressure of the syringe a first dose of active substance can be employed for rinsing under pressure, befnre the intraduetiQn of the active substanGe. occurs by gravity. In certain cases it is alsr, possible, that the amoiint of the fluid active substance necessary for the entire intraductian period is supplied by rnearis of the syringe.

According to a first aspect of the invention we provide a device for application of substances to tissue, said device comprising:
a porous padding adapted f+er applicatian upon a treatment surface of the tissue, a sealing cover for covering the treatment surface and the padding and sealing the treatment surPaee from the atmasphere, at least one supply line introduced into the padding for supplying a fluid substance to the treatment surface, and at least one removal line intr+adured into the padding for removing the fluid substance and tissue fluids from the treatment surface, the ram4val line oonnectable to a vacuum source, wherein the supply line and the removal line are provided with respective crantrQllable closure mechanisms, and 26 a controller which tempriraily. . controls the respective closure mechanisms so that the closure mechanism of the supply line and the closure mechanism of the removal line are not open at the same time and that in the time interval between the closure of the closure mechanism of the supply line and the opening of the closure mechanism of the removal line a treatment dweli time interval is provided, wherein eub-atrnaspheric pressure from the vacuum svurce is applied to the treatment surface to stimulate the tis$ue_ Said padding may be comprised of an elastic compressible peraus matarial.
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Said padding may be ccmprised of an open pored PVA-foam material.

The sealing cover may be a flexibla foil, which i$ air tight yet permeable to water vapor.
The supply line and the removal line may be introduced into the padding via a common drainage hose.

The supply line and the rerndval line may be respectively introduced into the 16 padding via separate drainage hoses.

Said cQntrcllcr, after a suctioning period, may determine a vacuurn time interval in which a predetermined vacuum is maintained in the padding.

The device may further comprise'= a pressure aen' sor adapted to be introduced under the sealing cover, and operably connected with said controller.

The closure mechanisms may be electromagnetic, pneumatic or hydraulic operated hose clamps.
At least one of said supply line and rarnoval line may be con!structed as a hose, wherein said hose clamps have a receptacle for receiving said supply line or removal line, and wherein said hose clamps have a piston responsive to .snid controller and adapted for sque&ing said hose against a hose clamp aidewall.

Said closure mechanisms may be multi-way valvas, Said multi-way valves may be operable via a step motor controlled by said controller.
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Said controller may be programmable electronic c3ontrolfer.

The padding may be adapted to be rinsed prior to introduction of the substance to clean the padding.
1[l The fluid substance may be an active sWbatar'~ce.

According to a second aspect of the invention we provide a deviCe fbr application af substances to tissue, said device comprising:
15 a par us pad, a seal adapted to cover a treatment surFaee of the tissue and the pad, and adapted to seal the treatment surface from the atmoaphere}
a supply line coupled to the pad and adapted to supply a substance to the treatment surPa+oe, and, 20 a removal line coupled to the pad at a first end and adapted to remove the substance and to remove tissue fluida frQm the treatment surFace, the removal line coupled to a vacuum source at the other end, wherein the supply line and the removal line are provided with respective controllable closure mechanisms, and 25 a controller coupled to the closure mechanisms, the cantraller being adapted to temporally controls the respective closure mechanisms and to create a treatment dwell time interval between predefined c,pertings and closings of the respective supply and removal finea, wherein sub-atmnspheric pressure from the vacuum acurca is applied 30 to the troatment surface to stimulate the tissue.

Brief Ciescription of the Drawings In the fvllcawing the inventiun wili be described in greater detail by reference to the illustrative embodiments shown in the figures. There are shown Figure I the deviee for application of active substances in a first embodiment, 6 Figure 2 a modifieation of the device, Figure 3 a time diagram of the process, and Figures 4 through 8 various illustrative embodiments for the closure mechanisms of the devide.

