Patent Description:
Negative or reduced pressure therapy may also be used for a therapeutic treatment that utilizes negative pressure for skin treatments and restorative purposes. In these instances the pressure used for skin treatments and restorative purposes may not need to be as low (offset from normal atmospheric pressure) as that used in NPWT. For example, where -<NUM> mmHg to -<NUM> or even -<NUM> mmHg may be desired for NPWT, for skin treatments and restorative purposes the pressure may need to be reduced to only -<NUM> mmHg or -<NUM> mmHg. As such, simply a reduced pressure may be desired in some instances, even including instances where a wound may be treated.

It is known to use a vacuum generation source, such as an electromechanical pump, to apply reduced pressure to the inside of a dressing on a dressing site. However, when a vacuum source operates using a chemical reaction in which a gas found in air is consumed to as to reduce the pressure at the dressing site, it is known to isolate a substrate impregnated with a reducing agent and an electrolyte solution from air using an air-tight foil packet. When it is desired to begin the chemical reaction, the substrate is exposed to air by tearing or removing a section of the air-tight foil packet. However, other manners to activate the chemical reaction may be desirable.

From <CIT> a controlled pressure device as a tissue treatment device is known. The known controlled pressure device includes a reactor housing element, a reactor, and a flowable cosmetic substance. The reactor housing element is configured to at least partially define an at least substantially air-tight enclosed volume around a tissue site when it is fixed in space in relation to the tissue site. The reactor is positioned in the enclosed volume and is configured to react with a selected gas (e.g. nitrogen, oxygen, carbon dioxide) found in air. The reactor consumes the selected gas within the enclosed volume. The flowable cosmetic substance is also located in the enclosed volume.

From <CIT> another wound therapy device is known. This known wound therapy devide includes including a skin contacting element or assembly and a pump housing element or assembly accommodating a pump therein. In use, the skin contacting assembly is positioned on and/or affixed to the skin of a patient surrounding a wound site or tissue site. The pump assembly can then be affixed to one or both the skin surrounding the tissue site or the skin contacting assembly to provide reduced pressure (typically below that of atmospheric pressure) to the tissue site.

<CIT> discloses a pouch for internal mixture of segregated reactants. The known pouch includes an outer containment envelope with a sealed reactant compartment inside. A middle shear strip and two outer strips, together defining two shear lines, are connected to the reactant compartment. The outer strips are folded under the reactant compartment with their tips anchored to the containment envelope. The middle strip extends away from the reactant compartment and through a slit in the containment envelope. Pulling on the middle strip causes the shear lines to lengthen until the reactant compartment is shorn open to release a reactant. A permeable second reactant compartment containing a second reactant may also be disposed inside the containment envelope, and may include a slit through which the middle strip passes. The reaction in the pouch may be exothermic and the pouch may be applied to any object to be heated such as a wet wipes dispenser.

<CIT> discloses a disposable combination package and applicator unit which comprises a flexible laminated strip of moisture impervious material. The laminated strip has at one surface a cell integrally formed within the strip which contains a fluent substance to be dispensed. The cell has a rupturable wall so disposed as to release the substance only at that one surface of said strip. Layers of soft absorbent pad material are secured in overlying relation upon both surfaces of the strip.

Documents <CIT> and <CIT> are entirely unrelated to wound therapy and to devices configured to perform such a therapy.

Document <CIT> discloses a device, method and assembly for use in wound treatment. Specifically <CIT> discloses a wound dressing device, an assembly, e. in the form of a kit-of-parts, which comprises the device as one of its components; and a method of wound dressing and a use wherein said device is a key component. The device comprises a cavity defined by concave walls surrounded by lips configured for attachment to skin in a fluid tight manner and a closure removably fixed to the lips and sealing the cavity. The assembly also comprises, as other of its components a device for introducing blood into the cavity after it is fixed over a wound to permit the blood to clot over the wound within said cavity. In use, the clotting mold device is fixed on top of a wound, and blood is introduced into the mold space to permit the blood to clot within the mold space to thereby form a blood clot over the wound.

The device defines with the wound an enclosed space which serves as a mold (cast) for clotting blood on top of the wound. Into this "mold space" blood is injected with a needle.

