Abstract:
A portable tissue cleaning apparatus comprising a housing with a base member and side walls mounted to the base member and a top cover having a motor contained within a housing. A manually operable switch assembly is mounted on the housing and is operable to control operation of the motor. A connector connects the motor to a rotatable basket assembly having a cylindrical container. A perforated basket is mounted in the cylindrical container and a cover mounted on the cylindrical container to provide a sealed fluid containment chamber. The perforated basket is cylindrical and has an impeller mounted on its bottom to direct fluid in a predetermined path when the same is rotated, and a divider comprising a tube with external slots formed therein and fin members mounted in the slots with the fin members extending outward towards an inner wall surface of the cylindrical perforated container to divide the perforated basket into sections. The motor rotatably drives the cylindrical container and perforated basket in sequential clockwise and counter clockwise directions a predetermined number of revolutions to clean tissue held therein.

Description:
RELATED APPLICATIONS 
       [0001]    There are no related applications. 
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not applicable. 
       REFERENCE TO SEQUENCE LISTING, A TABLE OR A COMPUTER PROGRAM LISTING COMPACT DISC APPENDIX 
       [0003]    None. 
       FIELD OF THE INVENTION 
       [0004]    The present invention relates generally to a tissue cleaning apparatus and more particularly, to a powered rotating perforated basket assembly which is sequentially reversed in clockwise/counterclockwise cycles to clean human tissues. 
       BACKGROUND OF THE INVENTION 
       [0005]    Several hundred thousand tissue transplants are annually performed in the United States. The single most variable factor with respect to allographic transplantation is the preparation of such bone and tissue segments. Procedure and protocol of the some 400 tissue banks in North America are quite varied and has resulted in various technology with developed processes. 
         [0006]    Allografts are vital for bone stock deficiencies that occur during orthopaedic trauma, joint reconstruction, or other reconstructive procedures. The main criteria for an orthopaedic allograft are the retention of strength, the retention of biologic factors, and the reduction of risk of disease transmission. The first two should not be affected by processing, while processing should eliminate the risk for disease transmission. 
         [0007]    There is no known industry standard specifying levels of cleanliness for cleaning and preparing bone segments. The problems associated with this lack of standards interpret to poor process control, inadequate removal of tissue from the parent surface and to a large extent lack of sterility during the tissue recovery process. 
         [0008]    Human bone obtained from cadaveric donors is typically procured under sterile conditions in an operating suite environment of local hospitals. The bone is stored frozen until it is further processed into small grafts under similar sterile conditions, or under clean-room conditions. Procurement and processing of human tissues is typically performed by groups certified by the American Association of Tissue Banks under standard operating procedures for the processing of each specific bone graft. Large bones such as the femur are thawed and debrided of excess tissue prior to being cut into smaller grafts. Processing of the smaller grafts includes cleaning of bone marrow from the cancellous bone spaces. Cleaning of bone marrow and tissue from small bone grafts has been described in the scientific literature and in brochures and documents made public by groups involved in the procurement and processing of human tissues. 
         [0009]    The use of prior art procedures to clean bone tissue involves the use of a pressurized flow of solution as a rapidly moving stream which dislodges bone marrow by impact of the solvent on the bone graft. In U.S. Pat. No. 5,333,626 issued Aug. 2, 1994, a high pressure wash is used to clean bone. The bone is cleaned with a high pressure detergent solution such as TritonX-100 and Tween 80 preferably from 37° C. to 80° C. The bone may be further decontaminated by exposing it to 3% hydrogen peroxide solution from 5 to 120 minutes (preferably 5 to 60 minutes) after which the residual hydrogen peroxide is removed by washing with sterile water. After cleaning, the bone is finally decontaminated by contacting the bone with a global decontaminate for 30 to 60 minutes. Such procedures tend to generate aerosols of tissue and solvent which can be hazardous to processing personnel. The present invention virtually eliminates this hazard. 
         [0010]    Ultrasonic cleaners are also used to clean bone tissue. Ultrasonic energy in liquid generated by piezoelectric or other types of transducers creates cavitation, which is the mechanism for ultrasonic cleaning. Cavitation consists of the formation and collapse of countless tiny cavities, or vacuum bubbles, in the liquid. The energy produces alternating high and low pressure waves within the liquid of a tank. The liquid is compressed during the high pressure phase of the wave cycle, then pulled apart during the low pressure phase. As the pressure in the liquid is reduced during the low pressure phase, cavities grow from microscopic nuclei to a maximum critical diameter. During the subsequent high pressure phase they are compressed and implode. The energy is powerful, but safe for parts because it is localized at the microscopic, i.e., cellular, scale. Factors affecting the strength of cavitation are temperature, surface tension, detergents or other agents which reduce surface tension are optimal, viscosity (medium vapor pressure is most conducive to ultrasound activity), and density (where high density creates intense cavitation with greater implosive force). 