Best Mode for Carrying Out the Invention For treatment of a large surface area deep wound 10 a padding 12 is applied.
The padding 12 is comprised of a porous elastic oampressibie material, preferably of an open pored PVA foam material. The padding 12 is cut or trirnmed tii cxorrespend to the contour of the wound 10. The wound 10 and the 16 padding 12 are covered over by a fail 14 and sealinginly closed off. The foil 14 is so cut, that it oavera over the padding 12 and the wound 10 and extends beyond the edges of the wound. The foil 14 is sealingly secured to the skin surface about the wound aircurnference, for example, it is ar3hered_ The fiail is flexible and is comprised of asyrithetic or plastic material, which permits the diffusion of water vapor, however, pr4vi+des an air-tight enclosure.

In the padding.12 there is intreduued a drainage tube 16, a so-called Redvn-tube, which is perforated in the end area lying in the padding 12. The not petfarated area of the drainage tube 16 is covered over by the foil 14 and extends out therefrom.

irr the illustrative embodiment of Fig. I there is introduced in the proxirnal end of the drainage tube 16 a Tshaped branch or manifoid pi'ece 20. On its one cQnnectian of the manifold 20 a hose is attached as supply side 22, which leads to a known infusion container 24. On the other connection of the man"d 20 a hose is attached as removal 26 which leads to a receptacle container 28 onto which, via a connection line 30. a vacuum source is cxanneetable. Such a roceptiacle container 28 is likewise known per se.

The supply line 22 has associated therewith a closure mechanism 32 a"d the 5 removal line 26 has a closure mechanism 34 associated therewith. The closure mechanisms 32 and 34 are continuously adjustable between a closed position and an open position and are operated via a controller 36.

In the here shown illustrative embodiments the closure mechanisms 32 ant! 34 10 are respectively constructed as hose clamps, which include a receptacle, in which the hose of the supply line 22 or, as the case may be, the removal line 26, can be intraduced. A plunger is, as indicated by arrows in the figure, controlled electrcarnapnetically, pneumatically, hydraulically or in an otherwise known manner by the controller 36, in order that the introduced hose is pressed against a side wall and with squeezing is closed off or in order that the cross-sectional area of the hose is continuously unimpeded.

In certain cases a pressure sensor 38 can be introduced in the wound area under the fQil 14, which senses the pressure existing under the foil 14 artd reports this to the controller 36.

In the infusion container 24 afluid active substance is pre-suppiied, which can be introduced to the padding 12 and therewith to the wound surface via the supply line 22 and the drainage hose 16 in the case of opened closure mechanism 32 and closed closure mechanism 34. In the case of the closed closure mechanism 32 arrd opened closure mechanism 34 the active substance and the wound secretion produced in the wound 10 can be auctiQned off via the removal line 26 into the receptade container 28.

Figure 2 shows a variation of the device, which in comparison to the illustrative embodiment of Figure 1 differs therein, that the padding 12 introduced in the wound 10 has introduced therein two drainage hosas 16 and 18. The drainage hose 16 is connected with the supply line 22, while the drainage hose 18 is corir,acted with the removal line 26. A t,raryoftiiryg is thus unnecessary.

In the illustrative embodiment according to Figure '1 the drainage hose 16 forms a hose dead-end, in which on the one hand the active substance can be introduced and out of which on the other hand the active substance can b6 suotioned out. Thereby during the introduction of the fluid active substance gas bubbles can be trapped in the drainage hose 16, which would interfere with the introductian of the active substance. This d[fF[cu[ty cannot occur in the embodiment according to- Figure 2, since any gas bubbles trapped in the drainage,hose 16 would be suotioned out via the drainage hose 18. The embodiment according to rigure 1 however has the advantage, that only one drainage hose must bd introduced under seal under the foil 14.

By reference to Figure 3 the process associated with the device of Figure 1 and 2 is further explained.

In Figure 3 the pressure P eAsting in the wound 10 under the foil 14 -is represented as a function of time t. The actual abscissa axis corresponds herein to the atrnospheric pressure.

