Patent Description:
Chronic wound infection represents a significant healthcare problem worldwide. Often the end objective of wound healing is the objective for new therapeutic options. Yet chronic wounds compromise a number of different and complex conditions that each interferes with the healing process. For example, a chronic wound can comprise necrotic tissue in need of debridement, bacterial infection in need of antimicrobial agents and compromised vasculature that impedes the normal healing process.

One element of the chronic wound infection condition that impedes healing is the formation of biofilm. Biofilm is the result of planktonic bacteria forming together and secreting exopolysaccharide (EPS) to adhere and protect the colonizing community. At the height of formation, EPS can make up between <NUM>-<NUM>% of the total biofilm composition (Regt). Biofilm inhibits healing by creating an optimal condition for bacteria to grow, while simultaneously preventing antimicrobial agents from direct access to bacteria.

Methods to remove biofilm include ultrasonic debridement, topical antimicrobials, suction, and surface cleansing. Each of these methods alone treat an aspect of biofilm. For example, ultrasonic debridement of wounds has proven to be the most effective mechanism in disrupting and debulking a majority of the biofilm formation. Yet even in this preferred method, biofilm debris can be left behind to propagate. Suction alone has not proven to be effective in removing biofilm, and can potentially interfere with the operation of other methods like ultrasonic debridement if applied simultaneously.

<CIT> describes a medical treatment apparatus that combines an ultrasound sonotrode with a suction sheath. The fixed position between the tip of the suction and the tip of the sonotrode only allows for one simultaneous operation. In particular this approach is limited due to the potential interference of the suction tip during the ultrasonic debridement operation.

<CIT> describes a method and apparatus for ultrasonic cleaning of biofilm coated surfaces for sinus cavities within a human head. The method describes an ultrasonic application in combination with irrigation and suction that is designed to not remove any of the surrounding underlying tissue. This differs significantly from an ultrasonic debridement of a wound bed, which requires the removal of tissue in combination with biofilm. Thus the ultrasonic probe needs to operate in a cavitation mode at the surface of a wound, causing destruction of the biofilm.

<CIT> discloses a spinal treatment device comprising an ultrasonic probe having an operative tip with a channel extending longitudinally therein and a sheath disposed about said probe wherein a distal end portion of said sheath extends distally beyond said operative tip.

Methods of mechanical removal of biofilm in wounds alone have proven to be inadequate. What does not exist and what would be beneficial to the market is a method to remove biofilm and prevent it from reforming in order to allow wounds to heal.

A particular kind of wound in which biofilm may form is at a site of prosthesis implantation. It is not uncommon for infection to crop up at sites of prosthetic implants. Frequently the prostheses must be removed in whole or in part to enable cleaning of the implantation site. In addition, the prosthetic parts, which are generally reinserted into the patient must be cleaned of biofilm.

The invention aims in part to provide a method and instrumentation for inhibiting or reducing biofilm from a hard target surface, e.g., metal, surface of a prosthesis or medical surgical instrument.

The present invention is more particularly or additionally directed to a method for removing biofilm which reduces and preferably minimizes any dispersion of atomized fluid particles from the target site, including surfaces of prostheses which have been removed from a host or patient. The present invention accordingly aims to provide apparatus for removing biofilm with structure to assist not only in biofilm reformation reduction but also in reduction of particle dispersion during the treatment or cleaning process.

According to an aspect of the invention, there is provided a device for removing biofilm from hard surfaces of manufactured articles such as surgical instruments and medical prostheses as claimed in claim <NUM>.

According to a further aspect of the invention, there is provided a cleaning method using a device for removing film from hard surfaces of manufactured articles such as surgical instruments and medical prostheses as claimed in claim <NUM>.

The present invention aims to provide apparatus that may be used for the inhibition of biofilm on wounds and injured organic tissues. The method and apparatus of the invention may be used in a surgical room cleansing process and a disruption and removal of biofilm from hard surfaces of a manufactured article and exemplarily from surgical instruments and prosthesis components.

A prosthesis and instrument cleaning method in accordance with the present invention utilizes an ultrasonic cleaning instrument having an ultrasonic probe with an operative tip and a first channel. The instrument includes a sheath or sleeve with a distal tip, the sheath or sleeve defining a second channel extending outside the probe. The second channel has an inlet proximate the distal tip of the sheath or sleeve. The method comprises manipulating the instrument to place the distal tip of the sheath or sleeve against a target surface such as a surface of a prosthesis needing cleaning. The instrument is manipulated to place the sheath or sleeve so that it extends in part distally of the operative tip of the probe and serves in part to maintain or create a spacing between the probe's operative tip and the target surface. The manipulating of the instrument to place the distal tip of the sheath or sleeve against the target surface inherently positions the operative tip at a distance from the target surface. This distance defines a space, chamber or fluid-holding area that constitutes an ultrasound coupling zone wherein irrigation liquid is temporarily contained. The irrigation fluid thus captured between the operative tip of the probe and the target surface serves to (a) transmit ultrasonic pressure waves to the target surface from the operative probe tip, (b) capture, entrain and emulsify biofilm fragments generated by the ultrasonic pressure waves or cavitation at the target surface, and (c) facilitate removal of the biofilm fragments as well as any toxins such as bacteria that may be present in the biofilm.

During contact of the distal tip of the sheath or sleeve with the target surface, one feeds an irrigation fluid through the channel in the probe to a region between the operative tip of the probe and the target surface. Also during contact of the distal tip of the sheath or sleeve with the target surface, an ultrasonic standing wave is generated in the probe to vibrate the operative tip thereof and thereby fragment undesired material at or on the target surface. During the generating of the ultrasonic standing wave, vacuum or negative pressure is applied to the second channel to remove fluid from the target surface.

The sheath or sleeve is longitudinally shiftable relative to the probe. The method further comprises shifting the sheath or sleeve in a distal direction along the instrument prior to the manipulating of the instrument to place the distal tip of the sheath against the target surface. Variability in the longitudinal position of the sheath or sleeve relative to the probe enables the user to adjust the height of the coupling space or chamber between the operative surface of the probe and the target surface. The height may be close to zero, in which case the operative tip of the probe may be placed in contact or near contact with a target surface.

The second channel is located between the sheath or sleeve and the probe of the instrument. The method also comprises shifting the sheath or sleeve in a proximal direction after the generating of the ultrasonic standing wave and thereafter applying a vacuum or negative pressure to the second channel to suck ambient air into and through the second channel.

Preferably, the irrigation fluid includes a disinfectant or biocide such as hypochlorous acid and/or metal ion hypochlorite. This disinfectant or biocide is advantageously generated on site, at or immediately prior to the treatment by ultrasound, thereby ensuring an effective concentration of the hypochlorous acid. The hypochlorous acid and/or metal ion hypochlorite may be produced from a sterile saline solution through an electrolytic process.

A device in accordance with the present invention comprises an ultrasonic probe having an operative tip and a first channel extending longitudinally therein. An electromechanical transducer is operatively connected to the probe for generating an ultrasonic standing wave in the probe to vibrate the operative tip at ultrasonic frequency. At least one sheath or sleeve is disposed about the probe and defines a second channel outside the probe. The second channel has at least a first port in a region about a distal end of the probe, proximate the operative tip. The sheath or sleeve has an operative configuration wherein a distal end portion of the sheath or sleeve extends distally beyond the operative tip of the probe to define or enclose an ultrasound coupling space between the operative tip and a hard target surface of a manufactured article such as a surgical instrument or medical prosthesis.