In view of the foregoing, a reduced pressure device includes a dressing and a reactor. The dressing covers a dressing site and defines an enclosed volume beneath the dressing and around the dressing site. The reactor is disposed with respect to the dressing so as to produce a reduced pressure beneath the dressing when activated. The reactor includes a reducing agent and an electrolyte solution. The electrolyte solution is configured to be selectively delivered to the reducing agent, and the reactor begins to react with at least one selected gas in the enclosed volume after the electrolyte solution is delivered to the reducing agent to consume the at least one selected gas within the enclosed volume.

<FIG> depicts a reduced pressure device <NUM>, which is not covered by claim <NUM>, useful for administering negative and/or reduced pressure therapy to a dressing site <NUM>. Reduced pressure described herein is pressure below atmospheric pressure. The reduced pressure device <NUM> includes a dressing <NUM> and a reactor <NUM>, which operates as a vacuum source. The dressing <NUM> is placed over the dressing site <NUM> on a patient's skin S. The dressing site <NUM> can be, but is not limited to, a wound, an incision, or skin where there is no wound or incision, for example in a cosmetic application. The reduced pressure device <NUM>, which can be used for NPWT or for instances where the pressure need not be reduced to what is typically achieved in NPWT, generally includes the dressing <NUM>, the reactor <NUM>, a drape <NUM>, an absorbent element <NUM>, and a sealing element <NUM>. The dressing <NUM> may further include valves, pressure indicators and the like.

The drape <NUM> can be made from a flexible material and can be a thin film capable of maintaining a reduced pressure underneath the drape <NUM> upon application of a vacuum. The thin film from which the drape <NUM> is made can be substantially impermeable to liquids but somewhat permeable to water vapor, while still being capable of maintaining reduced pressure underneath the drape <NUM>. For example, the thin film material from which the drape <NUM> is made may be constructed of polyurethane or other semi-permeable material such as that sold under the Tegaderm® brand or <NUM> TPU tape available from <NUM>. Similar films are also available from other manufacturers. The drape <NUM> can be made in a variety of shapes and sizes to cover a variety of dressing sites <NUM>.

The absorbent element <NUM> is made from an absorbent material that is capable of absorbing exudate from the dressing site <NUM>. The absorbent element <NUM> can be made from super absorbent acrylate, absorbent beads, foams, or natural absorbents. The absorbent element <NUM> can also be a hydroactive wound pad available under the trademark Vilmed®, which chemically absorbs exudate and precludes the exudate from passing through the absorbent element <NUM> toward the reactor <NUM> unlike a sponge.

The sealing element <NUM> cooperates with the drape <NUM> and skin S to create an enclosed volume <NUM> defined between the drape <NUM> and the dressing site <NUM> and surrounded by the sealing element <NUM>. The reactor <NUM>, which when activated operates as a vacuum source in fluid communication with the enclosed volume <NUM>, administers reduced pressure to the enclosed volume <NUM> so as to control the atmosphere within the enclosed volume <NUM>. The sealing element <NUM> can be separate from the dressing <NUM> or can instead be a component of the dressing <NUM>. The sealing element <NUM> functions like a gasket, as the sealing element <NUM> prevents fluid (including air) from escaping between the drape <NUM> and the skin S. The sealing element <NUM> can be made from a material such as silicone or a hydrogel material, for example.

The dressing <NUM> may further include a wound contact layer <NUM>. The wound contact layer <NUM> can be made of an elastomeric material, such as a polymeric material that has rubber-like properties. Furthermore, the wound contact layer <NUM> can be an elastomeric material that is a thin, flexible elastomeric film. Some examples of such materials include a silver coated nylon, a perforated silicone mesh, or other material that will not stick to the patient's tissue. The wound contact layer <NUM> can also be a polyurethane film layer in which holes can be provided. A silicone coating can also be provided on a skin-contacting side of the absorbent element <NUM> instead of the wound contact layer <NUM>.

A drape release liner (not shown in <FIG>) is disposed on a bottom surface of the drape <NUM>. The drape release liner is removed before the dressing <NUM> is applied to the dressing site <NUM>. When the drape release liner is removed, an adhesive <NUM> on the bottom surface of the drape <NUM> is exposed. As the dressing <NUM> is placed on the patient, the adhesive <NUM>, which can be an acrylic-based adhesive that is distinct from the sealing element <NUM>, secures the drape <NUM> to the patient's skin S around the dressing site <NUM>. Thus, contact is maintained between the drape <NUM> and the skin S.

