WO2014107800A1

WO2014107800A1 - Needle system and method of using same

Info

Publication number: WO2014107800A1
Application number: PCT/CA2014/000015
Authority: WO
Inventors: Joseph KERR; Michael FERNANDO
Original assignee: Fernando Kerr Design Inc.
Priority date: 2013-01-11
Filing date: 2014-01-13
Publication date: 2014-07-17

Abstract

A needle system including a needle assembly and a cap assembly. The cap assembly includes a cap body extending between inner and outer ends thereof. The cap body is connected with the needle assembly to permit relative movement between a needle of the needle assembly and the cap body. The cap body defines an inner chamber between the outer end and a nose end of a needle base of the needle assembly in which the needle is secured. The outer end of the cap body includes an aperture through which a tip segment of the needle is movable, to locate the tip segment beyond the outer end, and to permit the tip segment to be withdrawn through the aperture, to locate the tip segment of the outer portion in the inner chamber.

Description

NEEDLE SYSTEM AND METHOD OF USING SAME

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application No.

61/751,258, filed on January 11, 2013, the disclosure of which is fully incorporated herein by reference.

FIELD OF THE INVENTION

[0002] The present invention is a needle system having a needle and a method of using same in which the needle system includes a cap assembly with a cap body movable relative to the needle between an extended condition, in which a tip segment is in an inner chamber partially defined by the cap body, and a retracted condition, in which the tip segment extends from the cap body for use.

BACKGROUND OF THE INVENTION

[0003] Syringes are used in conjunction with needles in a variety of human and animal healthcare applications. A typical needle assembly 10 is shown in Figs. 1A and IB. (As will be described, the remainder of the drawings illustrate the present invention.) As can be seen in Figs. 1A and IB, the needle assembly 10 includes a syringe 12 and a needle subassembly 14. The syringe 12 includes a barrel 16 partially defined by a central axis 18 and a plunger 20 partially located in the barrel 16, and movable relative to the barrel 16, as is well known in the art.

[0004] As can also be seen in Figs 1A and IB, the needle subassembly 14 typically includes a needle base 22 securely engaged with the barrel 16 and a hollow needle 24 securely mounted in the needle base 22. As is also well known in the art, the needle 24 includes a bore therein (not shown in Figs. 1A and IB) that is substantially aligned with the central axis 18 when the needle subassembly 14 is secured to the barrel 16. Conventionally, an embedded portion (not shown in Figs. 1A and IB) of the needle 24 is secured to the needle base 22, and an outer portion 26 of the needle 24 projects from the needle base 22. When the needle assembly is used, an end part 28 of the outer portion 26 is inserted into the patient (not shown in Figs. 1A, IB). It will be understood that the extent of the outer portion 26 that is inserted into the patient varies, depending on a number of factors well known in the art. [0005] Examples of applications in which needle assemblies are used include, but are not limited to, blood sampling and intra-muscular injection. In blood sampling, in particular, there is a need for the healthcare professional to carefully insert the end part of the outer portion of the needle into a vein or artery in close proximity to the healthcare professional's fingers, which are used to stabilize the patient and sometimes to feel a pulse during the procedure. After the needle is removed and contaminated with the patient's blood, there is a strong possibility that inadvertent sudden movement of the patient or healthcare professional could result in a needle stick injury to the healthcare professional. This type of injury can be quite serious, depending on the biological or chemical contaminants that may be in the patient's blood. Lost time injuries of highly trained healthcare professionals represent a significant cost to the medical system as a whole and jeopardize patient safety.

[0006] Arterial blood sampling is a particular type of blood sampling with increased risk to the healthcare professional, due to the delicate nature of the procedure and the proximity of the professional's fingers to the exposed part of the needle during the procedure. First an artery is located by the physician by digital manipulation of the patient's arm, wrist, or other anatomical structure in the case of animals. Next, the end part of the outer portion of the needle is inserted at an angle of approximately 45° into an artery so that at least some of the needle end travels along the artery with the end part directed upstream into the blood flow through the artery. The depth of insertion is typically from three to five millimeters through the patient's skin. Once the artery is tapped, blood pressure within the artery causes the syringe to fill with a blood sample. It is important that the tip part of the needle not be inserted too deeply into the patient. Once the syringe has been filled to the desired volume, the end part is removed from the patient and pressure is applied to the exit wound. This typically occupies both hands of the healthcare professional.

[0007] Previous attempts to render the outer portion of the needle safe after such a procedure have included, for instance, the use of a rubberized foam block into which the outer portion is at least partially inserted after removal thereof from the patient. However, this is difficult in practice, because both of the healthcare professional's hands are occupied with the patient after the procedure, as described above. As a result, this cumbersome step is often omitted in practice. Even when the foam block is used, there is added risk of a needle stick to the professional's fingers during insertion of the outer portion into the foam block and the potential to inadvertently stick another person while searching for the foam block. [0008] In certain circumstances, it is important that the end part of the outer portion of the needle is inserted to only a predetermined depth (or to a limited range of predetermined depths, as the case may be) into the patient's body. Conventionally, reliance is placed on the skill and experience of the healthcare professional. However, it is sometimes difficult to ensure that the outer portion of the needle is inserted to only the predetermined depth.

SUMMARY OF THE INVENTION

[0009] For the foregoing reasons, there is a need for a system and a method that overcome or mitigate one or more of the disadvantages or defects of the prior art.

[0010] In its broad aspect, the invention provides a needle system including a needle assembly and a cap assembly. The needle assembly includes a syringe having a barrel extending between first and second ends thereof, and a needle subassembly having a needle base extending between a syringe end and a nose end thereof, the syringe end being secured to the first end of the barrel. The needle subassembly also includes an elongate needle including an embedded portion secured to the nose end of the needle base and an outer portion projecting from the nose end. The cap assembly includes a cap body extending between inner and outer ends thereof. The cap body is connected with the needle assembly to permit relative movement between the needle and the cap body. The cap body defines an inner chamber between the outer end and the nose end of the needle base. The outer end of the cap body includes an aperture through which a tip segment of the outer portion of the needle is movable, to locate the tip segment beyond the outer end, and to permit the tip segment to be withdrawn through the aperture, to locate the tip segment of the outer portion in the inner chamber.

[001 1] In another of its aspects, the cap body is movable in a first axial direction relative to the needle in which the outer end of the cap body is moved toward the nose end of the needle base, and the cap body is movable in a second axial direction in which the outer end of the cap body is moved away from the nose end of the needle base.