During the use of the instrument, an irrigant is delivered to the distal end of the probe preferably through the first channel but possibly through the second channel and accumulates to act as a coupling medium in the space between the operative tip of the probe and a selected target surface. The ultrasonic vibrations are transmitted through the coupling medium irrigant from the probe tip to generate disruptive cavitation or other micron-sized mechanical and thermal disturbances at the target surface.

The distal end portion of the sheath or sleeve, the operative tip of the probe, and the target surface define a chamber or enclosure that (<NUM>) ensures a separation of the operative probe tip from the target surface and yet (<NUM>) enables effective coupling for ultrasound pressure wave transmission, owing to the containment of liquid irrigant in the chamber or enclosure, while reducing spray or atomized detritus and containing the detritus and potential pathogenic particles for removal via the suction channel in the sheath or sleeve.

The sheath or sleeve is longitudinally slidable relative to the probe to shift between a distal or extended position in the operative configuration and a proximal or retracted position. In the distal-most or extended position of the sheath or sleeve the probe head is covered while in a proximal-most position of the sheath or sleeve at least a portion of the probe head is exposed. The instrument may be provided with a locking mechanism, such as a set screw, a clamp, or a friction fit, which holds the sheath or sleeve in either the extended position or the retracted position, and optionally any position therebetween.

Preferably, the probe and the sheath or sleeve define a first space or channel and a second space or channel generally laterally or to the side of the probe, the second space or channel being located proximally of the first space or channel and having a larger transverse cross-sectional area, in a plane orthogonal to an axis of the probe, than the first space or channel. The probe may be provided at or in a distal end portion with at least one aperture spaced from the outlet and communicating with the first space or channel, the sheath being provided with an aspiration arm having an aspiration channel communicating with the first space or channel and the second space or channel.

The probe may exemplarily include a proximal body section, a smaller-diameter horn section, and a probe head. The horn section extends distally of the body section, and the head is formed at a distal end of the horn section.

In a specific embodiment, the distal end portion of the sheath or sleeve is formed with a plurality of longitudinally extending fingers separated by one or more gaps or spaces.

The distal end portion of the sheath or sleeve is formed with one or more one apertures in a sidewall, the aperture(s) being spaced from the distal edge or tip of the sheath or sleeve. The gaps and apertures serve as air inlets for the ingress of air into the coupling space or chamber, which enables the removal of the coupling medium and collected detritus via a suction port typically at the proximal end of the coupling space or chamber, and which serves to prevent the egress of atomized irrigant and pathogenic particles from the treatment zone. The rate of irrigant flow is preferably sufficiently great not only to remove the biofilm particles and pathogenic components from the treatment site but also to cool the probe if warranted.

Disclosed for reference is the treatment of organic tissues by the use of an apparatus disclosed herein. This typically includes a mechanical (e.g., ultrasound) debridement for the removal of any existing necrotic tissue, surface infection or previously formed biofilm. The mechanical debridement process results in a clean wound bed of healthy granulated tissue. Substantially immediately following the mechanical debridement of a wound, an ultrasound biofilm disrupter pad may be placed on or near the wound to prevent bacterial adherence to the wound bed by excretion of EPS. The ultrasound biofilm disrupter prevents adherence of bacteria to the wound by application of surface acoustic waves at a sufficient frequency and amplitude to disrupt formation but below a threshold that stimulates bacterial growth. In order to accomplish this, a wound-dressing device, which incorporates a disposable ultrasonic transducer, may be applied to the wound site post debridement for duration sufficient to allow healing to occur.

Ultrasound is preferably combined with suction as discussed hereinabove to create an optimal combination for disruption and removal of biofilm from a target surface. As discussed above, the present method and apparatus provides a cavitation antechamber, as it were, distal of the ultrasonic probe which serves in part to optimize the capture and removal of mechanically removed biofilm remnants.

In this combined ultrasound and suction approach, the ultrasonic cleaning probe is housed by a suction probe that optionally operates in two stages. The first stage is with the ultrasonic cleaning probe in contact or near contact (via the coupling space or antechamber) with the target surface and the suction tip surrounding the ultrasound application tip so that it is in contact with the target surface simultaneously to remove the mechanically disrupted biofilm. In the second stage of operation the suction tip can be moved to a position that is not in contact or near contact with the target surface, but sufficient enough to capture any biofilm debris that is propelled into the area.

As indicated above, the combination of ultrasound and suction may have one or more stages of operation. The positioning of the suction tip in relationship to the ultrasound tip can be configured for a variety of different combinations to cause better mechanical disruption and capture of that disrupted biofilm. The combination of both ultrasonic energy to cause biofilm disruption and suction to cause removal can be done in a variety of different sequences. For example, ultrasonic mechanical biofilm removal can be performed prior to engaging suction to capture any remnant amounts of biofilm. In a preferred embodiment the ultrasonic mechanical action is performed simultaneous to applying suction either at the tip or near the tip.

The present invention contemplates that the suction is incorporated into the ultrasonic cleaning instrument to allow for a mechanical disruption and immediate capture of biofilm fragments. Preferably the suction port is proximate the tip of the ultrasonic cleaning probe to allow for maximum capture of the mechanically disrupted biofilm. The sheath or sleeve is disposable (to avoid risk of cross contamination) and incorporates a suction channel for capturing biofilm during an ultrasonic cleaning or biofilm-removal process. The sheath has multiple positions for use during an ultrasonic cleaning procedure. The sheath can capture both the debris that is expelled during the cleaning and any remaining debris at the target surface. The sheath may incorporate a sealing strategy to maintain suction pressure while still allowing for multi positioning on the suction tip in relationship to the ultrasonic cleaning tip.

In another embodiment, the suction is interspersed throughout the ultrasonic cleaning probe so that any area of mechanical disruption has a corresponding area of capture capability.

Accordingly, a medical prosthesis or instrument cleaning method pursuant to one aspect of the present invention utilizes an ultrasonic cleaning instrument having an operative tip and a suction channel. The method comprises (i) manipulating the instrument to place the operative tip a preselected target surface, (ii) during contact of the operative tip with the target surface, generating an ultrasonic standing wave in the instrument, thereby fragmenting biofilm and undesired organic material on the target surface, (iii) during the generating of the ultrasonic standing wave, disposing a suction inlet at a distal end of the suction channel proximate the surgical site and (iv) applying vacuum or negative pressure to the suction channel to remove organic debris or fragmented organic material from the target site via the suction inlet.

In the biofilm removal procedure as described herein, one may dispose a suction port at a selected position spaced from the target site, and during and/or after the generating of the ultrasonic standing wave and the fragmenting of biofilm and material, draw ambient air from a region about the target site through the suction port at the selected position. Preferably, the suction port is provided on the ultrasonic cleaning instrument, and the method includes operating an actuator to enable the sucking of air through the suction port.

As indicated above, the actuator may include the sheath or sleeve which is slidably mounted to the instrument for longitudinal motion alternately in opposing directions along the shaft or probe portion thereof. The operating of the actuator then includes shifting the sheath or sleeve in an axial direction along the instrument. Where the instrument includes a longitudinally shiftable sheath or sleeve, with the suction channel being located between the sheath or sleeve and a shaft or horn of the instrument, the suction inlet and the suction port may both be defined by the distal end of the sheath or sleeve, the position of the sleeve determining whether an intake opening is located at the operative tip of the instrument, and is thus the suction inlet, or is spaced from the operative tip and is therefore the suction port. Accordingly, the method may further comprise shifting the sheath or sleeve in a proximal direction after the applying of a vacuum or negative pressure and prior to the sucking of the ambient air through the suction port, a distal tip of the sheath or sleeve defining the suction inlet in a distal position of the sheath or sleeve, the distal tip defining the suction port in a proximal position of the sheath or sleeve.

