Abstract:
The present invention provides apparatus and methods for loading delivery systems, such as seed magazines and suture material, with seeds which greatly increases productivity, reduces process variation and reduces the risk of handling damage to the seeds. Importantly, the apparatus and methods of the present invention reduce potential risks to workers. In a first aspect of the invention there is provided an automated method of loading a delivery system for brachytherapy seeds which comprises the steps of a) securing the delivery system to be loaded; b) conmnunicating seeds from a supply of seeds into the delivery system; and c) repeating step b) to load a plurality of seeds. In a second aspect of the invention there is provided an apparatus for loading a delivery system for brachytherapy seeds comprising: a) means for retaining a delivery system to be loaded with seeds; and b) means for communicating individual seeds from a supply of seeds to said delivery system.

Description:
This application claims the benefit of Provisional application Ser. No. 60/128,496, filed Apr. 9, 1999. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to brachytherapy seeds used for radiation therapy. More particularly, the present invention relates to methods and apparatus for loading delivery systems for brachytherapy seeds used in radiation therapy. 
     2. Description of the Related Art 
     Radiation therapy is the treatment of diseases, especially the treatment of tumors, including malignant tumors, with radiation. In radiation therapy, the ultimate aim is to destroy the malignant tissue without causing excessive radiation damage to nearby healthy, and possibly vital, tissue. This is difficult to accomplish because of the proximity of malignant tissue to healthy tissue. 
     Medical personnel and investigators have developed methods for preferentially irradiating deep seated diseased tissue as opposed to healthy tissue. These methods include the use of high energy x-ray beams together with cross fire and rotational techniques which create a radiation pattern that is maximized at the site of the diseased tissue. Nonetheless, some absorption and damage inevitably occurs to healthy tissue in the path through which radiation passes to arrive at deep seated diseased tissue. 
     One method of limiting the zone of irradiation utilizes radioactive “seeds,” which are permanently implanted at the zone to be irradiated. Such seeds contain a radioactive isotope disposed within a capsule. The seeds are injected or implanted into body tissue at the site to be treated. The small size of therapeutic seeds allows the seeds to be inserted within tissue to be treated, in order to totally surround the tissue. 
     The advantage of interstitial implantation of a radiation-emitting article for localized tumor treatment have long been recognized. Interstitially implanted articles concentrate the radiation at a zone where radiation treatment is needed, i.e., near or within the tumor in order to directly affect surrounding tumor tissue, while exposing normal, healthy tissue to substantially less radiation than beaming radiation into the body from an external source. 
     Implanting radioactive articles directly into solid tumors to destroy the tumors is a therapy referred to as brachytherapy (i.e., short-range therapy). This form of therapy permits the application of larger doses of radiation directly to the tumor. 
     A seed applicator, such as shown and described in U.S. Pat. Nos. 5,860,909 and 5,242,373, the disclosures of which are hereby expressly incorporated herein by reference, can be used to accomplish correct placement of the seeds. The apparatus described in these patents are operable to implant individual seeds in spaced relationship. 
     Another method and approach for implanting brachytherapy seeds in or near a tumor utilizes seeds loaded within suture material, such as the RAPID STRAND® product available from Medi-Physics, Inc. Also, see Langton, et. al. U.S. Pat. No. 5,460,592, the disclosure of which is hereby incorporated herein by reference. The seeds are precisely positioned within the suture material, which may then be stiffened to retain the seeds therein and in their precise locations. An introducer is used to implant the strand of seed containing suture within the patient. The suture material retains the seeds at the desired locations until healing incorporates them into the tissue. The suture material is also bioabsorbable, and upon biodegradation of the suture material, the seeds are held in the tissue at the desired locations and with precise spacing. 
     The seeds utilized in either of these applications are remarkably small. The radioactive material itself, usually a portion of doped wire, is inserted and retained within a capsule. The capsule is typically a cylinder of less than 0.1550 in length and less than 0.030 in diameter. Alternatively, the capsule may have a spherical or oval shape 
     To facilitate handling of the seeds during implantation, the applicators described in U.S. Pat. Nos. 5,860,909 and 5,242,373 utilize a magazine that holds a number of seeds. The seeds are delivered from the magazine into the applicator, from which they are implanted within the patient. The RAPID STRAND® product itself retains the seeds and facilitates handling during implantation. 