[0012] In another aspect, the cap body is movable in the first axial direction to a retracted condition, in which the tip segment is located beyond the outer end, and the cap body is movable in the second axial direction to an extended condition, in which the tip segment of the outer portion of the needle is located in the inner chamber. [0013] In yet another aspect, the cap body additionally includes an internal wall spaced apart from the outer end and including an opening therein substantially aligned with the aperture through which the tip segment of the needle is movable. The cap body also includes an end wall at the outer end, the end wall including the aperture. The end wall at least partially defines an end chamber of the cap assembly between the end wall and the internal wall. The cap assembly also includes a blocking element at least partially located in the end chamber and movable between an open position, in which movement of the tip segment of the needle through the blocking element is permitted, and a blocking position, in which movement of the tip segment through the blocking element is prevented.

[0014] In another of its aspects, the invention provides a cap assembly for use with a needle assembly having a syringe and a needle subassembly secured to the syringe. The needle subassembly includes a needle base and a needle secured in the base with an outer portion of the needle extending from the needle base. The cap assembly includes a cap body extending between inner and outer ends thereof, the cap body being engageable at the inner end thereof with the needle assembly to permit relative movement between the cap body and the needle. The cap body defines an inner chamber between the outer end and the needle base. The outer end of the cap body includes an aperture through which a tip segment of the outer portion of the needle is movable to locate the tip segment beyond the outer end, and to permit the tip segment to be withdrawn through the aperture, to locate the tip segment in the inner chamber.

[0015] In yet another of its aspects, the invention provides a method of using a needle system relative to a preselected position on a patient's skin surface. The needle system includes a syringe and a needle subassembly secured to the syringe, the needle subassembly including a needle base and a needle having an outer portion extending from the needle base. The method includes moving a cap body of a cap assembly of the needle system relative to the needle to locate a tip segment of the outer portion of the needle beyond an outer end of the cap assembly. The patient's skin is pierced at the preselected position with an end part of the tip segment. The end part is removed from the patient. The cap body is moved relative to the needle to position the tip segment in an inner chamber at least partially defined by the cap body between the needle base and the outer end. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The invention will be better understood with reference to the attached drawings, in which:

[0017] Fig. 1A (also described previously) is a side view of a needle assembly of the prior art;

[0018] Fig. IB (also described previously) is an exploded view of the prior art needle assembly of Fig. 1A;

[0019] Fig. 2A is a cross-section of an embodiment of a cap assembly of the invention and a needle subassembly, drawn at a larger scale;

[0020] Fig. 2B is an exploded view of an embodiment of a needle system of the invention including the cap assembly of Fig. 2A, drawn at a smaller scale;

[0021] Fig. 2C is a partial cross-section of the needle system of Fig. 2B with a cap body of the cap assembly thereof in an extended condition, drawn at a larger scale;

[0022] Fig. 2D is a partial cross-section of the needle system of Fig. 2B with the cap body in a retracted condition;

[0023] Fig. 2E is another side view of the needle system of Fig. 2B;

[0024] Fig. 3A is a cross-section of another embodiment of the cap assembly of the invention including a blocking element in an open position thereof, and the needle subassembly, drawn at a larger scale;

[0025] Fig. 3B is a cross-section of the cap assembly of Fig. 3 A in which the blocking element is shown in a blocking position thereof, and the needle subassembly;

[0026] Fig. 3C is a partial cross-section of an embodiment of a needle system of the invention including the cap assembly of Figs. 3A and 3B in which the blocking element is in the open position and the cap body is in the extended condition thereof, drawn at a smaller scale;

[0027] Fig. 3D is a partial cross-section of the needle system of Fig. 3C in which the blocking element is in the open position and the cap body is in the retracted condition thereof; [0028] Fig. 3E is a partial cross-section of the needle system of Figs. 3C and 3D in which the blocking element is in the blocking position and the cap body is in the extended condition thereof;

[0029] Fig. 4A is a partial cross-section of another embodiment of the needle system of the invention including an alternative embodiment of the cap assembly of the invention in which the blocking element is shown in the open position and the cap body is in an initial extended condition;

[0030] Fig. 4B is a cross-section of the cap assembly and the needle subassembly of

Fig. 4A, drawn at a larger scale;

[0031] Fig. 4C is a cross-section of the cap assembly and the needle subassembly of

Fig. 4B in which the blocking element is in the open position and the cap body is in the retracted condition;

[0032] Fig. 4D is a cross-section of the cap assembly and the needle subassembly of

Fig. 4B in which the blocking element is shown in the blocking position and the cap body is in a final extended condition;

[0033] Fig. 4E is a cross-section of an exploded view of the cap assembly and the needle subassembly of Figs. 4A-4D, drawn at a smaller scale;

[0034] Fig. 5A is a side view of an alternative embodiment of the needle system of the invention including another embodiment of the cap assembly of the invention in which the cap body is shown in the extended condition thereof, drawn at a smaller scale;

[0035] Fig, 5B is a side view of the needle system of Fig. 5A in which the cap body is shown in the retracted condition;

[0036] Fig. 5C is a side view of the needle system of Figs. 5A and 5B in which the cap body is shown in a secured condition;

[0037] Fig. 6A is a cross-section of another embodiment of the cap assembly of the invention including a stop element in which the cap body is shown in the extended condition, drawn at a larger scale; [0038] Fig. 6B is a cross-section of the cap assembly of Fig. 6A in which the cap body is shown in the retracted condition;

[0039] Fig. 6C is a partial cross-section of an embodiment of the needle system of the invention including the cap assembly of Figs. 6A and 6B, drawn at a smaller scale;

[0040] Fig. 7 is a side view of an embodiment of the needle system of the invention in which an end part of a tip segment of the needle is shown inserted into a patient, drawn at a smaller scale;

[0041] Fig. 8 is a side view of another embodiment of the needle system of the invention; and

[0042] Fig. 9 is a side view of another embodiment of the needle system of the invention.