In the variation of a biofilm removal procedure, it is contemplated that the suction inlet and the suction port may be different and always mutually spaced from one another. The position of the slidable sheath or sleeve may determine whether the suction inlet and/or the suction port is active. Thus, the sheath or sleeve may include valves for opening and closing air pathways extending to the suction inlet and the suction port, in dependence on the longitudinal position of the sheath or sleeve. Alternatively, valves may be operated separately via respective electromechanical actuators so that the opening and closing of the suction inlet is controllable independently of the opening and closing of the suction port.

Thus, where the suction port is different from the suction inlet, the suction port being located proximally along the instrument from the suction input, the operating of the actuator may include directing suction under-pressure to the suction port. The actuation may include operating a valve to open a suction pathway to the suction port.

It is noted for reference that, should the inventive apparatus be used in a surgical procedure on tissues of a patient, the method may alternatively or additionally comprise placing an ultrasonic transducer on the patient at least proximate the surgical site after terminating of a debridement process and while the surgical site is free of discernible bacteria. Typically, the transducer is placed immediately after the surgical site has been cleaned of necrotic tissue and other undesirable debris and even prior to the removal of the patient from the operating room. After the placing of the transducer and while the transducer is in effective vibration-transmitting contact with the patient, an electrical energization waveform of an ultrasonic frequency is conducted to the transducer at least intermittently during a period of approximately one day or longer to prevent biofilm formation on the patient at the surgical site and facilitate a healing of the patient's tissue at the surgical site.

The transducer may be affixed to a carrier pad, the placing of the transducer on the patient including attaching the pad to the patient. Alternatively, the transducer may be disposed in a balloon or bladder inflated with a gel or other medium conducive to the effective transmission of ultrasonic pressure waves, the balloon or bladder being attached to the patient over or adjacent the surgical site. Other transducer carriers and methods of attachment to the patient will occur to those skilled in the art.

A surgical device described below comprises an ultrasonic probe having an operative tip, an electromechanical transducer operatively connected to the probe for generating an ultrasonic standing wave in the probe, and at least one sheath or sleeve disposed about the probe and defining at least a first suction port at a distal end of the probe, proximate the operative tip, and a second suction port spaced from the distal end of the probe.

The one or more sheaths or sleeves may take the form of exactly one sheath or sleeve slidably attached to the probe to shift between a distal position and a proximal position, wherein a distal end of the sheath or sleeve is alternately locatable (i) proximate the operative tip to define the first suction port and (ii) at a predetermined distance from the operative tip to define the second suction port.

Alternatively, the first suction port and the second suction port are different openings in the at least one sheath or sleeve. Their operational status may be separately controlled via respective valves. Moreover, the suction ports may be connectable to vacuum sources of different strengths. The magnitude of the vacuum or negative pressure applied to the proximal port is typically greater than the magnitude of the vacuum or negative pressure applied to the distal port.

The sheath or sleeve may define a first suction channel extending to the first suction port and a separate second suction channel extending to the second suction port, the first suction channel and the second suction channel being subjectable to different negative pressures.

Described herein is a method for bacterial containment during application of cleaning ultrasound. In a preferred embodiment, a suction device is incorporated adjacent to the ultrasound applicator to create a path of removal for any bacteria that is being displaced during the cleaning process. The suction device is incorporated in such a way as to orient the orifice of the suction to favorably capture any projected, predicted or anticipated paths of spray the would result from the applicator tip interacting with the target cleaning site. In this the suction device is optimized for the preferential capture of any bacteria that is displaced during ultrasonic fragmentation of biofilm on the target surface. The suction device can also be used to contain irrigation spray that results from the application of ultrasonic energy.

In another embodiment the suction device is integrated into the cleaning probe so that is has ports of capture that are strategically placed to remove bacteria that is displaced during the ultrasonic cleaning process. The suction device is incorporated in such a way as to orient the orifice of the suction to favorably capture any projected, predicted or anticipated paths of spray the would result from the applicator tip interacting with the targeted cleaning site. The suction device can also be used to contain irrigation spray that results from the application of ultrasonic energy.

In another embodiment the suction device is separate from the cleaning probe but is used in coordination to capture any bacteria that is displaced or dispersed during ultrasonic fragmentation, disruption and cleaning. The suction device can be strategically placed adjacent to the area to be cleaned in such a manner that the opening of the suction device creates a preferential path for the capture of displaced bacteria. The suction device can be a ring that defines a specific cleansing area around the ultrasound applicator. The ring device has capture ports that are oriented inward towards the potential treatment areas so that in any direction capture of bacteria that is displaced from the cleaning site. The suction device is incorporated in such a way as to orient the orifice of the suction to favorably capture any projected, predicted or anticipated paths of spray the would result from the applicator tip interacting with the targeted cleaning site. The suction device can also be used to contain irrigation spray that results from the application of ultrasonic energy. The suction device can be secured to the subject prosthesis or surgical instrument temporarily so that it creates a barrier for the bacteria or irrigation spray to be able to get beyond. The temporary attachment can be a strap, an adhesive pad, or another easy-to-place easy-to-remove approach.

In another embodiment, a suction device is incorporated adjacent to the ultrasound applicator to create a path of removal for any bacteria that is being displaced during the ultrasonic disruption, fragmentation and cleaning process. The suction device has two or more positions of use. In the first position the suction device is incorporated in such a way as to orient the orifice of the suction to favorably capture any projected, predicted or anticipated paths of spray the would result from the applicator tip interacting with the targeted site. In this the suction device is optimized for the preferential capture of any bacteria that is displaced by during ultrasound application. In the second position the suction device is incorporated in such a way to come into direct contact with the targeted surface to allow for direct removal of any residual bacteria. The suction device can also be used to contain irrigation spray that results from the application of therapeutic ultrasonic energy.

In another embodiment the suction device is incorporated into an ultrasound applicator that delivers an irrigation stream to the applicator tip. The suction device is a disposable sheath incorporated adjacent to the ultrasound applicator to create a path of removal for any bacteria or irrigation spray that is being displaced during the cleaning treatment. The suction device is incorporated in such a way as to orient the orifice of the suction to favorably capture any projected, predicted or anticipated paths of spray the would result from the applicator tip interacting with the targeted cleaning site. In this the suction device is optimized for the preferential capture of any bacteria that is displaced. The suction device can also be used to contain irrigation spray that results from the application of ultrasonic energy.

In another embodiment a suction device is incorporated into an ultrasound applicator that delivers an irrigation stream to the applicator tip. The suction device is a disposable sheath that is molded onto the single use ultrasound cleaning probe to create a path of removal for any bacteria or irrigation spray that is being displaced during the treatment. The suction device is incorporated in such a way as to orient the orifice of the suction to favorably capture any projected, predicted or anticipated paths of spray the would result from the applicator tip interacting with the targeted site. In this the suction device is optimized for the preferential capture of any bacteria that is displaced during ultrasound application. The suction device can also be used to contain irrigation spray that results from the application of therapeutic ultrasonic energy.

The present disclosure contemplates a two phase method for reducing the formation of biofilm. The first phase is performed where a wound site is being treated for removal of necrotic tissue, eschar or biofilm and includes an evacuation of ambient air from a region about the surgical or treatment site, to extract airborne or aerosolized bacteria ejected from the site by the treatment. The extracted bacteria are prevented from settling back onto the cleansed tissue surface, thus at least reducing colonial bacteriological growth and concomitantly exuded biofilm material. The second phase or approach for reducing biofilm involves the attachment of one or more ultrasonic transducers to the patient over or near a surgical treatment site after the surgery is terminated. Each applied ultrasonic transducer is used to vibrate the patient's tissues at the treatment site to disrupt biofilm formation. The two phases of treatment may be used separately depending on the application. Thus, ultrasonic biofilm disruption may be used at wound sites which have not been subjected to formal processes for removal of necrotic tissue, eschar or biofilm.

