Fluid path with particle filter

Abstract

A fluid path (22) for delivering therapeutic substance (30) includes a body needle (28) and delivery tubing (32) having a needle-interface segment (36). An upstream portion (40) of the body needle is disposed within the needle-interface segment. A downstream portion (42) of the body needle is advanced into a body of the subject. A gap (45) is defined along the upstream portion between an inner wall (46) of the needle-interface segment and the upstream portion. A first segment (48) of the upstream portion is upstream of a second segment 50 and is closed such that the substance flows into the gap, which causes some particles to be filtered out of the substance. The second segment is perforated with holes (54) through which the substance enters the body needle. The holes are sized to filter out particles small enough to enter the gap. Other applications are also described.

Description

[0001] PARTICLE FILTER

[0002] CROSS REFERENCE TO RELATED APPLICATION

[0003] The present application claims the priority of US 63 / 739, 947 to Ben-David et al . , filed December 30 , 2024 , entitled "Particle filter, " and which is incorporated herein by reference .

[0004] FIELD OF THE INVENTION

[0005] The present invention relates generally to delivery of a therapeutic substance to a subj ect, and more specifically to wearable drug delivery devices .

[0006] BACKGROUND

[0007] Pumps and inj ectors are often used in the medical industry for delivering therapeutic substances , e . g . , drugs , to subj ects . Therapeutic substances such as saline solution, insulin, antibiotics , and chemotherapy drugs may all be delivered to a subj ect with medical pumps . While hospitalization is required for delivery of some therapeutic substances , other therapeutic substances , such as for example insulin, do not require that the subj ect be in the hospital . Wearable medical pumps and inj ectors enable patients to go about their daily lives while receiving a therapeutic substance .

[0008] US Patent Application Publication 2016 / 0262732 to Weisman et al . describes a biopsy needle having a first lumen open to a tissue penetrating distal tip of the needle for receiving a tissue sample therein and a second lumen in combination with a filter separating the first and second lumens from one another, the filter being configured to permit fluids to pass therethrough while preventing the sampled tissue from passing therethrough . Other applications are also described .US Patent 6, 241 , 710 to VanTassel et al . describes surgical needles with a porous distal portion from which a liquid inj ectate will weep or ooze multi-directionally under inj ection pressure while the porous distal portion of the needle is inserted into a body surface . The porous distal portion of the needle can be fabricated from a porous carbon, metal , ceramic or polymer and preferably has a decreasing gradient of impedance to fluid flowing to the point of the needle to compensate for the falling off of inj ection pressure as fluid moves towards the point . This is described as ensuring uni form weeping of the inj ectate along the inj ection course . The needle is adapted for attachment to a catheter or syringe . In another embodiment, a surgical assemblage is provided wherein a porous distal portion having similar fluid flow characteristics is located along the distal end of a catheter, and a needle point is attached to the distal end of the catheter ( e . g . , a steerable catheter) for piercing tissue . A guidance catheter can be used to direct the invention devices to a remote internal inj ection site . The patent describes that the invention devices and methods can be used to inj ect fluids ( including those containing nucleic acids for gene therapy) into interior body walls or tissue, such as a beating heart, without substantial loss of fluid and without substantial damage to tissue caused by inj ectate . Other applications are also described .

[0009] US Patent Application Publication 2008 / 0097353 to Carr describes a single in-line filter hollow needle that has an outer wall , a proximal end, a distal end with a pointed tip and a central opening between the ends for communicating fluids therethrough . The proximal end is secured to a Luer lock for removable connection to a syringe . A filter is located in the central opening proximate to the tip . The outer wall of the needle has a frangible deformation proximate to the filter and remote from the end of theneedle whereby the needle may be broken to expose a fresh point after fluid is aspirated through the needle to the syringe is filtered . Other applications are also described .

[0010] US Patent Application Publication 2022 / 0226568 to Oberg et al . describes embodiments of devices and methods to maintain preservative concentration in a medication delivered using a medical device . A barrier layer can be used to prevent migration of preservatives . A vent can be used to allow release of preservatives prior to delivery to the patient . An absorbent element can be used to maintain preservative concentration at a desired level . A filter can be used to capture particulates from the medication prior to delivery to a patient . Other applications are also described .