     While use of applicators or the RAPID STRAND® product greatly facilitates the implantation of seeds into patients, the loading of seeds into magazines or suture material remains largely a manual task. A worker given sufficient training and learning time can become quite skilled at the tasks necessary for loading a magazine or suture with seeds. At best, however, the worker may become capable of preparing a single magazine or strand of suture in several minutes time. In addition, aside from the labor intensive nature of this process, fatigue, repetitive motion injuries and radiation exposure limit the time a skilled worker may continue in the task. Manual magazine or suture loading also requires the use of tweezers, necessary for handling the small seeds, which may also result in damage to the seeds, and process variation remains worker dependant and difficult to control. 
     SUMMARY OF THE INVENTION 
     The present invention provides apparatus and methods for loading delivery systems, such as seed magazines and suture material, with seeds which greatly increases productivity, reduces process variation and reduces the risk of handling damage to the seeds. Importantly, the apparatus and methods of the present invention reduce potential risks to workers. 
     In a first aspect of the invention there is provided an automated method of loading a delivery system for brachytherapy seeds which comprises the steps of: 
     a) securing the delivery system to be loaded; 
     b) communicating seeds from a supply of seeds into the delivery system; and 
     c) repeating step b) to load a plurality of seeds. 
     In a second aspect of the invention there is provided an apparatus for loading a delivery system for brachytherapy seeds comprising: 
     a) means for retaining a delivery system to be loaded with seeds; and 
     b) means for communicating individual seeds from a supply of seeds to said delivery system. 
     In one embodiment of either the first or second aspect of the present invention, a magazine to be loaded with seeds is positioned within a loading fixture. A vibratory feeder communicates seeds to a staging area adjacent the fixtured magazine, and a pusher member cycles to load seeds from the staging area into the magazine. 
     In another embodiment of either the first or second aspect of the present invention, suture material is loaded onto a cannula, which is then precisely positioned within the loading apparatus. A magazine containing a plurality of seeds is loaded to the loading apparatus. Seeds are introduced from the magazine into the cannula, and a pusher communicates the seeds along the cannula and proximate to an end thereof. A gripper, positioned adjacent the end of the cannula retracts the suture material drawing the seed from the cannula along with a precise length of suture material. The loader apparatus is operated until a desired number of seeds are loaded within the suture material, which is then removed from the loader and arranged for subsequent finish processing. 
     Definitions: 
     The following are definitions of various terms used in the foregoing specification. 
     Brachytherapy seed: A brachytherapy seed comprises: (1) a radioactive source, comprising (a) a radioisotope, disposed on (b) a carrier, and (2) a casing containing the radioactive source. In some embodiments, the carrier also serves as the casing. 
     The seed is of an overall size and dimensions suitable for its intended use. Seeds for use in the treatment of prostate cancer are, for example, typically substantially cylindrical in shape, about 4.5 mm long with a diameter of 0.8 mm. For use in the treatment of restenosis, a seed is of suitable dimensions to be inserted inside a coronary artery, for example, a length of about 10 mm and a diameter of about 1 mm, preferably a length of about 5 mm and a diameter of about 0.8 mm, and most preferably a length of about 3 mm and a diameter of about 0.6 mm. A seed also can be oval or substantially spherical in shape. 
     Radioisotope: The radioactive isotope disposed on the surface of the carrier is not limited and is selected based on the type and strength of the radiation that is desired, the half-life of the radioisotope, and the disease or condition to be treated. Non-limiting examples of useful radioisotopes include iodine-125, palladium-103, cesium-131, gold-198, thulium-170, chromium-56, arsenic-73, yttrium-90, and mixtures thereof. In addition, radioactive isotopes of samarium, tantalum, radon, radium, cobalt, iridium, and mixtures thereof, also can be used in brachytherapy seeds. Other gamma ray emitting elements and radioactive isotopes, including mixtures of one or more radiation sources capable of emitting therapeutically useful forms of radiation (e.g., gamma rays, alpha particles, beta particles, Auger electrons, X-rays, and electromagnetic waves) also are useful, provided they are presented in a form and in amounts which are useful in radiation therapy. Several other examples of useful radioisotopes are disclosed in Good, U.S. Pat. No. 5,342,283, the disclosure of which is hereby expressly incorporated herein by reference. The radioactive isotope is applied to the carrier by techniques that are well known in the art. Particularly preferred radioisotopes included palladium-103 and iodine-125. 
