RELATED APPLICATIONThe present invention claims the benefit, under 35 USC §119(e), of the filing of U.S. Provisional Patent Application Ser. No. 61/407,194, entitled “System and Methods For Electrically Detecting The Presence of Exudate In Reduced-Pressure Dressings,” filed 27 Oct. 2010, which is incorporated herein by reference for all purposes [VAC.0975PRO1]; U.S. Provisional Patent Application Ser. No. 61/418,730, entitled “Systems and Methods for Electrically Detecting the Presence of Exudate in Dressings,” filed 1 Dec. 2010, which is incorporated herein by reference for all purposes [VAC.0975PRO2]; U.S. Provisional Patent Application Ser. No. 61/445,383, entitled “Interactive, Wireless Reduced-Pressure Dressings, Methods, and Systems,” filed 22 Feb. 2011, which is incorporated herein by reference for all purposes [VAC.0999PRO]; and U.S. Provisional Patent Application Ser. No. 61/445,338, entitled “Reduced-Pressure Systems, Dressings, and Methods Employing a Wireless Pump,” filed 22 Feb. 2011, which is incorporated herein by reference for all purposes [VAC.1000PRO].
FIELDThe present disclosure relates generally to medical treatment systems and, more particularly, but not by way of limitation, to interactive, wireless dressings, methods, and systems for use with reduced pressure.
BACKGROUNDClinical studies and practice have shown that providing a reduced pressure in proximity to a tissue site augments and accelerates the growth of new tissue at the tissue site. The applications of this phenomenon are numerous, but application of reduced pressure has been particularly successful in treating wounds. This treatment (frequently referred to in the medical community as “negative pressure wound therapy,” “reduced pressure therapy,” or “vacuum therapy”) provides a number of benefits, which may include faster healing and increased formulation of granulation tissue. Typically, when applied to open wounds, reduced pressure is applied to tissue through a porous pad or other manifold device. The porous pad distributes reduced pressure to the tissue and channels fluids that are drawn from the tissue. At times, a patient may have a large wound requiring treatment at numerous sites or has a plurality of tissue sites requiring treatment. At times, reduced pressure may also be used within a body cavity to remove fluids among other things.
SUMMARYAccording to an illustrative embodiment, a system for treating at least one tissue site with reduced pressure includes a first, wireless, reduced-pressure dressing for disposing proximate to the tissue site. The first, wireless, reduced-pressure dressing includes a distribution manifold, a drape covering at least a portion of the distribution manifold, a Radio Frequency Identification (RFID) antenna, a first processor coupled to the RFID antenna, and a first sensor coupled to the first processor. The system also includes a remote base unit and a reduced-pressure source. The reduced-pressure source is fluidly coupled to the distribution manifold. The remote base unit includes a RFID antenna and a second processor.
According to another illustrative embodiment, a wireless, reduced-pressure dressing for treating a tissue site with reduced pressure includes a distribution manifold for placing adjacent to the tissue site and for providing reduced pressure to the tissue site, a drape covering at least a portion of the distribution manifold, a first processor, a RFID antenna coupled to the first processor, and a first sensor coupled to the first processor. The first sensor may be a pressure sensor.
According to another illustrative embodiment, a method for treating at least one tissue site with reduced pressure includes the steps of disposing a first, wireless, reduced-pressure dressing proximate to a first tissue site. The first, wireless, reduced-pressure dressing includes a distribution manifold for placing adjacent to the tissue site and for providing reduced pressure to the tissue site, a drape covering at least a portion of the distribution manifold, a first processor, a RFID antenna coupled to the first processor, and a first sensor coupled to the first processor. The first sensor is a pressure sensor. The method further includes providing a remote base unit that has a RFID reader, providing reduced pressure to the distribution manifold, transmitting a pressure inquiry signal from the RFID reader to the first, wireless, reduced-pressure dressing, and receiving a pressure message signal from the first, wireless, reduced-pressure dressing.
According to another illustrative embodiment, a method for treating at least one tissue site with reduced pressure includes the steps of disposing a first, wireless, reduced-pressure dressing proximate to a first tissue site. The first, wireless, reduced-pressure dressing includes a distribution manifold for placing adjacent to the tissue site and for providing reduced pressure to the tissue site, a drape covering at least a portion of the distribution manifold, a first processor, a RFID antenna coupled to the first processor, and a first sensor coupled to the first processor. The first sensor may be a pressure sensor. The method further includes providing a remote base unit having a RFID reader. The remote base unit also includes a second processor coupled to the RFID reader. The method further includes providing a reduced-pressure source; transmitting an ID inquiry signal from the remote base unit to the first, wireless, reduced-pressure dressing; receiving the ID inquiry signal at the first, wireless, reduced-pressure dressing and producing an ID message signal; transmitting the ID message signal from the first, wireless, reduced-pressure dressing to the remote base unit; receiving the ID message signal at the remote base unit; determining if the ID message signal is on an approved list; and activating the reduced-pressure source to provide reduced pressure to the distribution manifold if the ID message signal represents a dressing that is on the approved list or indicating an error if the ID message signal represents a dressing that is not on the approved list.