Accordingly, a medical therapeutic method may utilize an ultrasonic debridement instrument <NUM> (<FIG>) having an operative tip or surface <NUM> and a suction channel <NUM> defined between an outer surface <NUM> of an ultrasonic horn <NUM> and an inner surface <NUM> of a cannula or sheath <NUM>. The method comprises manipulating the instrument <NUM> to place the operative tip or surface <NUM> against a patient's tissues PT at a preselected surgical site SS. During contact of the operative tip <NUM> with the patient's tissues PT, one operates a waveform generator <NUM> to generate an ultrasonic standing wave in the instrument <NUM> and particularly in probe or horn <NUM>, to thereby fragment necrotic tissue and undesired organic material at the surgical site SS. During the generating of the ultrasonic standing wave, a suction inlet <NUM> at a distal end of the suction channel <NUM> is disposed proximate the surgical site SS and a vacuum or negative pressure is applied to the suction channel <NUM> to suck tissue debris and fragmented organic material from the surgical site SS via the suction inlet <NUM>. A suction port <NUM> of another instrument <NUM> is disposed at a position spaced at a distance D1 from the surgical site SS. During and/or after the generating of the ultrasonic standing wave and the fragmenting of tissue and material by instrument <NUM>, instrument <NUM> is operated to suck ambient air, as indicated by arrows <NUM>, from a region R about the surgical site SS through suction port <NUM>. While suction inlet <NUM> is typically located between <NUM> and <NUM> from the surgical site SS and the tissue surface at the surgical site, suction port <NUM> is typically located <NUM>-<NUM> from the tissue surface at the surgical site SS.

As depicted in <FIG>, instrument <NUM> may be formed at a distal end with an enlarged or expanded extension <NUM>, such as a cone, to funnel air <NUM> into the instrument. A suction source or vacuum generator <NUM> communicating with a lumen <NUM> of instrument <NUM> may exert a greater suction force than that of a suction source or vacuum generator <NUM> communicating with suction channel <NUM>.

In an alternative approach, instrument <NUM> is omitted. Instead, cannula or sheath <NUM> is shiftably mounted to probe or horn <NUM> for longitudinal motion alternately in opposing directions along the shaft or probe portion thereof, thereby enabling the user to position the suction port, defined in part by the distal edge of the sheath, in two or more alternative locations, a most distal location adjacent the operative tip <NUM> of the probe or horn <NUM> and a more proximal location. As indicated by a double headed arrow <NUM>, cannula or sheath <NUM> is pulled in a proximal direction after an operation removing tissue or other organic matter from surgical site SS so that suction port <NUM> is located at a distance d from the operative tip or surface <NUM> of instrument <NUM>. An actuator such as suction source <NUM>, or a switch component thereof, is operated to enable the sucking of air through suction port <NUM> at the retracted position of cannula or sheath <NUM>. In a simple configuration, suction source <NUM> may have twp operating states, on and off, the position of sheath <NUM> determining whether suction is applied at the surgical site SS or at a distance therefrom. In a slightly more complicated configuration, suction source <NUM> may be provided with three operating states, namely, off, high suction and low suction. The degree of suction may be selectable by the operator or may be automatically controlled in accordance with the longitudinal or axial position of sheath <NUM> along probe or horn <NUM>. For instance, sheath or sleeve <NUM> may be provided with valves (not shown) for opening and closing air pathways in dependence on the longitudinal position.

An alternative instrument assembly <NUM> depicted in <FIG> has an operative tip or surface <NUM> and a suction channel <NUM> located between an outer surface <NUM> of an ultrasonic horn <NUM> and an inner surface <NUM> of a first or inner sheath <NUM>. A second, outer, sheath <NUM> surrounds the first sheath <NUM> and defines therewith a second suction channel <NUM> for the evacuation of ambient air from a sizable region R' about the surgical site, exemplarily through a conical port element <NUM> at the distal end of the outer sheath <NUM>. The two suction channels <NUM> and <NUM> may be connected to respective suction sources or vacuum generators <NUM> and <NUM> via respective valves <NUM> and <NUM> both actuatable by the operator via a control unit <NUM>. Control unit <NUM> is tied to a control input (not separately designated) of an ultrasonic waveform generator <NUM> that is operatively connected to probe or horn <NUM> via an electromechanical transducer (not shown) such as a stack of piezoelectric crystals. Control unit <NUM> may be programmed to open valve <NUM> within a selectable time interval after the opening of valve <NUM> and the activation of waveform generator <NUM>.

In a surgical procedure, instrument assembly <NUM> is manipulated to place the operative tip or surface <NUM> against patient's tissues PT' at a preselected surgical site SS'. During contact of the operative tip <NUM> with the patient's tissues PT', control unit <NUM> is operated to activate waveform generator <NUM>, which generates an ultrasonic standing wave in probe or horn <NUM>, to thereby fragment necrotic tissue and undesired organic material at the surgical site SS'. During the generating of the ultrasonic standing wave, a suction inlet <NUM> at a distal end of inner suction channel <NUM> is disposed proximate the surgical site SS' and a vacuum or negative pressure is applied by suction source <NUM> to the suction channel <NUM> via valve <NUM> to suck tissue debris and fragmented organic material from the surgical site SS' through the suction inlet <NUM>. Conical port element <NUM> is disposed at a distance D2 from the surgical site SS'. During and/or after the generating of the ultrasonic standing wave and the fragmenting of tissue and material by instrument <NUM>, vacuum generator <NUM> and valve <NUM> are actuated by control unit <NUM> to suck ambient air, as indicated by arrows <NUM>, from region R' through suction port or cone <NUM>. Suction inlet <NUM> is typically located a minimal distance, exemplarily between about <NUM> and about <NUM>, from tissues at the surgical site SS' while suction port <NUM> distance D2 is typically <NUM>-<NUM> from the surgical site SS'.

Outer sheath <NUM> may be temporarily fixed to inner sheath <NUM> via a quick-release lock <NUM> such as a set screw. Thus, the relative axial positions of sheaths <NUM> and <NUM> may be adjusted to change distance D2. Control unit <NUM> may be connected to suction sources or vacuum generators <NUM> and <NUM> for varying the power usage thereof and average magnitudes of the negative pressures generated thereby.

<FIG> illustrates a modification of the instrument assembly <NUM> of <FIG>. Instead of outer sheath <NUM>, a suction nozzle <NUM> is attached to sheath <NUM>. Nozzle <NUM> is connected to suction source or vacuum generator <NUM> via a reinforced hose <NUM>. Nozzle <NUM> is removably secured to sheath <NUM> via a locking element <NUM> such as a ring clamp or a set screw. The operation of modified instrument <NUM> is as discussed above.

The present method alternatively or additionally comprises placing an ultrasonic transducer <NUM> (see, e.g., <FIG>) in effective contact with a patient TP at least proximate a surgical site SI after terminating of a debridement or other tissue cleaning procedure and while the surgical site SI is free of discernible bacteria. Typically, transducer <NUM> is placed immediately after the surgical site SI has been cleaned of necrotic tissue and other undesirable debris and even prior to the removal of the patient TP from the operating room. After the placing of transducer <NUM> and while the transducer is in effective vibration-transmitting contact with the patient TP, an electrical energization waveform of an ultrasonic frequency is conducted from a waveform generator <NUM> to transducer <NUM> at least intermittently during a period of approximately one day or longer to reduce, if not prevent, biofilm formation on the patient at the surgical site SI and thereby facilitate a healing of the patient's tissue at the surgical site.