         [0011]    A number of prior art references have used ultrasonics together with detergents and other solutions to clean bone. 
         [0012]    In U.S. Pat. No. 5,556,379 issued Sep. 17, 1996 and U.S. Pat. No. 5,976,104 issued Nov. 2, 1999, the processing of the smaller grafts including cleaning of bone marrow from the cancellous bone spaces using mechanical means, soaking, sonication, and/or lavage with pulsatile water flow under pressure is disclosed. This cleaning may use reduced or elevated temperatures, for example 4° C. to 65° C., and may also include the use of detergents, alcohol, organic solvents or similar solutes or combination of solutes designed to facilitate solubilization of the bone marrow. 
         [0013]    In the Simonds reference from the New England Journal of Medicine, page 726, Mar. 12, 1992, entitled TRANSMISSION OF HUMAN IMMUNODEFICIENCY VIRUS TYPE I FROM SERONEGATIVE ORGAN AND TISSUE DONOR, the bone was lyophilized and treated with ethanol. The lyophilized tissue has the soft tissue removed, followed by treatment with two antibiotics, irrigation with sterile water, packaging and refreezing and lyophilization to a residual moisture content of less than 5%. The ethanol treated tissue underwent ultrasonic cleaning in 30% ethanol, removal of marrow by water lavage and brief treatment in 100% ethanol. 
         [0014]    U.S. Pat. No. 5,095,925 issued Mar. 17, 1992 is directed toward a bone cleaning device using ultrasonics which removes gross tissue from bone to prepare the same for transplant and use in surgery. The bone is subjected to a positive pressure stream of sterile water, ultrasonically cleaning the same in a detergent followed by rinsing and soaking and reintroduced to the ultrasonic process if necessary within a preferred working temperature range of 27° C. to 33° C. 
         [0015]    U.S. Pat. No. 5,509,968 issued Apr. 26, 1996 is directed toward cleaning used orthopaedic implants which are decontaminated and made available for reuse by a three step process for removal of protein tissue, bone tissue and lipids using sonication. 
         [0016]    The implant is suspended in an aqueous bath of detergent suitable for emulsifying lipids at elevated temperatures, such as 40° C. to 60° C., and is typically treated for about 1 to 45 minutes by the use of an ultrasonic cleaning system. The solution in the treating container is discarded and the container and implant are washed with clean water. A container is filled with a dilute acid capable of dissolving bone salts (e.g., calcium phosphate minerals that are deposited in the collagen matrix of the bone). The implant is added to the container, and subjected to ultrasonic treatment for approximately the same time. After treatment, the solution containing dissolved bone salts is discarded and the implant and container are again rinsed with clean water. The implant is then subjected to a bath of an aqueous solution sodium hypochlorite of a concentration as sold for general cleaning purposes, (household bleach). This step removes any remaining organic bone tissue as well as protein. An ultrasonic cleaning system is again used for the same time and temperature. When this step is completed, the solution is discarded and both the implant and container rinsed with water. 
         [0017]    U.S. Pat. No. 5,797,871 issued Aug. 25, 1998 is also directed toward a bone cleaning process using ultrasonics in which the bone is sonicated in a solution of several detergents within a temperature range of 37° C. to 50° C. to produce bone grafts essentially free from bone marrow and detectable fungal and viral contamination. 
         [0018]    A number of prior art patents show the cleaning of bones through agitation and centrifugation. 
         [0019]    U.S. Pat. No. 5,513,662 issued May 7, 1996 discloses treating bone at less than ambient pressure and then agitated the same vigorously in an agitator. The U.S. Pat. No. 5,797,871 patent noted above also uses mild and vigorous agitation in connection with its bone cleaning sonication process. 
