Abstract:
A lubrication system for a pneumatically powered instrument is disclosed. In one example, a lubrication system for use with a surgical instrument includes: a first fluid path comprising a first fluid inlet, and a first fluid outlet wherein the first fluid outlet does not contact a lubricant; and a second fluid path comprising a second fluid inlet extending into the lubricant, a filtering system, and a controlled path, and a pressurized fluid flows through the first fluid path, causing at least a portion of the lubricant to flow through the second fluid

Description:
CROSS REFERENCE  
       [0001]     This application is related to the following U.S. patent applications: U.S. Ser. Nos. 60/301,491 filed on Jun. 28, 2001; 60/352,609 filed on Jan. 28, 2002; 60/360,332 filed on Feb. 26, 2002; and 10/180,47 filed on Jun. 26, 2002, all of which are hereby incorporated by reference. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention generally relates to surgical instruments. More particularly, the present invention relates to powered surgical instruments and a lubrication system for use therewith.  
       BACKGROUND  
       [0003]     Doctors and other medical professionals often use powered surgical instruments for dissecting bones, tissues and other purposes. Frequently, it is important to lubricate the instruments for proper usages. For example, a pneumatically powered surgical instrument may include a pneumatic motor that is connected to a fluid supply source, and a lubrication system is typically placed inline between the fluid supply source and the pneumatic motor to provide lubrication to the surgical instrument.  
         [0004]     Traditionally, the lubrication system must be manually calibrated and/or activated according to predetermined guidelines. For example, the lubrication system is typically set at a specific dripping rate for providing oil to the surgical instrument. Therefore, to supply a certain amount of lubrication to the instrument, it is important to maintain a proper dripping rate. However, since the manual operation is prone to mistakes and inaccuracy, the amount of supplied oil varies erratically, and too much or too little oil may be provided to the instrument.  
         [0005]     Therefore, it is desired to provide an improved lubrication system that supplies consistent lubrication to a surgical instrument. Is further desired to provide an improved lubrication system that does not require frequent manual operations.  
       SUMMARY  
       [0006]     The present invention provides an improved lubrication system for a surgical instrument.  
         [0007]     In one embodiment, a lubrication system for use with a surgical instrument comprises: a first fluid path comprising a first fluid inlet, and a first fluid outlet wherein the first fluid outlet does not contact a lubricant; and a second fluid path comprising a second fluid inlet extending into the lubricant, a filtering system, and a controlled path, wherein a pressurized fluid flows through the first fluid path, causing at least a portion of the lubricant to flow through the second fluid path.  
         [0008]     In a second embodiment, A surgical system comprising a pneumatically powered surgical instrument with a motor, and a lubrication system for providing lubrication to the motor, wherein the lubrication system comprises: a first enclosure positioned inline with a pressurized fluid path, the first enclosure comprising a large-diameter channel and a small-diameter channel; a second enclosure including a lubricant; a first fluid path comprising a first fluid inlet coupled with the large-diameter channel, and a first fluid outlet; and a second fluid path comprising a second fluid inlet extending into the lubricant, a filtering system, a controlled path, and a second fluid outlet coupled with the small-diameter channel, wherein at least a portion of a pressurized fluid flows from the large-diameter channel and through- the first fluid path, causing at least a portion of the lubricant to flow through the second fluid path and into the small-diameter channel.  
         [0009]     In a third embodiment, an inline oiler for use with a pneumatically powered surgical instrument comprises: a first inlet for receiving pressurized air; a first outlet for providing the pressurized air into an enclosure wherein the enclosure comprises a lubricant, wherein the first outlet does not contact the lubricant; a second inlet for receiving at least a portion of the lubricant wherein the second inlet extends into the lubricant; a filtering system for filtering the at least a portion of the lubricant; and a capillary tube for controlling the flow of the filtered lubricant.  
         [0010]     It should be understood that the present summary and the following detailed description, while indicating embodiments of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention beyond that described in the claims. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]     The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:  
         [0012]      FIG. 1A  illustrates a lubrication system for a pneumatically powered instrument according to one embodiment of the present disclosure.  
         [0013]      FIG. 1B  is a perspective view of the lubrication system of  FIG. 1A .  
         [0014]      FIG. 2A  is a side view of a partial lubrication system for a pneumatically powered instrument according to one embodiment of the present disclosure.  
