Patent Publication Number: US-2022211404-A1

Title: Wet jet debridement and wound bed preparation

Description:
This application claims priority to GB1908251.0, filed Jun. 10, 2019, hereby incorporated by reference in its entirety. 
     BACKGROUND OF THE INVENTION 
     The Smith &amp; Nephew Versajet™ Hydrosurgery system use a high pressure saline water jet for debridement and wound bed preparation. Components of the Versajet™ Hydrosurgery system are described in U.S. Pat. Nos. 9,597,107 and 9,341,184, hereby incorporated by reference in their entirety. Referring to prior art  FIGS. 1A-1C , saline water flows from a high pressure jet tube  11  at the top of the handle, turns 180° through the end  12  of the jet tube  11 , and is ejected from the jet tube  11  to an evacuation tube  7  at the bottom of the handle. The jet tube  11  is welded to a distal tip  5  that defines a treatment window  14 . 
     An orifice member (nozzle)  6  in the jet tube  11  is a key component in determining the water pressure and debridement effect. In the Versajet™ Hydrosurgery system, the orifice member  6  is assembled to the jet tube  11  by a crimping process. The orifice member  6  is placed on a flared end of the jet tube  11 , and the end of the jet tube  11  is crimped by being bent inward to secure the orifice member  6  in the jet tube  11 . 
     The orifice member is in the form of a ring configured to form a liquid jet and defines a liquid flow passage having a diameter that continuously decreases from a first terminal end to a location proximate to a second terminal end. The evacuation tube has an opening positioned opposite the orifice member and is configured to receive at least a portion of the liquid jet emitted from the orifice member and to convey a flow of liquid away from the opening. The pressure jet tube is configured and positioned to convey the flow of liquid to the orifice member. The pressure jet tube is mounted on an exterior surface of the housing and includes a holder located at a distal opening of the pressure jet tube. The holder forms a recessed well in the distal tip of the pressure jet tube and is configured to retain and position the orifice member completely inside the holder such that the orifice member is co-axial with a distal end of the pressure jet tube and the flow of liquid. The distal end of the opening of the pressure jet tube extends beyond a distal end of the evacuation tube such that, in operation, the flow of liquid from the orifice member is directed toward the handle. 
     A nozzle assembly is fabricated by affixing the orifice member in the shape of torus having a flat surface and a curved opposite surface to or within the holder. The nozzle assembly is able to withstand an internal liquid pressure of at least about 1,000 psig without failure. 
     As illustrated in prior art  FIG. 2 , the Versajet™ Hydrosurgery system includes a piston pump implemented into the single use hand piece. The pump includes a pump housing configured for removable receipt by a drive console. The pump housing including an insert section, a coupling section and a handle. The insert section, coupling section and handle are linearly arranged with the coupling section between the insert section and the handle. The insert section is configured to removably receive a push rod of the drive console. The coupling section includes an external oval flange. A valve assembly located in the pump housing includes an inlet passage, an outlet passage, an inlet ball valve, and an outlet ball valve. The inlet and outlet passages are located side-by-side in the pump housing and are in fluid communication with a chamber defined in the insert section. The chamber has a sloped wall is axially aligned with the inlet passage and the outlet passage. A piston is slidably received within the chamber and includes flexible members arranged within the chamber to be acted upon by the sloped wall to engage the push rod. The only external force required to couple the piston to the push rod is an axial force on the piston in a first direction, and the only external force required to de-couple the piston from the push rod is an axial force on the piston in a second direction opposite the first direction. 
     As illustrated in prior art  FIG. 3 , the Versajet™ Hydrosurgery system uses a single spike to connect with a saline bag. 
     SUMMARY 
     The handle of the Versajet™ Hydrosurgery system hand piece includes multiple parts requiring a complex assembly/weldment process. In particular, the distal tip  5  ( FIGS. 1A-1C ) of the Versajet™ Hydrosurgery system has a complex geometry formed by metal injection molding and requires laser welding to the thin jet tube  11 . 
     The current design reduces the number of parts and sub-assemblies, for example, several parts are integrated into one piece to avoid the assembly of the parts and maintain alignment of the parts. 
     A water jet hand piece for treating tissue includes a handle having an upper housing and a lower housing, a jet tube mounted to the upper housing, and a distal tip that receives liquid from the jet tube and defines a treatment window for treating tissue with a liquid jet. The distal tip is integral with the upper housing. 
     The top to bottom water flow in the Versajet™ Hydrosurgery system requires bending of the tip of the jet tube  11  as well as welding of the jet tube  11  to the distal tip  5 . 
     A particular embodiment of the current design switches the position of the jet tube and the evacuation tube, allowing a jet tube with a straight distal end region and the elimination of the distal tip. 