[0011] US Patent Application Publication 2023 / 0414865 to Zhao et al . describes a drug delivery device including a reservoir operable to contain a liquid drug, a fluid outlet including an outlet reservoir opening and an outlet fluid channel , wherein the outlet reservoir opening has a volume and is fluidly coupled to the outlet fluid channel , and an outlet filter plug operable to fill the volume of the outlet reservoir opening and collect particulate material as the liquid drug is expelled from the reservoir . Other applications are also described .

[0012] SUMMARY OF THE INVENTION

[0013] A fluid path is provided for delivering a therapeutic substance to a subj ect . For example, the fluid path may be used with a therapeutic substance delivery apparatus , such as a wearable medical patch pump and / or inj ector . Although the fluid path is typically manufactured in a clean room and sterilized, there is still the possibility of contamination particles , e . g . , visible and / or sub-visible particles entering the therapeutic substancepassing through the fluid path and being trans ferred to the subj ect via the therapeutic substance . As is generally known in the art, visible particles are particles that are larger than or equal to 100 microns , and sub-visible particles are particles smaller than 100 microns . For example, particles can enter the therapeutic substance from a therapeutic substance reservoir connected to the fluid path or from elements of the fluid path itsel f . Therapeutic substance reservoirs , e . g . , drug cartridges and vials , are often visually inspected for visible particulate contamination by pharmaceutical companies . However, in some cases visible particulate contamination may still be present in the therapeutic substance reservoir . Additionally, particles can become present in the fluid path during the manufacturing process or they can be generated during operation of a therapeutic substance delivery device connected to the fluid path due to mechanical action . In order to inhibit these particles from entering the patient, a particle filter is integrated into the fluid path .

[0014] Typically, the fluid path includes an access needle to a therapeutic substance reservoir, a body needle through which the therapeutic substance is delivered to the subj ect, and delivery tubing through which the therapeutic substance flows from the access needle to the body needle . For some applications , as further discussed hereinbelow, the particle filter is integrated into the body needle itself by an upstream portion of the body needle having a segment that is perforated with a plurality of discrete holes through which the therapeutic substance enters the body needle , the holes sized small enough to filter out particles that may be in the therapeutic substance . In order to force the therapeutic substance to enter the body needle through the discrete holes , an upstream end of the body needle is closed such that the therapeutic substance flows around the outside of the upstream endof the body needle and then enters the body needle through the plurality of discrete holes .

[0015] Typically, the upstream portion of the body needle is coupled to the delivery tubing by being disposed within a needle-interface segment of a downstream end of the delivery tubing . For some applications , the needle-interface segment and the body needle are dimensioned such that there is only a small gap along the upstream portion of the body needle between an inner wall of the needleinterface segment and the upstream portion of the body needle . Thus , when the therapeutic substance flows around the outside of the upstream end of the body needle (prior to entering the body needle via the plurality of discrete holes ) the therapeutic substance is forced to flow into the gap, whereby the size of the gap causes some particles to be filtered out of the therapeutic substance . This achieves a two-tiered particle filtering system whereby particles too big to enter the gap are filtered out when the therapeutic substance flows around the outside of the upstream end of the body needle , and particles small enough to enter the gap are filtered out of the therapeutic substance by the discrete holes .

[0016] There is therefore provided, in accordance with some applications of the present invention, apparatus for delivering a therapeutic substance to a subj ect, the apparatus including :

[0017] a fluid path for delivering the therapeutic substance to the subj ect, the fluid path including :

[0018] a body needle through which the therapeutic substance is delivered to the subj ect ; and

[0019] delivery tubing including a needle-interface segment at a downstream end of the delivery tubing,

[0020] wherein the body needle includes an upstream portion and a downstream portion, wherein :( i ) the body needle is disposed at the downstream end of the delivery tubing such that the upstream portion of the body needle is disposed within the needle-interface segment, the needle-interface segment and the body needle arranged such that a gap is defined along the upstream portion of the body needle between an inner wall of the needle-interface segment and the upstream portion of the body needle,

[0021] ( ii ) the downstream portion of the body needle is configured to be advanced into a body of the subj ect, and ( iii ) the upstream portion of the body needle is divided into a first segment and a second segment :

[0022] ( a) the first segment is upstream of the second segment,

[0023] (b) the first segment of the upstream portion is closed such that the therapeutic substance within the delivery tubing flows into the gap between the inner wall of the needle-interface segment and the upstream portion of the body needle, whereby the size of the gap causes some particles to be filtered out of the therapeutic substance, and

[0024] ( c) the second segment of the upstream portion is perforated with a plurality of discrete holes through which the therapeutic substance enters the body needle, each of the discrete holes sized such that particles small enough to enter the gap are filtered out of the therapeutic substance by the discrete holes .

[0025] For some applications , a width of the gap is 20 - 500 microns . For some applications , the size of the gap causes particles having a diameter larger than 20 - 500 microns to be filtered out of the therapeutic substance .For some applications , each of the discrete holes has a diameter of 0 . 5 - 20 microns .

[0026] For some applications , each of the discrete holes has a diameter of 20 - 50 microns .

[0027] For some applications , a length of the first segment of the upstream portion of the body needle is 0 . 5-20 mm.

[0028] For some applications , a length of the second segment of the upstream portion of the body needle is 0 . 5-20 mm.

[0029] For some applications , the second segment of the upstream portion is perforated with 10-1 , 000 discrete holes .

[0030] For some applications , at a plurality of locations along the second segment of the upstream portion of the body needle, 10-60% of the circumference of the body needle is occupied by the discrete holes .

[0031] For some applications , at least some of the plurality of discrete holes are spaced apart from each other by a distance of 0 .2-5 mm.

[0032] For some applications , an inner diameter of the body needle is 0 . 1-1 . 5 mm.

[0033] For some applications , an outer diameter of the body needle is 0 . 23-2 . 3 mm.

[0034] For some applications , the needle-interface segment is flexible .

[0035] For some applications , the fluid path includes a spacer disposed between the inner wall of the needle-interface segment and the upstream portion of the body needle at at least one radial location around the circumference of the body needle, the spacer arranged to separate the inner wall of the needle-interface segment from the upstream portion of the body needle .For some applications , the delivery tubing and the body needle are configured such that ( i ) when there is no therapeutic substance in the delivery tubing, the inner wall of the needle-interface segment is in contact with the upstream portion of the body needle, and ( ii ) flow of the therapeutic substance around the closed first segment of the upstream portion of the body needle causes the needle-interface segment to expand, thereby opening the gap between the inner wall of the needle-interface segment and the upstream portion of the body needle .

[0036] For some applications , the needle-interface segment is rigid . For some applications , the fluid path includes a spacer disposed between the inner wall of the needle-interface segment and the upstream portion of the body needle at at least one radial location around the circumference of the body needle, the spacer arranged to separate the inner wall of the needle-interface segment from the upstream portion of the body needle .

[0037] For some applications :

[0038] the apparatus includes two of the body needles , the two of the body needles comprising a first body needle disposed at the downstream end of the delivery tubing when the fluid path is packaged for commercial sale and a second body needle that is a replacement body needle for the first body needle, and

[0039] the first body needle is configured to be removed from the delivery tubing and replaced with the second body needle .

[0040] The present invention will be more fully understood from the following detailed description of applications thereof , taken together with the drawings , in which :

[0041] BRIEF DESCRIPTION OF THE DRAWINGSFig . 1 is a schematic illustration of a fluid path of a therapeutic substance delivery device, in accordance with some applications of the present invention;

[0042] Fig . 2 is a schematic illustration of a body needle of the therapeutic substance delivery device, in accordance with some applications of the present invention;

[0043] Figs . 3A-C depict a needle interface segment and an upstream portion of the body needle of Fig . 2 , in accordance with some applications of the present invention; and

[0044] Fig . 4 depicts the needle interface segment and upstream portion of the body needle of Fig . 2 , in accordance with some applications of the present invention .

[0045] DETAILED DESCRIPTION

[0046] Reference is now made to Fig . 1 , which is a schematic illustration of a fluid path 22 of a therapeutic substance delivery device 20 , in accordance with some applications of the present invention . Fluid path 22 is used for delivering a therapeutic substance to the subj ect . Typically, fluid path 22 includes an access needle 24 to a therapeutic substance reservoir 26, a body needle 28 through which the therapeutic substance is delivered to a subj ect 30 , and delivery tubing 32 through which the therapeutic substance flows from access needle 24 to body needle 28 . For some applications , delivery tubing 32 is split into an upstream tube 32a through which therapeutic substance flows from reservoir 26 to a pump chamber 34 , and a downstream tube 32b through which therapeutic substance flows from pump chamber 34 to body needle 28 . A needle-interface segment 36 of delivery tubing 32 is disposed at a downstream end 38 of the delivery tubing 32 . It is noted that while Fig . 1 shows therapeutic substance delivery device 20 as a pump or inj ector, this is for illustrative purposes onlyand is not limiting . For example, therapeutic substance delivery device 20 may be implemented as a syringe, or fluid path 22 may be configured for use with a therapeutic substance delivery device, e . g . , a fluid path set configured to be coupled to a therapeutic substance delivery device or a syringe .

[0047] Reference is now made to Fig . 2 , which is a schematic illustration of body needle 28 , in accordance with some applications of the present invention . For some applications , body needle 28 has an upstream portion 40 and a downstream portion 42 . Downstream portion 42 of body needle 28 is configured to be advanced into a body of subj ect 30 . As shown in the enlarged view circle 44 in Fig . 1 , body needle 28 is disposed at downstream end 38 of delivery tubing 32 such that upstream portion 40 of body needle 28 is disposed within needle-interface segment 36 of delivery tubing 32 . For some applications , needle-interface segment 36 is flexible . Alternatively, for some applications , needle-interface segment 36 is rigid .

[0048] Reference is now made to Figs . 3A-C, which depict needle interface segment 36 and upstream portion 40 of body needle 28 , in accordance with some applications of the present invention . For some applications , needle-interface segment 36 and body needle 28 are arranged such that a gap 45 is defined along upstream portion 40 of body needle 28 between an inner wall 46 of needle-interface segment 36 and upstream portion 40 of body needle 28 . Crosssection A--A of delivery tubing 32 shows upstream portion 40 of body needle 28 ( from a head-on view inside needle-interface segment 36 ) and gap 45 between inner wall 46 of needle-interface segment 36 and body upstream portion 40 of body needle 28 . Upstream portion 40 of body needle 28 is divided into a first segment 48 and a second segment 50 , first segment 48 being upstream of second segment 50 .First s egment 48 of upstream portion 40 i s closed ( e . g . , as shown , first segment 48 has no holes ) , such that the therapeutic substance within delivery tubing 32 flows into gap 45 between inner wall 4 6 of needle-interface segment 36 and ups tream portion 40 of body needle 28 , as illus trated by arrows 52 in Fig . 3B . Gap 45 functions as a first tier in the two-tiered filtering system described hereinabove , by the s i ze , i . e . , a width W, o f gap 45 causing some particl es to be f iltered out of the therapeutic substance as the therapeutic substance flows into gap 45 . For some applications , width W o f gap 45 i s at least 20 microns and / or les s than 500 microns . For some applications , the si ze of gap 45 cause s particle s having a diameter larger than 20 microns , e . g . , larger than 500 microns , to be f iltered out of the therapeutic substance .

[0049] The second ti er o f the two-tiered particle fi ltering i s achieved by second segment 50 of upstream portion 40 of body needle 28 being per forated with a plural ity of di screte hole s 54 , e . g . , at least 10 and / or l es s than 1 , 000 di screte hole s , through which the therapeutic substance enters body needle 28 . Each of the di screte holes i s si zed such that particl es small enough to enter gap 45 are fi ltered out o f the therapeutic substance by di screte holes 54 . As illustrated in Fi g . 3B , a downstream end 56 of needl e-interface segment 36 i s sealed around body needle 28 ( e . g . , with a sealant ( not shown ) ) , such that the therapeutic subs tance flowing through gap 45 i s forced to enter body needle 28 through holes 54 .

[0050] For some applications , each of the di s crete hol es has a diameter DI o f at least 0 . 5 microns and / or les s than 20 mi crons ( Fig . 3A) . Alternativel y, for some applications , each of the di screte holes has a di ameter of at leas t 20 microns and / or les s than 50 microns . For some applications , at a plurali ty o flocations along second segment 50 of upstream portion 40 of body needl e 28 , at least 10 % and / or les s than 60 % o f the circumference of body needle 28 i s occupied by di screte holes 54 , as illustrated by the cros s- s ection of second s egment 50 of body needle 28 in Fig . 3C . For some appli cations , at l east some o f di screte holes 54 are spaced apart from each other by a di s tance D2 of at least 0 . 2 mm and / or les s than 5 mm, such as i s illustrated in Fig . 3A .

[0051] For some applications , an inner di ameter D3 of body needle 28 i s at least 0 . 1 mm and / or l es s than 1 . 5 mm ( Fig . 3C ) . For some appli cations , an outer di ameter D4 of body needle 28 i s at l east 0 . 23 mm and / or l es s than 2 . 3 mm . For exampl e , the si ze of body needl e 28 may be at least 31G and / or les s than 14G .

[0052] For some applications , a l ength L I of first s egment 48 of upstream portion 40 of body needl e 28 , i . e . , the l ength along body needl e 28 that the therapeuti c substance f lows be fore entering body needle 28 through holes 54 , i s at least 0 . 5 mm and / or les s than 20 mm ( Fig . 3A) . For some applications , a length L2 of s econd segment 50 of upstream portion 40 of body needle 28 , i . e . , the length along body needl e 28 where there are hole s 54 , i s at least 0 . 5 mm and / or le s s than 20 mm . I t i s noted that lengths LI and L2 shown in Fig . 3A are for il lustration only and are not nece s saril y shown to scale . For example , the l engths of first segment 48 and second segment 50 in Fig . 3B are shown to a di f ferent scale than in Fi g . 3A, again for i llustration only .

[0053] Re ference i s now made to Fi g . 4 , which depicts needle inter face s egment 36 and ups tream portion 40 of body needle 28 , in accordance with some applications o f the present invention . Fi g .

[0054] 4 shows cros s- s ection A- -A of needl e-interface segment 36 and upstream portion 40 o f body needle 28 wi th the addition of a spacer 58 di spos ed between inner wal l 46 of needle-interf ace segment 36 and upstream portion 40 of body needle 28 at at least one radiallocation around the circumference of body needle 28 . Spacer 58 is arranged to separate inner wall 46 of needle-interface segment 36 from upstream portion 40 of body needle 28 . It is noted that spacer 58 may be utilized when needle-interface segment 36 is flexible or rigid .

[0055] Alternatively, for some applications , when there is no therapeutic substance in delivery tubing 32 , inner wall 46 of needle-interface segment 36 is in contact with upstream portion 40 of body needle 28 , and flow of the therapeutic substance around sealed first segment 48 of upstream portion 40 of body needle 28 , e . g . , flow shown in Fig . 3B by arrows 52 , causes needle-interface segment 36 to expand, thereby opening gap 45 between inner wall 46 of needle-interface segment 36 and upstream portion 40 of body needle 28 . It is noted that when needle-interface segment 36 is flexible and there is no spacer disposed between inner wall 46 of needle-interface segment 36 and upstream portion 40 of body needle 28 , then the width W of gap 45 may be uneven along the length of gap 45 .

[0056] For some applications , the apparatus includes two or more of body needle 28 . For example , the two body needles 28 include a first body needle 28 that is disposed at the downstream end of the delivery tubing when the fluid path is packaged for commercial sale and a second replacement body needle 28 or a plurality of replacement body needles 28 . The first body needle is configured to be removed from delivery tubing 32 and replaced with the second body needle 28 . For example, if holes 54 in second segment 50 of upstream portion 40 of the first body needle 28 become clogged, then first body needle 28 can be removed from delivery tubing 32 and replaced with a new body needle 28 .

[0057] For some applications , when fluid path 22 is integrated into a therapeutic substance delivery device, or coupled to atherapeutic substance delivery device, alternatively or additionally to body needle 28 having an upstream portion with a segment perforated with discrete holes that act as a filter for particles in the therapeutic substance, access needle 24 of reservoir 26 may have a downstream portion with a segment perforated with discrete holes that act as a filter for particles that may be present in therapeutic substance reservoir 26. It is noted that all features described hereinabove with respect to needle-interface segment 36 and upstream portion 40 of body needle 28 may apply, mutatis mutandis , to access needle 24 and a needleinterface segment 60 ( Fig . 1 ) of delivery tubing 32 , e . g . , of upstream tube 32a, that surrounds a downstream portion of access needle 24 . For these applications , the therapeutic substance flows through access needle 24 , and into the delivery tubing via the holes , such that particles within the therapeutic substance remain within access needle 24 rather than being conveyed to the patient .

[0058] It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described hereinabove . Rather, the scope of the present invention includes both combinations and subcombinations of the various features described hereinabove, as well as variations and modifications thereof that are not in the prior art, which would occur to persons skilled in the art upon reading the foregoing description .

Claims

1. CLAIMS1 . Apparatus for delivering a therapeutic substance to a subj ect, the apparatus comprising :a fluid path for delivering the therapeutic substance to the subj ect, the fluid path comprising :a body needle through which the therapeutic substance is delivered to the subj ect ; anddelivery tubing comprising a needle-interface segment at a downstream end of the delivery tubing,wherein the body needle comprises an upstream portion and a downstream portion, wherein :( i ) the body needle is disposed at the downstream end of the delivery tubing such that the upstream portion of the body needle is disposed within the needle-interface segment, the needle-interface segment and the body needle arranged such that a gap is defined along the upstream portion of the body needle between an inner wall of the needle-interface segment and the upstream portion of the body needle,( ii ) the downstream portion of the body needle is configured to be advanced into a body of the subj ect, and ( iii ) the upstream portion of the body needle is divided into a first segment and a second segment :( a) the first segment is upstream of the second segment,(b) the first segment of the upstream portion is closed such that the therapeutic substance within the delivery tubing flows into the gap between the inner wall of the needle-interface segment and the upstream portion of the body needle, whereby the si ze of the gap causes some particles to be filtered out of the therapeutic substance, and( c) the second segment of the upstream portion is perforated with a plurality of discrete holes through which the therapeutic substance enters the body needle , each of the discrete holes sized such that particles small enough to enter the gap are filtered out of the therapeutic substance by the discrete holes .2 . The apparatus according to claim 1 , wherein a width of the gap is 20 - 500 microns .3 . The apparatus according to any one of claims 1-2 , wherein the size of the gap causes particles having a diameter larger than 20 - 500 microns to be filtered out of the therapeutic substance . 4 . The apparatus according to any one of claims 1-3 , wherein each of the discrete holes has a diameter of 0 . 5 - 20 microns . 5 . The apparatus according to any one of claims 1-3 , wherein each of the discrete holes has a diameter of 20 - 50 microns .

6. The apparatus according to any one of claims 1-5 , wherein a length of the first segment of the upstream portion of the body needle is 0 . 5-20 mm.7 . The apparatus according to any one of claims 1- 6, wherein a length of the second segment of the upstream portion of the body needle is 0 . 5-20 mm.8 . The apparatus according to any one of claims 1-7 , wherein the second segment of the upstream portion is perforated with 10-1 , 000 discrete holes .

9. The apparatus according to any one of claims 1-8 , wherein at a plurality of locations along the second segment of the upstream portion of the body needle, 10-60% of the circumference of the body needle is occupied by the discrete holes .10 . The apparatus according to any one of claims 1-9, wherein at least some of the plurality of discrete holes are spaced apart from each other by a distance of 0 . 2-5 mm.11 . The apparatus according to any one of claims 1-10 , wherein an inner diameter of the body needle is 0 . 1-1 . 5 mm.12 . The apparatus according to any one of claims 1-11 , wherein an outer diameter of the body needle is 0 .23-2 . 3 mm.13 . The apparatus according to any one of claims 1-12 , wherein the needle-interface segment is flexible .14 . The apparatus according to claim 13 , wherein the fluid path comprises a spacer disposed between the inner wall of the needleinterface segment and the upstream portion of the body needle at at least one radial location around the circumference of the body needle, the spacer arranged to separate the inner wall of the needle-interface segment from the upstream portion of the body needle .15 . The apparatus according to claim 13 , wherein the delivery tubing and the body needle are configured such that ( i ) when there is no therapeutic substance in the delivery tubing, the inner wall of the needle-interface segment is in contact with the upstream portion of the body needle , and ( ii ) flow of the therapeutic substance around the closed first segment of the upstream portion of the body needle causes the needle-interface segment to expand, thereby opening the gap between the inner wall of the needleinterface segment and the upstream portion of the body needle .

16. The apparatus according to any one of claims 1-12 , wherein the needle-interface segment is rigid .17 . The apparatus according to claim 16 , wherein the fluid path comprises a spacer disposed between the inner wall of the needleinterface segment and the upstream portion of the body needle atat least one radial location around the circumference of the body needle, the spacer arranged to separate the inner wall of the needle-interface segment from the upstream portion of the body needle .18 . The apparatus according to any one of claims 1-17 , wherein :the apparatus comprises two of the body needles , the two of the body needles comprising a first body needle disposed at the downstream end of the delivery tubing when the fluid path is packaged for commercial sale and a second body needle that is a replacement body needle for the first body needle, andthe first body needle is configured to be removed from the delivery tubing and replaced with the second body needle .

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