The dressing <NUM> may also include a membrane <NUM> between the reactor <NUM> and the absorbent element <NUM>. In the embodiment shown in <FIG>, the membrane <NUM>, which can be a thin film similar to the drape <NUM>, is fixed to the bottom surface of the drape <NUM>. The membrane <NUM> includes at least one opening <NUM> or is pervious to air so that air is allowed to travel through the membrane <NUM>. Therefore, the reactor <NUM> is in fluid communication with the enclosed volume <NUM>. In an alternative embodiment shown in <FIG>, which is not covered by claim <NUM>, the membrane <NUM> can disposed over the dressing site <NUM> with the absorbent element <NUM> affixed to it. In this alternative embodiment, the dressing <NUM> can be what may be referred to as a two-piece dressing in which the membrane <NUM> and the absorbent element <NUM> are placed on the patient's skin S over the dressing site <NUM>, and then the drape <NUM> and the components affixed thereto are placed over the membrane <NUM> and the dressing site <NUM>. In the embodiment depicted in <FIG>, the membrane <NUM> would include an adhesive on a lower surface to allow the membrane to adhere to the skin S. The membrane <NUM> may also include a sealing element (similar to the sealing element <NUM>) which would allow the drape <NUM> to be adhered and sealed to the membrane <NUM> instead of the skin S.

The reactor <NUM> is configured to react with at least one selected gas found in air to remove the selected gas from air. The reactor <NUM> is located with respect to the drape <NUM> and the sealing element <NUM> so that the reactor <NUM> can be in fluid communication with the enclosed volume <NUM>. The reactor <NUM> consumes the selected gas from the enclosed volume <NUM> thereby removing the selected gas and reducing the gas pressure. For example, the reactor <NUM> can be an oxygen scavenger which removes oxygen from the air within the enclosed volume <NUM> so as to reduce gas pressure within the enclosed volume <NUM> by approximately <NUM>%. Since the vacuum source in this embodiment is the reactor <NUM> that consumes a gas found in air (as opposed to a mechanical pump), any leakage around the enclosed volume <NUM> is important to prevent. Uncontrolled ingress of outside oxygen, which could prematurely use up the reactor <NUM>, should be prevented or limited from penetrating either through the drape <NUM> or the sealing element <NUM> or between the sealing element <NUM> and the skin S.

The reactor <NUM> includes a reducing agent <NUM>, such as aluminum, zinc or iron, and an electrolyte solution <NUM>. An example of a substrate impregnated with a reducing agent and an electrolyte solution is found in <CIT>. Unlike the heater described in <CIT> in which a substrate having the reducing agent and a pad impregnated with the electrolyte solution are packaged in a hermetically sealed foil package, the electrolyte solution <NUM> is shielded from the reducing agent <NUM> until reduced pressure beneath the dressing <NUM> is ready to be administered obviating the need for the hermetically sealed foil package. When reduced pressure therapy is ready to be administered to the dressing <NUM>, the electrolyte solution <NUM> is introduced to the reducing agent <NUM>. The reactor <NUM> then begins to react with the at least one selected gas, e.g., oxygen, in the enclosed volume <NUM> to create reduced pressure at the dressing site <NUM>. As illustrated in <FIG>, the dressing <NUM> may further include a substrate <NUM> that includes the reducing agent <NUM> and a binding agent, such as polytetrafluoroethylene or a polyolefin. The term "substrate" means that the substrate <NUM> is a solid object, and not merely a mass of powdered chemicals; however, the reducing agent <NUM> could be provided in the dressing <NUM> as a mass of powdered chemicals, if desired.

In <FIG>, the electrolyte solution <NUM> is stored in a rupturable capsule <NUM> disposed adjacent to the reducing agent <NUM>. The capsule <NUM> can be any package that can be selectively ruptured to allow liquid contents disposed therein to leak from the package after it is ruptured. The user presses onto a pressing location <NUM> on the drape <NUM> over the capsule <NUM> to break the capsule <NUM>. Once the capsule <NUM> is broken, which is shown in <FIG>, the electrolyte solution <NUM> is delivered to the reducing agent <NUM>, and the reducing agent <NUM> begins to react with the at least one selected gas in the enclosed volume <NUM> so as to consume the selected gas from the enclosed volume <NUM>. The drape <NUM> may include a marking <NUM> disposed on a top surface of the drape <NUM> above the capsule <NUM> to indicate where the pressing location <NUM> is located to provide an indication to a user of the pressing location <NUM>. The marking <NUM> may be a circle disposed around a periphery of the pressing location <NUM>; however, the marking <NUM> can be any marking that indicates to a user where the pressing location <NUM> is located. A button may also be provided at the pressing location <NUM>.