         [0020]    U.S. Pat. No. 5,977,432 issued Nov. 2, 1999 is directed toward a process for removing essentially bone marrow from a cut bone graft. A large substantially intact bone is selected and excess cartilage and associated soft tissues are removed from the surface of the bone. The bone is left whole or may be cut into smaller pieces constituting cut grafts and bone marrow is removed from the cancellous bone spaces of the small cut grafts through the application of centrifugal force. Prior to and/or following the application of centrifugal force, the bone graft may optionally be pretreated with one or more decontaminating agents, and/or solubilizing agents 
       SUMMARY OF THE INVENTION 
       [0021]    The above and other objects, feature and advantages of the present invention will be apparent in the following detailed description thereof when read in conjunction with the appended drawings wherein the same reference numerals denote the same or similar parts throughout the several views. 
         [0022]    The present invention is a portable tissue cleaning apparatus constructed with a housing having a motor contained therein, the housing being provided with a base member, side walls mounted to the base member and a top cover mounted over the housing side walls. A switch assembly is mounted on the top cover for operation of the apparatus. A connector assembly connects the motor to a rotatable perforated basket assembly housing in a fluid container; which is rotated in sequential clockwise and counterclockwise cycles a set number of revolutions to clean bone tissue placed therein. Each sequential cycle is ramped up at the start and ramped down at the end of the cycle. The perforated basket is cylindrical with an impeller mounted on its bottom to direct cleaning fluid in a predetermined path, and the basket is divided into separate sections. 
         [0023]    The present invention addresses the needs and deficiencies noted above. It provides an apparatus with a temperature sensor to determine the temperature of the bone cleaning solution. 
         [0024]    It is an object of the invention to provide a simple but efficient way of cleaning bones by uniformly cleaning same. 
         [0025]    It is another object of the invention that it operates to effectively remove lipids and bone marrow form the cut bone pieces. 
         [0026]    It is still another object of the invention that to provide a portable cleaning device which can be easily moved to a desired area. 
         [0027]    It is another object of the invention to provide a device that can be simply operated with a minimum of training of personnel. 
         [0028]    It is yet another object of the invention that the device can be easily broken apart for sterilization and cleaning. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0029]    The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein. 
           [0030]      FIG. 1  is a perspective view of the inventive tissue cleaning apparatus; 
           [0031]      FIG. 2  is a perspective view of the tissue cleaning apparatus shown in  FIG. 1  with the basket assembly and fastening elements for same shown in exploded relationship; 
           [0032]      FIG. 3  is an exploded view of the components of the housing of the tissue cleaning apparatus shown in  FIG. 1 ; 
           [0033]      FIG. 4  is a perspective view of the basket assembly; 
           [0034]      FIG. 5  is a side elevation view of the basket assembly as shown in  FIG. 4 ; 
           [0035]      FIG. 6  is an exploded view of the basket assembly shown in  FIG. 4 ; 
           [0036]      FIG. 7  is a perspective view of the basket used in the basket assembly of  FIG. 4 ; 
           [0037]      FIG. 8  is a side elevation view of the basket shown in  FIG. 7 ; 
           [0038]      FIG. 8   a  is an enlarged side elevation view of the basket mounting taken from Circle A of  FIG. 8 ; 
           [0039]      FIG. 9  is an exploded view of the basket shown in  FIG. 7 ; 
           [0040]      FIG. 10  is a top plan view of the impeller of the basket assembly shown in  FIG. 7 ; 
           [0041]      FIG. 11  is an enlarged cross section taken from line  11 ′- 11 ′ of  FIG. 10 ; 
           [0042]      FIG. 12  is a bottom perspective view of the impeller shown in  FIG. 10 ; 
           [0043]      FIG. 13  is a top perspective view of the impeller shown in  FIG. 10 ; and 
           [0044]      FIG. 14  is an enlarged view taken from Circle B of  FIG. 13 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0045]    The preferred embodiment and best mode of the invention is shown in  FIGS. 1 through 14 . While the invention is described in connection with certain preferred embodiments, it is not intended that the present invention be so limited. On the contrary, it is intended to cover all alternatives, modifications, and equivalent arrangements as may be included within the spirit and scope of the invention as defined by the appended claims. 
         [0046]    The present invention generally refers to a portable tissue cleaning apparatus  20  constructed with a drive and control housing  30  having a basket assembly  100  mounted thereon. The basket assembly  100  is mounted on the bearing assembly  94  of the servo motor by three mounting bracket assemblies  140  positioned equal distant around the circumference of bearing assembly  94  and basket bearing housing  103  of the basket assembly  100 . Each mounting bracket assembly  140  is constructed with a mounting bracket  142 , a 5/16×0.875 inch screw  144  and a 5/16 inch rosette thumb screw knob  146  which fits over the head  145  of the screw  144  as is shown in  FIG. 2 . The bracket assembly  140  is mounted to the basket bearing assembly  103  and the servo motor bearing housing  94 . 