         [0015]      FIG. 2B  is a perspective view of a partial lubrication system for a pneumatically powered instrument according to one embodiment of the present disclosure.  
         [0016]      FIG. 2C  is a top view of a partial lubrication system for a pneumatically powered instrument according to one embodiment of the present disclosure.  
         [0017]      FIG. 2D  is a bottom view of a partial lubrication system for a pneumatically powered instrument according to one embodiment of the present disclosure.  
         [0018]      FIG. 2E  is a cross-sectional view taken along the line  2 E- 2 E of  FIG. 2D .  
         [0019]      FIG. 2F  is a cross-sectional view taken along the line  2 F- 2 F of  FIG. 2D .  
         [0020]      FIG. 2G  is a side view of a first conduit of a lubrication system for a pneumatically powered instrument according to one embodiment of the present disclosure.  
         [0021]      FIG. 2H  is a cross-sectional view taken along the line  2 H- 2 H of  FIG. 2G .  
         [0022]      FIG. 3  is a cross-sectional view of a lubrication system for a pneumatically powered instrument according to one embodiment of the present disclosure.  
         [0023]      FIG. 4A  is an exploded view of an injector system of from the lubrication system of  FIG. 3 .  
         [0024]      FIG. 4B  is a perspective view of assembled components selected from  FIG. 4A .  
         [0025]      FIG. 4C  is a perspective view of the assembled components of  FIG. 4B  rotated by 180 degrees. 
     
    
     DETAILED DESCRIPTION  
       [0026]     For the purposes of promoting an understanding of the principles of the invention, references will now be made to the embodiments, or examples, illustrated in the drawings and specific languages will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Any alterations and further modifications in the described embodiments, and any further applications of the principles of the invention as described herein are contemplated as would normally occur to one skilled in the art to which the invention relates. Further, it will be understood that the present disclosure is not limited to any particular surgical application but has utility for various applications in which it is desired, including but not limited to:  
         [0027]     1. Arthroscopy—Orthopaedic  
         [0028]     2. Endoscopic—Gastroenterology, Urology, Soft Tissue  
         [0029]     3. Neurosurgery—Cranial, Spine, and Otology  
         [0030]     4. Small Bone—Orthopaedic, Oral-Maxiofacial, Ortho-Spine, and Otology  
         [0031]     5. Cardio Thoracic—Small Bone Sub-Segment  
         [0032]     6. Large Bone—Total Joint and Trauma  
         [0033]     7. Dental and other applications  
         [0034]     Referring now to  FIG. 1A , shown therein is a lubrication system  10  for a pneumatically powered surgical instrument according to one embodiment of the present disclosure. In this illustration, the lubrication system  10  may be used with a pneumatically powered surgical instrument  11 . An exemplary surgical instrument  11  is shown in a commonly assigned U.S. Pat. No. 5,505,737, which is hereby incorporated by reference as if fully set forth herein. It is contemplated that the teachings of the present disclosure also apply to other powered instruments.  
         [0035]     As lubrication systems have been fully described in the U.S. patent application Ser. No. 10/180,470 filed on Jun. 26, 2002 (which is hereby incorporated by reference), many components of the lubrication system  10  will only be briefly described herein.  
         [0036]     Referring now to  FIG. 1B , in one embodiment, the lubrication system  10  may include a body or housing  12 , a first conduit  18  for delivering a source of pressurized air to the pneumatically powered instrument  11 , and a second conduit  20  for returning exhaust gases from the pneumatically powered instrument  11  to the housing  12  of the lubrication system  10 . Although the first and second conduits  18 ,  20  are coaxial as illustrated in  FIG. 1B , it is understood that in other embodiments, those conduits may be separate (not coaxial). It is also contemplated that the lubrication system  10  may comprise a single conduit or more than two conduits.  
         [0037]     The lower portion of the lubrication system  10  will now be further described. Referring now to  FIGS. 2A-2F , in one embodiment, a lower portion  16  of the housing  12  may comprise a generally cylindrical shape. In one application, the lower portion  16  of the housing  12  may comprise plastics. Alternatively, the lower portion  16  may comprise any other suitable material, such as stainless steel, titanium, shape memory alloys, polymers, carbon fiber, and porous material.  