DETAILED DESCRIPTION

[0043] In the attached drawings, like reference numerals designate corresponding elements throughout. To simplify the description, the numerals used previously in describing Fig. 1A and IB will be used again after increasing the numerals by 100 (or multiples thereof) where the parts to be described correspond to parts already described. Reference is first made to Figs. 2A-2E to describe an embodiment of a needle system in accordance with the invention indicated generally by the numeral 130. In one embodiment, the needle system 130 preferably includes a needle assembly 110. The needle assembly 1 10 preferably includes a syringe 112, a barrel 116 extending between first and second ends 132, 134 thereof, and a needle subassembly 114 having a needle base 122 extending between a syringe end 136 and a nose end 138 thereof, secured to the first end 132 of the barrel 116. The needle subassembly 1 14 also includes an elongate needle 124 with an embedded portion 140 secured to the nose end 138 of the needle base 122 and an outer portion 126 projecting from the nose end 138. In one embodiment, it is also preferred that the needle system 130 includes a cap assembly 144 having a cap body 146 extending between inner and outer ends 148, 150 thereof. As will be described, the cap body 146 preferably is connected with the needle assembly 1 10 to permit relative movement between the needle 124 and the cap body 146. It is also preferred that the cap body 146 defines an inner chamber 152 between the outer end 150 and the nose end 138 of the needle base 122. In one embodiment, the outer end 150 of the cap body 146 preferably includes an aperture 154 through which a tip segment 156 of the outer portion 126 of the needle 124 is movable, to locate the tip segment 156 beyond the outer end 150, and to permit the tip segment 156 to be withdrawn through the aperture 154, to locate the tip segment 156 of the outer portion 126 in the inner chamber 152.

[0044] Preferably, the cap body 146 is movable in a first axial direction (indicated by arrow "A" in Fig. 2C) relative to the needle 124 in which the outer end 150 of the cap body 146 is moved toward the nose end 138 of the needle base 122, and the cap body 146 is movable in a second axial direction (indicated by arrow "B" in Fig. 2D) in which the outer end 150 of the cap body 146 is moved away from the nose end 138 of the needle base 122. It will be understood that the first and second axial directions are substantially parallel to an axis 118 of the needle assembly 110 (Figs. 2C, 2D). In one embodiment, it is preferred that the cap body 146 is movable in the first axial direction to a retracted condition (Fig. 2D), in which the tip segment 156 is located beyond the outer end 150, and the cap body 146 is movable in the second axial direction to an extended condition (Fig. 2C), in which the tip segment 156 of the outer portion 150 of the needle 124 is located in the inner chamber 152.

[0045] Preferably, when the needle system 130 is provided to the healthcare professional ready for use, the cap body 146 is in the extended condition (Fig. 2C). The cap body 146 is then moved by the healthcare professional to the retracted condition (Fig. 2D). As can be seen in Fig. 2D, when the cap body 146 is in the retracted condition, the tip segment 156 is ready for use. After an end part 128 of the tip segment 156 has been inserted into a patient "P" (Fig. 7) and subsequently removed therefrom, the tip segment 156 (i.e., including the end part 128) preferably is returned to the inner chamber 152 promptly, to minimize the risk of an inadvertent needle stick of the healthcare professional or another by the then-contaminated end part 128. It is preferred that, after use of the tip segment 156, the tip segment 156 is positioned in the inner chamber 152 as described above, i.e., by movement of the cap body 146 from the retracted condition to the extended condition. The needle system 130 may then be discarded in accordance with standard protocols.

[0046] It will be understood that the tip segment 156 preferably is maintained in the inner chamber 152 (i.e., as illustrated in Figs. 2A and 2C) until the needle system 130 is to be used, e.g., to take blood from the patient. (It will also be understood that the syringe 112 is omitted from Fig. 2A for clarity of illustration.) For the purposes hereof, it will be understood that the extended condition of the cap body before the needle system has been used is sometimes referred to as an "initial extended condition".

[0047] Those skilled in the art would appreciate that the needle system 130 preferably is packaged in a blister pack or otherwise suitably packaged (such packaging not shown) upon its manufacture to protect the needle system 130 from contamination prior to use. In order to maintain the cap body in the initial extended condition while the needle system is in the packaging, it is also preferred that a suitable means (not shown) for temporarily securing the cap body relative to the needle is applied or engage to the needle system, before the needle system is package. For example, such means may be suitable adhesive tape, securing the inner end 148 of the cap body 146 to the syringe barrel 1 16 until the packaging is removed from the needle system 130. In order to use the needle system 130 after the packaging is removed, the securing means (i.e., the adhesive tape) is removed, to permit the cap body thereafter to be moved to the retracted condition.

[0048] As described above, the tip segment 156 is exposed for use when the healthcare professional moves the cap body 146 to the retracted condition. Preferably, the healthcare professional does not move the cap body 146 to the retracted condition until shortly before the healthcare professional is ready to insert the end part 128 into the patient.

[0049] After the end part 128 of the tip segment 156 is inserted into the patient and then withdrawn therefrom (i.e., after the needle system has been used), the cap body 146 preferably is moved to the extended condition thereof, so that the tip segment 156 (and the contaminated end part 128) are located in the inner chamber 1 2. For the purposes hereof, it will be understood that the extended condition of the cap body after the needle system has been used is sometimes referred to as a "final extended condition". Those skilled in the art would appreciate that the risk of an inadvertent needle stick after the tip segment 156 is returned to the inner chamber 152 is relatively low.

[0050] Those skilled in the art would also appreciate that the cap body 146 and the needle assembly 110 may be connected in any suitable manner. Preferably, any such manner of connection permits movement of the cap body 146 relative to the needle 124 between the extended and retracted conditions, as described above. In one embodiment, the cap assembly 144 preferably includes a connector 158 for connecting the needle assembly 1 10 and the cap body 146. It is also preferred that the cap body 146 is slidably engaged with the connector 158. Those skilled in the art would also appreciate that the connector 158 may be mounted on the needle assembly 110 in any suitable manner. Preferably, and as will be described, the connector 158 is positioned between the needle base 122 and the syringe 1 12 and is substantially stationary relative to the needle base 122.

[0051] In one embodiment, the connector 158 preferably includes one or more engagement elements 160 (Fig. 2E) formed and positioned for sliding engagement with edges 162 that define one or more slots 164 along sides 166 of the cap body 146 (Fig. 2B). The connector 158 preferably has any suitable shape. In one embodiment, the connector 158 preferably is formed to locate the engagement element(s) 160 for sliding engagement with the edges 162 of the slots 164. In one embodiment, the cap body 146 preferably includes two opposed slots 164, and the connector 158 preferably includes two engagement elements 160, one of which is slidably engaged with the edges 162 defining each of the slots 164 respectively. Preferably, the engagement elements 160 extend into the slots 164, as can be seen in Fig. 2E.