         [0047]    The housing  30  as shown in exploded view in  FIG. 3  is formed with a flat rectangular shaped bottom plate  32  having seating bumpers  33  secured thereto, a rectangular gasket  34  which is placed on the top surface of the bottom plate  32  and is secured around the outer periphery of the bottom plate  32  by screws and/or adhesives. Side panels  36  and  38  are formed with a perpendicular lip  39  which is seated on the gasket  34  and held in place by screws. Each of the side panels  36 / 38  are trapezoidal shaped with angled front edge  40  having a 60° angle from the base and a perpendicular rear edge  41  and have a flat surface. Side panel  38  has a plurality of holes cut therein to allow for ventilation of the interior of the housing. Reinforcing ribs  35  about each of the side panels to provide housing stability. Handles  43  are mounted to the flat surface of each of the side panels  36  and  38  to allow the device to be easily moved from one area to another. Mounted to side panel  38  over the plurality of ventilation holes is a ventilation base enclosure member  50  with a louver  52  for ventilation of the interior of the housing  30 . A top cover panel  42  is mounted over the side panels  36  and  38  with the front section  44  of the cover panel  42  having the same angle as the front edge of the side walls  36 / 38  and a top section  46  being planar and parallel to the bottom plate  32 , with the rear section  48  being perpendicular and fitting over the rear edges  40  of the side panels  36 / 38 . Both front section  44  and rear section  48  have an inwardly projecting lip  47  allowing the top cover panel to be mounted on gasket  34  and secured to bottom plate  32 . The rear section  48  has a plurality of holes  49  cut in the upper surface of the section to allow ventilation. The bottom plate  32 , side panels  36 / 38  and top cover panel  42  are preferably constructed of stainless steel. Mounted to the rear section  48  of the top cover panel  42  is a ventilation base enclosure member  54  with a louver  56  allowing the interior of the housing to be ventilated. A tube axial fan  58  is mounted to the rear of the rear panel  42  to assist in circulation of the air within the housing. 
         [0048]    The front section  44  has a plurality of holes cut therein in a linear alignment to receive a number of controls to operate the cleaning apparatus. As can be seen in  FIGS. 1 and 2 , a three position select power switch  60  is located on the far left of the front section with an emergency stop button  62  being located next to the switch  60 . Switch  60  is a main power switch with an off/on/reset select position. The reset of switch  60  is used to reset servo drive faults. The stop button  62  is used as an emergency stop. Next to the stop button  62  is a two position select switch  64 . This switch has a preset  1  and a preset  2  allowing for different servo motor profiles. Currently preset  1  and preset  2  are both set at 1000 rpm but if desired they can be programmed for different speeds. A green start push button  66  is located adjacent the two position select switch  64  and is used to start the apparatus. Next to the green push button  66  in the same linear alignment is a red stop push button  68  which is used to stop the a device. Located beneath the two position select switch  64  is a temperature switch  70  which indicates current temperature. This allows authorized personnel to change temperature at which the machine cycle is disabled and adjacent to the temperature switch is a red fault indicator  72  which is an alarm indicator indicating a fault with the servo drive. Adjacent the red fault indicator  72  is a temperature indicator  74  which indicates that the cleaning solution temperature has reached the preset value. An electronic control card which operates the servo motor in response to the actuation of the various switches and buttons is mounted on the inside of the housing. 
         [0049]    A servo motor mount assembly  80  is mounted on the top section  46  and is connected to the basket bearing assembly  103  for driving the basket assembly  100 . The servo motor mount assembly  80  is constructed with a 1⅛ inch buna-n u-cup  82 , a junction box assembly  84 , and a servo mount base  86  defining a central aperture  87 . A coupling member  88  is mounted in central aperture  87  of the servo mount base  86  and an o ring  90  is placed around the periphery of the servo mount base  86  to provide a seal with the servo mount bearing housing  94 . The coupling has a solid square shaped distal drive end  89 . A double sealed ball bearing race  92  is seated over coupling member  88  and is held in place by a second ⅝ inch buna-n u-cup  93 . A servo motor mount bearing housing  94  is mounted to the coupling member  88 . The servo mount bearing housing  94  is provided with a hub  96  which receives the basket assembly  100 . The bearing housing  94  is mounted to the coupling member  88 . 