At the time t'1 the closure mechanisms 32 and 34 are controlled by the controller 36 to be closed. In the wound there exists a vacuum of apprQximate[y'IU to 80 kPa, On the basis of this vacuurrr the fbi1 14 is pressed against the wound surface, wherein the elastic padding 12 is compromised. At the time t'1 there is now controlled by the controller 36 that the c[osure mechanism 32 is opened, so that the fluid active substance can flow out of the infusion container 24 via the supply line 22 and the drainage hose 16 into the padding 12. During the inflow time interval T'I the padding 12 suctions [tsetf to fullness with fluid active substance, whereby it expands on the basis of its elastic spring resilience. At the time Q the padding 12 is suctioned full of fluid active substance, whereby under the foil 14 a+oertain over-pressurizaticn exists, which is preferably determined by the height of the infusion container 24 with respect to the wound 10. In certain cases a pressure controlled pump can be introduced in the supply line 22 controlled by the pressure sensor 38.
The opening of the closure mechaniam 32 of the supply line 22 in the introduction time interval T'I is controlled by means of the controller 36 in such a timed manner, that the volumetric flow of the fluid active substance only increases slowly, which in Figure 3 is shown by the continuous line. A sudden opening of the closure mechanism 32 would result in a very rapid influx of the active substance, as shown in Figure 3 with a dash-and-period line. This can result in wound pain to the patient, in particular since the fluid active substance as a rule does not correspond to the body temperature of the patient.
is During the vacuum phase in certain circumstances the pores of the compromised padding 12 can adhere or stick together. Such an adhesion prevents the influx of the active substance under only gravity, which is determined by the height of the infusion contairtir:r 24 with respect to the wound 10. Such a possible adhesion of the pores can be rinsed clean thereby that during the opening of the cl6sure mechanism 32 first a certain volume of the fiuid active substance is introduced under pressure. For this a suitable volume of the active substance can be introduced by means of a piston syringe via the supply line 22. The piston syringe is therefore preferably connected to the supply line 22, feir which for example a three-way cook or valve can be associated with the supply line 22, onto which the piston syringe is connected.

As soon as the padding 12 has suction-filled itself with fluid active aubstance, the closure mechanism 32 of the supply side 22 is closed at time t2. For a treatmenf dwell time interval T2 the closure mechanisms 32 and 34 of the supply line 22 and the removal line 26 remain closed, so that the active substance contained in the padding 12 can act upon the surface of the wound 10. The durativn of the treatment dwell time interval T2 can be predetennined by the controiler 36 and is based upon the type and condition of the wound 10 and according to the type and concentration of the active substance. When the aWve substance during the time interval T2 has had asufFiuient effect or action upon the wound surface, then at time tS the closure mechanism 34 of the removal line 26 is opened. Thereby via the vaeuurn e)(isting through the connection line 30 the fluid active substanm is suctioned out of the padding ar,d the wound 10 via the drainage hose 16 (in Figure 1) or as the case may be the drainage hose 18 (in Figure 2)_ At the same time the wound fluid or secreticrr, is rvu4tiQned out:, which has accumulated in the wound 10 in the treatment dwell time %nterval T2 and which contains decomposition and breakdown products produced through the action of the active substance.
The opening of the closure mechanism 34 is timely eQ controlled by the controller 365 that the flow-through cross-section of the removal line 26 opens only siowly and the vacuum in the padding 1,2 and the wound 10 only increases gradually, as this is shnwn in Figure 3 through the continuous line.
An immediate and complete opening of the clasure mechanism 34 would lead to a very rapid pressure drop in the area of the wound which is shown via a dash-and-dot line in Figure 3, which would be associated with wound pains for the patient.

Should at time t4 the original vacuum again be achieved, which in certain cases can be monitored by the pressure sensor 38, so the fluid active substanue can again be compiatoly removed from the wound 10 and the padding 12. The vacuum is then maintained for a vacuum time interval T4.
Thereby as a rule the closure mechanism 34 remains open, so that the vacuum is continuously maintained by the vacuum source 30, and the produted wound secretion is continuously suctioned off into the receptacle retainer 28. It is also possible, that the closure mechanism 34 is closed or temporarily closed and only opened for short period of times when the vacuum mnnitnreci hy prp.sstirnsery.qnr Si3 rnList be regenerateed.

in the case that the next treatment of the wound 10 is to be aommplished with a fluid active substance, then at time tl the closure mechanism 34 is c[cas6d and then closure mechanism 32 of supply line 24 is again opened so that the de:Acrihed cycle again starts fmm the beginning.