According to another illustrative embodiment, a system for treating at least one tissue site with reduced pressure includes a first, wireless, reduced-pressure dressing for disposing proximate to the tissue site. The first, wireless, reduced-pressure dressing includes a distribution manifold, a drape covering at least a portion of the distribution manifold, a reduced-pressure interface for providing reduced pressure to the distribution manifold, a first RFID antenna, a first processor coupled to the first RFID antenna, a first sensor coupled to the first processor, and a membrane. The membrane covers at least a portion of the reduced-pressure interface and is initially in an occlusive state that prevents or hinders fluid flow through the reduced-pressure interface. The first, wireless, reduced-pressure dressing further includes a dissolution element proximate to the membrane that is adapted to change the membrane from the occlusive state to a non-occlusive state. When changed to the non-occlusive state, the membrane allows flow through reduced-pressure interface. The system further includes a remote base unit having a RFID reader and a second processor. The system also includes a reduced-pressure source fluidly coupled to the distribution manifold. The second processor is configured to transmit an activation signal with the RFID reader to the first, wireless, reduced-pressure dressing and wherein in response to the activation signal, the first processor is configured to deliver power to the dissolution element to change the membrane from the occlusive state to the non-occlusive state. The second processor is configured to transmit an ID inquiry signal with the RFID reader to the first, wireless, reduced-pressure dressing, and wherein, in response to the ID inquiry signal, the first processor is configured to transmit an ID message signal with the first RFID antenna. The second processor is adapted to receive the ID message signal via the RFID reader and to determine if the ID message signal represents an acceptable dressing.
According to another illustrative embodiment, a system for treating a tissue site with reduced pressure includes a wireless, reduced-pressure dressing that includes a distribution manifold, a drape covering the distribution manifold, and a reduced-pressure interface. The system also includes a WISP device associated with the wireless, reduced-pressure dressing, a remote base unit comprising a RFID reader, and a reduced-pressure source fluidly coupled to the wireless, reduced-pressure dressing.
According to another illustrative embodiment, a method for treating at least one tissue site with reduced pressure includes disposing a first, wireless, reduced-pressure dressing proximate to a first tissue site. The first, wireless, reduced-pressure dressing includes a distribution manifold for placing adjacent to the tissue site and for providing reduced pressure to the tissue site, a drape covering at least a portion of the distribution manifold, a reduced-pressure interface, and a membrane. The membrane is initially occlusive and covers at least a portion of the reduced-pressure interface. The membrane is adapted to prevent fluid flow through the reduced-pressure interface when in the occlusive state. The first, wireless, reduced-pressure dressing also includes a first processor, a RFID antenna coupled to the first processor, a first sensor coupled to the first processor, and a dissolution element proximate to the membrane that is operable, when activated, to change the membrane from an occlusive state to a non-occlusive state. The first sensor is a pressure sensor. The dissolution element is coupled to the first processor. The method further includes providing a remote base unit having a RFID reader. The remote base unit includes a second processor. The method also involves providing a reduced-pressure source fluidly coupled to the reduced-pressure interface, transmitting an activation signal from the remote base unit to the first, wireless, reduced-pressure dressing, whereupon the first processor activates the dissolution element to change the membrane to the non-occlusive state, and providing reduced pressure from the reduced-pressure source to the reduced-pressure interface.
Other features and advantages of the illustrative embodiments will become apparent with reference to the drawings and detailed description that follow.
BRIEF DESCRIPTION OF THE DRAWINGSFIG. 1 is a schematic diagram, with a portion shown in cross section, of an illustrative embodiment of a system for treating at least one tissue site with reduced pressure;
FIG. 2 is a schematic top view of a first, wireless, reduced-pressure dressing of the system ofFIG. 1;
FIG. 3 is a schematic diagram, with a portion shown in cross section, of an illustrative embodiment of a system for treating at least one tissue site with reduced pressure;
FIG. 4 is a schematic top view of an illustrative embodiment of a first, wireless, reduced-pressure dressing;
FIG. 5 is a schematic diagram, with a portion shown in cross section, of an illustrative embodiment of a system for treating at least one tissue site with reduced pressure; and
FIGS. 6A and 6B are an illustrative embodiment of a process flow chart for a system for treating at least one tissue site with reduced pressure.
DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTSIn the following detailed description of the illustrative embodiments, reference is made to the accompanying drawings that form a part hereof. These illustrative embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is understood that other embodiments may be utilized and that logical structural, mechanical, electrical, and chemical changes may be made without departing from the spirit or scope of the invention. To avoid detail not necessary to enable those skilled in the art to practice the embodiments described herein, the description may omit certain information known to those skilled in the art. The following detailed description is not to be taken in a limiting sense, and the scope of the illustrative embodiments are defined only by the appended claims.
In treating a tissue site or sites on a patient with reduced pressure, it is typically desirable to maintain the reduced pressure in a therapeutic range. While the amount and nature of reduced pressure applied to a tissue site will typically vary according to the application, the reduced pressure will typically be between −5 mm Hg and −500 mm Hg and more typically −75 mm Hg and −300 mm Hg, and more typically still, −100 to −200 mm Hg. In some instances, failure to provide reduced pressure to a tissue site can lead to serious consequences. Accordingly, it may be desirable to monitor the pressure at each tissue site undergoing treatment.
To accommodate multiple tissue sites, e.g., multiple wounds, multiple conduits may be used to deliver reduced pressure. For example, a single reduced-pressure source may be used with the multiple conduits branched off of one conduit. Currently, pressure monitoring is typically located in existing reduced-pressure sources and only one conduit communicates pressure to the reduced-pressure source. If only one conduit, which is associated with one tissue site, is monitored, as is the case when monitoring is done at the reduced-pressure source alone, pressures at other tissue sites are unmonitored. With at least some of the illustrative embodiments herein, each tissue site of the plurality of tissue sites is monitored so that issues with reduced pressure delivery may be identified and addressed. Moreover, other parameters may be monitored to track progress or identify issues with healing of the tissue sites.
