Patent Publication Number: US-2007100286-A1

Title: Needle assembly for radiating bioactive compounds through tissue

Description:
BACKGROUND ART  
      1. Field of the Invention  
      The invention mainly relates to needle assemblies used for injecting tissues with bioactive compounds. More specifically, the invention relates to needle assemblies capable of radiating the bioactive materials through the tissue that requires the compounds.  
      2. Description of the Related Art  
      Current techniques in transferring bioactive compounds into mammalian tissue is done through a standard needle assembly. The needle is forced through the tissue whereafter the bioactive compound is pushed through the syringe and the needle into the tissue. The technique is somewhat more complicated when the tissue is hard tissue, such as bone. In this situation, the needle assembly has to create a space in which the bone could receive the bioactive compounds (hereinafter the bioactive compounds will be referred to as medicine). To create the space in which the medicine is going to be received in the hard tissue, the needle must force itself into the hard tissue to create a type of reservoir to receive the medicine therein. With the creation of the reservoir, the medicine will fill that void and work in that specific area. Should the medicine be required in multiple locations, multiple injections will be required. This can become painful to the patient.  
      A type of hard tissue surgical needle is disclosed in U.S. Pat. No. 4,513,747, issued to Smith on Apr. 30, 1985. This needle defines a tip that is created by cutting edges converging together. This makes it easier to create the space in which the medicine is to be received. Once the space is created, the hard tissue surgical needle must be removed and a needle that can transfer medicine to the space is then injected into the patient. This disclosure of the hard tissue surgical needle is deficient in that each procedure requires at least two needle sticks to the patient to accomplish the transfer of medicine into the desired location. In addition, the medicine, once injected, is concentrated in a single location.  
      A biopsy needle is disclosed in U.S. Pat. 5,807,275 issued to Jamshidi on Sep. 15, 1998. In this reference, a single opening is disposed adjacent the tip of the needle assembly. The needle is injected into the patient, whereafter a handle is turned and a piece of tissue is retained in the tip of the needle. Once the needle is removed from the patient a biopsy may be performed on the tissue that was removed therefrom. This biopsy needle is not used for the transfer of medicine to a patient.  
     SUMMARY OF THE INVENTION  
      A needle assembly prepares tissue for the receipt of medicine or treatment electrodes. The needle assembly includes a body extending between a handle end and an insertion end. The body includes a hollow interior. A pointed tip is fixedly secured to the insertion end to reduce forces required to insert the needle assembly through the tissue to create a central cavity. A plurality of openings is spaced about the body at the insertion end. The plurality of openings provides access from the hollow interior into the tissue. The needle assembly also includes a plurality of stylets extendable through the hollow body and movable axially with respect thereto. Each of the plurality of stylets exits out each of the plurality of openings to create supplemental tubular cavities radiating out from the central cavity such that the medicine forced through the hollow interior of the body will exit through the plurality of openings and into the central and supplemental cavities to more effectively distribute the medicine through the tissue. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      Advantages of the invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:  
       FIG. 1  is a perspective view, partially cut away, of one embodiment of the invention being injected into hard tissue of a patient;  
       FIG. 2  is a perspective view, partially cut away, of a second embodiment of the invention being injected into soft tissue of a patient;  
       FIG. 3  is a side view, partially cut away, of an insertion end of the invention with a set of obturating stylets closing the end thereof;  
       FIG. 4  is a side view, partially cut away, of the insertion end of the invention with stylets extending out therefrom;  
       FIG. 5  is a side view, partially cut. away, of the insertion end of the invention with hollow stylets in the extended position; and  
       FIG. 6  is an exploded perspective view partially cut away of a third embodiment of the invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      Referring to  FIG. 1 , a first embodiment of a needle assembly is generally indicated at  10 . This needle assembly  10  is designed to prepare hard tissue  12  for the receipt of medicine (indicated by arrows  14  in  FIG. 2 ) therein. The needle assembly  10  is designed to prepare the hard tissue, e.g. bone, by making the hard tissue  12  as accessible as possible with the least amount of injections into the patient. In addition, the needle assembly  10  is designed to distribute as much medicine  14  as uniformly as possible throughout the hard tissue  12 .  