In place of the shown ele+Gtromagnetic, pneumatic or hydraulic operated hose clamps $2, and 34 shown in Figures 'i and 2 the closure mechanisms for the supply line 22 and the removal line 26 can be constructed as multi-way valves.
Apprapriate examples are shown in Figures 4 through 8. The construction of the closure device as a multi-way valve results in a simple construction and a 16 reliable awitchang of the closure device. In particular there results a simplified aantrci of the closure device, when the multi-way valve is controlled by means of a electricai step motor,.which in a simple manner can be achieved by the respective driving of the plug or cock via the respactive step motor. The re-pcsitioning of the multi-way valve via a step motor makes possible a simple electronic control. This control can be programmed in a simple manner and wi-kh great flexibility, in arder to achieve an adaptation to the d+esired treatment cycle. The control and the treatment cycle can in this manner be programmed individually for each patient and each indication. Also the opening and closing of the multi-way valve can be precisely and flexibly temporally controlled electrically by the step motor in order to realize the pressure sequence shown in Figure 3.

In the Figures 4 through 8 there are shown respectively only the closure mechanisms of the device. Otherwise the device corresponds to the examples of Figures 1 and 2.

In the illustrative embodiment in Figure 4 only one drainage hose 16 is provided. The supply line 22 and the removal line 26 are alternatively communicating with the drainage hose 16 via a three-way cock or valve 38.
By means of the electronic contmi 36 a here not shown step motor is 6 programmably controlled, which operates the three-way valve 38_ In the position "a" the supply line 22 is connected to the drainage hose 16 via a three-way valve 38, so that the active gub$tance can be introduced into the porous padding 12. Subsequently the three-way valve 38 is repositioned to position "b", in which the drainage hose 16 is blecked, in order that the introduced active substance can work an the vmvnd. For $uctiening off the three-way valve 38 is rntated to position "c", in which the drainage hose 16 is connected to the drainage line 26.

The illustrative embodiment of Figure 5 shows the device with a drainage hose 10 for the supply and a drainage hose 18 for the suctioning. Both in the supply line 22 as well also in the removal line 26 there is interposed respectively a two-way valve 40 or as the case may be 42, so that the functianality results, which is described in the illustrative embodiment according to Figure 2. In the position "a," the two-way valve 40 is open and the tvwo-way valve 42 closed, so that the supply line 22 is connected to the drainage hose 16, while the drainage hu$e 18 is blocked. In this position "a" the fluid active substanm is intrnduced via the drainage hose 16 into the padding 12. Subsequently the two-way valve 40 is dosed, so that the position "b" is assumed. Both the supply line 22 as well also the removal line 26 are blocked, so that the active substance received by the padding 12 can act. After ending the active dwell phase, the two-way valve 42 is opened, corresponding to positinn "c", so that now the active svbstance and any secretion which may be present can be suetior~ed off via the drainage hose 18 and the removal line 26. After a more-or-less lengthy vacuum interval it is swite-hed back to position a", in order to reintrodue* a treatment substance.

The embodiment according to Figure 6 corresponds functionally to the illustrative ert7budiment according to Figure 5. Essentially in place of the tw two-way valves 40 and 42 one fQur-way valve 44 is provided. The four-way valve 44 connects in position "a" th+s supply line 22 with the drainage hose 916, blocks in position "b" both the supply line 22 as well also the removal line 26, and connects in position "c" the removal line 26 with the drainage hose 18.

In the until now described embodiments there is respectively provided only one supply line 22, so that only one infusion container 24 can be connected.
Should various active substances be supplied, then the infusion container 24 connected with the supply line 22 must be changed out. Likewise the infusion oor7tainer 24 must be removed and be traded out with a piston syringe, when the padding 12 in the case of adhesion of the pores should be rinsed clean.
These disadvantages can be overcome by the illustrative embodiment of Figures 7 and 8.

