Flexible Needle

Abstract

The exemplary needle (100) defines a lumen (110) and includes a proximal portion (120) and a distal portion (130). The proximal portion defines a first port (112) of the lumen and the distal portion defines at least one second port (113) of the lumen, the lumen extending between and connecting the first port and the at least one second port. The distal portion also defines a tip portion (140) configured for insertion into a patient's skin. In certain embodiments, the distal portion includes a compressible region (150) including at least one slit (152). In certain embodiments, the distal portion includes an aperture (164) and a ramp (162) configured to bias patient tissue within the distal portion toward the aperture upon insertion of the distal portion into the patient tissue. In certain embodiments, the needle is formed of Nitinol.

Description

[Technical field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates generally to needles and more particularly, but not exclusively, to flexible needles configured for use in injection devices. [Background technology]

[0002] Many current injection devices utilize soft cannulas and require a stiff needle for insertion into patient tissue. The insertion needle can increase pain and tissue trauma associated with the insertion due to the difference in size between the needle and the cannula. More specifically, by providing a soft cannula around the needle, the wound caused by the needle is too small for the soft cannula. Thus, the cannula typically must be forced through a smaller hole, causing more pain to the patient. Furthermore, many soft cannulas do not tolerate kinking well and may stop the flow of therapeutic agent. On the other hand, when injections are performed using conventional needles, the tip of the stiff needle may engage adjacent tissue during patient movement, exacerbating the wound and causing additional trauma to the patient. For these reasons, among others, there is still a need for further improvements in this field of technology. Summary of the Invention [Means for solving the problem]

[0003] An exemplary needle defines a lumen and includes a proximal portion and a distal portion. The proximal portion defines a first port of the lumen and the distal portion defines at least one second port of the lumen, the lumen extending between and connecting the first port and the at least one second port. The distal portion also defines a tip portion configured for insertion into the skin of a patient. In certain embodiments, the distal portion includes a compressible region including at least one slit. In certain embodiments, the distal portion includes an opening and a ramp configured to bias patient tissue within the distal portion toward the opening upon insertion of the distal portion into the patient tissue. In certain embodiments, the needle is formed of Nitinol. Further embodiments, forms, features, and aspects of the present application will become apparent from the description and drawings provided herein. [Brief description of the drawings]

[0004] [Figure 1] FIG. 2 is a first perspective view of a flexible needle according to certain embodiments. [Diagram 2] FIG. 2 is a second perspective view of the flexible needle. [Diagram 3] 1 shows a distal portion of a flexible needle with a compressible region in an expanded state. [Figure 4] 1 shows a distal portion of a flexible needle with a compressible region in a compressed state. [Diagram 5] FIG. 2 is a perspective view of the tip of a flexible needle. [Figure 6] FIG. 2 is a cross-sectional view of the tip portion of a flexible needle. [Figure 7] 1 is a graph illustrating certain properties of Nitinol. [Figure 8] 1 is a stress-strain diagram comparing certain properties of an illustrative flexible needle with a conventional needle. [Figure 9] 1 is a graph showing martensite start temperature versus nickel / titanium ratio for Nitinol. [Figure 10] 1 illustrates a distal portion of a needle according to certain embodiments. [Figure 11]1 is a graph illustrating certain characteristics of needles according to certain embodiments compared to conventional cannulas. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0005] While the concepts of the present disclosure are susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and are herein described in detail, It is to be understood, however, that it is not intended to limit the concepts of the present disclosure to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives consistent with the disclosure and the appended claims.

[0006] References herein to "one embodiment," "embodiment," "exemplary embodiment," and the like, indicate that the described embodiment may include a particular feature, structure, or characteristic, but that all embodiments may or may not include the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. Furthermore, references to "preferred" components or features may indicate the desirability of a particular component or feature with respect to an embodiment, but it should be understood that the present disclosure is not so limited with respect to other embodiments that may omit such components or features. Moreover, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is believed to be within the knowledge of one of ordinary skill in the art to implement such feature, structure, or characteristic in connection with other embodiments, whether or not expressly described.