With reference to <FIG>, in an embodiment, which is covered by claim <NUM>, an opening, which is in the form of a slit <NUM> in the illustrated embodiment, is disposed on the drape <NUM>. A first pull tab <NUM> extends from beneath the drape <NUM> to ambient through the slit <NUM> and is connected to a separable layer <NUM> of the capsule <NUM>. The separable layer <NUM> isolates the electrolyte solution <NUM> within the capsule <NUM> and from the reducing agent <NUM>. The first pull tab <NUM>, which could also be in the form of a string, can be pulled to remove the first pull tab <NUM> and the separable layer <NUM> from the slit <NUM>. When the first pull tab <NUM> is pulled, the separable layer <NUM> is removed from the capsule <NUM> and, if desired, from the enclosed volume <NUM> through the slit <NUM>, exposing the reducing agent <NUM> to the electrolyte solution <NUM>. After the removal of the separable layer <NUM>, the electrolyte solution <NUM> is delivered to the reducing agent <NUM>, which begins to react with a selected gas, e.g., oxygen, in the enclosed volume <NUM>.

A second pull tab <NUM> is connected to a cover layer, which can be a thin film <NUM> placed over and adhered to a portion of the top surface of the drape <NUM>. The thin film <NUM> could be made integral with the drape <NUM>. The thin film <NUM> can include a flap <NUM> and, as depicted in <FIG>, the slit <NUM> is disposed underneath the flap <NUM>. The second pull tab <NUM> can be connected to or provided as a release layer provided on a bottom surface of the thin film <NUM> in the region of the flap <NUM>. The release layer covers an adhesive (not visible in <FIG>) on a bottom surface of the thin film <NUM>. When the second pull tab <NUM> is pulled, which occurs after the first pull tab <NUM> has been removed from the slit <NUM>, the second pull tab <NUM> disconnects the release layer from the flap <NUM> and the adhesive disposed on the bottom surface of the flap <NUM> is exposed. The flap <NUM> is then moved towards the drape <NUM> to cover the slit <NUM>. When the thin film <NUM> covers the slit <NUM>, the reactor <NUM> is closed off from ambient and reacts with the selected gas found in the enclosed volume <NUM> under the dressing <NUM>. Reduced pressure is therefore developed in the enclosed volume <NUM>.

Referring to <FIG>, which shows an embodiment that is not covered by claim <NUM>, the electrolyte solution <NUM> can be injected into the dressing <NUM> when reduced pressure therapy is ready to be administered. For example, the electrolyte solution <NUM> can be injected into the substrate <NUM> having the reducing agent <NUM> or into a mass of powdered chemicals making up the reducing agent <NUM> by a syringe <NUM>. An injection port <NUM> can be disposed on the drape <NUM> for guiding a user for injecting a needle <NUM> of the syringe <NUM> into the substrate <NUM> or mass of powdered chemicals making up the reducing agent <NUM>. When reduced pressure is ready to be administered, the user injects the electrolyte solution <NUM> into the substrate <NUM> to impregnate the substrate <NUM> with the electrolyte solution <NUM> or into the mass of powdered chemicals making up the reducing agent <NUM>. Once the reducing agent <NUM> is wetted with the electrolyte solution <NUM>, the reactor <NUM> begins to react with the selected gas in the enclosed volume <NUM> and consuming the selected gas. After finishing injecting the electrolyte solution <NUM> into the dressing <NUM>, the injection port <NUM> can be covered with a thin film in a similar manner to the slit <NUM> shown in <FIG>.