The illustrative embodiment according to Figure 7 ccarreaponds with the illustrative embodiments of Figure I insofar, that only one drainage hose 16 is provided for, the supply and the removal. The drainage hose 16 ia connected via two in-line associated three-way valves 46 and 48, 7he first three-way velve 46 a+eieutively connects a first supply line 22.1 or a removal line 26 to the connecting line to the second three-way valve 48, The second three-way valve 48 selectively connects this connection line or a second supply line 22.2 to the drainage hose 16. In the position "a" the first three-way valve 48 connects the first supply line 22.1 wiith the connection line and the second three-way valve 48 of this Gonnection line with the drainage hose 16. A first active substance can be introducnd via the first supply line 22.1. The second aupply li"e 22.2 and the removal line 26 are blocked. In position "b" the first three-uvay valve 46 blocks any connections, while the seoond three-way valve 48 connects the second supply line 22.2 with the drainage hose 16. In this position a second adive subatanc.e can be introduced via the supply line 22.2.

In the position "c" both three-way valves 46 and 46 block'all supply lines, so that the introduced sctive Substances can act over a controllable time interval.
Subsequently in position "d" the drainage hose 16 is oannected via the second three-way valve 48 with the connection line, while the first three-way valve connects the mnnection line with the removal line 26. At this time the active substance and any wound secretion can be suctioned from padding 12 via the drainage hose 16 and the removal line 26.

The embodiment accQrding to Figure 7 was also suitable thenefore, to rinse clean the padding 12 at the beginning of the introduction phase. ln this case a piston syringe is connected to the supply line 22.1, while on the supply line 22.2 the infusion container 24 is connected. First in the position "s" the adhered padding 12 is rinsed clean by means of the piston syringe, in order then in the position "a" the active substance is supplied from the infusion oDntainer 22 by gravity via the second supply line 22.2. The rin5ing clean by means of a piston syringe can thus be carried out, without requiring any change in the connection of the connections.

In this embodiment it is also p,assible that the infusion container 24 connected to the second supply line 22.2 be used only as a supply container for the fluid active sUbstaryw and to apply this exriusively by means of the syringe connected in the first supply line 22.1. For this the first three-way valve 46 is brought into the position of Figure 7a, while the second three-way valve 48 in cornparison to this position is so rotated or repositioned, that it connects the second supply line 22.2 with the connection line to the first three-way valve 46.
Now the fluid active substance can be conveyed out of the infusion container 24 connected via the first three-way valve 46 intu the pistcn synnge connected W the first supply line 22.1, in order to fill this. As soon as the piston syringe is filled, the second three-way valve 48 is brought into the position of Figure 7a, so that the fluid active substance can now be applied by means the piston syringe.

Figure 8 shows an embodiment, which again correspcnds to the principle of the main embodiment of Figure 2, in which one drainage hose 16 is provided for the supply and one drainage hose 18 for the removal. The introduction can however be accomplished via two supply lines 22.1 and 22.2. There exists herewith also the possibility to supply two different active substances via the supply lines 22.1 and 22.2 or via one of the supply lines to supply the active substance via the syringe and via the second supply line to supply the active s+ubstanoo from an infusion container. The drainage hose 16 is connectable with the two supply lines 22.1 and 22.2via a three-way valve 50, while the cirainaga hose 1$ is connected to the rem+aval line 26 via a two-way valve 52.
In the pasiticn "a" the first supply line 22.1 is connected with the drainage hose 16, in brder to supply a frst activ+e substance or in order to rinse clean the padding 12. The two-way valve 52 blocks the second drainage hose 16. In the position b" a second active substance is supplied via the second supply line 22,2. In the pQsition "c" the three-way valve 50 as well also as the two-way valve 52 are blocked for the action of the active substance. In the position "d" tho three-way valve 50 blocks all connections, while the two-way valve 52 connects the drainage hose 18 with the removal line 2G in order to suction off , the activo substance.
Here also an infusiun container 24 can be connected to the attachment 22.2, which is employed only as supply container for the #luid active substance, while this fluid active substance is applied via a syringe connected to the supply line 22.1. In a position rotated about 1804 to that of position "b" the thraa-way valve 50 connects thereby the supply infusion cxontainer 54 connected to the supply line 22.2 with the piston syringe oonnected to the supply iine 22.1, in order to fill this.