[0007] Additionally, it should be understood that an item listed in the format "at least one of A, B, and C" can mean (A), (B), (C), (A and B), (B and C), (A and C), or (A, B and C). Similarly, an item listed in the format "at least one of A, B, or C" can mean (A), (B), (C), (A and B), (B and C), (A and C), or (A, B and C). An item listed in the format "A, B, and / or C" can also mean (A), (B), (C), (A and B), (B and C), (A and C), or (A, B and C). Additionally, with respect to the claims, the use of phrases such as "a," "an," "at least one," and / or "at least a portion," should not be construed as limiting only those elements, unless specifically stated to the contrary, and the use of phrases such as "at least a portion" and / or "a portion," should be construed as encompassing both embodiments including only a portion of such elements and embodiments including such elements in their entirety, unless specifically stated to the contrary.

[0008] In the figures, some structural or method features may be shown in a certain arrangement and / or order. However, it should be understood that such a specific arrangement and / or order may not necessarily be required. Rather, in some embodiments, such features may be arranged in a different manner and / or order than that shown in the exemplary figures, unless specifically indicated to the contrary. Furthermore, the inclusion of a structural or method feature in a particular figure does not imply that such feature is required in all embodiments, and in some embodiments, it may be omitted or combined with other features.

[0009] 1 and 2, a flexible needle 100 is shown according to certain embodiments. The needle 100 defines a lumen 110 and generally includes a proximal portion 120 and a distal portion 130. The distal portion 130 includes a tip portion 140 and may further include one or both of a distal compressible region 150 and / or a tab 160. In certain configurations, the proximal portion 120 includes a proximal compressible region 170 and a sheath 180 that covers the compressible region 170. In the illustrated configuration, the needle 100 is configured for use with an injection device, with the proximal portion 120 mounted within the injection device and the injection device operable to insert the distal portion 130 into patient tissue.

[0010] The needle 100 has an exterior surface 102 and an interior surface 104, the interior surface 104 at least partially defining a lumen 110. It has been found desirable for the exterior surface 102 and the interior surface 104 to have different hydrophobic / hydrophilic properties. More specifically, it has been found desirable for the exterior surface 102 to be more hydrophilic while the interior surface 104 is more hydrophobic. It has been found that a relatively hydrophilic exterior surface 102 can aid in adhesion to tissue, and human tissue is more receptive to the presence of inert foreign bodies if its surface is hydrophilic. A relatively hydrophobic interior surface 104 can aid in the dispersion of a therapeutic agent by preventing the therapeutic agent from adhering to the interior surface 104. In certain embodiments, one or both of the exterior surface 102 and / or the interior surface 104 may include a surface treatment that alters the hydrophobic / hydrophilic properties of the surface. Such surface treatments may include, for example, the use of chemical treatments, electrochemical treatments, polishing, diamond, etching, and / or coatings.

[0011] In certain embodiments, such as those in which needle 100 is formed of Nitinol, at least one surface treatment may include exposing exterior surface 102 to ultraviolet light while leaving interior surface 104 unexposed to ultraviolet light. Such treatment reduces the contact angle of exterior surface 102 to a relatively low contact angle (e.g., about 20°) while the contact angle of interior surface 104 remains relatively high (e.g., about 80°).

[0012] The lumen 110 includes a first port 112 defined by a proximal portion 120 and at least one second port 113 defined by a distal portion 130. In use, a therapeutic agent (e.g., insulin or a chemotherapy agent) is provided to the lumen 110 via the first port 112 and flows through the lumen 110 for release into the patient tissue via the at least one second port 113. Thus, the first port 112 may be referred to herein as an inlet 112 and the second port 113 may be referred to as an outlet 113. Although the needle 100 is described herein with particular reference to an injection device, it should be understood that the needle 100 may be utilized to withdraw fluid from the patient tissue. In such a case, the first port 112 may be an outlet and one or more of the second ports 113 may be an inlet. As described herein, the illustrated needle 100 includes multiple second ports 113 that facilitate distribution of the therapeutic agent to the patient tissue.