Reduced pressure may be used to treat open wounds to promote the granulation tissue. Reduced pressure may also be applied to a tissue site internal to a patient to remove fluids. For example, reduced pressure may be used to remove ascites from a patient's abdomen. In such situations it may be desirable to know the pressure at the internal location as well as other parameters. Reduced pressure may be used for other applications to promote healing. The illustrative embodiments herein may be operable to perform these tasks.
The illustrative embodiments herein involve using Radio Frequency Identification (RFID) technology, including enhanced RFID technology, to wirelessly transmit and receive sensing information from a reduced-pressure dressing. RFID uses a RFID tag or label that is on a target and a RFID reader that energizes and reads a signal from the RFID tag. Most RFID tags include an integrated circuit for storing and processing information, a modulator, and demodulator. To enhance the RFID tag, a microcontroller (or processor) and sensor are incorporated that allow sensing and optional computational functions to occur. RFID tags can be passive tags, active RFID tags, and battery-assisted passive tags. Generally, passive tags use no battery and do not transmit information unless they are energized by a RFID reader. Active tags have an on-board battery and can transmit autonomously (i.e., without being energized by a RFID reader). Battery-assisted passive tags typically have a small battery on-board that is activated in the presence of a RFID reader.
In one illustrative embodiment, the enhanced RFID technology is a Wireless Identification and Sensing Platform (WISP) device. WISPs involve powering and reading a WISP device, analogous to a RFID tag (or label), with a RFID reader. The WISP device harvests the power from the RFID reader's emitted radio signals and performs sensing functions (and optionally performs computational functions). The WISP device transmits a radio signal with information to the RFID reader. The WISP device receives power from the RFID reader. The WISP device has a tag or antenna that harvests energy and a microcontroller (or processor) that can perform a variety of tasks, such as sampling sensors. The WISP device reports data to the RFID reader. In one illustrative embodiment, the WISP device includes an integrated circuit with power harvesting circuitry, demodulator, modulator, microcontroller, sensors, and may include one or more capacitors for storing energy. A form of WISP technology has been developed by Intel Research Seattle (www.seattle.intel-research.net/wisp/).
Referring now to the drawings and initially toFIGS. 1-3, asystem100 for treating at least onetissue site102, e.g., awound site104, with reduced pressure is presented. Theillustrative wound site104 is shown throughepidermis108 and into thesubcutaneous tissue110 of apatient106. Thetissue site102 may be the bodily tissue of any human, animal, or other organism, including bone tissue, adipose tissue, muscle tissue, dermal tissue, vascular tissue, connective tissue, cartilage, tendons, ligaments, or any other tissue. Treatment oftissue site102 may include removal of fluids, e.g., exudate or ascites. Unless otherwise indicated, as used throughout this document, “or” does not require mutual exclusivity. Treatment of atissue site102 may include removal of fluids, e.g., exudate or ascites.
Thesystem100 may be used to treat thetissue site102 with reduced pressure to help form granulation tissue (reduced pressure therapy), to remove fluids with out promoting tissue growth, or any other purpose for which reduced pressure is helpful. Thesystem100 includes a first, wireless, reduced-pressure dressing112 for disposing proximate to thetissue site102, aremote base unit114, and a reduced-pressure source116.
The first, wireless, reduced-pressure dressing112 may include adistribution manifold118, a sealing member120 (or drape) covering at least a portion of thedistribution manifold118, afirst RFID antenna122, afirst processor124 coupled to thefirst RFID antenna122, and afirst sensor126 coupled to thefirst processor124. Thefirst processor124 andfirst sensor126 may be associated with aboard127 or housing.
The sealingmember120 creates a fluid seal over thedistribution manifold118 on a portion of a patient'sepidermis108 or may help provide a fluid seal at other locations. “Fluid seal,” or “seal,” means a seal adequate to maintain reduced pressure at a desired tissue site given the particular reduced-pressure source or subsystem involved. The sealingmember120, may include anattachment device128. The sealingmember120 creates a sealedspace130 in which thedistribution manifold118 may be positioned. A reduced-pressure interface132 may be placed through an aperture in the sealingmember120 to provide reduced pressure into the sealedspace130 and in particular to thedistribution manifold118. Other wireless reduced-pressure dressings may be used as part of thesystem100 to accommodate multiple tissue sites, and the additional wireless reduced-pressure dressings may be analogous to the first, wireless, reduced-pressure dressing112.
With respect to thedistribution manifold118, the term “manifold” as used herein generally refers to a substance or structure that is provided to assist in applying reduced pressure to, delivering fluids to, or removing fluids from a tissue site, e.g.,tissue site102. Thedistribution manifold118 typically includes a plurality of flow channels or pathways that distribute fluids provided to and removed from thetissue site102 around thedistribution manifold118. In one illustrative embodiment, the flow channels or pathways are interconnected to improve distribution of fluids provided or removed from thetissue site102. Thedistribution manifold118 may also be a biocompatible material that is capable of being placed in contact with thetissue site102 and distributing reduced pressure to thetissue site102. Examples ofmanifolds118 may include, without limitation, devices that have structural elements arranged to form flow channels, such as, for example, cellular foam, open-cell foam, porous tissue collections, liquids, gels, and foams that include, or cure to include, flow channels. The examples are not mutually exclusive.
Thedistribution manifold118 may be porous and may be made from foam, gauze, felted mat, or any other material suited to a particular biological application. In one embodiment, thedistribution manifold118 is a porous foam and includes a plurality of interconnected cells or pores that act as flow channels. The porous foam may be a polyurethane, open-cell, reticulated foam such as GranuFoam® material manufactured by Kinetic Concepts, Incorporated of San Antonio, Tex. Other embodiments may include “closed cells.” In some situations, thedistribution manifold118 may also be used to distribute fluids such as medications, antibacterials, growth factors, and various solutions to thetissue site102. Other layers may be included in or on thedistribution manifold118 such as absorptive materials, wicking materials, hydrophobic materials, and hydrophilic materials.