When used in this specification and claims, the terms "ccamprises" and "comprising" and variations thereof mean that the specified features, steps or integer-* are included. The terms are not to be interpreted to exclude the presence of other features, steps Qr components.

The features disclosed in the foregOing descriptinn, or the following claims, or 6 the accompanying drawirtgs, expressed irt their spsc'rfic farms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utiiisad for realising the invention in diverse forms thereof.

Claims

1. A device for application of substances to tissue, said device comprising:
a porous padding (12) adapted for application upon a treatment surface of the tissue, a sealing cover (14) for covering the treatment surface and the padding (12) and sealing the treatment surface from the atmosphere, at least one supply line (22) introduced into the padding (12) for supplying a fluid substance to the treatment surface, and at least one removal line (26) introduced into the padding (12) for removing the fluid substance and tissue fluids from the treatment surface, the removal line (26) connectable to a vacuum source, wherein the supply line (22) and the removal line (26) are provided with respective controllable closure mechanisms (32, 34), and a controller which temporally controls the respective closure mechanisms (32, 34) so that the closure mechanism (32) of the supply line (22) and the closure mechanism (34) of the removal line (26) are not open at the same time and that in the time interval between the closure of the closure mechanism (32) of the supply line (22) and the opening of the closure mechanism (34} of the removal line (26) a treatment dwell time interval is provided, wherein sub-atmospheric pressure from the vacuum source is applied to the treatment surface to stimulate the tissue.

2. The device according to claim 1, wherein said padding (12) is comprised of an elastic compressible porous material.

3. The device according to claim 1 or 2, wherein said padding (12) is comprised of an open pored PVA-foam material.

4. The device according to any preceding claim, wherein the sealing cover (14) is a flexible foil, which is air tight yet permeable to water vapor.

5. The device according to any preceding claim, wherein the supply line (22) and the removal line (26) are introduced into the padding (12) via a common drainage hose (16).

6. The device according to any preceding claim, wherein the supply line (22) and the removal line (26) are respectively introduced into the padding (12) via separate drainage hoses.

7. The device according to any preceding claim, wherein said controller, after a auctioning period, determines a vacuum time interval in which a predetermined vacuum is maintained in the padding (12).

8. The device according to any preceding claim, further comprising a pressure sensor adapted to be introduced under the sealing cover (14), and operably connected with said controller.

9. The device according to any preceding claim, wherein the closure mechanisms (32, 34) are electromagnetic, pneumatic or hydraulic operated hose clamps.

10. The device according to claim 9, wherein at least one of said supply line (22) and removal line (26) are constructed as a hose, wherein said hose clamps have a receptacle for receiving said supply line (22) or removal line (26), and wherein said hose clamps have a piston responsive to said controller and adapted for squeezing said hose against a hose clamp sidewall.

11. The device according to any preceding claim, wherein said closure mechanisms (32, 34) are multi-way valves.

12. The device according to claim 11, wherein said multi-way valves are operable via a step motor controlled by said controller.

13. The device according to any preceding claim, wherein said controller is programmable electronic controller.

14. The device according to any preceding claim, wherein the padding (12) is adapted to be rinsed prior to introduction of the substance to clean the padding (12).

15. The device according to any preceding claim, wherein the fluid substance is an active substance.

16. A device for application of substances to tissue, said device comprising:
a porous pad (12), a seal (14) adapted to cover a treatment surface of the tissue and the pad (12), and adapted to seal the treatment surface from the atmosphere, a supply line (22) coupled to the pad (12) and adapted to supply a substance to the treatment surface, and a removal line (26) coupled to the pad (12) at a first end and adapted to remove the substance and to remove tissue fluids from the treatment surface, the removal line (26) coupled to a vacuum source at the other and, wherein the supply line (22) and the removal line (26) are provided with respective controllable closure mechanisms (32,34), and a controller coupled to the closure mechanisms (32,34), the controller being adapted to temporally controls the respective closure mechanisms (32, 34) and to create a treatment dwell time interval between predefined openings and closings of the respective supply (22) and removal lines (26), wherein sub-atmospheric pressure from the vacuum source is applied to the treatment surface to stimulate the tissue.