[0052] Those skilled in the art would appreciate that the components of the needle system 130 may be assembled in any suitable manner. In one embodiment, in order to assemble the needle system 130, the syringe 1 12 preferably is first inverted, i.e., the syringe 1 12 is positioned substantially vertical, with the first end 132 of the barrel 116 located above the second end 134 thereof. It will be understood that, while the syringe 1 12 is held inverted, the other components are also assembled in inverted positions. As can be seen in Fig. 2B, the barrel 1 16 includes a barrel body 170 and a relatively narrow barrel tip 172 extending from the barrel body 170 at the first end 132 of the barrel 1 16. In one embodiment, the connector 158 preferably is positioned on the barrel tip 172, by sliding the connector 158 thereon in the direction indicated by arrow "C" in Fig. 2B, while the syringe 1 12 is inverted. Next, the syringe end 136 of the needle base 122 is positioned on the barrel tip 172, by sliding the needle base 122 onto the barrel tip 172 in the direction indicated by arrow "C" in Fig. 2B, while the syringe 112 is inverted.

[0053] Those skilled in the art would appreciate that the connector 158 and the needle base 122 preferably are secured to the barrel tip 172. The connector 158 and the needle base 122 may be secured to the barrel tip 172 in any suitable manner. In one embodiment, it is preferred that the connector 158 and the syringe end 136 of the needle base 122 are formed to fit securely onto the barrel tip 172, with the connector 158 preferably secured between the syringe end 136 of the needle base 122 and the barrel body 170. Preferably, the connector 158 and the syringe end 136 of the needle base 122 define bores 174, 176 therein respectively that are each formed so that the connector 158 and the needle base 122 are secured the barrel tip 172 in any suitable manner. In one embodiment, it is preferred that the barrel body 170 includes a substantially planar surface 178 to which the barrel tip 172 is secured, and the connector 158 includes a mating surface 180 that conforms to the surface 178 when the connector 158 is mounted on the barrel tip 172. The needle base 122 preferably is secured to the barrel tip 172 using conventional means, except that the connector 158 is positioned between the needle base 122 and the barrel body 170 after the connector 158 and the needle base 122 are secured to the barrel tip 172.

[0054] From the foregoing, it can be seen that the needle assembly is generally conventional, except that the connector 158 is located between the needle base 122 and the barrel body 170. The cap assembly of the invention preferably is made of any suitable material. Those skilled in the art would be aware of suitable medical grade plastics, e.g., various types of polycarbonate resin. It is preferred that the material of the cap assembly is substantially clear (i.e., transparent) or translucent, to enable the user to observe the position of the tip segment in the inner chamber.

[0055] Another embodiment of the needle system 230 of the invention, including another embodiment of the cap assembly 244 of the invention, is illustrated in Figs. 3C-3E. It will be understood that the needle system 230 preferably also includes the needle assembly 110, described above. Figs. 3 A and 3B are cross-sections of the cap assembly 244, and the needle subassembly 114. (It will also be understood that the syringe 1 12 is omitted from Figs. 3A and 3B for clarity of illustration.) Preferably, the cap assembly 244 includes a cap body 246 having an internal wall 282 spaced apart from an outer end 250 of the cap body 246 (Figs. 3A, 3B). It is also preferred that the internal wall 282 includes an opening 284 therein that is substantially aligned with an aperture 254 in the outer end 250, through which the tip segment 156 of the needle 124 is movable. In one embodiment, the cap body 246 additionally includes an end wall 286 at the outer end 250, the end wall 286 including the aperture 254. Preferably, the end wall 286 at least partially defines an end chamber 288 of the cap assembly 244 between the end wall 286 and the internal wall 282. (It will be understood that the end chamber 288 is included in the inner chamber 252.) It is also preferred that the cap assembly 244 additionally includes a blocking element 290 at least partially located in the end chamber 288 and movable between an open position (Figs. 3A, 3C), in which movement of the tip segment 156 of the needle 124 through the blocking element 290 is permitted, and a blocking position (Figs. 3B, 3D), in which movement of the tip segment 156 through the blocking element 290 is prevented.

[0056] The blocking element 290 preferably is held between the internal wall 282 and the end wall 286. Preferably, the blocking element 290 is held therein sufficiently loosely to permit its movement from the open position to the blocking position. In one embodiment, and as will be described, the blocking element 290 preferably is biased to the blocking position.

[0057] It is also preferred that the blocking element 290 includes a channel 292 therethrough, as can be seen in Figs. A and 3B. It is preferred that the channel 292 is substantially straight, and is large enough that part of the tip segment 156 may pass therethrough. Preferably, the blocking element 290 is movable between the open position (Fig. 3A), in which the channel 292 is substantially aligned with the aperture 254 to permit the tip segment 156 of the needle 124 to be at least partially positioned in the channel 292, and the blocking position (Fig. 3B), in which the channel 292 is non-aligned with the aperture 254, and the blocking element 290 prevents movement of the tip segment 156 into the channel 292.

[0058] In one embodiment, the needle system 230, when ready for use, preferably includes the blocking element 290 in the open position. As can be seen in Fig. 3A, the tip segment 156 preferably is partially inserted into the channel 292. Specifically, it is preferred that only a part 294 of the tip segment 156 is positioned in the channel 292 when the needle system 230 is manufactured, to hold the blocking element 290 in the open position prior to the needle system's use. For example, the needle system 230 illustrated in Fig. 3C is ready for use. Those skilled in the art would appreciate that, because the blocking element 290 is biased to the blocking position, the part 294 of the tip segment 156 functions as a brake or a stop, holding the blocking element 290 in the open position until the needle system 230 has been used.

[0059] As can be seen in Fig. 3C, when the needle system 230 is ready for use as described above, the cap body 246 preferably is in the initial extended condition. When the cap body 246 is in the initial extended condition, the tip segment 156 is in an inner chamber 252 located between the outer end 250 and the nose end 138 of the needle base 122. (The inner chamber 252 is partially defined by the cap body 246 between the outer end 250 and the nose end 138 of the needle base 122 (Fig. 3B).) In particular, and as described above, when the cap body 246 is in the initial extended condition, only the part 294 of the tip segment 156 is positioned in the channel 292, and the tip segment 156 does not extend beyond the outer end 250.