     A water jet hand piece for treating tissue includes a handle including an upper housing and a lower housing. The lower housing defines a treatment window. The hand piece includes a jet tube mounted to the lower housing. The jet tube has a straight distal end region. The treatment window is configured for treating tissue with a liquid jet delivered to the treatment window via the jet tube. The hand piece includes an evacuation tube mounted to the upper housing. 
     The piston pump of the Versajet™ Hydrosurgery system also includes multiple parts requiring a complex assembly. 
     The current design reduces the number of parts and sub-assemblies, for example, several parts are integrated into one piece to avoid the assembly of the parts and maintain alignment of the parts. 
     A piston pump of a water jet debridement and wound bed preparation system includes an integrated, one-piece piston assembly including a fitting retainer, feed line fittings, and a support screen. Embodiments of this aspect may include two handle halves that are connectable to form an interior cavity that houses the components of the piston pump including the integrated, one-piece piston assembly. 
     The use of a single spike in the Versajet™ Hydrosurgery system may allow air to enter the tube and interlock the saline tubing if the saline bag is empty. 
     The two spike assembly of the current design enables air to be expelled from an open spike. 
     A water jet debridement and wound bed preparation system includes a piston pump, and two spikes with tubing extending from an inlet of the piston pump and configured to control air entering the system. 
     According to one aspect, a water jet hand piece for treating tissue includes a handle housing, a jet tube mounted to the housing, and a distal tip that receives liquid from the jet tube and defines a treatment window for treating tissue with a liquid jet. The distal tip is integral with the housing. 
     Embodiments of this aspect may include one or more of the following features. 
     The housing includes an upper housing and a lower housing and the distal tip is integral with the upper housing. The upper housing includes a distal housing and a proximal housing, and the distal tip and the distal housing are an integral, one-piece component. The water jet hand piece includes an evacuation tube received by the lower housing. The jet tube includes a 180 degree curved distal end. The water jet hand piece includes an orifice member. 
     According to another aspect, a water jet hand piece for treating tissue includes a handle including an upper housing and a lower housing, a jet tube mounted to the lower housing, and an evacuation tube mounted to the upper housing. The lower housing defines a treatment window. The jet tube has a straight distal end region. The treatment window is configured for treating tissue with a liquid jet delivered to the treatment window via the jet tube. 
     Embodiments of this aspect may include the lower housing defining a distal inner surface and the upper housing defining a distal inner surface. The distal inner surfaces are configured to guide the liquid jet from the treatment window to the evacuation tube. 
     According to another aspect, a water jet hand piece for treating tissue includes a distal tip defining an internal flow path and a treatment window, a distal tip cap, and an orifice member positioned between the distal tip and the cap. The hand piece is configured for liquid flow through the flow path and out the orifice member to the treatment window. 
     According to another aspect, a pump for a water jet debridement and wound bed preparation system includes an integrated, one-piece piston assembly including a fitting retainer, feed line fittings, and a support screen. 
     Embodiments of this aspect may include one or more of the following features: a handle, a piston, a piston cap, a single O-ring, and two valve balls. In an illustrated embodiment, the pump includes two handle halves that are connectable to form an interior cavity that houses the integrated, one-piece piston assembly. The connected handle halves form a piston cap. 
     According to another aspect, a water jet debridement and wound bed preparation system includes a piston pump, and two spikes with tubing extending from an inlet of the piston pump and configured to control air entering the system. 
     According to another aspect, a water jet hand piece for treating tissue includes a jet tube, an orifice member received in a distal end of the jet tube, and a spacer received in the distal end of the jet tube on top of the orifice member between the orifice member and a fluid outlet of the jet tube. In an illustrated embodiment, the spacer is welded to the jet tube. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1A-1C  illustrates a prior art handle of a water jet debridement and wound bed preparation system. 
         FIG. 2  illustrates a prior art piston pump of a water jet debridement and wound bed preparation system. 
         FIG. 3  illustrates a prior art single spike connection to a saline bag in a water jet debridement and wound bed preparation system. 
         FIGS. 4A-41  include various views of a handle of a water jet debridement and wound bed preparation system. 
         FIG. 5  is a cross-section view of an alternative embodiment of a handle of a water jet debridement and wound bed preparation system. 
         FIGS. 6A-6D  include various views of another alternative embodiment of a handle of a water jet debridement and wound bed preparation system. 
         FIGS. 7A-7F  shows various embodiments of the industrial design of the hand piece. 
         FIGS. 8A-8D  include various views of a piston pump of a water jet debridement and wound bed preparation system. 
         FIGS. 9A-9D  include various view of an alternative embodiment of a piston pump of a water jet debridement and wound bed preparation system. 
         FIGS. 10 and 11  illustrate a dual-spike saline bag assembly of a water jet debridement and wound bed preparation system. 
         FIG. 12  illustrates a drip chamber of a water jet debridement and wound bed preparation system. 
         FIGS. 13A-13C  illustrate a console of a water jet debridement and wound bed preparation system. 
         FIGS. 14A-16B  illustrate various embodiments of orifice member assembly processes. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIGS. 4A-4H , a hand piece  20  of a water jet debridement and wound bed preparation system includes a handle top housing  22  and a handle bottom housing  24 . The handle top housing  22  has a proximal housing  22   a  and a distal housing  22   b  with a distal tip  26 , which is an integral component of the distal housing  22   b , for example, one plastic molded or machined part such that the distal tip  26  and distal housing  22   b  are an integral, one-piece component and assembly of the hand piece does not include attachment of the distal tip  26  to the distal housing  22   b . Received within the distal housing  22   b  is a jet tube  28  having a liquid outlet orifice member  30 . The distal tip  26  of the distal housing  22   b  defines a treatment window  36  for treating tissue with a jet of liquid. Received within the proximal housing  22   a  is a high pressure hose  23  through which the high pressure water is fed to the jet tube  28 . Making the distal tip  26  integral with the distal housing  22   b  eliminates the need to weld the jet tube to the distal tip. 
     Referring also to  FIGS. 4H and 41 , the handle bottom housing  24  has a proximal housing  24   a  and a distal housing  24   b . When assembled, the proximal housing  24   a  mates with the proximal housing  22   a , and the distal housing  24   b  mates with the distal housing  22   b . Leading from a proximal end  36   a  of the treatment window  36  to the distal housing  24   b  is an evacuation tube  32  partly covered by the distal housing  24   b . A connection tube  33  leads from the evacuation tube  32  to a hose  34  through which the return flow exits the hand piece. 
     As compared to the prior art Versajet™ Hydrosurgery system, the high pressure jet tube  28  is shorter and the evacuation tube  32  is shorter. 
     Referring to  FIG. 5 , in an alternative embodiment, a hand piece  40  of a water jet debridement and wound bed preparation system includes a jet tube  42  having a liquid outlet orifice member  44 . The jet tube  42  is received in a handle bottom housing  46 , and an evacuation tube  48  is received in a handle top housing  50 . As compared to the jet tube  28  of  FIG. 4D , the jet tube  42  has a straight distal end region  52 . In addition, the hand piece  40  does not include a component corresponding to the distal tip  26  of  FIG. 4D . 
     In use, the liquid is ejected from the orifice member  44  of the jet tube  42 , travels across a tissue treatment window  54  where the jet acts to debride the wound bed, hits inner surfaces  56 ,  58  of the handle bottom and top housings  46 ,  50 , respectively, and flows into the evacuation tube  48 . 
     Referring to  FIGS. 6A-6D , in an alternative embodiment, a hand piece  200  incudes a metal injection molded distal tip  202  and a metal injection molded distal tip cap  204 . Trapped against the distal tip  202  by the tip cap  204  is a liquid outlet orifice member  206  and an O-ring  203 . Liquid is delivered to the distal tip  202  by a high pressure line  208  and liquid exits via an evacuation tube  210 . Liquid flows from the high pressure line  208  through paths  212 ,  214  in distal tip  202 , out the orifice member  206 , across a treatment window  216 , and through evacuation tube  210 . 
       FIGS. 7A-7D  illustrate alternative handle designs. 
       FIGS. 7E and 7F  illustrate alternative handle designs corresponding to the embodiment of  FIG. 6A . 
     Referring to  FIGS. 8A-8D , a piston pump  60  has a reduced number of parts and sub-assemblies as compared to the piston pump of  FIG. 2 . The piston pump  60  includes an integrated, one-piece piston assembly  62  including a fitting retainer  64 , feed line fittings  66 ,  68 , and a support screen  70 , negating the need for assembling the feed line fittings to the fitting retainer with the dowel pins  16  of  FIG. 2  and the need for placement of the support screen  17  in the assembly of  FIG. 2 . The integrated piston assembly  62  can be manufactured by, for example, metal injection molding, machining and/or ceramic injection molding. 
     Rather than the two O-rings  18  of  FIG. 2 , the piston pump  60  includes a single O-ring  71 . The piston pump  60  includes a handle  72  defining two channels  73  that receive the fittings  66 ,  68 . The piston pump  60  further includes two ball valves  73 , a pump body  74 , a piston  75 , and a piston cap  76 . 