In one illustrative embodiment, thedistribution manifold118, or portions of thedistribution manifold118, may be constructed from bioresorbable materials that may remain in a patient's body following use of the wireless, reduced-pressure dressing112. Suitable bioresorbable materials may include, without limitation, a polymeric blend of polylactic acid (PLA) and polyglycolic acid (PGA). The polymeric blend may also include without limitation polycarbonates, polyfumarates, and capralactones. Thedistribution manifold118 may further serve as a scaffold for new cell growth, or a scaffold material may be used in conjunction with thedistribution manifold118 to promote cell growth. A scaffold is a substance or structure used to enhance or promote the growth of cells or formation of tissue, such as a three-dimensional porous structure that provides a template for cell growth. Illustrative examples of scaffold materials include calcium phosphate, collagen, PLA/PGA, coral hydroxy apatites, carbonates, or processed allograft materials.
The sealingmember120 may be any material that provides a fluid seal. The sealingmember120 may, for example, be an impermeable or semi-permeable, elastomeric material. “Elastomeric” means having the properties of an elastomer. It generally refers to a polymeric material that has rubber-like properties. More specifically, most elastomers have ultimate elongations greater than 100% and a significant amount of resilience. The resilience of a material refers to the material's ability to recover from an elastic deformation. Examples of elastomers may include, but are not limited to, natural rubbers, polyisoprene, styrene butadiene rubber, chloroprene rubber, polybutadiene, nitrile rubber, butyl rubber, ethylene propylene rubber, ethylene propylene diene monomer, chlorosulfonated polyethylene, polysulfide rubber, polyurethane (PU), EVA film, co-polyester, and silicones. Additional, specific examples of sealing member materials include a silicone drape, 3M Tegaderm® drape, polyurethane (PU) drape such as one available from Avery Dennison Corporation of Pasadena, Calif.
Theattachment device128 may be used to maintain the sealingmember120 against the patient'sepidermis108 or another layer, such as a gasket or additional sealing member, or another location. Theattachment device128 may take numerous forms. For example, theattachment device128 may be a medically acceptable, pressure-sensitive adhesive that extends about a periphery, a portion, or theentire sealing member120.
The first, wireless, reduced-pressure dressing112 provides reduced pressure to one ormore tissue sites102. As used herein, “reduced pressure” generally refers to a pressure less than the ambient pressure at a tissue site that is being subjected to treatment. In most cases, this reduced pressure will be less than the atmospheric pressure at which the patient is located. Alternatively, the reduced pressure may be less than a hydrostatic pressure at the tissue site. Reduced pressure may initially generate fluid flow in thedistribution manifold118 and proximate thetissue site102. As the hydrostatic pressure around thetissue site102 approaches the desired reduced pressure, the flow may subside, and the reduced pressure may be maintained. Unless otherwise indicated, values of pressure stated herein are gauge pressures. Absolute pressure is referenced at times. The reduced pressure delivered may be constant or varied (patterned or random) and may be delivered continuously or intermittently. Although the terms “vacuum” and “negative pressure” may be used to describe the pressure applied to the tissue site, the actual pressure applied to the tissue site may be more than the pressure normally associated with a complete vacuum. Consistent with the use herein, an increase in reduced pressure or vacuum pressure typically refers to a relative reduction in absolute pressure.
The reduced-pressure interface132 may be a structure or means for fluidly coupling a reduced-pressure delivery conduit134 to thedistribution manifold118. The reduced-pressure interface132 may be a molded structure, a medical conduit (e.g., a portion of reduced-pressure delivery conduit134) applied to thedistribution manifold118, or other device for coupling. As discussed in connection withFIG. 4, a membrane, when in an occlusive state, may prevent or hinder flow of fluid through the reduced-pressure interface132.
The reduced-pressure source116 provides reduced pressure. The reduced-pressure source116 may be any device or source for supplying a reduced pressure, such as avacuum pump136, wall suction, micro-pump, or other source. As an aspect of the reduced-pressure source116 or as a separate member, acanister138 may be included to receive and retainfluids139. Theremote base unit114 may be electrically coupled by coupling140, e.g., wire or wireless signal, to the reduced-pressure source116 to provide a pressure control signal to control the delivery of reduced pressure to the first, wireless, reduced-pressure dressing112 as will be discussed further below. The reduced-pressure source116 and theremote base unit114 may be an integrated unit in some embodiments. “Remote” as used in the context of “remote base unit” typically means displaced from a wireless, reduced-pressure dressing by a distance greater than several millimeters and may include a base unit immediately adjacent to a wireless, reduced-pressure dressing but not electrically coupled.
Thefirst sensor126 may be a pressure sensor and may be coupled to thefirst processor124. Thefirst processor124 is coupled to, or in communication with, thefirst RFID antenna122. Thefirst sensor126 may thus develop a signal indicative of pressure experienced at a desired site in or on the first, wireless, reduced-pressure dressing112 and that signal may be referred to as a pressure message signal. In other embodiments, thefirst sensor126 may be another type of sensor. For example, the first sensor may be one of the following: a pressure sensor, temperature sensor, pH sensor, humidity sensor, Volatile Organic Compounds (VOC) sensor, blood sensor, or growth factors sensor. The reduced-pressure interface132 may include one or more pressure conduits orchannels144 to provide reduced pressure for sampling purposes to thefirst sensor126.