         [0038]     In this example, the lower portion  16  may include an outer cylindrical wall  22 , a concentrically arranged inner cylindrical wall  24 , and a bottom wall  26 . A first generally cylindrical cavity  28  may be defined between the inner and outer cylindrical walls  22  and  24 . A second generally cylindrical cavity  30  may be defined by the inner cylindrical wall  24 .  
         [0039]     In furtherance of the example, as shown in  FIG. 2F , an oil saturated cellulose fiber material  31  may be disposed in the second cavity  30 . Also, a dry cellulose fiber material  33  may be disposed within the first cavity  28 . It will be understood that the cellulose fiber materials  31 ,  33  are merely examples of absorbent materials, and other materials, such as foam, wool felt, porous plastics, porous metals and/or other type materials, are also contemplated. As described below, oil may be drawn from the second cavity  30  and into a flow stream. Exhaust gases, which may include spent oil, may be returned to the first cavity  28 . The dry cellulose fiber material  33  may filter the oil from the exhaust gases. The filtered exhaust gases are permitted to pass through a plurality of exhaust apertures  32  in the bottom wall  26  of the lower portion  16 .  
         [0040]     The upper portion of the lubrication system  10  will now be further described. Referring now to  FIGS. 2G and 2H , shown therein is the first conduit  18  of the lubrication system  10  according to one embodiment of the present disclosure. In this embodiment, the first conduit  18  may be a hollow tubular member, which may comprise plastics or other suitable materials. The first conduit  18  may define a central channel, and a first end  56  of the first conduit  18  may be coupled to an air source (not shown). A second end  58  of the first conduit  18  is reduced in diameter and may be coupled to the pneumatically powered instrument  11  through a hose (not shown).  
         [0041]     As particularly shown in  FIG. 1B , in one embodiment, the second conduit  20  may be a hollow tubular member. The second conduit  20  may be received within the upper portion  14  of the housing  12  and cooperate with the upper portion  14  to define a fluid path for returning exhaust gases from the pneumatically powered instrument  11  to the outer cylindrical cavity  28  of the lower portion  16 . The second conduit  20  may concentrically surround the second end  58  of the first conduit  18 .  
         [0042]     In an exemplary operation, pressurized air may be introduced into the first end  56  of the first conduit  18 . In one particular application, the air may be introduced at a pressure of approximately 120 psi. Further, an on/off control mechanism, such as a foot pedal, may be disposed between a compressed air source and the instrument  11 , such as at the first end  56  of the first conduit  18 . The pressurized air may pass through the channel  54  defined by the first conduit  18 , and draw oil from the wet fiber cellulose material  31  in the chamber  30  into the air stream. As a result, the oil is delivered with the air stream into the motor of the pneumatically powered instrument for lubrication.  
         [0043]     Referring back to  FIG. 1B  and  FIGS. 2E-2F , in furtherance of the exemplary operation, exhaust gases carrying spent oil from the motor of the pneumatically powered instrument may be returned through the second conduit  20 . These exhaust gases may be introduced into the outer cylindrical chamber  28  containing the dry fiber cellulose material  33  through a pathway (not shown) defined in the upper portion  14  of the housing  12 . The dry fiber cellulose material  33  in the cavity  28  may filter the spent oil from the exhaust gases and allow the exhaust gases to pass through the plurality of apertures  32  in the bottom wall  26 .  
         [0044]     Referring now to  FIG. 3 , shown therein is a lubrication system  100  according to one embodiment of the present disclosure. The lubrication system  100  may include a body  120 , which may comprise an inlet tube  112  and an outlet tube  114 . The inlet tube  112  may be connected to a source of pressurized fluid, which may be pressurized air. As shown in  FIG. 1B , a coaxial hose may be connected to the lubrication system  100 —a higher pressure hose may be coupled with flanges  116 , and a lower pressure exhaust hose may be coupled with an aperture  118 . The body  120  may comprise a shell  124 , which may be substantially cylindrical or in other suitable shapes. The shell  124  may comprise an opening at one end to receive a lubrication fluid reservoir and exhaust filter unit, and one or more locking slots  126  adapted to receive projections on the exterior of the lubrication fluid reservoir and exhaust filter unit and to retain it within the body  120 . Internal grooves  122  may extend from the opening to the locking slots  126 , so that the projections may be advanced into the interior of the body  120 . The locking slots  126  may comprise a helical path, which may help to advance the lubrication and filter unit into the body  120 . Further, the locking slots  126  may include substantially flat portions at their termination, so that the lubrication and filter unit may be locked into position in the body  120 . The body  120  may comprise aluminum or other suitable materials, such as stainless steel, titanium, shape memory alloys, polymers, carbon fiber, and porous material.  
         [0045]     The lubrication system  100  may include fluid passageways adapted for providing pressurized fluid and lubrication to the surgical instrument. In one example, a first channel  130  having a diameter D 1  may be in fluid communication with the pressurized fluid from the inlet tube  112 . A second channel  132  with a reduced diameter D 1  may provide a conduit between the first channel  130  and an outlet channel  136  within the outlet tube  114 . Within the wall defining the first channel  130 , an aperture may communicate with a first fluid inlet  140 . Similarly, within the wall defining the second channel  132 , an aperture may communicate with a second fluid outlet  158 . An injector system  200  may be joined to the body  120  and substantially centered within the cylindrical shell  124 . The injector system  200 , which will be further described below in connections with  FIGS. 4A-4C , may comprise a distribution system  142 , a first fluid outlet  154 , a second fluid inlet  146 , a filtering system  144 , and a tube  150  that includes a controlled path  152 . The distribution system  142  may be in communication with the first fluid outlet  154 , while the second fluid inlet  146  may be in communication with the filtering system  144 , which in turn may be in communication with the tube  150 . The filtering system  144  may be used to prevent large particles from entering into and clogging the controlled path  152 . It may be a screen mesh or any other suitable filtering device, and each opening of the filtering system  144  may be smaller than the opening of the controlled path  152 .  
         [0046]     The lubricant  160  may simply reside in a chamber (not show). Alternatively, any absorbent material residing in the chamber, such as foam, wool felt, porous materials, or cellulose fiber materials, may be used to saturate the lubricant  160 . In this example, the second fluid inlet  146  may be at least partially submerged in and compress the absorbent material (or the lubricant  160 ). However, it is also contemplated that the second fluid inlet  146  may not be submerged in the absorbent material. In addition, the first fluid outlet  154  may not directly contact the lubricant  160 . However, it is also contemplated that the first fluid outlet  154  may contact the lubricant  160 . The lubrication system  100  may be pre-filled with the lubricant  160 . The amount of the lubricant  160  may be sufficient to ensure lubrication of the motor of the pneumatically powered instrument throughout a surgical procedure. Accordingly, when the lubrication system  100  functions properly, the risk of lacking the lubricant  160  during a surgical procedure may be effectively eliminated. After the surgical procedure is completed, the lubrication system  100  may be disconnected from the surgical instrument, and reused or discarded.  
         [0047]     Referring also to  FIGS. 4A and 4C , the present embodiment may incorporate a flow control mechanism that is accomplished at least in part by the controlled path  152 . It will be understood that it is known in the art that partially based on the diameter and the length of the controlled path  152 , and the viscosity of the lubricant  160 , the volume of the lubricant  160  flowing through the controlled path  152  and into the surgical instrument may be calculated and determined. Therefore, to supply lubrication to a variety of surgical instruments, a great range of the diameter and length of the controlled path  152  is anticipated. In one example, the controlled path  152  may be a capillary tube. In a specific example, the diameter of the controlled path  152  may be 1/5000 inch, and the length of the controlled path  152  may be 1/10 inch. However, it is contemplated that other diameter and/or length figures for the controlled path  152  are also contemplated.  
         [0048]     The injector system  200  will now be further described. Referring now to  FIGS. 4A , shown therein is the injector system  200  according to one embodiment of the present disclosure. In this embodiment, the injector system  200  may comprise an upper portion  216  and a lower portion  148 . The upper portion  216  may comprise the tube  150 , an  0  ring  202 , a distributor  220  that comprises an opening  214  adapted for receiving the tube  150 , and an o ring  206 . The lower portion  148  may comprise an opening  210  adapted for receiving the upper portion  216 , the second fluid inlet  146 , and the first fluid outlet  154 . The assembled upper portion  216  is shown in  FIGS. 4B-4C . The tube  150  may be loosely coupled with the opening  210 , so that the lubricant  160  may travel between them as indicated by an arrow A 5 .  
         [0049]     In operation, the lubrication system  100  may include air and lubricant paths. In one embodiment, the air path may comprise the first channel  130 , the first fluid inlet  140 , the distribution system  142 , and the first fluid outlet  154 . The lubricant path may comprise the second fluid inlet  146 , the filtering system  144 , the controlled path  152 , the second fluid outlet  158 , and the second channel  132 . As indicated previously, the first channel  130  has the diameter D 1 , which may be larger than the diameter D 2  of the second channel  132 .  
         [0050]     In furtherance of the example, high pressurized air, which may be at a pressure of approximately 120 psi, may be generated from a source. An on/off control mechanism, such as a foot pedal, may be disposed between a compressed air source and the surgical instrument. The pressurized air may flow through a chamber  161  and into the first channel  130 , and then encounter restriction at the smaller second channel  132 . As indicated by arrows A 1 -A 3 , a portion of the high pressurized air may enter the first fluid inlet  140 , travel through the distribution system  142 , the operation of which will be further described below in connections with  FIGS. 4A-4C , and exit through the first fluid outlet  154 . As the high pressurized air exits from the first fluid outlet  154 , it may cause the lubricant  160 , which may be oil or any other suitable lubrication fluid, to enter into the second fluid inlet  146  and travel in the direction indicated by an arrow A 6 . There, the lubricant  160  may encounter the filtering system  144 , the operation of which will be further described below. The filtering system  144  may stop undesirable large particles mixed with the lubricant  160 , and allow the filtered lubricant  160  to travel downward and along the exterior of a tube  150 , and then upward into the controlled path  152  as indicated by an arrow A 5 . Once inside the controlled path  152 , the lubricant  160  may flow into and through the second fluid outlet  158 , and exit into the second channel  132 . As indicated by an arrow A 4 , the lubricant  160  may then travel through the outlet channel  136  along with the high pressurized air from the channel  132 , so that the lubricant  160  may be used by a surgical instrument. It will be understood that in this illustration, the first fluid inlet  140  may have a lower altitude than that of the controlled path  152 , and that the first fluid outlet  154  may have a higher altitude than that of the second fluid inlet  146 . However, other arrangements of relative altitudes are also contemplated.  
         [0051]     The operation of the distribution system  142  will not be further described. Referring now to  FIG. 4A , in one embodiment, the distribution system  142 , which may comprise the distributor  200 , the O ring  206 , and a substantially circular path  218 , may direct the pressurized air in the following manner: the pressurized air may travel to the indented component  212 , exit from the distributor  220 , then continue along the substantially circular path  218  as indicated by the arrows A 2 , and finally exit into the first fluid outlet  154 . It is contemplated that the distribution system  142  may employ other means to direct pressurized fluid from the first fluid inlet  140  to the first fluid outlet  154 . In one example, the distribution system  142  may be a channel between the first fluid inlet  140  and the first fluid outlet  154 . In another example, the first fluid inlet  140  may simply be in fluid communication with the first fluid outlet  154 .  
         [0052]     The operation of the filtering system  144  will now be further described. As indicated by the arrow A 5  of  FIG. 4A , the lubricant  160  may travel from the filtering system  144  of  FIG. 3 , continue along the space between the tube  150  and the opening  210 , and then travel into the controlled path  152 .  
         [0053]     Generally, when a lubrication system fails to provide a proper amount of lubrication to the surgical instrument, it is preferable to supply zero or very limited amount of lubrication. Therefore, the lubrication system  100  may employ a number of features to cope with a system failure, and to prevent the surgical instrument from being overwhelmed with an excessive amount of the lubricant. Referring back to  FIG. 3 , in one example, when the controlled path  152  becomes clogged and is no longer able to effectively control the flowing amount of the lubricant, it simply decreases the volume of the lubricant that flows into the surgical instrument. In another example, a seal  156 , which may be an O ring, is utilized, so that high pressurized air from the distribution system  142  will not be improperly diverted into the second fluid outlet  158 . However, when the seal  156  fails, the high pressurized air may simply enter into the second fluid outlet  158 . As a result, a decreased amount of the lubricant will be provided to the surgical instrument.  
         [0054]     Although only a few exemplary embodiments of this invention have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Also, features illustrated and discussed above with respect to some embodiments can be combined with features illustrated and discussed above with respect to other embodiments. Accordingly, all such modifications are intended to be included within the scope of this invention.