     Referring to  FIGS. 9A-9D , in another embodiment, a piston pump  80  includes two handle halves  82 ,  84  that are longer than the handle  19  of  FIG. 2  and the handle  72  of  FIG. 8A , and that, when connected, form an interior cavity that houses the components of the piston pump, including the integrated, one-piece piston assembly  62 . The piston pump  80  includes a valve socket  85  that receives the O-ring  71  and one of the ball valves  73 . The valve socket  85  is received within an opening  90  to the feed-line fitting  68 . The handle halves  82 ,  84  define slots  86  that receive fins  88  of the piston assembly  62 . When connected, the handle halves form a piston cap  92 . The handle halves  82 ,  84  facilitate assembly of the piston pump  80 , and do not require the fluid channels  15  and  73  in the handles of  FIG. 2  and  FIG. 8A . 
     Referring to  FIGS. 10 and 11 , a water jet debridement and wound bed preparation system  98  includes two saline tubes  100 ,  102  extending from an inlet  104  of a piston pump handle  106 . Saline tube  100  terminates in a spike  107  that connects to a saline bag  108 . Saline tube  102  can be open to atmosphere ( FIG. 10 ) or include a spike  109  that connects to a second saline bag  110  ( FIG. 11 ). In the assembly of  FIG. 10 , air is expelled from the open tube  102  with a clamp  111  in an open position when there is an airlock in the system. Tube  102  of  FIG. 10  is illustrated without a spike, but may optionally include a spike. In the assembly of  FIG. 11 , the two spikes  107 ,  109  are connected to the separate saline bags  108 ,  110  with respective clamps  112 ,  114  on the tubing  100 ,  102 . In use, one of the clamps, for example, clamp  112 , is closed and the other clamp, for example, clamp  114 , is open. The saline water in the clamp open bag  110  is used first. When the saline bag  110  is empty, air will enter the tube  102  and the pump, which can result in airlocking of the system. To re-prime the pump and remove the airlock, clamp  112  is opened allowing saline to flow down the tube  100  from the bag  108 , through the pump chamber and back up the tube  102  towards the empty bag  110 , thus flushing out the air locked in the system. Once no more air can be seen exiting the pump, the clamp  114  is closed and the pump is now primed and will draw fluid from the bag  108 . 
     Referring to  FIG. 12 , in an alternative embodiment, a drip chamber  120  is used in the saline lines, which allow air to rise out from the liquid so that it is not passed downstream. The drip chamber should be maintained about half full to prevent air from getting into the saline tubing, which could block the tube and stop the procedure. As compared to the embodiments of  FIGS. 10 and 11 , if air is already in the tubing, the priming will stop. The embodiments of  FIGS. 10 and 11  allow the air to rise out even if the air is already in the saline tubing such that the procedure is not impacted. 
     Referring to  FIGS. 13A-13C , a console  250  of a water jet debridement and wound bed preparation system includes an LCD screen  252  for displaying device state information, for example, power level, procedure running time, out-patient/operating room mode, and service reminders. The console includes an interface  254  for receiving the piston pump  256 , and an RFID reader  258  and antenna  260  for identifying an RFID tag  262  installed in the piston pump hand piece. 
       FIGS. 14A-16B  illustrate various embodiments of orifice member assembly processes. 
     Referring to  FIGS. 14A and 14B , to provide additional securement of the orifice member  308  to the jet tube  306 , a metal spacer  302 , for example, a gasket or bushing, is added to the assembly. In the assembly process, the end  304  of the jet tube  306  is flared and the orifice member  308  is placed within the end of the jet tube. The metal gasket or metal bushing  302  is then placed on top of the orifice member  308  between the orifice member  308  and the fluid outlet at the end  304  of the jet tube. The end  304  of the jet tube  306  is crimped to press the gasket or bushing  302  against the orifice member  308  and crimp the gasket or bushing together with the orifice member to the jet tube. The addition of the gasket or bushing ensures the orifice member has less space to move during the assembly process, which increase the crimping process consistency and improves on yield rate. 
     Referring to  FIG. 15 , the orifice member  308  can be laser-welded directly into the end of jet tube  306 . The orifice member is placed in the flared end of the jet tube followed by laser welding. The weld bump secures the orifice member in place. 
     Referring to  FIGS. 16A and 16B , the gasket or bushing  302  position above the orifice member  308  of  FIGS. 14A and 14B  can be combined with laser-welding. The orifice member  308  is placed in the end of the flared jet tube  306  followed by placement of the metal gasket or bushing on top of the orifice member. Laser welding is performed all around the top of the metal gasket or bushing. The metal gasket or bushing ensures that the orifice member has less space to move during assembly process. Laser welding on the metal gasket has the advantage of avoiding direct heat from the laser welding to the orifice member which may change the material property or weaken the orifice member. Laser welding has high consistency and repeatability, which ensure higher yield rate during manufacturing. 
     In an alternative embodiment, the orifice can be directly fabricated on the jet tube by micro-machining or EDM technology. 
     Other embodiments are within the scope of the following claims.