     Carrier: Suitable carriers for the radioisotopes include, but are not limited to, support materials, such as plastics, graphite, zeolites, ceramics, glasses, metals, polymer matrices, ion-exchange resins, and other, preferably porous, materials. The support material can be in the form of a bead, wire, or rod. The support materials can be encapsulated in a hollow sealed casing, for example a metal container, or the support material can be coated with an electroplated shell, for example a layer of a metal, such as silver or nickel. Alternatively, the carrier can be a hollow sealed container directly encapsulating the radioisotope, without, for example, the need for a biocompatible support material. 
     The carrier incorporating the radioisotope also can be a polymer matrix, or a plastic or ceramic composite, and/or may form part of a container wall. For example, if a metal alloy is used to form a container, then a component of the alloy can be a suitable radioisotope. If a container is made from a composite material, a component of the composite may be a suitable radioisotope. 
     Specific, non-limiting, examples of carriers are silver and copper because these metals provide good X-ray visualization and because commonly used radioactive isotopes, such as iodine and palladium, can be easily attached to a silver or copper surface by chemical or electroplating processes. Other X-ray opaque metals, such as gold and iron, for example, can be used as a carrier for purposes of the invention. Likewise, a suitable metal can be deposited (chemically or by using “sputtering” and “ion plating” techniques) onto a substrate other than a metal, e.g., a polypropylene filament, preferably such that the thickness of the metallic coating on the substrate exceeds about 0.050 mm to ensure X-ray visualization. 
     Casing: Suitable casing materials include biocompatible metals or metal alloys such as titanium, gold, platinum and stainless steel: plastics such as polyesters and vinyl polymers of polyurethane, polyethylene and poly(vinyl acetate); composites of graphite, and glass such as matrices comprising silicon oxide. The container also can be plated on the outside with a biocompatible metal, for example, gold or platinum. 
     Preferred suitable casing materials are biocompatible metals, and typically low atomic numbered metals, such as stainless steel alloy or titanium. Higher atomic number metals, such as gold and platinum, attenuate too much radiation emanating from the radioisotope-laden carrier to be useful per se. However, higher atomic numbered biocompatible metals are useful as a plating over various low atomic number materials such as beryllium, which otherwise is too toxic if used without an outer coating. Other suitable casing materials include, but are not limited to, tantalum, nickel alloys, copper alloys, and aluminum alloys. 
     Titanium, which has a low atomic number and a high strength-to-weight ratio, is the most preferred casing material. Titanium is exceptionally corrosion-resistant, and is satisfactory from the standpoint of tissue compatibility and non-toxicity. Preferably, the titanium is a pure alloy to assure good working properties. 
     The casing can have at least part of one surface of which is roughened, shaped, or otherwise treated whereby ultrasound visibility of the seed is enhanced. 
     Suture Material: The suture material is a bioabsorbable material made of any natural or synthetic material that is absorbable in a living body. Non-limiting examples of natural absorbable materials, as disclosed in U.S. Pat. No. 4,697,575, are the polyester amides from glycolic or lactic acid, such as the polymers and copolymers of glycolate and lactate, polydioxanone and the like. Such polymeric materials are more fully described in U.S. Pat. Nos. 3,565,869; 3,636,956; 4,052,988 and European Patent Application 30822. Specific and non-limiting examples of absorbable polymeric materials that can be used as suture materials are polymers marketed by Ethicon, Inc., Somerville, N.J. under the trademarks “VICRYL” and “PDS.” 
     The suture material preferably maintains its integrity for from 1 to about 14 days. Preferably, the suture material is absorbed in living tissue in a period of time from about 70-120 days. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front elevation view of an apparatus in accordance with a preferred embodiment of the present invention; 
     FIG. 2 is a plan view of the apparatus shown in FIG. 1; 
     FIG. 3 is aright side elevation of the apparatus shown in FIG. 1; 
     FIG. 4 is a left side elevation of the apparatus shown in FIG. 1; 
     FIG. 5 is a partial cross-section view taken along line  5 — 5  of FIG. 1; 
     FIG. 6 is a partial plan view of the portion of the apparatus illustrated in FIG. 5; 
     FIG. 7 is a front elevation view of a seed loading finger in accordance with the preferred embodiments of the present invention; 
     FIG. 8 is a partial cross-section view taken along line  8 — 8  of FIG. 6 illustrating the apparatus in a first operating position; 
     FIG. 9 is a view similar to FIG. 8 illustrating the apparatus in a second operating position; 
     FIG. 10 is a front elevation view of an apparatus in accordance with an second preferred embodiment of the present invention; 
     FIG. 11 is a plan view of the apparatus show in FIG. 10; 
     FIG. 12 is a front elevation view of an apparatus similar to that shown in FIG. 10; 
     FIG. 13 is a plan view of the apparatus show in FIG. 12; 
     FIG. 14 is a schematic illustration of a first operating position of the apparatus shown in FIG. 10; 
     FIG. 15 is a view similar to FIG. 14 illustrating a second operating position of the apparatus shown in FIG. 10; 
     FIG. 15 a  is a view similar to FIG. 15 illustrating insertion of spherical seeds into suture material; 
     FIG. 16 is a partial plan view of the apparatus illustrated in FIG. 10; 
     FIG. 17 is a partial front elevation of the apparatus illustrated in FIG. 10; 
     FIG. 18 is a front elevation of a seed pusher for use in the apparatus shown in FIG. 10; 
     FIG. 19 is a partial cross-section of the seed pusher illustrated in FIG. 18; 
     FIG. 20 is an enlarged view of an end portion of the seed pusher illustrated in FIG. 18; 
     FIG. 21 is a partial front elevation of the apparatus illustrated in FIG. 10; 
     FIG. 22 is a plan view of the portion of the apparatus illustrated in FIG. 21; 
     FIG. 23 is a partial front elevation of the apparatus illustrated in FIG. 10; 
     FIG. 24 is a plan view of the portion of the apparatus illustrated in FIG. 23; 
     FIG. 25 is a side elevation of the portion of the apparatus illustrated in FIG. 23; 
     FIG. 26 is a front elevation of a cannula for use in the apparatus illustrated in FIG. 10; 
     FIG. 27 is a partial cross-section view of the cannula illustrated in FIG. 26; 
     FIG. 28 is a left side view of the cannula illustrated in FIG. 26; 
     FIG. 29 is an enlarged view of an end portion of the cannula illustrated in FIG. 26; 
     FIG. 30 is a partial front elevation view of a portion of the apparatus illustrated in FIG. 10; 
     FIG. 31 is a partial plan view of the portion of the apparatus shown in FIG. 30; 
     FIG. 32 is a partial front elevation view of a portion of the apparatus illustrated in FIG. 10; 
     FIG. 33 is a partial plan view of the portion of the apparatus illustrated in FIG. 32; 
     FIG. 34 is a partial left side elevation of the portion of the apparatus illustrated in FIG. 32; 
     FIG. 35 is a partial front elevation of the apparatus illustrated in FIG. 10; 
     FIG. 36 is a right side elevation of the portion of the apparatus illustrated in FIG. 35; and 
     FIG. 37 is a partial right side elevation of the portion of the apparatus illustrated in FIG.  30 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The invention is described as follows in terms of several preferred embodiments. These embodiments should be taken only as examples of preferred implementations, and in no way should be considered limiting of the invention. 
     Referring to the drawings, FIGS. 1-9 illustrate a magazine loading apparatus  10  supported on a base  12 . Secured to the base  12  are a plurality of standards  14  supporting elements of a safety light curtain (illustrated in phantom as  16 ). A light emitter  18  sends a light beam that is reflected by a first mirror element  20  and a second mirror element  21  to a light receiver  22 . The light curtain  16  operates as is well known for inhibiting operation of apparatus  10  when a portion of an operator&#39;s body or any other object is located in a manner that may interfere with operation of the apparatus  10 . 
     As shown in FIG. 2, base  12  is formed from a plate, preferably metallic and, more preferably, aluminum, and includes a channel  24  extending about a periphery thereof As will be appreciated from the following discussion, channel  24  advantageously captures seeds which may be inadvertently ejected from the apparatus  10 . Furthermore, base  12  is preferably painted or anodized a color that contrasts with the color of the seeds to make locating them should they fall onto base  12  and into channel  24  easier. 
     A vertical support  26  extends from the base  12  and pivotably secured thereto is a magazine loader  28 . More particularly, an air cylinder  30  couples to an arm  32  that is coupled to a pivot shaft  34  journally supported on a sleeve bearing  36  through the vertical support  26 . A bracket  38  is secured to the vertical support  26  and includes a bumper  40  for the arm  32 . The air cylinder  30  is operable to pivot the magazine loader  28  between a first position and a second position. Pivoting the magazine loader  28  facilitates insertion of a magazine  72  therein, provides for orderly insertion of seeds  99  into magazine  72 , and advantageously utilizes the shielding properties of the stainless steel to reduce the radiation exposure to the operator. 
     Supported on the pivot shaft  34  is a right-angled swing arm  44  onto which are secured a first air cylinder  46  and a second air cylinder  48 . Each include a drive rod,  50  and  52  respectively, that couple at a first end to a slide block  54 . Disposed opposite slide block  54 , each drive rod,  50  and  52 , includes a bumper stop  56  and  58 , respectively, secured by a clamp  59 . The bumper stops  56  and  58  are sized to provide a first stroke length and a second stoke length, respectively. 
     A tooling nest  60  is secured to the swing arm  44  and a slide rod  62  extends outwardly therefrom and is secured thereto by a block  63 . The tooling nest is preferably constructed from a radiation shielding material. The slide block  54  slides on the slide rod  62  and with respect to the tooling nest  60  responsive to driving action of either first air cylinder  46  or second air cylinder  48 . Further extending from the tooling nest  60  is a dowel  64  onto which a hold down block  66  slides. Hold down block  66  is further biased in a first position by action of a bias spring (not shown). 
     The tooling nest  60  is formed with a receiver area  70  adapted to receive the magazine  72 , which is preferably constructed in accordance with the aforementioned U.S. Pat. Nos. 5,860,909 and 5,242,373. Once positioned within receiver area  70 , a loading end  74  of the magazine  72  is positioned adjacent a staging area  76 . 
     Pivotably secured to an underside portion of tooling nest  60  is a finger member  78  (best seen in FIGS.  7 - 9 ). The finger member  78  is biased in a first position by a spring  80  which bears between a lower portion  82  of the finger member  78  and an end block  84  of the tooling nest  60 . An upper portion  86  of the finger member  78  is formed with a notch portion  88  and an angled portion  90  forming a finger  92 . 
     Secured to the slide block  54  is a pusher member  94 . The pusher member  94  has a rectangular shape including a width approximately the length of a seed and a thickness approximately the diameter of a seed. The pusher member  94  slides relative to the receiver area  70 . A clear cover  96  is secured to an upper portion of the tooling nest  60  and adjacent to the receiver area  70 . 
     Further secured to the base  12  is a vibratory feeder  96  including a hopper  98  and a feed path  95  leading from the hopper  98  to the receiver area  70 . The vibratory feeder  96  is sized and its operating frequency is, preferably, tuned such that approximately 1500-2500 seeds may be loaded therein and such that hopper  98  substantially completely empties between batches. The vibratory feeder  96  is adapted to align seeds end-to-end along the feed path  95  and to communicate the seeds from the hopper  98  to the staging area  76 . An air jet (illustrated in the attached photographs) is further coupled adjacent feed path  95  to assist seeds communicated along feed path  95  toward the staging area  76  and to ensure all seeds are emptied from the hopper  98 . 
     The entire apparatus  10  is secured within a housing (not shown) which includes radiation shielding and access hatches as is very well known in the art. Preferably operation of apparatus  10  may be viewed through a lead loaded acrylic viewing window formed in the housing, and access to the apparatus during operation is by access gloves. 
     The seed loading process begins with the swing arm  44  in the first position in which the tooling nest  60  is preferably tilted down and forward to allow access thereto. A magazine  72  is inserted into the receiver area  60  with the loading end  74  adjacent the staging area  76 . Air cylinder  46  is actuated to move pusher member  94  to its fully extended position, and the loading end  74  of the magazine  72  is secured over pusher member  94 . Actuation of the air cylinder  30  then pivots magazine loader  28  to the second position. 
     Referring to FIGS. 8 and 9, in the second position, staging area  76  is adjacent the feed path  95 . The air cylinder  46  is retracted, which permits the finger member  78  to move to its first position, and to introduce a seed  99  communicated along feed path  95  into staging area  76 . Repeated actuation of air cylinder  98  then acts to load a plurality of seeds  99  into the magazine  72 . Forward motion of pusher member  94  engages the seed  99  and the angled surface  90  of the finger member  78  causes it to move it to its second position. Further forward motion of the pusher member  94  then introduces the seed into the loading end  74  of the magazine  72 . As the pusher member  94  is retracted, the finger member  78  then moves again to its first position to retain the loaded seed  99  within the magazine and to allow a next seed  99  into the staging area  76 . To load the final seed  99  into the magazine  72 , air cylinder  46  is actuated which introduces the final seed  99  into the magazine  72  and further advances pusher member  94  to its fully extended position to secure and retain the seeds  99  within the magazine  72 . A swing arm  97  is provided pivoted from vertical support  26 . With the magazine loader  28  in the second position, swing arm  97  is disposed over staging area  76  to assist in directing the seeds  99  into the magazine  72  and for retaining the seeds  99  therein. The components shown in FIGS. 8 &amp; 9 are, preferably, constructed from stainless steel in order to be resistant to rusting. 
     Air cylinder  30  is then actuated to pivot magazine loader  28  back to its first position so that the now loaded magazine  72  may be removed from the apparatus  10 . Cycle time is approximately about 7.5 seconds as compared to minutes for manual loading. Furthermore, the process significantly reduces operator repetitive motions, fatigue and radiation exposure. 
     FIGS. 10-37 illustrate an apparatus  100  for loading seeds into suture material  101 . Apparatus  100  includes a base  102  and a wall  104  extending substantially perpendicularly from base  102 . Base  102  is formed with a channel  106  and has secured thereto side shields,  108 - 112 , respectively (best seen in FIG.  16 ). Base  102  and wall  104  are preferably made of painted or anodized aluminum to contrast the color of the seeds. Side shields  108 - 112  and channel  106  cooperate to contain seeds that may be inadvertently ejected from the apparatus  100  during loading. A plurality of standards  114  extend from base  102  and support elements of a safety light curtain (shown in phantom as  116 ). A light emitter  18  sends a beam of light to a light receiver  122 . The light curtain  116  is coupled to a control system for apparatus  100  and operates as is well known for inhibiting operation of the apparatus  100  when a portion of an operator&#39;s body or any other object is located in a manner that may interfere with operation of the apparatus  100 . 
     Referring still to FIGS. 10-13 and now more particularly to FIGS. 14 and 15, apparatus  100  includes a seed pusher portion  124  and a suture feeder portion  126 . In general, seed pusher portion  124  is adapted to accept a seed  99  from a magazine. The magazine may be any suitable magazine holding a plurality of seeds. Preferably, the magazine is a magazine  72  as described above and loaded with seeds  99  using apparatus  10 . The magazine permits introduction of a plurality of seeds  99  into a cannula  128 . The pusher portion  124  communicates the seed  99  to the end of the cannula  128  such that a portion of the seed  99  extends approximately one half its length from an end thereof. Suture material  101  is predisposed over the cannula  128 , and a suture clamp  130  applies precise pressure to the suture material  101  around the cannula  128 . A suture gripper  132  securely grips an end of the suture material  101 . The suture gripper  132  is coupled to a precision linear slide  134  for linear motion. Once a seed  99  is positioned at the end of the cannula  128 , the slide  134  advances suture gripper  132  away from suture clamp  130 . This motion draws the suture material  101  snugly around the portion of the seed  99  protruding from the end of the cannula  128 , and the seed  99  is then drawn from the cannula  128  upon further linear movement of the suture gripper  132 . A precise, predetermined length of suture material  101 , with the seed placed therein, is then drawn from the cannula  128 , and seed pusher portion  124  cycles again to introduce another seed  99  to the end of the cannuila  128 . This is repeated until apparatus  100  has introduced a predetermined number of seeds  99  into the suture material  101 , with precise spacing. A strand of suture material  101 , now loaded with seeds  99 , is then removed from apparatus  100 , inserted into a resin carrier (not shown) and then into a metal storage and shielding capsule (not shown). Within the capsule, the suture material  101  may be heat treated if necessary to stiffen the suture material  101  to thereby secure the location of the seeds  99 . FIG. 15 a , similar to FIG. 15, illustrates operation of the apparatus using spherical seeds  99   a.    
     With reference again to FIGS. 10-13 the seed pusher portion  124  includes a servo motor  136  coupled by a gearbox reducer  138  to a drive arm  140 . The servo motor  136  and gearbox reducer  138  are secured to the wall  104  by a motor mounting plate  142 . The drive arm  140  is preferably journally supported through the motor mounting plate  142 . The drive arm  140  is coupled by a first cam  144  to a first linear slide  146  and by a second cam  145  to a second linear slide  148 . The first linear slide  146  slides in a support member  150  and has a pusher block  152  secured to an end thereof Secured to the pusher block  152  is a seed pusher  154 . Referring briefly to FIGS. 18-20, seed pusher  154  includes an elongate rod  156  fitted with a mounting block  158  at a first end and has a polished radius second end  160 . The rod  156  has a diameter of slightly less than the diameter of the seeds, and preferably about 0.029 inch, and may be preferably made from 12 gauge stainless steel music wire. 
     The second linear slide  148  slides in a support member  162 , and has fitted on an end thereof a rod support  164 . Rod support  164  extends from second linear slide  148  and is formed with an aperture, and rod  156  is disposed through the aperture. The servo motor  136  rotates drive arm  140  through an included angle of approximately 62 degrees, and first linear slide  146  and second linear slide  148  are translated in response thereto. Preferably first linear slide  146  translates through a stroke of about 6 inches while the second linear slide  148  has a stroke of approximately 3 inches. As will be appreciated, translation of the first linear slide  146  advances the seed pusher  154 . Simultaneous therewith, the rod support  164  is translated, approximately half the total translation of seed pusher  154 , for supporting the rod  156  during operation of seed pusher portion  124 . 
     With continued reference to FIGS. 10-13, a pair of brackets  166  are secured to the wall  104  that support a pair of proximity probes  168  that are arranged to detect a second end of the first linear slide  146  in its retracted most position. A bracket  170  is also secured to the wall  104  and supports a proximity probe  172  that is arranged to detect an extended most position of second linear slide  148 . 
     The pusher block  152  includes an end wall  174 . The end wall  174  is mounted on a pivot  176  supported on a lower support member  178 . Rod block  158  is secured to the end wall  174 , and the end wall  174  is held in place by a magnet. If a force on seed pusher  154  exceeds a predetermined value, such as would indicate a jamming of apparatus  100 , the magnet force holding the end wall  174  in place is overcome and the end wall  174  pivots open. A proximity sensor  180  is mounted to a flange portion  182  of the pusher block  152  and detects the opening of the end wall  174  signaling the overload condition and permitting the shutting down of the apparatus  100  prior to damaging the seed pusher  152  or another portion of the apparatus  100 . The force exerted by the magnet may be selected to provide varying levels of overload protection. 
     As is best seen in FIG. 12, the end  160  of the rod  156  is received within a magazine loader  184  of the apparatus  100  and to which the cannula  128  is secured. With the first linear slide  146  fully retracted, the end  160  is retracted from the cannula  128  and a magazine secured to the magazine loader  184 . As the first linear slide  146  is extended, the end  160  engages a seed  99  from the magazine and upon further extension of linear slide  146  communicates the seed  99  into the cannula  128  and along its length for loading into the suture material as described above. 
     With reference still to FIGS. 10-13, and also now to FIGS. 21-25, the magazine loader  184  is secured to a bracket  185  extending from the wall  104 . The magazine loader  184  is formed with an square aperture  186  into which a magazine retainer  188  is disposed. The magazine is secured to the magazine retainer  188 . The magazine retainer  188  is secured between a pair of tapers  190  and  192 , respectively formed in magazine lock  194  and cannula hub  196 . Magazine lock is spring biased to bear against magazine retainer  188 , and thereby secures and accurately positions the magazine retainer  188 , and hence the magazine, with respect to cannula hub  196 , and hence cannula  128 . Cannula  128 , including cannula hub  196 , is held in magazine retainer  196  by the engagement of cannula lock  198  with a groove  200  formed in cannula hub  196 . Cannula  128  and cannula hub  196  are shown in more detail in FIGS. 26-29. 
     The extension of seed pusher  124  into magazine retainer  188 , engages the rod end  160  with a seed  99  held within the magazine and communicates the seed into cannula  128 . The tapers  190  and  192  ensure precise alignment of the rod  156 , the magazine and particularly a discharge aperture formed therein, and the lengthwise aperture  129  formed within the cannula  128 . The tapers further ensure precise linear relationship between the apparatus  100  and the end  202  of the cannula  128 . This feature ensures that after cannula  128  has been removed from the magazine retainer  188  in order to place suture material  101  thereon, it is once again quickly and easily realigned with the apparatus  100 . 
     With continued reference to FIGS. 21-25, also secured to magazine retainer  188  is an air cylinder  204  having a cylinder rod  206 . A first end of the cylinder rod  206  is fitted with a knob  208  and a second end is fitted with a slider  210  that is formed with an aperture. Cannula  128  is received through the aperture, and the slider  210  engages suture material disposed on the cannula  128 . As the first linear slide  146  is advanced, it engages the knob  208  thereby advancing the rod  206 . The slider  210  engages the suture material disposed on the cannula  128  and bunches it toward and end thereof. This feature ensures proper feeding of suture material during seed loading. Air cylinder  204  is then operable to return the rod  206  to its retracted position with the return of the linear slide  146  to its retracted position. 
     With reference now to FIG.  12  and FIGS. 30-37, suture clamp  130  is disposed adjacent the end of cannula  128  and includes a lower clamping member  208  and an upper clamping member  210 , each of which are formed with arcuate reliefs  212  and  214 , respectively. Suture clamp  130  is arranged to clamp around the cannula  128  and to engage the suture material disposed thereon to ensure a desired tension in the suture material as it is drawn off of the cannula  128 . The lower clamping member  208  and the upper clamping member  210  are each made from steel that is flash plated with chrome to resist wear. The lower clamping member  208  is secured by a bracket  216  to the wall  104 . The upper clamping member  210  is pivotably secured to the lower clamping member  208  and is further coupled to an air cylinder  218 . The air cylinder  218  is secured to a bracket  220  on an opposite side of the wall  104 , and has a rod  222  that extends through an aperture in the wall  104  and that couples to the upper clamping member  210 . 
     The suture gripper  132  is secured to a gripper mount  224  that in turn is secured to the linear slide  134 . The linear slide  134  is preferably a precision linear slide that is coupled to a servo motor  226  via a reduction gearbox  228 . The suture gripper  132  includes a first gripper member  230  and a second gripper member  232 , which are preferably made of stainless steel, coupled via a toggle mechanism to an air cylinder  234  (shown in phantom). Actuation of the air cylinder  234  draws together the first and second gripper members  230  and  232 , to securely grip the suture material. The opening range of the first and second gripper members  230  and  232  is preferably limited to prevent catching an operator&#39;s fingers therein. 
     The linear slide  134  acts to extend suture gripper  132  upon detection of a seed  99  at the end of cannula  128 . A first standard  236  and a second standard  238  respectively support a laser sending device  240  and a laser detection device  242  that is positioned to observe the end of the cannula  128 . In this manner, the presence of a seed at the end of the cannula  128  is detected prior to extending the suture gripper  132  from suture clamp  130 . 
     A finishing jig  244  is secured to the base  102  that includes a channel  246  into which a resin retainer is held. Suture material  101  having seeds  99  disposed therein is positioned within the resin retainer, and then into the storage capsule. The resin retainer also advantageously permits visual inspection of the strand to ensure that the correct number of seeds  99  has been disposed within the suture material  101  with the correct spacing. 
     As should be further appreciated suitable pneumatic couplings, solenoid actuated valves, electrical actuators and programmable controllers are operatively coupled to apparatus  10  and apparatus  100  for operation in accordance with the foregoing description.