      The needle assembly  10  includes a body  16  that extends between a handle end  18  and an insertion end  20 . The body  16  defines a hollow interior  22  that extends along the entire body  16 . The body  16  defines a longitudinal axis  24  about which the hollow interior  22  is coaxial therewith. The body  16  is cylindrical and includes a cylinder wall  26  of uniform thickness extending between an exterior  28  and the hollow interior  22 . For soft tissue penetration, the cylinder wall  26  may be fabricated from a translucent material such that an operator of the needle assembly  10  can see the contents of the hollow interior  22 . In  FIG. 1  the body  16  is fabricated from a non-translucent material, e.g., steel, so that it can effectively prepare the hard tissue  12  for the medicine  14 . In this instance, a window (not shown) may extend along the cylinder side wall  26  of the body  16  so that the operator of the needle assembly  10  may still view the contents of the needle assembly  10  as they are distributed into the hard tissue  12 . The diameter for the body  16  may vary depending on the use thereof. It is, however, envisaged that the diameter for human use would be 11 or 13 G.  
      The needle assembly  10  also includes a pointed tip  30  that is fixedly secured to the insertion end  20 . The pointed tip  30  is used for penetration into the hard tissue  12 . Therefore, the pointed tip  30  reduces the forces required to insert the needle assembly  10  through the hard tissue  12  to create a central cavity  32 . The central cavity  32  is created inside the hard tissue  12  and will receive medicine  14  therein once the hard tissue  12  is finally prepared to receive the medicine  14 .  
      A plurality of openings  34  extends through the cylinder side wall  26  of the body  16  at the insertion end  20 . In the embodiment shown, each opening  34  is spaced equidistantly about the body  16  from each other. It should be appreciated by those skilled in the art that the openings  34  may also be concentrated in a portion of the cylinder side wall  26  to extend the stylets  36  through one aspect of a region. In addition, the locations of the openings  34  may vary along the length of the cylinder side wall  26 . The plurality of openings  34  provide access from the hollow interior  22  into the hard tissue  12 . In the embodiment shown, each opening  34  is oval in shape and is cut through the hollow interior  22 . It should be appreciated by those skilled in the art that each opening  34  may be cut through the cylinder side wall  26  in any shape that would facilitate the function of the opening  34 .  
      The needle assembly  10  also includes a plurality of stylets  36  that extend through the hollow body  16 . The stylets  36  are removable from the body  16  when it is time to inject medicine into the hard tissue  12 , should the needle assembly  10  be used as the medicine delivery mechanism. The stylets  36  move axially with respect to the body  16 . Each of the plurality of stylets  36  defines a terminal end  38 . The terminal end  38  includes a cutting edge  40  that aids in the passing of the stylets  36  through the openings  34  and into the hard tissue  12 . The stylets  36  are fabricated from a hard material, e.g., steel, such that the stylets  36  may work through the hard tissue  12  to create channels for medicine  14  to be received therein. While it is contemplated that the stylets  36  are fabricated from a hard material, it should also be appreciated that the stylets  36  are flexible. The stylets  36  need to be flexible because they will be extending down through the hollow interior  22  of the body  16  coaxial with the longitudinal axis  24  thereof. The stylets  36  may also be made of spring retaining memory alloy with a preset bend along the shaft close to the terminal end  38  such that when forced through the hollow interior  22 , they assume a straight configuration inside the hollow interior  22  and then spring back to their original bent configuration once they are forced to exit through the openings  34 .  
      As the stylets  36  reach the openings  34 , the stylets  36  will be forced to bend to exit the hollow interior  22  radially outward therefrom. When the stylets  36  move outwardly from the hollow interior  22  through the openings  34 , the stylets  36  create supplemental cavities  42  that radiate out from the central cavity  32  such that medicine  14  forced through the hollow interior  22  of the body  16  will exit through the plurality of openings  34  and into the central  32  and supplemental  42  cavities to more effectively distribute the medicine  14  through the hard tissue  12 . Because the stylets  36  move out of the hollow interior  22  through the openings  34 , the supplemental cavities  42  will be in fluid communication with the central cavity  32 , thus facilitating the transfer of medicine  14  from the central cavity  32  radially outwardly through the supplemental cavities  42  to more evenly and thoroughly distribute the medicine  14  through the hard tissue  12 . While the guides  44  are shown to have the same acute angle, it should be appreciated that each of the guides  44  could have an angle different from the others to vary the direction that the stylets  36  exit the needle assembly  10 .  
      To aid in the directing of the stylets  36  out of the hollow interior, each of the plurality of openings  34  include a guide  44  (shown in  FIGS. 3 and 4 ). The guide  44  directs each of the plurality of stylets  36  radially outwardly therefrom. Each guide  44  is a surface that extends at an acute angle with respect to the body  16 . The surface  46  may extend into the hollow interior  22  beyond the cylindrical wall  26  to receive each of the plurality of stylets  36  prior to guiding the stylets  36  out of the hollow interior  22 .  