[0060] When the healthcare professional is ready to use the needle system 230, the cap body 246 is moved in the first axial direction relative to the needle 124, to the retracted condition (Fig. 3D). The first axial direction is indicated by arrow "A|" in Fig. 3C. As the cap body 246 is moved in the first axial direction, the blocking element 290 is also moved in the first axial direction, so that the blocking element 290 is moved past part of the tip segment 156, to locate a covered part "Q" of the tip segment 1 6 in the channel 292 when the cap body 246 is in the retracted condition (Fig. 3D). The movement of the blocking element 290 past part of the tip segment 156 as the cap body is moved in the first axial direction is permitted by the alignment of the tip segment 256 with the channel 292 when the blocking element 290 is in the open position.

[0061 ] From the foregoing, it can be seen that the movement of the cap body 246 to the retracted condition (Fig. 3D) from the initial extended condition (Fig. 3C) is possible because the blocking element 290 is held in the open position when the cap body 246 is in the initial extended condition.

[0062] As described above, once part of the tip segment 156 is positioned beyond the outer end 250, the healthcare professional preferably uses the tip segment 156 for a selected procedure, e.g., taking blood. Once the procedure is completed, the cap body 246 is moved in the second axial direction (indicated by arrow "Bi" in Fig. 3D) to a final extended condition (Fig. 3E).

[0063] In the embodiments illustrated in Figs. 3A-3E, the position of the cap body

246 relative to the needle 124 in the initial extended condition differs from the position of the cap body 246 relative to the needle 124 in the final extended condition. As described above, when the cap body 246 is in the initial extended condition, the blocking element 290 is held in the open position by the part 294 of the tip segment 156, which is inserted in the channel 292 (Fig. 3A). However, and as can be seen in Fig. 3E, when the cap body 246 is in the final extended condition, no part of the tip segment 156 remains in the channel 292. Because no part of the tip segment 156 remains in the channel 292 at this point, and because the blocking element 290 is biased to the blocking position, the blocking element 290 is allowed to move to the blocking position when the cap body 246 is in the final extended condition.

[0064] It can be seen in Fig. 3E that, if an attempt to move the cap body 246 to the retracted condition from the final extended condition were made, the movement could not take place because the blocking element 290 is in the blocking position, i.e., the blocking element's channel 292 is not aligned with the tip segment 156. In this way, the needle system 230 provides a mechanism for preventing inadvertent movement of the cap body 246 to the retracted condition after the cap body 246 is moved to the final extended condition, thereby significantly reducing the risk of an accidental needle stick with a contaminated needle.

[0065] Those skilled in the art would appreciate that the blocking member 290 may be biased to the blocking position in any suitable manner. In one embodiment, for example, the blocking member 290 preferably is formed to have a center of gravity so that the blocking member 290 tends to move itself, under the influence of gravity, to the blocking position unless prevented by another element (e.g., the needle) from doing so. This arrangement is illustrated in Figs. 3A-3E. Preferably, the blocking element 290 is held between the end wall 286 and the internal wall 282. In one embodiment, the internal wall 282 includes a surface 296 engaged by the blocking element 290 that preferably is substantially planar, except for the opening 284 therein. It can be seen in Fig. 3B that the blocking element 290 preferably has rounded ends "E", "F" that facilitate the movement of the blocking element 290 to the blocking position.

[0066] Another embodiment of the cap assembly 344 of the invention is illustrated in

Figs. 4A-4E. The cap assembly 344 is included in another embodiment of the needle system 330 of the invention (Fig. 4A). It will be understood that the needle system 330 preferably also includes the needle assembly 1 10, described above. As will be described, the cap assembly 344 preferably includes an internal wall 382 having a surface 396 engaged with a blocking element 390 and configured to bias the blocking element 390 to the blocking position. [0067] Preferably, the cap assembly 344 includes a cap body 346 configured to bias the blocking element 390 to the blocking position. The cap body 346 extends between an inner end 348 and an outer end 350 (Fig. 4B).

[0068] The cap assembly 344, with the needle subassembly 1 14, is illustrated in Figs.

4B-4D in an initial extended condition, in a retracted condition, and in a final extended condition respectively. It will be understood that the syringe 1 12 is omitted from Figs. 4B- 4D for clarity of illustration. The cap body 346 defines an inner chamber 352 between the outer end 350 of the cap body 346 and the nose end 138 of the needle base 122.

[0069] As can be seen in Figs. 4B and 4D, the surface 396 of the internal wall 382 preferably is not substantially planar. In one embodiment, it is preferred that the surface 396 includes a substantially centrally-located convex region 397 and an annular region 398 surrounding the convex region 397. Preferably, the convex region 397 protrudes toward an outer end 350 of the cap body 346 relative to the annular region 398. In particular, and as can be seen in Figs. 4B-4D, the convex region 397 is curved to define a convex arc, bulging toward the outer end 350.

[0070] The surface 396 is configured in this way to urge the blocking member 390 to move from the open position thereof to the blocking position. In addition, the surface 396 is configured to obstruct the blocking element, once in the blocking position, from returning to the open position. It will be understood that the blocking element 290 preferably has any suitable shape so that it is biased, at least partially due to the influence of gravity, to the blocking position. Preferably, the blocking member 390 is formed in a general diamond shape (e.g., a tetrahedron, or a bisphenoid), so that when in the open position, its ends "E" and "F" (Fig. 4D) engage the part of the convex region 397 around an opening 384 in the internal wall, and the part of an end wall 386 around an aperture 354 therein. However, the blocking element 390 is not held securely between the internal wall 382 and the end wall 386. Because the blocking element 390 has a general diamond shape and is positioned on its ends when in the open position, the blocking element 390 is unstable in this position. In particular, because the end "E" is engaged with a rounded part of the convex region 397, the blocking element 390 is unstable. Accordingly, when part of the tip segment 156 of the needle 124 is removed from the blocking element 390 (as will be described), the top end "E" of the blocking element 390 tends to slide off the convex region 397, to locate the blocking element 390 in the blocking position. [0071] In Fig. 4B, the cap body 346 is in the initial extended condition, ready for use.

As can be seen in Fig. 4B, the tip segment 156 includes a part 394 that is positioned in a portion of a channel 392 through the blocking element 390. In the same manner as described above, the part 394 of the needle 124 serves to hold the blocking element 390 in the open position prior to use.

[0072] When the user is ready to use the needle, the cap body 346 is moved relative to the needle in a first axial direction, indicated by arrow "A₂" in Fig. 4B, to the retracted condition (Fig. 4C). In this condition, part of the tip segment 156 extends beyond the outer end 350, ready for use in a selected procedure.