In yet another embodiment, which is not covered by claim <NUM>, with reference to <FIG>, the electrolyte solution <NUM> can be stored in a flexible chamber <NUM> until the reduced pressure therapy is ready to be administered. The flexible chamber <NUM> can be located externally from the dressing <NUM>. The flexible chamber <NUM> is connected to the substrate <NUM> having the reducing agent <NUM> or the mass of powdered chemicals making up the reducing agent <NUM> by a flow conduit <NUM>. The flow conduit <NUM> can further include a seal <NUM>. The seal <NUM> can be located at any portion of the flow conduit <NUM>. When reduced pressure therapy is to be administered, the flexible chamber <NUM> is pressed and/or squeezed and the flow pressure of the electrolyte solution <NUM> breaks the seal <NUM>, and the electrolyte solution <NUM> is delivered to the substrate <NUM> or the mass of powdered chemicals making up the reducing agent <NUM>.

<FIG>, which shows an embodiment that is not covered by claim <NUM>, depicts an example in which the reactor <NUM> is positioned outside of the dressing <NUM> while still being positioned with respect to the dressing <NUM> so as to produce a reduced pressure beneath the dressing <NUM> when activated. The reactor <NUM> is positioned within a chemical pump housing <NUM>. The chemical pump housing <NUM> can either connect directly to a fitting <NUM> provided on the dressing <NUM> via a fitting or valve <NUM> (<FIG>) on the chemical pump housing <NUM> or can connect via a hose (not shown) to the dressing <NUM> via the fitting <NUM> or something similar. When properly connected with the dressing <NUM>, an inner chamber <NUM> of the chemical pump housing <NUM> is in fluid communication with the enclosed volume <NUM>.

Where the chemical pump housing <NUM> is made from a rigid plastic, a flexible section or button <NUM> can be disposed on a surface of the chemical pump housing <NUM>. The flexible section or button <NUM> is preferably disposed on a top surface of the chemical pump housing <NUM>. The flexible section or button <NUM> can be aligned with the capsule <NUM> so as to be a pressing location where a user can press to break the capsule <NUM> containing the electrolyte solution <NUM>. After the capsule <NUM> is ruptured, the electrolyte solution <NUM> is delivered to the substrate <NUM> or mass of powdered chemicals making up the reducing agent <NUM>. Similar to that described above, after the reducing agent <NUM> is wetted with the electrolyte solution <NUM>, the reactor <NUM> begins to consume the selected gas in the enclosed volume <NUM> and the inner chamber <NUM>.

With reference to <FIG>, which shows an embodiment covered by claim <NUM>, a slit <NUM> is disposed on the chemical pump housing <NUM> instead of the dressing <NUM>. When the slit <NUM> is disposed on the chemical pump housing <NUM>, a first pull tab <NUM> extends from the inner chamber <NUM> to ambient and is connected to a separable layer <NUM> of the capsule <NUM>. The separable layer <NUM> isolates the electrolyte solution <NUM> within the capsule <NUM> and from the reducing agent <NUM>. The first pull tab <NUM>, which could also be in the form of a string, can be pulled to remove the first pull tab <NUM> and the separable layer <NUM> from the slit <NUM>. When the first pull tab <NUM> is pulled, the separable layer <NUM> is removed from the capsule <NUM> and, if desired, from the inner chamber <NUM> through the slit <NUM>, exposing the reducing agent <NUM> to the electrolyte solution <NUM>. After the removal of the separable layer <NUM>, the electrolyte solution <NUM> is delivered to the reducing agent <NUM>, which begins to react with a selected gas, e.g., oxygen, in the inner chamber <NUM> and the enclosed volume <NUM>.

Also, a cover layer, which can be a thin film <NUM>, is disposed on the chemical pump housing <NUM>. A second pull tab <NUM> is connected to the thin film <NUM>, which is placed over and adhered to a portion of the top surface of the chemical pump housing <NUM>. The thin film <NUM> includes a flap <NUM> and, as depicted in <FIG>, the slit <NUM> is disposed underneath the flap <NUM>. The second pull tab <NUM> can be connected to or provided as a release layer provided on a bottom surface of the thin film <NUM> in the region of the flap <NUM>. The release layer covers an adhesive (not visible in <FIG>) on a bottom surface of the thin film <NUM>. When the second pull tab <NUM> is pulled, which occurs after the first pull tab <NUM> has been removed from the slit <NUM>, the second pull tab <NUM> disconnects the release layer from the flap <NUM> and the adhesive disposed on the bottom surface of the flap <NUM> is exposed. The flap <NUM> is then moved towards the chemical pump housing <NUM> to cover the slit <NUM>. When the thin film <NUM> covers the slit <NUM>, the reactor <NUM> is closed off from ambient and reacts with the selected gas found in the inner chamber <NUM> and the enclosed volume <NUM> under the dressing <NUM>. Reduced pressure is therefore developed in the enclosed volume <NUM>.