Asecond sensor142 may also be included and coupled to thefirst processor124. Thesecond sensor142 may be any type of sensor such as those previously mentioned for thefirst sensor126. It will be appreciated that thefirst RFID antenna122,first processor124, andfirst sensor126 may comprise a Wireless Identification and Sensing Platform (WISP) device. Thefirst sensor126,second sensor142, or any other sensors may be located at any location in the first, wireless, reduced-pressure dressing112. In one illustrative embodiment, thefirst sensor126 may be adjacent to thedistribution manifold118. In another illustrative embodiment, thefirst sensor126 may be at a remote portion of the sealingmember120. In one illustrative embodiment, the sensors, e.g., thefirst sensor126, may be laminated to the sealingmember120 or otherwise attached to a portion of the sealingmember120 and may sample pressure in the sealedspace130. While twosensors126,142 have been mentioned, it should be understood that additional sensors could be provided if desired.
In one illustrative embodiment, a battery is not associated, with the first, wireless, reduced-pressure dressing112. In other words, the first, wireless, reduced-pressure dressing112 is passive. In such an embodiment, all the necessary energy for thefirst processor124 and first sensor126 (and any additional, optional sensors, e.g., second sensor142) is harvested from signals received by thefirst RFID antenna122 from theremote base unit114. In other embodiments, a battery may be included to provide the necessary power. With the power from the battery, the first, wireless, reduced-pressure dressing112 may transmit signals independent of any signal from theremote base unit114. In another illustrative embodiment, a battery may be included to provide a portion of the necessary power.
Theremote base unit114 may include a board orother structure115 that includesRFID reader146 and asecond processor148. Theremote base unit114 may also include afirst display152, e.g., apressure indicator154. Thefirst display152 or indicator is for displaying a quantity measured by thefirst sensor126 or an indication of adequate pressure. Similarly, additional displays or indicators may be included, e.g., atemperature display156. One display may be used for displaying multiple items, e.g., the data from multiple sensors. Acontrol panel158, such as a push-button panel or graphical user interface, may be included to receive input from a user. Thesecond processor148 may be coupled by coupling140 to the reduced-pressure source116 to provide a control signal. The control signal allows for automated adjustments to the pressure at thetissue site102 by controlling the pressure supplied by the reduced-pressure source116.
TheRFID reader146 may be a transceiver for transmitting to and receiving signals from thefirst RFID antenna122. If not already converted, theRFID reader146 may convert received signals to digital format and provide the signals to thesecond processor148. Theremote base unit114 may read signals as close as several millimeters away or as far as 30 feet or more away or any distance between, e.g., 5, 10, or 20 feet. Theremote base unit114 may poll as often as desired, e.g., every ½ second, every second, every hour, or any other time interval.
Thesecond processor148 includes memory and instructions necessary to perform various desired steps. For example, a pairing protocol may be executed. In the pairing protocol, thesecond processor148 with theRFID reader146 transmits an ID inquiry signal to the first, wireless, reduced-pressure dressing112 to inquire about the identification of the first, wireless, reduced-pressure dressing112. In response, thefirst processor124 transmits an ID message signal. If the first, wireless, reduced-pressure dressing112 is not suitable for use with theremote base unit114 as determined by comparing the ID message with an approved list or by information contained in the ID message signal itself, theremote base unit114 will not proceed with executing instructions as part of therapy. This protocol should safeguard against using a dressing that is not approved and which may underperform with theremote base unit114.
As an illustrative example, thesecond processor148,RFID reader146,first RFID antenna122, andfirst processor124 may be configured to perform the following steps: transmitting an ID inquiry signal from theremote base unit114 to the first, wireless, reduced-pressure dressing112; receiving the ID inquiry signal at the first, wireless, reduced-pressure dressing112 and producing an ID message signal; transmitting the ID message signal from the first, wireless, reduced-pressure dressing112 to theremote base unit114; receiving the ID message signal at theremote base unit114; determining if the ID message signal represents a dressing on an approved list; and activating the reduced-pressure source116 to provide reduced pressure to thedistribution manifold118 if the ID message signal represents a dressing that is on the approved list (or otherwise acceptable) or indicating an error if the ID message signal represents a dressing that is not on the approved list.
Referring now primarily toFIG. 4, another illustrative embodiment of a first, wireless, reduced-pressure dressing112 is presented. The first, wireless, reduced-pressure dressing112 is analogous to the first, wireless, reduced-pressure dressing112 ofFIGS. 1-3 in most respects. A sealingmember120, or film, covers thefirst RFID antenna122,first processor124, andfirst sensor126. In this embodiment, a reduced-pressure interface (not shown but analogous to reduced-pressure interface132 ofFIG. 1) may be coupled over anaperture121 in the sealingmember120 to allow fluid communication, but initially amembrane160 prevents or hinders flow through theaperture121.
Themembrane160 may have an occlusive state and a non-occlusive state. Themembrane160 may be in the occlusive state when themembrane160 is an integral layer and may be non-occlusive when one or more apertures are created in themembrane160 that allow fluid flow through the membrane. When initially overaperture121 in the occlusive state, flow through theaperture121 is prevented (or substantially hindered), but when themembrane160 is changed to the non-occlusive state, flow through themembrane160 and, thus, through theaperture121 may occur. Themembrane160 may move from the occlusive state to the non-occlusive state in response to an activating event, e.g., the application heat, light, ultrasound, a chemical, or other activating agent. For example, in one illustrative embodiment, adissolution element162 is disposed proximate to themembrane160 and is adapted to (or operable to) change themembrane160 from an occlusive state to a non-occlusive state. Thedissolution element162 may be activated by thefirst processor124 to produce the activating event. In other embodiments, thedissolution element162 may be activated by thesecond processor148 or an external stimulus.
Thedissolution element162 may be, for example and not by way of limitation, an electrically resistive heating element. Power may be supplied from thefirst processor124 to thedissolution element162 to sufficiently activate the electrically resistive heating element to melt, dissolve or otherwise create an aperture in themembrane160. In another illustrative embodiment, thedissolution element162 is an ultrasonic device that creates an aperture inmembrane160 when activated. In another illustrative embodiment, thedissolution element162 is a chemical distribution device that upon receiving a signal from thefirst processor124 releases an agent that causes themembrane160 to dissolve, at least in part, to create anaperture121. In still another illustrative embodiment, thedissolution element162 is a light with a first wavelength and themembrane160 reacts to the light with the first wavelength and dissolves at least a portion to create an aperture.
Themembrane160 may be made from numerous materials depending on the activation device used as thedissolution element162. For example, themembrane160 may comprise a semi-crystalline thermoplastic film, such as LDPE, HDPE, PP, PA, having a thickness in the range 15-100 μm. The exact thickness of themembrane160 depends on the material selected and the level of reduced pressure that themembrane160 will be required to resist. The temperature required to rupture themembrane160 should be approaching or at the melting point of the polymer chosen. If heated whilst themembrane160 is under strain from applied negative pressure, the temperature required to breakdown or dissolve themembrane160 may be reduced.
Thedissolution element162 may be a component laminated to themembrane160 during the manufacture of themembrane160 or attached later in production. Thedissolution element162 may be a conductive component that is molded into themembrane160 or added to themembrane160 so that themembrane160 itself is conductive. The conductive material may be metallic or one of the other materials that are commonly used to provide conductivity to polymers. Although the temperature required to melt some of the membrane or film materials mentioned may be greater than 100° C., thedissolution element162 is separated from the patient sufficiently to avoid injury or other potential complications. Moreover, themembrane160 may be extremely thin such that very little energy is required to form an aperture through themembrane160.
Referring now primarily toFIGS. 1-4, if the first, wireless, reduced-pressure dressing112 includes themembrane160 anddissolution element162, an initial activation may be carried out by theremote base unit114 andfirst processor124. As an illustrative example, theremote base unit114 may transmit an activation signal from theremote base unit114 to the first, wireless, reduced-pressure dressing112. Upon receiving the activation signal, thefirst processor124 activates thedissolution element162 to change themembrane160 to the non-occlusive state such as by creating an aperture over theaperture121. Reduced pressure from the reduced-pressure source116 may then be delivered through the reduced-pressure interface132 and theaperture121 to thedistribution manifold118. If a user is attempting to use a remote base unit that is not designed for use with the first, wireless, reduced-pressure dressing112, the remote base unit will not respond to the activation signal and will not change themembrane160 from the occlusive state to the non-occlusive state. Accordingly, the first, wireless, reduced-pressure dressing112 would be unable to establish fluid flow through themembrane160 to thedistribution manifold118.
According to one illustrative embodiment, in operation, the first, wireless, reduced-pressure dressing112 is disposed proximate to thetissue site102. Thedistribution manifold118 is placed adjacent to thetissue site102. The sealingmember120 is releaseably attached to theepidermis108 with theattachment device128. The reduced-pressure delivery conduit134 is fluidly coupled between the reduced-pressure interface132 and the reduced-pressure source116. Theremote base unit114 may be activated by the user with thecontrol panel158.
Theremote base unit114 may initially transmit an activation signal to the first, wireless, reduced-pressure dressing112 to cause themembrane160 to change from an occlusive state to a non-occlusive state as previously described. Theremote base unit114 may then transmit an ID inquiry signal to identify the dressing type. The first, wireless, reduced-pressure dressing112 receives the ID inquiry signal and, in response, transmits an ID message signal indicative of the dressing type. Thesecond processor148 may receive the ID message signal and look up the ID message signal or otherwise determine if the dressing represented by the ID message signal is acceptable. If the dressing is acceptable, thesecond processor148 may cause a control signal to be sent, e.g., by coupling140, to the reduced-pressure source116 to activate the reduced-pressure source116 and begin treatment with reduced pressure. In another embodiment, the dressing type may be validated before an activation signal is sent.
Theremote base unit114 may be configured to transmit a pressure inquiry signal to the first, wireless, reduced-pressure dressing112. In response, the first, wireless, reduced-pressure dressing112 ascertains the pressure with thefirst sensor126 and transmits a pressure message signal to theremote base unit114. Based on the pressure message signal, theremote base unit114 determines if the pressure is greater than a first target pressure (on an absolute scale), and if so, continues operation of the reduced-pressure source116. But if the pressure message signal indicates that the pressure is less than the first target pressure (on absolute scale), thesecond processor148 may send a control signal stopping the reducedpressure source116 from delivering reduced pressure. Operation of the reduced-pressure source116 may be by manipulation of a valve or power to a vacuum pump or other like techniques. Theremote base unit114 may interrogate the first, wireless, reduced-pressure dressing112 from time to time to monitor the pressure. If the pressure becomes greater than the first target pressure (on an absolute scale), the reduced-pressure source116 will again be activated by a control signal. Thus, a feedback loop may be utilized.
If a patient has a plurality oftissue sites102 requiring treatment, a plurality of wireless, reduced-pressure dressings may be used. For example, the first, wireless, reduced-pressure dressing112 may be placed at thefirst tissue site102 and a second, wireless, reduced-pressure dressing (not shown, but analogous to the reduced-pressure dressing112) may be placed at a second tissue site. Because the signals include unique identification information, theremote base unit114 may communicate with both the first, wireless, reduced-pressure dressing112 and the second, wireless, reduced-pressure dressing. This arrangement allows monitoring and control of reduced pressure at each of the plurality of tissue sites. Multipleremote base units114 may also be used. For example, eachfirst processor124 may include dynamic RAM that includes a register that is configured when paired to a particularremote base unit114. Thus, the first, wireless, reduced-pressure dressing112 is able to distinguish whichremote base unit114 has been assigned. The first, wireless, reduced-pressure dressing112 may include a reset button that transmits a reset signal to thefirst processor124 to allow the dressing and base association to be changed.