[0073] After use, the cap body 346 preferably is moved by the user in the second axial direction, indicated by arrow "B₂" in Fig. 4C, to the final extended condition (Fig. 4D). As can be seen in Fig. 4D, once the tip segment 156 is removed from the channel 392 (i.e., by movement of the blocking member 390 in the second axial direction), the blocking element 390 rotates or otherwise moves to the blocking position, in which the channel 392 is non- aligned with the opening 384 and the aperture 354. As described above, the advantage of the blocking element 390 being biased to the blocking position is that the tip segment 156 cannot again be extended beyond the outer end 350 after the cap body 346 has been moved to the final extended condition.

[0074] Another embodiment of the needle system 430 of the invention is illustrated in

Figs. 5A-5C. The needle system 430 includes an embodiment of a cap assembly 444 of the invention. It will be understood that the needle system 430 preferably also includes the needle assembly 110, described above. The cap assembly 444 preferably has a cap body 446 that includes one or more lock elements 401. As will be described, each of the lock elements 401 is activated upon the cap body 446 being positioned relative to the needle subassembly 114 of the needle system 430 in a secured condition, in which a tip segment 156 of the needle 124 is located in an inner chamber 452. A connector 458 preferably engages the lock element 401 to secure the needle subassembly 114 and the cap body 446 together when the lock element 401 is activated. The cap body 446 extends between an inner end 448 and an outer end 450. The cap body 446 preferably defines the inner chamber 452 between the outer end 450 and the nose end 138 of the needle base 122 (Fig. 5C). [0075] In one embodiment, the cap body 446 is configured to lock the tip segment

156 of the needle 124 in the inner chamber 452 upon the cap body 446 being positioned in the secured condition (Fig. 5C) relative to the needle subassembly 114 including the needle 124. As will be described, the cap body 446 is movable relative to the needle subassembly 114 in the second axial direction past the initial extended condition to the secured condition.

[0076] In Fig. 5A, the cap body 446 is shown in the initial extended condition. The cap body 446 is moved in the first axial direction relative to the needle 124 (indicated by arrow "A3" in Fig. 5A) to the retracted condition. After use, the cap body 446 is moved in the second axial direction relative to the needle 124 (indicated by arrow "B₃" in Fig. 5B) to the secured condition (Fig. 5C). As the cap body 446 is moved to the secured condition, the lock element 401 mounted on the cap body 446 is thereby moved in the second axial direction to position the lock element(s) 401 against the connector 458, thereby preventing subsequent movement of the cap body 446 in the first axial direction relative to the needle 124.

[0077] From the foregoing, it can be seen that, due to the lock elements 401, the needle system 430 enables the user to move the cap body 446 to the secured condition after use, thereby locking the contaminated tip segment 156 in a covered location to minimize the risk of an inadvertent needle stick.

[0078] Another alternative embodiment of the cap assembly 544 of the invention preferably is included in another embodiment of the needle system 530 of the invention. It will be understood that the needle system 530 also includes the needle assembly 1 10. As can be seen in Figs. 6A-6C, the cap assembly preferably includes one or more stop elements 503 for locating a predetermined length "L" of the tip segment 156 outside an outer end 550 of a cap body 546 when the cap body 546 is in the retracted condition. (It will be understood that the syringe 1 12 is omitted from Figs. 6A and 6B for clarity of illustration.)

[0079] The cap body 546 extends between an inner end 548 and an outer end 550.

Preferably, the cap body 546 defines an inner chamber 552 between the outer end 550 and the nose end 138 of the needle base 122 (Fig. 6A).

[0080] The cap body 546 is movable between an extended condition and a retracted condition, similar to the embodiments described above. The cap assembly 544 and the needle subassembly 114 are shown in Fig. 6A with the cap body 546 in the extended condition. When the cap body 546 is in the extended condition (Fig. 6A), the tip segment 156 is located in the inner chamber 552. When the cap body 546 is in the retracted condition (Fig. 6B), the tip segment 156 extends beyond the outer end 550.

[0081] In one embodiment, the stop element 503 preferably is configured for engagement with the needle base 122 to provide the predetermined length "L" of the tip segment 156 positioned beyond the outer end 550 when the cap body 546 is in the retracted condition. Those skilled in the art would appreciate that the stop element 503 may be supported for engagement with the nose end 138 in various ways. In one embodiment, as illustrated in Figs. 6A-6C, the stop element 503 preferably is mounted on an internal wall 582 of the cap assembly 544 that is located inside the cap body 546 and spaced apart from the outer end 550. Preferably, the stop element 503 includes a bore 504 therethrough to permit the stop element 503 to be moved past the tip element 156 as the cap body 546 is moved from the extended condition (Fig. 6A) to the retracted condition (Fig. 6B).

[0082] When the healthcare professional is ready to use the needle system 530, the cap body 546 is moved in the first axial direction (indicated by arrow "A₄" in Fig. 6A) to the retracted condition, illustrated in Fig. 6B. As can be seen in Fig. 6B, the stop element 503 prevents movement of the cap body 546 in the first axial direction once the cap body 546 is in the retracted condition, because the stop element 503 engages the nose end 138 of the needle base 122.

[0083] Those skilled in the art would appreciate that because certain procedures require that only a preselected length of the exposed tip element of the needle be inserted into the patient, the stop element 503 preferably may be used to ensure that only the required length of the tip segment 156 extends beyond the outer end 550. In practice, it is preferred that the stop element 503 in a particular needle system product is formed to permit a specific length of the tip segment to extend beyond the outer end 550. In this way, a number of such products may be provided, to enable the user to select the product that will provide the required length of exposed tip segment for a particular procedure.

[0084] Once the needle system has been used, the cap body 546 preferably is moved in the second axial direction (indicated by arrow "B4" in Fig. 6B), to return the cap body 546 to the extended condition (Fig. 6C), in which the tip segment 156 is located in the inner chamber 552. INDUSTRIAL APPLICABILITY

[0085] In use, an embodiment of a method of the invention preferably includes moving the cap body of the cap assembly of the needle system relative to the needle to locate the tip segment of the outer portion of the needle beyond the outer end of the cap assembly. Next, the patient's skin is pierced at a preselected position thereon with the end part of the tip segment. The end part is removed from the patient. The cap body preferably is moved relative to the needle to position the tip segment in an inner chamber at least partially defined by the cap body between the needle base and the outer end.

[0086] In another embodiment of the method of the invention, illustrated in Fig. 7, the cap body 146 preferably is moved relative to the needle 124 to locate the tip segment 156 of the outer portion 126 of the needle 124 beyond the outer end 150 of the cap assembly 144, as described above (Figs. 2C, 2D). As can been seen in Fig. 7, a finger 605 is positioned on the patient's skin 607 near a preselected position 609 thereon to engage the outer end 150, for positioning the tip segment 156 proximal to or at the preselected position 609. The patient's skin 607 is pierced at the preselected position 609 with the end part 128 of the tip segment 156, and the end part is thereafter removed from the patient "P". The cap body 146 is moved relative to the needle 124 to position the tip segment 156 in the inner chamber 152 at least partially defined by the cap body 146 between the needle base 122 and the outer end 150, as shown in Figs. 2C and 2D.

[0087] Various embodiments of the needle system of the invention are described herein. It will be understood that any of the embodiments of the needle system described herein, or combinations thereof, may be used with a user's finger and described and illustrated in Fig. 7 to locate the extended tip segment 156 relative to the predetermined position 609 on the patient's skin where the needle is to be inserted. As can be seen in Fig. 7, because the outer end 150 of the cap body 146 is relatively large compared to the tip segment's diameter, the healthcare professional can use his or her finger 605 to engage the outer end (i.e., the end wall), with minimal risk of the extended tip segment 1 6 accidentally being inserted into the finger 605.

[0088] Another embodiment of the needle system 730 is illustrated in Fig. 8, in which a cap assembly 744 preferably includes a resilient element 711 that biases a cap body 746 of the cap assembly to an extended condition thereof. (It will be understood that the cap body 746 as illustrated in Fig. 8 is between extended and retracted conditions thereof.)

[0089] Preferably, the resilient element 711 is a compression spring in the form of a coil spring. However, those skilled in the art would be aware that the resilient element may be provided in various suitable forms, and mounted relative to the cap body in any suitable manner. Any element that urges the cap body to the extended condition would be suitable. In one embodiment, and as shown in Fig. 8, the resilient element 71 1 preferably is mounted between a connector element 758 and an internal wall 782.

[0090] The advantage of the needle system 730 is that the cap body 746 tends to move, relative to the needle 124, to the extended condition, unless the cap body 746 is prevented from doing so. For example, after the needle 124 has been used, the user may allow the cap body 746 to move to the extended condition, so that the risk of an accidental needle stick with the contaminated tip segment 156 is thereby automatically minimized. In circumstances where the healthcare professional may have only one hand free after the needle has been used, this feature would be useful.

[0091 ] Another alternative embodiment of the needle system 830 is illustrated in Fig.

9. (It will be understood that the cap body as illustrated in Fig. 9 is between extended and retracted conditions thereof.) In this embodiment, the embodiment of the cap assembly 844 preferably includes a sleeve element 813 formed to assist the healthcare professional positioning the tip segment relative to the patient's skin surface (not shown in Fig. 9). For example, sleeve 813 as illustrated in Fig. 9 includes a contact surface for contacting the patient's skin surface, at an angle relative to the central axis (i.e., relative to the needle 124) identified as a relative to a substantially planar portion of the patient's skin surface. The contact surface 815 preferably is substantially planar. If, for instance, the needle tip is intended to be inserted at an angle of approximately 45° to the patient's skin surface, then the angle a is 45°. It can be seen from Fig. 9 that the sleeve 813 would facilitate the proper positioning of the needle system relative to the patient.

[0092] In one embodiment, the sleeve 813 is cylindrical and fits over an end region

817 of the cap body 846. Preferably, the sleeve 813 fits over the end region 817 of the cap body 846 in a sliding fit. It will be understood that the sleeve 813 as illustrated in Fig. 9 is shown spaced apart from the cap body 846 for clarity of illustration, and that the sleeve 813 preferably is slidingly engaged with the side of the cap body 846.

[0093] It will also be understood that the sleeve 813 preferably is positioned on the cap body 846 when the cap body 846 is in the initial extended condition. However, the sleeve 813 is used when the cap body 846 is in the retracted condition thereof (not shown in Fig. 9). When the cap body 813 is in the retracted condition, the sleeve 813 preferably is positioned on the end region 817 of the cap body 846, to assist the healthcare professional in maintaining a preselected insertion angle as the needle is inserted into the patient. In one embodiment, the contact surface 815 preferably includes an anti-slip covering that is configured for minimizing the risk of slippage of the needle system relative to the patient's skin once the contact surface 815 is engaged therewith. Preferably, the sleeve 813 is made of any suitable material that is transparent or translucent.

[0094] Those skilled in the art would appreciate that certain elements of the embodiments of the cap assembly of the invention described above may be used with others. For example, the stop element 503 may be included in the cap assembly that includes the blocking element, and also such cap assembly may include the internal wall that has the convex region formed thereon (illustrated in Figs. 4A-4E). Similarly, the lock elements 401 may be included in embodiments of the cap assembly that include other elements, e.g., the stop element 503 and the blocking element.

[0095] Accordingly, it would be appreciated by those skilled in the art that the invention can take many forms and that such forms are within the scope of the invention as claimed. The scope of the claims should not be limited by the preferred embodiments set forth in the examples, but should be given the broadest interpretation consistent with the description as a whole.

Claims

A needle system comprising: a needle assembly comprising: a syringe comprising a barrel extending between first and second ends thereof; a needle subassembly comprising: a needle base extending between a syringe end and a nose end thereof, the syringe end being secured to the first end of the barrel; an elongate needle comprising an embedded portion secured to the nose end of the needle base and an outer portion projecting from the nose end; a cap assembly comprising a cap body extending between inner and outer ends thereof; the cap body being connected with the needle assembly to permit relative movement between the needle and the cap body; the cap body defining an inner chamber between the outer end and the nose end of the needle base; and the outer end of the cap body comprising an aperture through which a tip segment of the outer portion of the needle is movable, to locate the tip segment beyond the outer end, and to permit the tip segment to be withdrawn through the aperture, to locate the tip segment of the outer portion in the inner chamber.

A needle system according to claim 1 in which the cap body is movable in a first axial direction relative to the needle in which the outer end of the cap body is moved toward the nose end of the needle base, and the cap body is movable in a second axial direction in which the outer end of the cap body is moved away from the nose end of the needle base.

3. A needle system according to claim 2 in which the cap body is movable in the first axial direction to a retracted condition, in which the tip segment is located beyond the outer end, and the cap body is movable in the second axial direction to an extended condition, in which the tip segment of the outer portion of the needle is located in the inner chamber.

4. A needle system according to claim 1 in which the cap assembly comprises a connector for connecting the needle assembly and the cap body.

5. A needle system according to claim 4 in which the cap body is slidably engaged with the connector.

6. A needle system according to claim 5 in which the connector is positioned between the needle base and the syringe and is substantially stationary relative to the needle base.

7. A needle system according to claim 1 in which the cap body additionally comprises an internal wall spaced apart from the outer end and comprising an opening therein substantially aligned with the aperture through which the tip segment of the needle is movable.

8. A needle system according to claim 7 in which the cap body additionally comprises: an end wall at the outer end, the end wall comprising the aperture; the end wall at least partially defining an end chamber of the cap assembly between the end wall and the internal wall; and in which the cap assembly additionally comprises: a blocking element at least partially located in the end chamber and movable between an open position, in which movement of the tip segment of the needle through the blocking element is permitted, and a blocking position, in which movement of the tip segment through the blocking element is prevented.

A needle system according to claim 8 in which the blocking element is biased blocking position.

10. A needle system according to claim 9 in which the internal wall comprises a surface engaged with the blocking element and configured to bias the blocking element to the blocking position.

11. A needle system according to claim 9 in which the cap body is configured to bias the blocking element to the blocking position.

12. A needle system according to claim 1 in which the cap assembly additionally comprises a blocking element comprising a channel therethrough, the blocking element being movable between an open position, in which the channel is substantially aligned with the aperture to permit the tip segment of the needle to be at least partially positioned in the channel, and a blocking position, in which the channel is non-aligned with the aperture, and the blocking element prevents movement of the tip segment into the channel.

13. A needle system according to claim 12 in which the blocking element is biased to the blocking position.

14. A needle system according to claim 4 in which the cap body additionally comprises at least one lock element activated upon the cap body being positioned relative to the needle subassembly in a secured condition, in which the tip segment of the outer portion of the needle is located in the inner chamber, the connector engaging said at least one lock element to secure the needle subassembly and the cap body together when said at least one lock element is activated.

15. A needle system according to claim 3 in which the cap body is configured to lock the tip segment in the inner chamber upon the cap body being positioned in a secured condition relative to the needle subassembly in which the tip segment is located in the inner chamber, the cap body being movable relative to the needle subassembly in the second axial direction past the extended condition to the secured condition.

16. A needle system according to claim 3 in which the cap assembly additionally comprises at least one stop element for locating a predetermined length of the tip segment outside the outer end of the cap body when the cap body is in the retracted condition.

17. A needle system according to claim 3 in which the cap assembly additionally comprises at least one stop element for engagement with the needle base to provide a predetermined length of the tip segment positioned beyond the outer end when the cap body is in the retracted condition.

18. A cap assembly for use with a needle assembly comprising a syringe and a needle subassembly secured to the syringe, the needle subassembly comprising a needle base and a needle secured in the base with an outer portion of the needle extending from the needle base, the cap assembly comprising: a cap body extending between inner and outer ends thereof; the cap body being engageable at the inner end thereof with the needle assembly to permit relative movement between the cap body and the needle; the cap body defining an inner chamber between the outer end and the needle base; and the outer end of the cap body comprising an aperture through which a tip segment of the outer portion of the needle is movable to locate the tip segment beyond the outer end, and to permit the tip segment to be withdrawn through the aperture, to locate the tip segment in the inner chamber.

19. A cap assembly according to claim 18 in which the cap body is movable in a first axial direction relative to the needle in which the outer end is moved toward the needle subassembly to a retracted condition, in which the tip segment is located beyond the outer end, and the cap body is movable in a second axial direction relative to the needle in which the outer end is moved away from the needle subassembly to an extended condition, in which the tip segment is located in the inner chamber.

20. A cap assembly according to claim 18 in which the cap assembly comprises a connector for connecting the needle assembly and the cap body.

21. A cap assembly according to claim 20 in which the cap body is slidably engaged with the connector.

22. A cap assembly according to claim 21 in which the connector is positioned between the needle base and the syringe and is substantially stationary relative to the needle base.

23. A cap assembly according to claim 18 in which the cap body additionally comprises an internal wall spaced apart from the outer end and comprising an opening therein substantially aligned with the aperture through which the tip segment is movable.

24. A cap assembly according to claim 23 in which the cap body additionally comprises: an end wall at the outer end, the end wall comprising the aperture; the end wall at least partially defining an end chamber of the cap assembly between the end wall and the internal wall; and in which the cap assembly additionally comprises: a blocking element at least partially located in the end chamber and movable between an open position, in which movement of the tip segment through the blocking element is permitted, and a blocking position, in which movement of the tip segment through the blocking element is prevented.

25. A cap assembly according to claim 18 in which the blocking element is biased to the blocking position.

26. A cap assembly according to claim 18 in which the internal wall comprises a surface engaged with the blocking element and configured to bias the blocking element to the blocking position.

27. A cap assembly according to claim 18 in which the cap body is configured to bias the blocking element to the blocking position.

28. A cap assembly according to claim 18 in which the cap body additionally comprises at least one lock element activated upon the cap body being positioned relative to the needle subassembly in a secured condition in which the tip segment is located in the inner chamber, the needle base engaging said at least one lock element to secure the needle subassembly and the cap body together when said at least one lock element is activated.

29. A cap assembly according to claim 19 in which the cap assembly additionally comprises at least one stop element for locating a predetermined length of the tip segment outside the outer end of the cap body when the cap body is in the retracted condition.

30. A method of using a needle system relative to a preselected position on a patient's skin surface, the needle system comprising a syringe and a needle subassembly secured to the syringe, the needle subassembly comprising a needle base and a needle having an outer portion extending from the needle base, the method comprising:

(a) moving a cap body of a cap assembly of the needle system relative to the needle to locate a tip segment of the outer portion of the needle beyond an outer end of the cap assembly;

(b) piercing the patient's skin at the preselected position with an end part of the tip segment;

(c) removing the end part from the patient; and

(d) moving the cap body relative to the needle to position the tip segment in an inner chamber at least partially defined by the cap body between the needle base and the outer end.