      The needle assembly  10  is generally provided with two sets of stylets  36 . The second set  36 ″ (shown in  FIG. 4 ) is of the same length as the body  16  of the needle assembly and therefore do not protrude out of side openings  34 . This second set  36 ″ acts as an obturator for the needle assembly  10  while the needle assembly  10  is plunged into hard tissue  12  to prevent its bending. A solid inner body  47  may be used with the second set of stylets  36 ″ secured to the end thereof. Once in place, the first set of stylets  36  replaces the second set  36 ″. The first set of stylets  36  is longer than the body  16  so an application of a force will have the first set of stylets  36  forced into the hard tissue  12  to create the supplemental cavities  42 . More specifically, when advanced into the cylinder body  16 , the first set of stylets  36  eventually will protrude out of the openings  34  and create the supplemental cavities  42 . The length of the stylets  36  may be equal and therefore all protrude to the same distance outside body  16  or may be of different lengths and therefore one or more stylets may extend to a greater distance into the tissue than others depending on the anatomy of where the needle is being used.  
      The external ends of the stylets may be attached to a plunger  52  which constitute the movable part of the handle end  18 . The fixed part of the handle  54  is attached to the handle end  18  of the body  16 . Moving the plunger  52  down to be in contact with the handle  18  brings all the stylets  36  out of their side openings  34  to their maximum excursions into the tissue. The stylets  36  may be provided with graduations in centimeters or inches or another unit to mark the extent of protrusion into the tissue. Alternatively, they can be provided with a movable stopper made of a metal clip or similar arrangement that can be moved along the shaft of the stylets to stop their excursion into the tissue as the stopper comes in contact with the handle  18 .  
      The body  16  of the needle assembly  10  may be totally hollow with the stylets  36  entering the handle end  18  and traversing the body  16  to reach the insertion end  20  where they are forced to bend freely according to the angles of the guides  44  at the side openings  34 . Another embodiment, (not shown), entails that the handle end is provided with panel containing pores, at set distances to guide the entry of the stylets towards their side openings  34 . In a different embodiment (also not shown), the hollow shaft of the needle is divided into hollow compartments extending between the handle  18  and the exit  20  ends. Each stylet  36  would enter through one of the compartments to reach its opening  34 .  
      Referring to  FIG. 2 , a second embodiment of the needle assembly is generally indicated at  10 ′, wherein like prime numerals represent similar elements as those of the first embodiment, discussed above. The needle assembly  10 ′ is designed to be used in soft tissue, generally indicated at  48 . It is contemplated that the soft tissue  48  may be a tumor in which it would be desired to have an even distribution of a medicine  14  throughout the body of the tumor defined by its outer periphery  50 . In this instance, the stylets  36 ′ are hollow and not solid. The stylets  36 ′ may be fabricated from polyurethane or similar material. Each of the plurality of hollow stylets  36 ′ move through each of the plurality of openings  34 ′ to extend radially out therefrom. Once the stylets  36 ′ are in position, medicine is pushed through each of the plurality of stylets  36 ′ to radiate the medicine  14 ′ outwardly radially into regions in the soft tissue  48  away from the body  16 ′ of the needle assembly  10 ′. The stylets  36 ′ include output ports  52  disposed adjacent the cutting edge  40 ′ of the terminal end  38 ′. The output ports  52  allow the medicine  14 ′ to move out from the stylets  36 ′ into the supplemental cavities  42 ′ created by the stylets  36 ′.  
      Referring to  FIG. 6 , a third embodiment of the invention is generally indicated at  10 ′″. The needle assembly  10 ′″ has a body  16 ′″ with a non-cylindrical inner wall, generally shown at  52 . The inner wall defines a plurality of lobes  54 . Each of the plurality of lobes  54  receives one of the stylets  36 ′″ therein. It should be appreciated by those skilled in the art that the number of lobes  54  and the number of stylets  36 ′″ may vary depending on the design of the needle assembly  10 ′″.  
      The lobes  54  may extend down the entire length of the body  16 ′″. Alternatively, the plurality of lobes  54  may only exist at the handle end  18 ′″thereof. In fact, the plurality of lobes  54  may be created in a cap-like structure (not shown) that may be inserted over the top of the handle end  18 ′″ of the body  16 ′″. Each of the lobes  54  aides in the maintenance of the stylet  36 ′″ in a particular position with respect to the body  16 ′″ so that it may be received by a lumen  34 ′″ in a manner which will not require the stylets  36 ′″ to be rotated once inside the body  16 ′″ to ensure that each of the stylets  36 ′″ are capable of being pushed through a lumen  34 ′″.  
      The invention has been described in an illustrative manner. It is to be understood that the terminology, which has been used, is intended to be in the nature of words of description rather than of limitation.  
      Many modifications and variations of the invention are possible in light of the above teachings. Therefore, within the scope of the appended claims, the invention may be practiced other than as specifically described.