As depicted in <FIG>, transducer <NUM> may be affixed to a carrier pad <NUM>, exemplarily sandwiched between layers <NUM> of a biocompatible and ultrasound transmitting material. The placing of transducer <NUM> on the patient TP preferably includes attaching pad <NUM> to the patient, for example, via an adhesive layer <NUM>. As depicted in <FIG>, pad <NUM> is disposed alone or together with one or more other carrier pads <NUM>', on a tissue surface TS proximate surgical site SI. Alternatively, pad <NUM> may be placed directly over the surgical site SI shortly, if not immediately, after tissue removal is complete. In that case adhesive layer <NUM> may be omitted in favor of a layer of gel. The gel may be oxygenated and contain antibiotics. As depicted in <FIG>, straps or bands <NUM> may be provided for securing the pad <NUM> to the patient TP.

Alternatively, as depicted in <FIG>, an electromechanical, specifically, a piezoelectric, transducer <NUM> may be disposed inside a balloon or bladder <NUM> inflated with a gel or other medium <NUM> conducive to the effective transmission of ultrasonic pressure waves, the balloon or bladder being attached to a patient TP' over or adjacent a surgical site SI'. Balloon or bladder <NUM> is affixed to a patient, e.g., around an arm or leg PL, over or near a surgical site ST and an ultrasonic waveform generator <NUM> is activated to generate ultrasonic vibrations conducted into the patient's tissue to disrupt biofilm formation. Other transducer carriers and methods of attachment to the patient will occur to those skilled in the art.

A medical therapeutic method utilizing one or more of the transducer devices shown in <FIG>, first comprises cleaning surgical site SI or ST of necrotic tissue and undesired organic material, for instance via ultrasonic debridement and suction as discussed above with reference to <FIG>. Shortly thereafter, while the surgical site SI or ST is free of discernible bacteria, one places at least one ultrasonic transducer <NUM>, <NUM> on the patient TP, TP' proximate or on the surgical site SI, ST, and thereafter, while the transducer is in effective vibration-transmitting contact with the patient TP, TP', conducting an electrical energization waveform of an ultrasonic frequency to the transducer <NUM>, <NUM> at least intermittently during a period of approximately one day or longer. The waveform has frequency, amplitude and duration parameters selected to effectively reduce biofilm formation on the patient TP, TP' at the surgical site SI, ST and thereby facilitate a healing of the patient's tissue at the surgical site. The ultrasound generates a surface acoustic wave, exemplarily at <NUM> or within a frequency range about <NUM>, e.g., preferably <NUM>-<NUM>, more preferably <NUM>-<NUM>, and most preferably <NUM>-<NUM> illustratively with an acoustic power output of <NUM>-<NUM> w/cm<NUM>. The treatment period is long enough to enable healthy tissue formation. The placing of the transducer <NUM>, <NUM> preferably includes removably attaching the transducer to the patient atop tissues at the surgical site SI, ST.

As depicted in <FIG>, an ultrasonic surgical device <NUM> comprises an ultrasonic probe <NUM> that is operatively connected to a source <NUM> of ultrasonic vibratory energy including an ultrasonic signal generator <NUM> and a stack of piezoelectric crystals <NUM> for vibrating at an ultrasonic frequency as symbolized by a double-headed arrow <NUM>. Probe <NUM> extends longitudinally through an inner sheath <NUM> that is provided at a distal end region with one or more apertures <NUM>, <NUM>. Probe <NUM> and sheath <NUM> define an annular inner channel <NUM> that is connected at a proximal end of the instrument to a suction or vacuum source <NUM>. An outer sheath <NUM> surrounds the inner sheath <NUM> and defines therewith an annular outer channel <NUM>.

During use of the surgical device or assembly <NUM> of <FIG>, irrigant flows from a supply <NUM> through an inlet port <NUM> and into outer channel <NUM>, as indicated by arrows <NUM>. The irrigant exits the outer channel <NUM> along two paths, firstly through a distal end opening <NUM>, per arrows <NUM>, <NUM>, and secondly through apertures <NUM>, <NUM> into inner channel <NUM> where the liquid or irrigant is drawn in a proximal action, as indicated by arrows <NUM>, toward suction source <NUM>.

At a surgical site <NUM>, tissue fragments <NUM> and <NUM> are separated by ultrasonic vibration of a distal end surface <NUM> of probe <NUM> placed into contact with the surgical site. A vacuum underpressure at the distal end (not designated) of inner channel <NUM> draws tissue fragments <NUM>, <NUM> into the inner channel, together with irrigant present at the surgical site <NUM> owing to outflow from outer channel <NUM> via distal end opening <NUM>. Further irrigant entering inner channel <NUM> via apertures <NUM>, <NUM> facilitates emulsion flow.

Device or assembly <NUM> is different from surgical aspirators where disrupted tissue is being aspirated through the center of a mostly cylindrical cannulated probe or small cross-section. In device <NUM> of <FIG>, the dual irrigant capture scheme faciliates the delivery of sufficient liquid to ensure the occurrence of cavitation as well as to maintain safe temperature levels of both the probe <NUM> and the tissue at the surgical site <NUM>. By capturing liquid via apertures <NUM>, <NUM>, before the irrigant can reach the surgical site <NUM>, the device <NUM> reduces the volume of liquid that could be atomized by the probe <NUM>.

The reduction of atomized irrigant is even more desirable in wound debridement procedures. This is due to the much larger size of the probe tip area normally used for large scale debridement, which is up to <NUM> times that of surgical aspirator probes, and also due to the larger volumes of irrigant required to maintain safe temperature levels in the tissue and probe.

As depicted in <FIG> and <FIG>, a surgical device <NUM> for debriding or removing biofilm from a wound site comprises an ultrasonic probe <NUM> which is attached at a proximal end via threaded connector <NUM> to a driver <NUM> is operatively connected to a generator of vibratory energy, typically a piezoelectric transducer array <NUM>. Both the driver <NUM> and the piezoelectric transducer <NUM> are located in a handpiece which has a cover or housing (not shown) connected to a casing <NUM>. Probe <NUM> tapers down on a distal side to a distal end section <NUM>. It is to be noted that the terms "horn" and "probe" are used synonymously.

Driver <NUM> and probe <NUM> are formed with mutually aligned axial channels or bores <NUM> and <NUM> that define a lumen (not separately designated) for the delivery of irrigant to a distal end aperture <NUM> in probe horn section <NUM>, as indicated by flow arrows <NUM>.

Surgical device or instrument <NUM> further includes a sheath or sleeve <NUM> that is shiftably mounted to casing <NUM> to vary a position of a distal tip <NUM> of the sheath relative to a distal tip or end face <NUM> of probe <NUM>. Sheath <NUM> includes a cylindrical rear section <NUM> and a rectangularly prismatic forward section <NUM>, which correspond geometrically to cross-sections of horn <NUM> and a proximal portion <NUM> of probe, <NUM>, respectively. (Other cross-sectional shapes are possible. For instance, forward section <NUM> could be oval or circular, where horn <NUM> has an oval or circular cross-section. ) Sheath <NUM> may be rigid in its entirety or, alternatively, at least forward section <NUM> may be semi-rigid or flexible, to better conform to target tissue topography.

Together with an outer surface (not designated) of probe horn <NUM>, forward sheath section <NUM> defines a forward or distal channel or conduit <NUM>, which is rectangular in cross-section. Together with an outer surface (not designated) of proximal probe portion <NUM>, rear sheath section <NUM> defines a rearward or proximal channel or conduit <NUM>, which is circular in cross-section. At a distal end, rearward channel <NUM> expands to an enlarged space <NUM> owing to the tapering of the probe at <NUM>.