Referring now primarily toFIG. 5, another illustrative embodiment of asystem100 for treating at least onetissue site102 with reduced pressure is presented. Thesystem100 includes a first, wireless, reduced-pressure dressing112. Thesystem100 is analogous in most respects to thesystem100 ofFIG. 1, except that a reduced-pressure source116 is a micro-pump117, e.g., a piezoelectric pump, and is adjacent to thedistribution manifold118. In addition, anabsorbent layer119 is also explicitly included. As used throughout this document in connection with the micro-pump117, “adjacent” means next to, in the vicinity of, and also includes in.
Adedicated battery166 may be coupled to the micro-pump117 to provide power to themicro-pump117. Avent line168 may be used to allow the micro-pump117 to vent or exhaust outside of the first, wireless, reduced-pressure dressing112. In this embodiment, a first processor (analogous tofirst processor124 ofFIG. 3) that is associated with a WISP orRFID device170, may be instructed by theremote base unit114 to deliver a control signal to the micro-pump117 when necessary. In another illustrative embodiment, the first processor may receive a pressure message signal indicative of the pressure at thedistribution manifold118, compare the pressure to a target pressure, and in response deliver a control signal to themicro pump117 to control the micro-pump117 as needed. In another illustrative embodiment, thedevice170 may harvest power to not only energize the first processor and first sensor, but also the micro-pump117. It should be noted that a capacitor (not explicitly shown) may be included to help build and retain a charge for powering devices in the first, wireless, reduced-pressure dressing112.
Referring now toFIGS. 3,4, and6, and primarily toFIG. 6, a treatment process that may be executed with thesystem100 is presented. The process begins at200. Atstep202, theremote base unit114 transmits an activation signal to the first, wireless, reduced pressure dressing112. Thefirst RFID antenna122 receives the activation signal. The activation signal energizes thefirst processor124. Thefirst processor124 activates thedissolution element162. Thedissolution element162 changes themembrane160 from an occlusive state to a non-occlusive state that allows flow. It should be appreciated that the need to change themembrane160 to a non-occlusive state helps make sure that only appropriate (approved)remote base units114 are used with the first, wireless, reduced-pressure dressing112.
Atstep204, theremote base unit114 transmits an ID inquiry signal to the first, wireless, reduced-pressure dressing112. Thefirst RFID antenna122 receives the ID inquiry signal. The ID inquiry signal energizes thefirst processor124 and provides an identification request to thefirst processor124. In response, thefirst processor124 transmits an ID message signal from thefirst RFID antenna122 to theRFID reader146 on theremote base unit114. Theremote base unit114 waits for the ID message signal atinterrogatory206.
Atinterrogatory206, thesecond processor148 waits a predetermined time for the ID message signal. If the ID message signal is not received during the predetermined time, the process proceeds to step208 where an error flag is posted and the process ends at210. The error flag may include posting a message for display atcontrol panel158 or sounding an alarm or providing other notification. If the ID message signal is received, the process proceeds tointerrogatory212.
Atinterrogatory212, inquiry is made as to whether the ID message signal represents a dressing that is acceptable or approved. To answer the inquiry, thesecond processor148 compares the dressing represented by the ID message signal with a list of acceptable or approved dressings. If the dressing represented by the ID message signal is on the list of acceptable or approved dressings, the process continues to step214 and if not the process proceeds to step208 and an error flag is posted and the process ends at210.
Atstep214, a first chronograph, T1, is initiated to keep a running cycle time. The process then proceeds to step216. Atstep216, thesecond processor148 provides a control signal viacoupling140 to the reduced-pressure source116 to activate the reduced-pressure source116. Once the reduced-pressure source116 is activated, reduced pressure flows to the first, wireless, reduced-pressure dressing112.
Atstep218, theremote base unit114 transmits a pressure inquiry signal to the first, wireless, reduced-pressure dressing112. Thefirst RFID antenna122 receives the pressure inquiry signal. The pressure inquiry signal energizes thefirst processor124 andfirst sensor126. In response, thefirst processor124 transmits a pressure message signal to theremote base unit114. TheRFID reader146 receives and delivers the pressure message signal to thesecond processor148. Atinterrogatory220, thesecond processor148 then compares the pressure message signal, which indicates the pressure substantially at thedistribution manifold118 or other desired location, with a target pressure. If the pressure message signal indicates a pressure that is greater than the target pressure on an absolute scale, then more reduced pressure is needed and the delivery of reduced pressure continues. The process proceeds tointerrogatory222. On the other hand, if the pressure message signal indicates a pressure that is less than the target pressure on an absolute scale, then the process proceeds to step224.
Atdecision step222, thesecond processor148 compares the elapsed time of the first chronograph, T1, with a maximum time, T1max. If the maximum time has been exceeded, the process continues to step226. Atstep226, thesecond processor148 posts an error flag and the process ends at228. The error flag may include sounding an alarm or displaying a message on thecontrol panel158 or otherwise notifying the user of a problem. If the maximum time has not been exceeded, the process returns to step218. The loop (218,220,222,218, . . . ) continues until the maximum time is exceeded or a suitable reduced pressure is reached.