         [0050]    The basket assembly  100  which is shown in exploded view in  FIG. 6  is mounted to the hub  96  of the servo mount. A connector shaft  102  is mounted in the basket bearing housing  103  which is mounted by mounting brackets  140  to the servo motor hub  96 . The connector shaft  102  extends through an aperture  105  cut in a base plate  104  of the basket assembly. The base plate  104  has a stepped recess  106  cut around its periphery which holds the end  109  of cylindrical container  108  and has a toothed bottom hub  105 ( a ) around aperture  105  as shown in  FIGS. 8 and 8   a  to receive stepped teeth  102   a  formed on connector shaft  102 . The base plate  104  and cylindrical container  108  are secured together by screws  107  which are mounted through equal distant spaced holes in the stepped recess  106  and threaded into threaded holes cut in the end rim  109  of the cylindrical container  108 . A perforated basket  110  is mounted in the cylinder container  108  to hold the tissue to be cleaned. The basket  110  has linear rows of holes  111  which are alternatively staggered. The perforated basket  110  which is shown in enlarged view in  FIG. 7  and exploded view in  FIG. 9  is cylindrical and is divided into two sections by a central positioned tube  112  through which connector shaft  102  is mounted and two opposed separator fin members  114  and  116 . The fin members are mounted into slots  113  cut into the tube  112  as is shown in  FIG. 9 . The separator fin members  114  and  116  extend outward from the tube  112  exterior surface until they engage the inner surface of the cylindrical perforated basket  110 . The separator members  114  and  116  are perforated with a plurality of linearly aligned holes  117  having a diameter ranging from 0.18 to 0.20 inches. The base of the perforated basket  110  has an impeller  120  as shown in  FIGS. 9 through 14 . The impeller  120  is disc shaped and has a plurality of linear radially extending rows of angled through going holes  121  and trapezoidal shaped cutouts  123  on one face. The cutouts have sidewalls which are aligned with two rows of the holes  121  to form 30° wedge segments. The holes have a preferred diameter of about 0.125 inches. The impellor has a central hole  125  which allows connector shaft  102  to be inserted there through. An end cap member  122  fits into the end of tube  112  holding the basket in a fixed axial position on the shaft  102 . The end cap member  122  is held in place on shaft  102  by means of a screw  124  which is mounted through the end cap member  122  into the end of shaft  102 . A container cover  126  is mounted over the cylindrical container  108  and held in place on the cylindrical container  108  by clamp members  128  which are mounted on clamp blocks  130  secured to the outer surface of the cylindrical container  108 . The container cover  126  is stepped and the top of the cylindrical container is sealed by an o-ring  132 . 
         [0051]    In operation the bone tissue to be cleaned is placed into perforated basket  100  that has fin dividers  114  and  116 . As the basket spins, the tissue is forced to spin in the same rate as the basket  100 . The basket  100  has an impeller  120  at the bottom which forces cleaning solution up through the basket  100  and promotes fluid circulation over the tissue. Two liters of cleaning solution such as 0.1% Triton X-100 or 0.1% Tween 80 is used per cycle. The basket  100  has a ramped acceleration and deceleration which prevents the tissue from being damaged. The basket spins at a speed of 1000 rpm for 420 revolutions, then stops and spins in the opposite direction for 420 revolutions (equal to 25 seconds CW, 25 seconds CCW). The CW/CCW cycle continues until the operator stops the machine or until the cleaning solution reaches a temperature of 104° F. The inherent temperature rise of the cleaning solution at current setting (1000 rpm, 420 revolutions in the CW and CCW directions) is 0.6° F. per minute. The temperature of the cleaning solution is monitored to ensure that the machine shuts down if 104° F. is reached to prevent temperature damage of the BMP&#39;s and growth factors of the tissue. The number of revolutions that the basket  100  turns in each direction is programmable. The direction is reversed to reposition the tissue to ensure even cleaning of all tissue and helps eliminate the possibility that the tissue and cleaning solution reach the same speed. If the tissue and cleaning solution travel at the same speed and in the same direction, there will not be a washing effect as it would be more of a soaking effect. The basket  100  is removable from the cylindrical container and the tissue is removed from the basket for further processing. The basket  100  is autoclaved between each donor tissue usage to ensure sterility and donor separation. 
         [0052]    The principles, preferred embodiments and modes of operation of the present invention have been described in the foregoing specification. However, the invention should not be construed as limited to the particular embodiments which have been described above. Instead, the embodiments described here should be regarded as illustrative rather than restrictive. Variations and changes may be made by others without departing from the scope of the present invention as defined by the following claims: