Abstract:
A Body Access System for the collection of samples and the administration of fluids comprising means to prevent complete withdrawal of a needle stylet, means to dispose of needles and needle stylets provides for limited exposure to samples collected, needle sticks and stylet sticks.

Description:
This is a continuation-in-part of U.S. patent application Ser. No. 08/795,342, filed Feb. 4, 1997, now U.S. Pat. No. 5,836,928. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to an improved body access system for the safe collection of samples and administration of fluids. 
     BACKGROUND OF THE INVENTION 
     The need for protection from exposure to needle sticks has been the impetus to the development of needle guards and needle protectors. Furthermore, an increased awareness of transmission of infections from exposure to body fluids or other samples has led to the development of improved means to limit exposure to samples collected. 
     An example of both a risk of sustaining a needle stick and also exposure to collected samples is the current procedure for the drawing of spinal fluid during a spinal tap. Typically, a needle with a stylet is inserted between the appropriate vertebrae, the stylet is removed and multiple vials are handled during the procedure. There is risk of breakage and leakage and consequent exposure of personnel to the samples collected. Also, when the needle or stylet is withdrawn during and after the procedure, there is risk of being stuck by either the needle or the stylet. 
     A number of systems have been devised to protect individuals from needle sticks while using syringes and angiocatheters. However, users of needles for other purposes, such as spinal taps, still have no protective devices suitable for their needs. 
     In U.S. Pat. No. 5,396,899, Strittmatter disclosed an apparatus to limit leakage when spinal fluid is collected. 
     In application Ser. No. 08/795,342 means were introduced to limit exposure to needle sticks, stylet sticks, and spinal fluid samples during the performance of a spinal tap. 
     The means introduced in application Ser. No. 08/795,342 for spinal taps are applicable for the collection of other body samples. 
     SUMMARY OF THE INVENTION 
     This application introduces means for the safe collection of spinal fluid and other body samples. The means introduced in application Ser. No. 08/795,342 are illustrated with additional examples in the figures. Furthermore, modifications to the means introduced in application Ser. No. 08/795,342 are introduced to demonstrate the utility of the invention in the collection of other body samples, such as, for example, blood samples and tissue biopsies. 
     The invention relates to the introduction of a system that decreases exposure to needle sticks and stylet sticks by capturing the needle and stylet within a cylinder as they are withdrawn from the body. The needle unit of the invention comprises a needle and a hub and, optionallly, may also comprise a stylet. The needle may be a solid needle, such as ones used in an angiocatheter, or a hollow needle, such as those used for spinal taps and tissue biopsies. A hollow needle may also contain a stylet, such as, for example, a conventional spinal tap stylet or a tissue biopsy stylet. Furthermore, as is the case in currently used means for tissue biopsies, the needle may be a cutting needle and the stylet a device to passively retain the cut tissue, or the stylet itself may be a cutting stylet. 
     It is an object of the present invention to provide means for limiting exposure to needle sticks from spinal tap needles during and after the performance of a spinal tap. It is another object of the present invention to provide means for limiting exposure to sticks from spinal tap stylets during and after the performance of a spinal tap. 
     It is a further object of the present invention to provide means for limiting exposure to spinal fluid samples during and after the performance of a spinal tap. 
     It is a further object of the invention to introduce means to limit exposure to needles used in obtaining body fluid and tissue samples. 
     It is yet another object of the invention to introduce means to limit user exposure to stylets used in body access procedures. 
     It is still another object of the invention to limit exposure to body fluid and tissue samples. 
     A body access system is disclosed which provides for the safe collection of samples and the safe administration of fluids. The system provides protection from inadvertent needle sticks in the collection of samples. The system can be utilized not only for the collection of blood but also for the collection of other body fluids and biopsies, such as, for example, spinal taps, liver biopsies, renal biopsies, pleural biopsies, pericardiocentesis, thoracocentesis, paracentesis, and dialysis. The system also provides protection from inadvertent exposure to the samples themselves, such as, for example, blood and spinal fluid. 
     This invention proposes the use of a protective cylinder into which a needle can be withdrawn. The needle hub is engaged and the needle is then withdrawn into the cylinder or the cylinder is pulled over the needle. 
     It is an object of this invention to introduce a body access system to protect a user from both inadvertent needle sticks and from inadvertent exposure to body samples. 
     It is another object of this invention to introduce a protective cylinder into which a needle can be withdrawn. 
     It is a further object of this invention to introduce needle hub engagement means that are engaged for the subsequent withdrawal of said needles into protective cylinders. 
     It is an object of this invention to introduce a protective sample collection device to prevent a user from being exposed to the sample collected. 
     It is another object of this invention to introduce a protective sample collection device to prevent a user from being exposed to the sample collected by gravity flow. 
     It is a further object of this invention to introduce a protective sample collection device to prevent a user from being exposed to the sample collected by a vacuum. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a cross-sectional view of a disposal unit, a stylet, a needle unit and a guide. 
     FIG. 2 is a cross-sectional view of an assembly of the disposal unit, stylet, needle unit and guide illustrated in FIG.  1 . 
     FIG. 3 is a cross-sectional view of another embodiment of a disposal unit, stylet, needle unit and guide of the invention. 
     FIG. 4 is a cross sectional view of an assembly of the disposal unit, stylet, needle unit and guide illustrated in FIG.  3 . 
     FIG. 5 is a cross-sectional view of another embodiment of a disposal unit, stylet, needle unit and guide of the invention. 
     FIG. 6 is a cross sectional view of an assembly of the disposal unit, stylet, needle unit and guide illustrated in FIG.  5 . 
     FIG. 7 is a cross-sectional view of another embodiment of a disposal unit, stylet, needle unit and guide of the invention. 
     FIG. 8 is a cross sectional view of an assembly of the disposal unit, stylet, needle unit and guide illustrated in FIG.  7 . 
     FIG. 9 is a cross-sectional view of another embodiment of a disposal unit, stylet, needle unit and guide of the invention. 
     FIG. 10 is a cross sectional view of an assembly of the disposal unit, stylet, needle unit and guide illustrated in FIG.  9 . 
     FIG. 11 a  illustrates the use of a catheter with an assembly of the invention. 
     FIG. 11 b  illustrates a single port catheter. 
     FIG. 11 c  illustrates a multi-port catheter. 
     FIG. 12 a  is an exploded view of a container and an assembly of a transmission means and container holding means of the invention. 
     FIG. 12 b  illustrates the container of FIG. 12 a  being held in the assembly of FIG. 12 a.    
     FIG. 13 a  illustrates the external connections of the assembly of FIG. 12 b.    
     FIG. 13 b  illustrates a variation of the assembly illustrated in FIG. 13 a.    
     FIG. 14 is another embodiment of a container and assembly of the invention. 
     FIG. 15 is a cross-sectional view of a system of the invention. 
     FIG. 16 a  is a detailed cross-sectional view of another disposal unit of the invention. 
     FIG. 16 b  is a detailed cross-sectional view of another guide of the invention. 
     FIG. 16 c  is a detailed cross-sectional view of another needle unit of the invention. 
     FIG. 17 a  is an exploded cross-sectional view of the transmission means of the invention. 
     FIG. 17 b  is an exploded cross-sectional view of the container holding means of the invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The system is fully understood by referring to a description of the figures. 
     FIG. 15 is a cross-sectional view of a system of the invention. The system illustrated in FIG. 15 is particularly suited for the performance of spinal taps. 
     Referring to FIG. 15, the system comprises needle unit  10 , guide  20 , disposal unit  21 , transmission means  40 , container holding means  50 , and optional cover  80 . One or more adapters, not shown, may also be included in the system to connect the guide to the transmission means. The hub of the needle unit is positioned within the guide. The guide and the hub are attached to the disposal unit. The guide is attachable either directly or indirectly to the transmission means. The transmission means and the container holding means function together as a unit. An optional cover is latched onto the container holding means and provides further protection in the event of breakage or leakage of one of the enclosed containers. Preferably, the parts of the system, especially the guide and the hub, are transparent to enable viewing the flow of fluid, such as the flow of spinal fluid during the spinal tap procedure. 
     When the system is used as described for a spinal tap, any spinal fluid collected will remain enclosed within the system and exposure to needle stick or spinal fluid will be minimized. 
     Prior to performing a spinal tap or other procedure, the user configures the system for his or her convenience. If the needle unit is not already positioned within the guide, the needle unit is inserted within the guide. If the disposal unit is attached to the guide and to the hub of the needle unit, the disposal unit is detached. If sample collection containers have not already been inserted into the container holding means or if the user desires different containers, the appropriate changes are made. Preferably, a cover is applied. And, the attachment of the guide to the transmission unit is configured as desired by the user. In the preferred embodiment, once the configuration is complete, the system is completely enclosed. 
     In the performance of a spinal tap, utilizing sterile technique, the user inserts the spinal needle into the subarachnoid space. The needle stylet is withdrawn and spinal fluid flows into the hub of the needle. The spinal fluid then flows from the hub, through a port in the guide and then either directly or through one or more adapters to the transmission means. In the embodiment depicted in FIG. 15, a flexible tube, not shown, conveys fluid from the guide to the adapter shown. The adapter is attached either directly or indirectly to the transmission means and spinal fluid flows through the adapter to the transmission means. Adapters are used for the convenience and preference of the individual user. However, the guide can be directly attached to the transmission means. 
     The transmission means and the container holding means function as a unit. These means are movable relative to each other. Movement of the transmission means relative to the container holding means or of the container holding means relative to the transmission means permits the sequential filling of sample containers held in the container holding means. Said movement may be circular, linear or any other displacement of the transmission means and the container holding means relative to each other which permits the sequential filling of sample containers held in the container holding means. 
     In the embodiment depicted in FIG. 15, the transmission means is rotatable relative to the container holding means. The container holding means holds one or more sample collection containers. Rotation of the transmission means of FIG. 15 enables the sequential filling of the sample collection containers held in the container holding means. When the desired amount of fluid has been collected in a given container, the transmission means is rotated and the next container is filled to the desired level. When the desired number of containers have been filled to their desired levels, the stylet is reinserted into the needle and the spinal needle is removed from the subarachnoid space. 
     Once the spinal tap procedure is completed, the disposal unit is attached to the guide and to the hub of the needle unit. The needle unit, including the stylet, is withdrawn into the disposal unit and the entire system is sent to the laboratory where the samples collected are removed for analysis and the system is disposed of under controlled conditions. 
     In FIGS. 16 a ,  16   b  and  16   c  the complementary relationship of needle unit  10 , guide  20 , and disposal unit  21  are illustrated. 
     The system uses a number of complementary engagement means. Complementary engagement means can be used, but are not required on transmitting and receiving ports. Transmitting and receiving ports are adapted to each other, using complementary engagement means or otherwise, such as by means of conventional seals, in order to limit leakage and to direct flow. Complementary engagement means are also used to maintain or establish an attachment of one part of the system to another part of the system. Specific complementary engagement means are illustrated and described for convenience of explanation. However, the complementary parts of any suitable fastener may be used as complementary engagement means in place of those illustrated and described. One example of complementary engagement means is an internal thread and an external thread. Another example of complementary engagement means is a snap comprising a hole and a projection, such as, for example, a plug or ball, which fits snugly into said hole. Thus, when an external thread is employed as the engagement means of the hub, an internal thread is employed as the engagement means of the disposal unit; or when an external thread is employed as the engagement means of the disposal unit, an internal thread is employed as the engagement means of the hub. Furthermore, instead of using a set of threads as the complementary engagement means of the hub and the disposal unit, another type of complementary engagement means, such as, for example, a snap can be used. 
     Referring to FIG. 16 c , needle unit  10  comprises hollow needle  11 , hub  12  and a needle stylet. 
     Preferably, needle  11  is permanently attached to hub  12  at the distal end of the hub. The hub comprises engagement means  15  at the distal end of the hub, engagement means  16  at the proximal end of said hub, chamber  18 , and port  19 . Port  19  communicates directly with chamber  18 . When the stylet is removed from the lumen of the needle, spinal fluid flows through the lumen and an aperture at the distal end of the hub into chamber  18  of the hub. An aperture at the proximal end of the hub permits the slidable displacement of the stylus within the hub and the needle. The distal end of the stylus is wider than the aperture at the proximal end of the hub. The distal end  13  of the stylet is broader than the shaft  14  of the stylet. Preferably, the stylet is tapered from the distal end  13  to the shaft  14 . Only the distal end of the stylet enters the subarachnoid space during a spinal tap procedure. During the performance of a spinal tap the stylet is withdrawn through the aperture at the proximal end of the hub. The cross-sectional dimensions of the aperture at the proximal end of the hub permit passage of the shaft of the stylet and prevent passage of the distal end of the stylet. Upon optimal withdrawal of the stylet, the distal end of the stylet remains within the hub but does not occlude the flow of spinal fluid through any port in the hub. That is, optimal withdrawal of the stylet permits unobstructed flow through any port in the hub. The shaft of the stylet fits snugly in the aperture at the proximal end of the hub to limit any leakage of spinal fluid. Since only the shaft is small enough to pass through the aperture at the proximal end of the needle hub, upon maximum withdrawal of the stylet from the needle, the end of the stylet which had entered the subarachnoid space remains within the needle hub. 
     Guide  20  comprises engagement means  25  at the distal end of the guide, engagement means  17  at the proximal end of the guide, chamber  28 , and port  29 . Engagement means  25  is complementary to engagement means  15 . Hub  12  is securely positioned within guide  20  by the engagement of engagement means  15  and engagement means  25 . In the illustration of FIGS. 16 a ,  16   b  and  16   c  engagement means  15  and engagement means  25  are threads. However, any suitable complementary means can be substituted for these threads. Port  29  of guide  20  is aligned with port  19  of hub  12  so that spinal fluid in chamber  18  of the hub flows through port  19  and then through port  29 . 
     Disposal unit  21  comprises rigid cylinder  22  and plunger  23 . Rigid cylinder  22  comprises engagement means  27  at the distal end of the rigid cylinder and plunger  23  comprises engagement means  26  at the distal end of the plunger. Engagement means  27  is complementary to engagement means  17 . Rigid cylinder  22  securely attaches to guide  20  by the engagement of engagement means  17  and engagement means  27 . Engagement means  17  and engagement means  27  are any suitable complementary engagement means such as, for example, threads. At the end of the spinal tap procedure, the user engages engagement means  27  and engagement means  17  to securely hold and stabilize guide  20 . Then the user engages engagement means  26  and engagement means  16 . Engagement means  26  is complementary to engagement means  16 . Preferably, the engagement of engagement means  27  and engagement means  17  prevents the rotation of guide  20 . Hub  12  is removed from within guide  20  by the engagement of engagement means  16  and engagement means  26  and the simultaneous disengagement of engagement means  15  and engagement means  25 . In the illustrations of FIGS. 2 a ,  2   b , and  2   c  engagement means  16  and engagement means  26  are threads. However, any suitable complementary means can be substituted for these threads. In the embodiment illustrated, the threading of complementary engagement means  15  and  25  are the reverse of the threading of complementary engagement means  16  and  26  so that a turning of plunger  23  to engage engagement means  16  and  26  simultaneously disengages engagement means  15  and  25 . Once engagement means  15  are disengaged from engagement means  25 , the user can turn or pull plunger  23  to withdraw the needle unit into the disposal unit. 
     In FIGS. 16 a ,  16   b  and  16   c  plunger  23  is internally threaded to engage the externally threaded distal end of hub  12 . If the entire length of the internally threaded plunger  23  is threaded and the external threads of the distal end of the hub are of suitable diameter, for example, greater than the diameter of the remainder of said hub, when the hub is engaged by the plunger, a turning of the plunger withdraws the needle unit into the disposal unit. 
     If only a segment of plunger  23  is internally threaded to engage the externally threaded distal end of hub  12 , when the hub is engaged by the plunger, a pulling of the plunger withdraws the needle unit into the disposal unit. 
     FIGS. 17 a  and  17   b  depict detailed cross sections of transmission means  40  and container holding means  50 . Cover  80  is reversibly attached to the container holding means by latch  84 . 
     The transmission means comprises a channel to transmit fluid from a needle unit to a container holding means. Either a needle unit or as guide is adapted to engage the transmission means either directly or by means of one or more adapters. The transmission unit is also adapted to engage a sample container, either directly or by means of one or more adapters. Thus, the transmission unit is adapted to receive fluid from the needle unit and to transmit fluid from the needle unit to the container. For example, as illustrated in FIGS. 3 a  and  3   b , transmission means  40  comprises external port  41 , channel  43  and internal port  42 . External port  41  is adapted to engage port  29  of guide  20 , or the port of an adapter. That is, external port  41  and port  29  are complementary engagement means. Spinal fluid received either directly or indirectly from port  29  at external port  41  then flows through channel  43  to internal port  42 . 
     Container holding means  50  comprises at least one adapter  53 , and at least one container holding recess  54 . Adapter  53  comprises an external port  51  and an internal port  52 . Sample container  81  comprises an optional cap  82 . Each sample container comprises a port that is adapted to engage internal port  52  of adapter  53 . In the embodiment illustrated, cap  82  comprises the port adapted to engage internal port  52  of adapter  53 . In operation, a container  81  is positioned in one or more container holding recesses  54 . Adapter  53  is adapted at external port  51  to receive spinal fluid from internal port  42  of transmission means  40  and adapted at internal port  52  to transmit said spinal fluid to the port of a sample container or a sample container cap. That is, external port  51  and internal port  42  are complementary engagement means and internal port  52  and the port of the sample container are complementary engagement means. 
     The transmission means and the container holding means are movable relative to each other. In the embodiment illustrated, said movement is a circular rotation. The transmission means preferably comprises an internally threaded engagement means  44  adapted to engage the external threads of port  29  or the external threads of a port of an adapter. Engagement means  44  is rotatably attached to the transmission means. When engagement means  44  engages the external threads of port  29  or the external threads of a port of an adapter, port  41  is securely but rotatably engaged to port  29  or an externally threaded port of an adapter and port  41  is freely rotatable relative to port  29 . Preferably, engagement means  29  and engagement means  41  are seals, such as, for example, O-rings, which are sealably pressed together when engagement means  44  engages the external threads of port  29 . 
     In the embodiment illustrated in FIGS. 17 a  and  17   b , spinal fluid flows from external port  41  through channel  43  to internal port  42 . Flow continues through port  42 , into port  51 , through adapter  53  to port  52 . From port  52  flow then goes through a port in cap  82  into container  81 . Once the desired quantity of fluid is collected in a sample container, the transmission means is rotated until port  52  engages a port in another cap  82 . Preferably, the interface between the transmission means and the top of the containers is a seal, such as an O-ring, which prevents leakage from filled containers. Thus, once a container is filled to the desired level, the rotation of the transmission means to enable the filling of the next container in sequence, also seals the tops of containers which have already been filled. 
     Preferably, in order to prevent leakage, an O-ring or other seal is placed between the transmission means and the container holding means, between ports  29  and  41 , between ports  42  and  51 , between port  52  a port in cap  82 , and in any other part of the system where leakage might occur. The seal between the transmission means and the container holding means is utilized to prevent leakage from sample containers. Also, it is preferred to include an index means in the system which will stop rotation of the transmission means when port  52  engages and is aligned with a port in another cap  82 . Any suitable index means can be used. For example, the index means illustrated comprises ball  68 , spring  67 , and hemispherical indent  69 . During rotation of transmission means  40 , whenever ball  68  engages a hemispherical indent  69 , the tension of spring  67  forces ball  68  into a hemispherical indent  69  and stops said rotation. A slight force is applied by the operator to overcome the resistance of the spring so that the transmission means can be rotated to the next desired position. It is preferred that a brake be provided after the filling of the last sample container. Said brake functions in the same manner as the index means and can utilize the same ball and spring with the replacement of the hemispherical indent with a deeper indent. When the ball falls into said deeper indent, further rotation of the transmission means is prevented. There is one hemispherical indent  69  or a brake for each recess  54 . It is also preferred that air vents  65  be provided where needed to enable release of air through caps  82  during the filling of containers  81 . 
     In FIG. 1 the complementary relationship of needle unit  110 , guide  120 , and disposal unit  121  are illustrated. Needle unit  110  comprises hollow needle  111 , hub  112  and needle stylet  114 . 
     Preferably, needle  111  is permanently attached to hub  112  at the distal end of the hub. The hub comprises engagement means  215  at the distal end of the hub, engagement means  216  at the proximal end of said hub, chamber  118 , and port  119 . Port  119  communicates directly with chamber  118 . When the stylet is removed from the lumen of the needle, fluid flows through the lumen and an aperture at the distal end of the hub into chamber  118  of the hub. An aperture at the proximal end of the hub permits the slidable displacement of the stylet within the hub and the needle. Distal end  113  of stylet  114  is wider than the aperture at the proximal end of the hub. Distal end  113  of stylet  114  is broader than the shaft of stylet  11 . Preferably, the stylet is tapered from the distal end to the shaft. Only the distal end of the stylet enters the subarachnoid space during a spinal tap procedure. During the performance of a spinal tap the stylet is withdrawn through the aperture at the proximal end of the hub. The cross-sectional dimensions of the aperture at the proximal end of the hub permit passage of the shaft of the stylet and prevent passage of the distal end of the stylet. Proximal end  326  of chamber  118  is shaped to prevent complete removal of the stylet from the hub. Upon optimal withdrawal of the stylet, the distal end of the stylet remains within the hub but does not occlude the flow of spinal fluid through any port in the hub. That is, optimal withdrawal of the stylet permits unobstructed flow through any port in the hub. The shaft of the stylet fits snugly in the aperture at the proximal end of the hub to limit any leakage of spinal fluid. Since only the shaft is small enough to pass through the aperture at the proximal end of the needle hub, upon maximum withdrawal of the stylet from the needle, the end of the stylet which had entered the subarachnoid space remains within the needle hub. Preferably, upon maximum withdrawal of the stylet, the stylet is firmly held in the maximal withdrawal position such that the stylet will remain in the maximally withdrawn position, and will not fall, even if positioned vertically with the stylet tip pointed downward. Thus, for example, when proximal end  326  of chamber  118  engages proximal end  316  of distal end  113  of stylet  114 , stylet  114  is firmly held in place by friction regardless of the position of hub  112 . 
     Guide  120  comprises engagement means  225  at the distal end of the guide, engagement means  217  at the proximal end of the guide, chamber  128 , and port  129 . Engagement means  225  is complementary to engagement means  215 . Hub  112  is securely positioned within guide  120  by the engagement of engagement means  215  and engagement means  225 . In the illustration of FIG. 1 engagement means  215  is a slot and engagement means  225  is a pin of a bayonet mount. However, any suitable complementary means can be substituted for this bayonet mount. When assembled, as in FIG. 2, port  129  of guide  120  is aligned with port  119  of hub  112  so that spinal fluid in chamber  118  of the hub flows through port  119  and then through port  129 . 
     Disposal unit  121  comprises rigid cylinder  122  and plunger  123 . Rigid cylinder  122  comprises engagement means  227  at the distal end of the rigid cylinder and plunger  123  comprises engagement means  226  at the distal end of the plunger. Engagement means  227  is complementary to engagement means  217 . Rigid cylinder  122  securely attaches to guide  120  by the engagement of engagement means  217  and engagement means  227 . Engagement means  217  and engagement means  227  are any suitable complementary engagement means such as, for example, the threads of a leur lock. At the end of a spinal tap or other procedure, the user engages engagement means  227  and engagement means  217  to securely hold and stabilize guide  120 . Then the user engages engagement means  226  and engagement means  216 . Engagement means  226  is complementary to engagement means  216 . Preferably, the engagement of engagement means  227  and engagement means  217  prevents the rotation of guide  120 . Hub  112  is removed from within guide  120  by the engagement of engagement means  216  and engagement means  226  and the simultaneous disengagement of engagement means  215  and engagement means  225 . In the illustrations of FIG. 1, engagement means  216  is a pin and engagement means  226  is a slot of a bayonet mount. However, any suitable complementary means can be substituted for this bayonet mount. In the embodiment illustrated in FIG. 1, the engagement of complementary engagement means  215  and  225  are the reverse of the engaging of complementary engagement means  216  and  226  so that a turning of plunger  123  to engage engagement means  216  and  226  simultaneously disengages engagement means  215  and  225 . Once engagement means  215  are disengaged from engagement means  225 , the user pulls plunger  123  to withdraw the needle unit into the disposal unit. 
     Notch  315  at the proximal end of stylet  114  and ridge  325  at the proximal end of hub  112  are optional complementary orientation means used to properly aligned the stylet within the needle. Optional adapter means can also be provided such as, for example, the leur lock thread  301  at the distal end of guide  120 . Another option is the provision of an adhesive or silicon sealant to provide a penetrable seal means to prevent fluid flow through the guide port. Similar seals and adapters can be used in other components of the invention such as, for example, the ports of the needle hub. 
     FIG. 2 is a cross-sectional view of an assembly of the disposal unit, stylet, needle unit and guide illustrated in FIG.  1 . In FIG. 2 b  the needle is fully extended and the disposal unit attached as would be the case just after the completion of a procedure such as, for example, a spinal tap. In FIG. 2 b , the needle and hub have been withdrawn into the disposal unit. Note that the cavity at the distal end of plunger  123  accommodates the proximal end of stylet  114 . 
     FIGS. 3 and 5 illustrate optional features that can be added to the components illustrated in FIG.  1 . In FIG. 3, guide chamber  321  and window  320  are provided to allow viewing of fluid flow into the hub as the needle is withdrawn. In FIG. 5, port  329  is an additional port in guide  120 . Port  319 , illustrated in FIGS. 3 and 5, communicates with optional guide chamber  321  when the hub is properly aligned within the guide as illustrated in FIG.  4  and communicates with optional port  329  when the hub is properly aligned within the guide as illustrated in FIG.  6 . 
     FIG. 7 illustrates that the shape of port  119  is variable and is dependent on the type of port to which it will be aligned, such as port  229  of the guide. The angle of the ports of the guide and hub depend on the application for which they will be used. FIG. 8 illustrates the alignment of ports  119  and  229  of FIG. 7 when the hub is properly aligned within the guide. In conjunction with a spinal tap or epidural needle, when the stylet is optimally withdrawn, a port angled like port  229  in FIGS. 7 and 8 may serve to insert an epidural catheter. 
     FIGS. 9 and 10 illustrate the application of the invention to biopsy needles and stylets. 
     In FIG. 9, cutting stylet  214  is illustrated. Distal end  213  of cutting stylet  214  comprises a recess. Also illustrated in FIG. 9 is needle unit  210 , which comprises needle  211 . Needle  211  comprises a recess. Also illustrated are ports  419  and  429 . It is noted that the size and shapes of these ports is dependent on the purpose for which they are used. FIG. 10 a  illustrates the alignment of the components of FIG. 9 when the cutting stylet is fully inserted into the needle and FIG. 10 b  illustrates an alignment of the components when the stylet withdrawn. It is noted that various combinations of biopsy stylets and needles can be used in this invention. For example, a cutting needle with a cutting recess can be used in conjunction with a stylet without a recess. In another example, a cutting stylet with a recess can be used with a needle without a recess. The exact biopsy stylet and needle used will depend on the method used for obtaining a biopsy. 
     In one conventional procedure for the performance of biopsies, a cutting stylet is inserted through a needle or rigid catheter into the body tissue to be biopsied. The distal end of the cutting stylet extends beyond the distal end of the needle or catheter into the tissues to be biopsied and is then withdrawn back into the catheter or needle. Upon withdrawal of the cutting stylet, the stylet cuts the tissue to be biopsied and retains a piece of the cut tissue in a recess in the cutting stylet. 
     An alternative procedure is to insert a stylet with a recess into the tissue to be biopsied. A piece of the tissue to be biopsied settles into the recess. A cutting needle is then inserted over the stylet and cuts the piece of tissue that settled into the recess. The stylet remains within the needle and then the stylet and needle are withdrawn together along with the tissue trapped inside the recess. In this method, the stylet and cutting needle are inserted together; the distal end of the stylet is then extended beyond the distal end of the cutting needle, and then the cutting end of the cutting needle is push towards the distal end of the stylet to cut the tissue trapped in the recess. In the alternative, the stylet is first inserted and then the cutting needle, using the stylet as a guide, is inserted over the stylet to cut the tissue trapped in the recess. 
     In another alternative method, a needle with a stylet is inserted into the tissue to be biopsied, the stylet is at least partially withdrawn and the needle is rotated and/or pushed further into the tissue to obtain a core of tissue. Subsequently, after the needle is withdrawn, the stylet is used to push the tissue obtained back out of the needle. 
     In a further alternative method, a needle with a stylet is inserted into the tissue to be biopsied, the stylet is withdrawn to uncover a cutting recess in the needle and the needle is withdrawn. As the needle is withdrawn, tissue is cut and retained in the needle cutting recess. 
     Accordingly, in some instances, the biopsy stylet is longer than the needle so that it can extend beyond the needle at some point in time during the procedure. It follows that, when the distal end of the stylet is withdrawn to rest completely within the needle, the length of the stylet that extends beyond the proximal end of the needle hub is dependent on the length of the stylet. Furthermore, since the cavity at the distal end of the plunger accommodates the proximal end of the stylet, the depth of the cavity varies with the length of the stylet. 
     FIG. 11 illustrates the use of catheters with the invention. Ports  129  and  301  comprise engagment means to which complementary egagement means can be affixed. As illustrated in FIGS. 11 a ,  11   b  and  11   c , catheters  411  and  412  comprise engagement means, such as leur locks,  311  and  312  that can engage an engagement means on port  301 . Each engagement means  311  and  312  comprises seal  413 . Seal  413  is a seal, such as a capless valve, which is closed when not engaged by complementary egagement means and open when engaged by complementary engagement means. When used in conjunction with a spinal tap needle or epidural needle, catheters such as those illustrated in FIGS. 11 a ,  11   b  and  11   c  may serve as introducers for epidural catheters. 
     FIGS. 12 a ,  12   b ,  13   a ,  13   b  and  14  illustrate the collection valve module introduced in this invention. Each collection valve module comprises a transmission means and a valve switch. Fluid received by a transmission means is transmitted to a collecting tube when a valve switch is open. 
     FIGS. 12 a  and  12   b  depict detailed cross sections of collection valve module  600 . Each module comprises transmission means  550  and valve switch  551 . 
     Fluid received by transmission means  550  is transmitted to a collecting tube when valve switch  551  is open. 
     Transmission means  550  comprises channel  605  to transmit fluid from a needle unit to a container through internal port  614  and valve switch  551  when channel  624  of valve switch  551  is positioned to receive fluid flow from internal port  614 . Either a needle unit or a guide is adapted to engage the transmission means either directly or by means of one or more adapters, such as adapter  630  illustrated in FIG. 13 a . The transmission unit is also adapted to engage a sample container, either directly or by means of one or more adapters. Thus, the transmission unit is adapted to receive fluid from the needle unit and to transmit fluid from the needle unit to the container. For example, as illustrated in FIGS. 12 a ,  12   b ,  13   a  and  13   b  transmission means  550  comprises external receiving port  630 , channel  605  and internal port  614 . Transmission means  550  further comprises optional external transmitting port  640 , optional tube extensions, such as, for example, tube extension  631 , and optional external transmitting port cap  632 . External receiving port  630  is adapted to engage a port of a guide or the port of an adapter. Fluid received either directly or indirectly at external port  630  then flows through channel  605  to internal port  614 . 
     Valve switch  551  comprises spring  541 , actuator  544  and channel  624 . When a user presses on actuator  544 , as illustrated in FIG. 12 b , channel  624  is positioned to receive fluid flow from internal port  614 . Fluid received by channel  624  flows to a container through a container adapter. 
     As illustrated in FIG. 12 a , when fluid flow is controlled by gravity, a collecting tube  607  is attached to container adapter  620  by means of adapter  610  and collecting tube  607  moves along with the movement of valve switch  551 . In this situation, vent  612  allows air displaced by the fluid entering the collecting tube to flow from collecting tube  607  through optional vent channels  623 ,  613  and  606 . 
     When actuator  544  is released, fluid flow ceases or bypasses port  614  to flow to external transmitting port  640  and thence to an external receiving port of a subsequent module. 
     Seals  621  and  611  serve to prevent leakage. 
     As illustrated in FIG. 14, for collection valve module  601 , when fluid flow is controlled by a vacuum tube, a vacuum collecting tube  608  is held in a stationary position, such as, for example, by an extension of transmitting unit  550 . When a user presses on actuator  544 , channel  624  is positioned to receive fluid flow from internal port  614 . Fluid received by channel  624  flows to a container through a container adapter. In this situation, the container adapter to which fluid flows from channel  624  comprises a needle such as, for example, a vacutainer needle  615  and sleeve  616 . The needle pierces indent  625  in cap  626  and the vacuum tube is filled. 
     In both the gravity fill scenario and the vacuum tube scenario, a series of modules can be connected together such as in a rigid manifold or a flexible strap to permit a series of tubes to be filled without need for the user to reach for and exchange one tube after another as is currently done in drawing blood using a conventional vacutainer system. An alternative in the vacuum tube scenario is a number of collecting tubes contained in a rigid manifold or a strap can be presented in series to a single valve module. 
     The foregoing description and accompanying drawings are provided for illustration and example. It is understood that various changes, adaptations and modifications may be made without departing from the spirit of the invention which is limited only by the scope of the claims which follow.