Once the pressure is suitable, the process proceeds to step224 where thesecond processor148 initiates a therapy chronograph that keeps an elapsed time, T2, for therapy. Next, atstep230, thesecond processor148 initiates a cycle chronograph, T3. The process then proceeds tointerrogatory232, wherein the elapsed therapy time, T2, is compared to a maximum allowed value. If the elapsed therapy time, T2, is greater than the maximum allowed value, then a flag indicating that therapy is complete is given atstep234 and the process ends250. Otherwise, the process continues to step236.
Atstep236, theremote base unit114 transmits a pressure inquiry signal to the first, wireless, reduced-pressure dressing112. Thefirst RFID antenna122 receives the pressure inquiry signal. The pressure inquiry signal is then delivered to thefirst processor124. The pressure inquiry signal energizes thefirst processor124 and thefirst sensor126. In response, thefirst processor124 develops a pressure message signal. Thefirst processor124 andfirst RFID antenna122 transmit the pressure message signal to theremote base unit114. The pressure message signal is received and delivered to thesecond processor148. Atinterrogatory238, the pressure at the distribution manifold118 (or other desired location) as represented by the pressure message signal is compared to a target value on an absolute scale. If the pressure is greater than the target value, reduced pressure needs to be applied (or continued), and thesecond processor148 transmits (or continues) a control signal to the reduced-pressure source116 atstep240. If the pressure is less than the target value, the process pauses atstep242 and continues to monitor pressure by returning to step230.
Atinterrogatory244, the elapsed cycle time, T3, is compared to a maximum value, T3max. If the elapsed cycle time T3 is greater than the maximum value T3max, thesystem100 is apparently unable to adequately lower the pressure. Such a condition may occur because of a leak. Accordingly, an error flag or alarm is initiated atstep246 and the process ends248. If the elapsed cycle time, T3, is less than the maximum value, T3max, the cycle continues with the process going to interrogatory232.
The process presented inFIGS. 6A-6B is one illustrative embodiment. Many embodiments are possible. Other process flows may include analogous instructions for receiving temperature message signals from thesecond sensor142 or other data depending on the sensor type. In another illustrative embodiment, the activation step may follow the steps required to confirm an approved dressing.
Since the pressure measurements are taken at the first, wireless, reduced-pressure dressing112 and wirelessly transmitted to theremote base unit114, the reduced-pressure delivery conduit134 may be relatively smaller as a pressure sensing lumen is not required as part of the reduced-pressure delivery conduit134. In other words, pressure is measured and the pressure signal is transmitted to theremote base unit114 without transmission through a wire and without requiring sampling pressure to be communicated through the reduced-pressure delivery conduit134.
In another illustrative embodiment, the first, wireless, reduced-pressure dressing may be a distribution manifold enclosed by a drape that has been fenestrated or otherwise allows flow. This illustrative embodiment is suitable for use in a body cavity that is closed, such as placing one in an abdominal cavity and monitoring pressure therein. In such an embodiment, the pressure sensor or other sensors may be located anywhere in or on the dressing and are operable to communicate with a remote base outside of the body cavity. In one embodiment, the pressure sensor may be located at peripheral edge of the dressing that is used in an abdominal cavity. The peripheral edge is disposed near the patient's paracolic gutter to monitor pressure and fluid removal.
The RFID antenna and first processor may be adapted to provide an identification message signal for other purposes than those previously presented. For example, in addition to utilization of the identification message signal to confirm proper pairing of a dressing and base, the identification message signal may be used for inventory purposes. A scanner with a RFID reader may be used to scan a wireless, reduced-pressure dressing and receive the identification message signal.
In another illustrative embodiment, a release pouch is provided that contains a fluid. The release pouch may be formed as part of a wireless, reduced-pressure dressing. The release pouch may be formed, for example, by an additional membrane attached on a patient-facing side of the sealing member. A dissolution element analogous todissolution element162 may be associated with the release pouch. The dissolution element allows thefirst processor124 to selectively dissolve or open a portion of the release pouch to release any contents of the pouch. Thus, the release pouch may be used to retain medicines or other substances and a wireless signal may be sent to the wireless, reduced-pressure dressing causing release of the medicine. For example, if a sensor detects bacterial colonization, a signal may be sent, opening the pouch and releasing an anti-biotic, or if high blood content is detected, a signal may be sent releasing a coagulent.
In some embodiments of the wireless, reduced-pressure dressing, the RFID antenna may be remote from the first processor, but electrically coupled to the first processor. For example, a larger RFID antenna may be used on the patient near the tissue site to be treated, and a coupling wire may extend from the RFID antenna to the first processor or first sensor adjacent to or on the distribution manifold.
Although the present invention and its advantages have been disclosed in the context of certain illustrative, non-limiting embodiments, it should be understood that various changes, substitutions, permutations, and alterations can be made without departing from the scope of the invention as defined by the appended claims. It will be appreciated that any feature that is described in connection to any one embodiment may also be applicable to any other embodiment.
It will be understood that the benefits and advantages described above may relate to one embodiment or may relate to several embodiments. It will further be understood that reference to “an” item refers to one or more of those items.
The steps of the methods described herein may be carried out in any suitable order, or simultaneously where appropriate.
Where appropriate, aspects of any of the embodiments described above may be combined with aspects of any of the other embodiments described to form further examples having comparable or different properties and addressing the same or different problems.
It will be understood that the above description of preferred embodiments is given by way of example only and that various modifications may be made by those skilled in the art. The above specification, examples and data provide a complete description of the structure and use of exemplary embodiments of the invention. Although various embodiments of the invention have been described above with a certain degree of particularity, or with reference to one or more individual embodiments, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the scope of the claims.