With reference to <FIG>, which shows an embodiment that is not covered by claim <NUM>, the electrolyte solution <NUM> can be injected into the substrate <NUM> or mass of powdered chemicals making up the reducing agent <NUM> through the chemical pump housing <NUM> when reduced pressure therapy is ready to be administered. An injection port <NUM> can be disposed on the chemical pump housing <NUM> for guiding a user for injecting the needle <NUM> of the syringe <NUM> into the substrate <NUM> or mass of powdered chemicals making up the reducing agent <NUM>. When reduced pressure is ready to be administered, the user injects the electrolyte solution <NUM> into the substrate <NUM> to impregnate the substrate <NUM> with the electrolyte solution <NUM> or into the mass of powdered chemicals making up the reducing agent <NUM>. Once the reducing agent <NUM> is wetted with the electrolyte solution <NUM>, the reactor <NUM> begins to consume the selected gas in the enclosed volume <NUM> and the inner chamber <NUM> of the chemical pump housing <NUM>. After finishing injecting the electrolyte solution <NUM> into the dressing <NUM>, the injection port <NUM> can be covered with the thin film <NUM> and the flap <NUM> in a similar manner to the slit <NUM> shown in <FIG>. Also, the electrolyte solution <NUM> stored in the flexible chamber <NUM> shown in <FIG> can deliver the electrolyte solution <NUM> through the injection port <NUM> in the chemical pump housing <NUM> similar to the syringe <NUM>.

Claim 1:
A reduced pressure device (<NUM>) comprising:
a dressing (<NUM>) configured to cover a dressing site (<NUM>) and define an enclosed volume (<NUM>) beneath the dressing (<NUM>) and around the dressing site (<NUM>); and
a reactor (<NUM>) disposed with respect to the dressing(<NUM>) so as to produce a reduced pressure beneath the dressing (<NUM>) when activated, the reactor (<NUM>) including a reducing agent (<NUM>) and an electrolyte solution (<NUM>), wherein the electrolyte solution (<NUM>) is configured to be selectively delivered to the reducing agent (<NUM>), and the reactor (<NUM>) begins to react with at least one selected gas in the enclosed volume (<NUM>) after the electrolyte solution (<NUM>) is delivered to the reducing agent (<NUM>) to consume the at least one selected gas within the enclosed volume (<NUM>),
wherein the electrolyte solution (<NUM>) is stored in a rupturable capsule (<NUM>) positioned adjacent to the reducing agent (<NUM>), and the rupturable capsule (<NUM>) is configured to rupture to deliver the electrolyte solution to the reducing agent;
wherein the rupturable capsule (<NUM>) is configured to rupture by way of pulling a tab (<NUM>; <NUM>) operatively connected with the rupturable capsule (<NUM>);
wherein the reduced pressure device (<NUM>) includes a slit (<NUM>; <NUM>) through which the tab (<NUM>; <NUM>) extends to ambient, the tab (<NUM>; <NUM>) being configured to be pulled through the slit;
wherein the reduced pressure device (<NUM>) further includes a cover layer (<NUM>; <NUM>) having an adhesive disposed thereon, the cover layer (<NUM>; <NUM>) being configured to be applied over the slit (<NUM>; <NUM>) to cover the slit (<NUM>; <NUM>) after removal of the tab (<NUM>; <NUM>),
wherein either
(i) the reactor (<NUM>) is disposed beneath the dressing (<NUM>), the dressing (<NUM>) including the slit (<NUM>) and the cover layer (<NUM>), and the tab (<NUM>) extending from beneath the dressing (<NUM>) to ambient,
or
(ii) the reduced pressure device further includes a chemical pump housing (<NUM>) connected the dressing (<NUM>), the chemical pump housing (<NUM>) including an inner chamber (<NUM>) in which the reactor (<NUM>) is disposed, the rupturable capsule (<NUM>) being positioned in the inner chamber (<NUM>), the chemical pump housing (<NUM>) including the slit (<NUM>) and the cover layer (<NUM>), and the tab (<NUM>) extending from beneath the inner chamber (<NUM>) to ambient.