Sheath <NUM> is provided with an arm <NUM> that is connected at a forward or distal end to forward section <NUM> and is angled outwardly at a proximal side. Sheath arm <NUM> includes a main aspiration channel <NUM> that communicates at a distal end with forward channel <NUM>. At a more proximal location, aspiration channel <NUM> of arm <NUM> communicates with rearward channel <NUM> and more particularly with enlarged space <NUM>. At a proximal end, arm <NUM> is provided with an undercut connector port <NUM> which receives a resilient aspiration tube <NUM> in a friction fit. Aspiration tube <NUM> is fastened to casing <NUM> via a pair of clips <NUM> each formed with a pair of slotted annular rings <NUM> and <NUM> for receiving casing <NUM> and aspiration tube <NUM>, respectively.

At a forward or distal end, probe horn <NUM> is formed with one or more apertures or cross-bores <NUM> and <NUM> that communicate on an inner side with channel or lumen <NUM> and on an outer side with forward channel <NUM>. At a rear end, rear section <NUM> of sheath <NUM> is inserted between proximal probe portion <NUM> and a distal end of casing <NUM>. An O-ring seal <NUM> is provided between casing <NUM> and an outer surface of sheath rear section <NUM>.

A distal end of horn section <NUM> is formed into a probe head <NUM> that is extended in a traverse dimension, orthogonally to a longitudinal axis of the probe <NUM>. Head <NUM> may particularly take a form disclosed in <CIT>, Publication No. <CIT>,. In particular, head <NUM> includes a plurality of teeth <NUM> arranged in two mutually parallel rows along opposing edges or sides of the distal end face <NUM> of the probe head.

As indicated above, sheath <NUM> is slidable or longitudinally shiftable relative to probe <NUM> so as to be continuously adjustable as to axial or longitudinal position relative to probe head <NUM> anywhere from a fully extended position, where the distal tip <NUM> of sheath <NUM> is essentially coplanar with the distal end face <NUM> of probe head <NUM>, to a retracted position where at least the teeth <NUM> of probe head <NUM> are fully exposed. O-ring <NUM> enables the adjustable positioning of sheath <NUM>.

Apertures or cross-bores <NUM> and <NUM> serves as bypass holes, regardless of the relative longitudinal positioning of sheath <NUM> and probe <NUM>. A vacuum under-pressure applied to the internal spaces of sheath <NUM>, i.e., aspiration channel <NUM>, forward channel <NUM>, and rearward channel <NUM>, by a suction source (not shown) enables the capturing and removal of most of the irrigant that is delivered through central channel <NUM> (flow arrows <NUM>). Accumulation of irrigant within sheath <NUM>, especially when the device is used in a predominantly vertical orientation, is prevented by the provision of two suction pathways, namely, between aspiration channel <NUM> and each of the forward channel <NUM> and rearward channel <NUM>. Irrigant not captured via a distal pathway is captured in a proximal pathway.

Where tissue fragments are small enough to be aspirated through the gap between the probe <NUM> and the sheath <NUM>, clogging is prevented by designing the aspiration pathway of channel <NUM> to gradually increase in cross-sectional area from the probe-sheath gap at the distal end of the instrument all the way to the aspiration line. A vent port <NUM> may be provided in the rear sheath section <NUM> to reduce the magnitude of vacuum-generated pull force acting on the tissue which is driven towards and into the probe-sheath gap during debridement.

Matching or cooperating features <NUM> and <NUM> are respectively disposed on the outer side of the probe <NUM> and the inside of rear sheath section <NUM>, in close proximity to a nodal plane or the probe, to facilitate probe-sheath alignment. This minimizes the chances of a probe-sheath contact at the points of maximum vibratory motion (antinodes), particularly at end face <NUM> of probe head <NUM>. Due to their placement at a location of minimal vibratory displacement, e.g., the junction <NUM> between cylindrical probe portion <NUM> and tapering probe section <NUM>, the alignment features <NUM> and <NUM> allow for the probe-sheath contact necessary for preventing or minimizing the unwanted interaction in the area of maximum vibratory displacement.

As depicted in <FIG>, another ultrasonic surgical device <NUM> for debriding or removing biofilm from a wound site comprises a handpiece <NUM> provided at a distal end with a sheath <NUM> and a suction or evacuation attachment <NUM> swingably attached to the sheath at pivot pins <NUM> (only one shown). An ultrasonic probe is disposed inside handpiece <NUM> and sheath <NUM> and terminates and a distal end in a head <NUM> formed with crenulations or teeth <NUM>.

Suction attachment <NUM> includes a body portion <NUM> at a proximal end and a pair of hollow arms <NUM>, <NUM> extending in a distal direction from the body portion. Arms <NUM> and <NUM> are joined to one another at their distal end by a cross-piece <NUM> serving as a suction head. As shown in <FIG>, suction head <NUM> is formed on a lower side with a plurality of longitudinally extending runners or ribs <NUM> and a recess <NUM>, which is bridged by the runners or ribs and which communicated with aspiration channels (not shown) in the hollow arms <NUM>, <NUM>. Body portion <NUM> is provided with a port connector <NUM> to which an aspiration tube (like tube <NUM>) is attached. Liquid irrigant is guided to an outlet port (not shown) in probe head <NUM> via a chanel (not shown) in the probe. The irrigant, together with tissue fragments and other surgically generated debris, is drawn from the surgical site via suction attachment <NUM>. More particularly, during a debridement operation, suction head <NUM> is placed in essential contact with the tissue at the surgical site. Irrigant and tissue debris are collected via recess <NUM> and guided through arms <NUM> and <NUM> and out through port connector <NUM>.

The pivotable mounting of suction attachment <NUM> enables suction head <NUM> and particularly recess <NUM> to remain juxtaposed to a tissue surface even as the rest of the instrument particularly handpiece <NUM>, sheath <NUM> and the probe are tilted to assume different angles relative to a normal to the tissue surface.

<FIG> shows a suction device <NUM> in the form of a ring that is placed on a tissue surface <NUM> for purposes of removing airborne particles generated by use of an ultrasonic instrument <NUM> on tissue at a surgical site <NUM>. Ring <NUM> is provided along an inner cylindrical surface with a plurality of spaced suction ports <NUM>. Ports <NUM> may be tilitably mounted to the ring <NUM>, e.g., via universal joints that have joint balls <NUM> that are perforated. Ring <NUM> is at least partially hollow so that suction ports <NUM> may communicate via a hose <NUM> with a suction source (not shown). Ring <NUM> may be attached to a patient, e.g., to a limb <NUM>, via one or more of various coupling devices, such as a strap <NUM> with buckles or hook-and-loop fabric fasteners, or an adhesive layer <NUM>.

<FIG> depict modifications to the instrument assembly of <FIG>, which facilitates use of the instrument to clean biofilm from hard surfaces such as those of a prosthesis or a surgical instrument. The above disclosure with reference to <FIG> is hereby repeated with respect to the modifications of <FIG> and incorporated therein. Selected reference numerals in <FIG> are used in <FIG> to designate the same or like structures.

As described above with reference to <FIG>, ultrasonic probe <NUM> has operative tip or end face <NUM> and an axial or longitudinal channel <NUM> for the delivery of irrigant to distal end aperture <NUM> in probe horn section <NUM>, as indicated by flow arrows <NUM>. Electromechanical transducer <NUM> is operatively connected to probe <NUM> for generating an ultrasonic standing wave therein to vibrate operative tip <NUM> at ultrasonic frequency. Sheath or sleeve <NUM> is disposed about probe <NUM> and defines channel <NUM>, <NUM>, <NUM>, <NUM> (<FIG>) outside the probe. Channel <NUM>, <NUM>, <NUM>, <NUM> has at least a first port <NUM> in a region about a distal end of probe <NUM>, proximate the operative tip <NUM>. Port <NUM> is specifically a gap between an inner surface (not designated) of sheath or sleeve <NUM> and an outer surface (not designated) of probe <NUM> in the region of the distal end face or operative tip <NUM> thereof. Sheath or sleeve <NUM> has an operative configuration wherein a distal end portion <NUM> of the sheath or sleeve extends distally beyond operative tip or end face <NUM> of probe <NUM> to define or enclose an ultrasound coupling space or antechamber <NUM> between operative tip <NUM> and a target surface TS.

As depicted in <FIG>, the distal end portion of sheath or sleeve <NUM> may be formed with a plurality of longitudinally extending fingers <NUM> separated by one or more gaps or spaces <NUM>. Gaps or spaces <NUM> are slots in the distal end portion of sheath or sleeve <NUM> extending rearwardly from a rounded rectangular distal edge <NUM>. As depicted in <FIG> and <FIG>, the distal end portion of sheath or sleeve <NUM> may be alternatively formed with one or more apertures <NUM> in a sidewall (not separately labeled) of the sheath or sleeve, the aperture(s) <NUM> being spaced from distal edge or tip <NUM> of the sheath or sleeve. Gaps <NUM> and apertures <NUM> enable an ingress of air into coupling space or antechamber <NUM> for the removal of the coupling medium (irrigant) and collected detritus as a slurry via suction or inlet port <NUM>. This operation mode of sheath or sleeve <NUM> serves to prevent or reduce the egress of atomized irrigant and pathogenic particles from the treatment zone.

The treatment zone may be defined as the area of the target surface surrounded by or bounded by distal edge <NUM> of the sheath or sleeve <NUM>. The treatment zone typically moves about a larger surface during debridement of organic tissues at a wound site or biofilm reduction at a wound site or on a hard surface. The rate of irrigant flow distally through probe channel <NUM> and the associate rate of slurry removal via suction channel <NUM>, <NUM>, <NUM>, <NUM> is preferably sufficiently great not only to remove the biofilm particles and pathogenic components from the treatment zone but also to cool probe <NUM> and the treatment site, at least in the case of debridement of a wound bed or tissue injury site.

During the use of the instrument, irrigant delivered to the distal end of probe <NUM> accumulates to act as a coupling medium in the coupling space or antechamber <NUM>. Ultrasonic compression waves are transmitted through the coupling medium irrigant from the probe tip or end face <NUM> to generate disruptive cavitation or other micron-sized mechanical and thermal disturbances at the target surface TS.

Antechamber or enclosure <NUM>, which is defined or formed by the distal end portion of sheath or sleeve <NUM>, the operative tip or end face <NUM> of probe <NUM>, and the target surface TS, functions in part to ensure a separation of the operative probe tip <NUM> from the target surface TS. Antechamber or enclosure <NUM> also functions to enable effective ultrasound pressure wave coupling, owing to the containment of liquid irrigant in the antechamber or enclosure. Antechamber or enclosure also serves to reduce spray or atomized detritus and contain the detritus and potential pathogenic particles for removal via the suction channel <NUM>, <NUM>, <NUM>, <NUM> in the sheath or sleeve <NUM>.

As shown in <FIG>, an ultrasonic instrument <NUM> for use in biofilm removal, particularly from target tissue TT' on a patient, includes a probe <NUM> longitudinally traversing a sheath or sleeve <NUM>. Probe <NUM> includes a head <NUM> with a bowl-shaped concavity or recess <NUM> surrounded by a distal lip of rim <NUM> of head <NUM>. During use of the probe <NUM> to remove biofilm, rim <NUM> is typically the only part of the probe that comes into actual contact with target tissue TT'. During a biofilm removal operation, irrigant flows under pressure through a channel <NUM> in probe <NUM>, as indicated by arrows <NUM>, and fills cavity or recess <NUM> to form a pool. The irrigant and potential contaminants as well as tissue and biofilm fragments are removed, as indicated by arrows <NUM>, via suction applied via sheath or sleeve <NUM> (see discussion above). Probe <NUM> may be provided exemplarily in head <NUM> with one, two or more bypass ports or bores <NUM> that communicate on an inner side with channel <NUM> and on an outer side with sheath or sleeve <NUM> and more particularly with a lumen (not separately designated) of sheath or sleeve <NUM>. Ports or bores <NUM> are oriented generally transversely to channel <NUM> and concomitantly perpendicularly to a longitudinal axis (not shown) of probe <NUM>.

As illustrated in <FIG>, another ultrasonic probe <NUM> for use in biofilm removal includes a probe head <NUM> having an array of projections or raised elements <NUM> mutually spaced on an end face <NUM> of the probe head. Projections or raised elements <NUM> may exemplarily take a conical, pyramidal or pointed tooth shape. An irrigation output port <NUM> typically, but not necessarily, at the center of end face <NUM> communicates with a plurality of radiating grooves <NUM> that distribute the irrigant from port <NUM> across end face <NUM>. Projections or raised elements <NUM> are distributed across the entire end face <NUM> between outlet port <NUM> and an edge or periphery of the end face. One or more bypass ports or bores <NUM> may be provided in probe <NUM>, exemplarily in probe head <NUM>. Ports or bores <NUM> extend from a channel <NUM> in probe <NUM> to an outer surface (not separately designated) thereof. Probe <NUM> is typically used with a sheath or sleeve (not shown) as discussed hereinabove, for instance with respect to <FIG>.

As depicted in <FIG>, a further ultrasonic probe <NUM> for use in biofilm removal both in vivo from a tissue site and also, alternatively, from a surface of a prosthesis or a surgical instrument, includes a probe head <NUM> having an array of metallic hairs or filaments <NUM> mutually spaced on an end face <NUM> of the probe head. An irrigation output port <NUM> is typically formed at the center of end face <NUM>. Head <NUM> with filaments <NUM> is an ultrasonic brush head, where the flexibility of the filaments makes the probe <NUM> compatible for removal of biofilm from hard surfaces. Hairs or filaments <NUM> are distributed across the entire end face <NUM> between outlet port <NUM> and an edge or periphery of the end face. One or more bypass ports or bores <NUM> may be provided in probe <NUM>, exemplarily in probe head <NUM>. Ports or bores <NUM> extend from a channel (not shown) in probe <NUM> to an outer surface (not separately designated) thereof. Probe <NUM> is typically used with a sheath or sleeve (not shown) as discussed hereinabove, for instance with respect to <FIG>.

As described herein above with reference to <FIG>, sheath or sleeve <NUM> is longitudinally slidable relative to probe <NUM> to shift between a distal or extended position (<FIG>) in the operative configuration and a proximal or retracted position. In the distal-most or extended position of the sheath or sleeve <NUM>, the probe head particularly including operative tip or end face <NUM> is covered while in a proximal-most position of the sheath or sleeve at least a portion of the probe head necessarily including operative tip or end face <NUM> is exposed. The instrument may be provided with a locking mechanism <NUM> (<FIG>), such as a set screw, a clamp, or a friction fit, which holds the sheath or sleeve <NUM> in either the extended position or the retracted position, and optionally any position therebetween. Such a locking mechanism <NUM> is preferably located at a vibration node of the probe <NUM>, so that the lock does not affect the generation of a standing wave in the probe, as is well known in the art.

It is seen from <FIG> that probe <NUM> and sheath or sleeve <NUM> define a first space or channel <NUM> and a second space or channel <NUM> both generally laterally or to the side of the probe, and particularly surrounding the same. The second space or channel <NUM> is located proximally of the first space or channel <NUM> and has a larger transverse cross-sectional area, in a plane orthogonal to an axis of the probe <NUM>, than the first space or channel <NUM>. As discussed above (<FIG>) probe <NUM> may be provided at or in a distal end portion with at least one aperture <NUM> spaced from the outlet and communicating with the first space or channel <NUM>. Sheath or sleeve <NUM> is provided with an aspiration arm <NUM> having an aspiration channel <NUM> communicating with the first space or channel <NUM> and the second space or channel <NUM>.

The ultrasonic debridement instrument <NUM> as modified per <FIG> is manipulated to place the distal tip or edge <NUM> of sheath or sleeve <NUM> against a target surface TS such as a wound site or a surface or a prosthesis needing cleaning. The instrument <NUM> is manipulated to place the sheath or sleeve so that it extends in part distally of the operative tip or end face <NUM> of the probe <NUM>, as shown in <FIG> and serves in part to maintain or create a spacing between the probe's operative tip and the target surface TS. The spacing or distance between operative tip or end face <NUM> and target surface TS must be large enough, for hard surfaces TS, to avoid contact between the probe tip and the hard surface but cannot be so large as to damp the ultrasonic vibration energy so as to render that energy ineffective in the disruption and fragmentation of biofilm adhering to the hard surface. Typically, the spacing or height or the antechamber or coupling enclosure <NUM> is between about <NUM> microns and several millimeters. The manipulating of the instrument <NUM> to place the distal tip or edge <NUM> of sheath or sleeve <NUM> against the target surface TS inherently positions the operative tip <NUM> or the probe at a desired distance from the target surface.

During contact of the distal tip or edge <NUM> of sheath or sleeve <NUM> with the target surface TS, one feeds an irrigation fluid (flow arrows <NUM>) through channel <NUM> in probe <NUM> to the antechamber or coupling enclosure <NUM>. Also during contact of the distal tip or edge <NUM> of the sheath or sleeve <NUM> with the target surface TS, an ultrasonic standing wave is generated in the probe <NUM> to vibrate the operative tip or end face <NUM> thereof and thereby fragment undesired material at or on the target surface. During the generating of the ultrasonic standing wave, vacuum or negative pressure is applied to the second channel by a vacuum generator or suction source <NUM> (<FIG>) to remove fluid from the target surface TS.

Preferably, the irrigation fluid (<NUM>) includes a disinfectant or biocide such as hypochlorous acid and/or metal ion hypochlorite. This disinfectant or biocide is advantageously generated on site, at or immediately prior to the treatment by ultrasound, thereby ensuring an effective concentration of the hypochlorous acid. The hypochlorous acid and/or metal ion hypochlorite may be produced from a sterile saline solution by an electrolytic generator <NUM> (<FIG>) as described in <CIT>.

As discussed above, sheath or sleeve <NUM> is slidably mounted so that the sheath or sleeve is longitudinally shiftable relative to probe <NUM>. Sheath or sleeve <NUM> is shifted in a distal direction along the instrument prior to the manipulating of the instrument to place the distal tip or edge <NUM> of the sheath or sleeve against the target surface TS. Variability in the longitudinal position of sheath or sleeve <NUM> relative to probe <NUM> enables the user to adjust the height of the coupling space or antechamber <NUM> between the operative surface <NUM> of probe <NUM> and the target surface TS. The height may be close to zero, in which case the operative tip <NUM> of probe <NUM> may be placed in contact or near contact with a target surface TS such as organic tissue at a site of a patient wound or injury. This option is described above with reference to <FIG>.

Typically the second channel <NUM>, <NUM>, <NUM>, <NUM> is located between sheath or sleeve <NUM> and probe <NUM>. The method may also comprise shifting sheath or sleeve <NUM> in a proximal direction after the generating of the ultrasonic standing wave and thereafter applying a vacuum or negative pressure to the suction channel <NUM>, <NUM>, <NUM>, <NUM> to suck ambient air into and through the suction channel.

The method described hereinabove is advantageous in cleaning biofilm from a hard target surface TS such as a surface of a prosthesis. The cleaning of the prosthesis may be effectuated in vivo, where open surgery uncovers at least a portion of a prosthesis, or ex vivo, where the prosthesis has been temporarily removed from the patient. The method of the invention as claimed in claim <NUM> is effectuated ex vivo.

Where the present method is used to clean a hard target surface, the spacing of the vibrating operative probe surface <NUM> from the target surface TS by the distally extended or projecting sheath <NUM> prevents high frequency impact of the metal or alloy probe with a prosthesis that is also typically made of a metal or alloy. Thus the likelihood of inadvertent damage to the prosthesis is reduced if not eliminated, while resonance operation of the probe is maintained.

The target surface may alternatively be a surface of a surgical instrument.

The present invention provides an additional benefit which applies both where the target surface TS is patient tissue and where the target surface is an instrument or prosthesis surface. That is an enhanced effectiveness in reducing the incidence of airborne pathogens. The atomization and dispersal or liquid from the treatment site is controlled or limited by a barrier formed by the distal end of the sheath or sleeve <NUM>, in combination with the suction applied to the coupling space or antechamber <NUM>. Sheath or sleeve <NUM> encloses the treatment site and thus contains fragmented biofilm and/or tissue for immediate removal through the suction channel <NUM>, <NUM>, <NUM>, <NUM> of the instrument. The distal end portion of the sheath or sleeve <NUM> is provide with openings, i.e., gaps <NUM> or apertures <NUM>, that are limited in cross-sectional area, just to permit the ingress or air for enabling effective suctioning of the slurry produced at the treatment site.

Although the invention has been described in terms of particular embodiments and applications, one of ordinary skill in the art, in light of this teaching, can generate additional embodiments and modifications without departing from the scope of the claimed invention. Moreover, the phase shift might be varying, for instance, where the vibration modes are of different frequencies. Accordingly, it is to be understood that the drawings and descriptions herein are proffered by way of example to facilitate comprehension of the invention and should not be construed to limit the scope thereof.

Claim 1:
A device for removing biofilm from hard surfaces of manufactured articles such as surgical instruments and medical prostheses, comprising:
an ultrasonic probe (<NUM>) having an operative tip (<NUM>) and a first channel extending longitudinally therein;
an electromechanical transducer operatively connected to said probe (<NUM>) for generating an ultrasonic standing wave in said ultrasonic probe (<NUM>) to vibrate said operative tip (<NUM>) at an ultrasonic frequency; and
at least one sheath or sleeve (<NUM>, <NUM>, <NUM>) disposed about said ultrasonic probe (<NUM>) and defining a second channel outside said ultrasonic probe (<NUM>), said second channel having at least a first port (<NUM>) in a region about a distal end of said ultrasonic probe (<NUM>) and being proximate said operative tip (<NUM>), said sheath or sleeve (<NUM>, <NUM>, <NUM>) having an operative configuration wherein a distal end portion (<NUM>) of said sheath or sleeve (<NUM>, <NUM>, <NUM>) extends distally beyond said operative tip (<NUM>) of said ultrasonic probe (<NUM>) to define an ultrasound coupling space (<NUM>) between said operative tip (<NUM>) and a hard target surface (TS) of a manufactured article such as a surgical instrument or medical prosthesis;
said distal end portion of said sheath or sleeve (<NUM>) having a distal-most edge (<NUM>) and is provided with at least one aperture (<NUM>) in a sidewall, said aperture (<NUM>) being spaced from said distal-most edge (<NUM>);
said sheath or sleeve (<NUM>) being longitudinally slidable relative to said ultrasonic probe (<NUM>) to shift between a distal position when said sheath or sleeve is in said operative configuration and a proximal position.