[0013] In the illustrated configuration, the proximal portion 120 is configured to mount within an injection device and provide sufficient rigidity to enable a force acting on the proximal portion 120 to be utilized to push the distal portion 130 into patient tissue. In certain configurations, the proximal portion 120 can include an attachment mechanism 122 that facilitates coupling of the proximal portion 120 to an injection device and can orient the needle 100 in a particular orientation to facilitate proper orientation of the tip portion 140 entering the patient tissue. As described herein, the illustrated proximal portion 120 also includes a compressible region 170 that includes a number of slits 172, and a sheath 180 covers the compressible region 170 to prevent fluid from leaking through the slits 172. It is also contemplated that the compressible region 170 and sheath 180 may be omitted in certain embodiments.

[0014] Distal portion 130 extends along a distal portion longitudinal axis 131 and includes a tip portion 140 that is configured for insertion into patient tissue and that facilitates such insertion as described herein. Distal portion 130 can further include one or both of compressible regions 150 and / or tabs 160, the functions of which are described herein.

[0015] 3, the tip portion 140 extends along a longitudinal axis 141 of the tip portion and includes at least one sharpened tip 142 to facilitate insertion into patient tissue, and in the illustrated embodiment includes a plurality of sharpened tips 142 spaced apart by recesses 144. More specifically, the illustrated tip portion 140 includes a pair of sharpened tips 142 positioned diametrically opposite one another relative to the longitudinal axis 141 of the tip portion, with a first transverse axis 146 extending between the tips 142 and a second transverse axis 148 extending between the recesses 144. The first transverse axis 146 and the second transverse axis 148 are transverse to one another and to the longitudinal axis 141, and in the illustrated embodiment, the axes 141, 146, 148 are mutually orthogonal.

[0016] While the illustrated tip portion 140 includes a pair of tips 142, it is envisioned that the tip portion 140 may include more sharpened tips 142. For example, the tip portion 140 may include three sharpened tips spaced about 120° apart from one another relative to the longitudinal axis 141. In the illustrated form, the tip portion 140 is an open tip portion that defines at least one of the second ports 113. For example, in embodiments in which one or more second ports 113 are formed in the compressible region 150, it is also envisioned that the tip portion 140 may be a closed tip portion that does not define a port in the lumen 110.

[0017] As discussed above, the illustrated tip portion 140 includes multiple sharpened tips 142. In alternative embodiments, the tip portion 140 may include a single sharpened tip 142. However, it has been found that providing multiple tips 142 can provide more stability to the needle 100 during insertion. For example, in embodiments having a single tip 142, insertion of the tip portion 140 can result in the generation of forces transverse to the insertion axis, which can cause the needle 100 to bend from the desired insertion angle. However, when multiple tips 142 are provided that taper towards the recess 144, the generation of such bending moments can be reduced or prevented.

[0018] 4, the compressible region 150 includes at least one slit 152, with each slit 152 defining a corresponding one of the second ports 113. In the illustrated form, the compressible region 150 comprises a plurality of individual slits 152, with the remaining material forming a serpentine structure 154. More specifically, the slits 152 extend transversely to the longitudinal axis 131 of the distal portion, and in the illustrated form, extend generally perpendicular to the longitudinal axis 131 of the distal portion. In addition to or as an alternative to extending transversely to the longitudinal axis 131, one or more slits 152 may extend in the direction of the longitudinal axis 131. By way of example, the compressible region 150 may include one or more spiral slits.

[0019] As discussed above, the illustrated compressible region 150 includes a serpentine structure 154 defined at least in part by a plurality of slits 152. The serpentine structure 154 includes a transverse section 155 extending transversely to the longitudinal axis 131 and a longitudinal connecting portion 156 extending in the direction of the longitudinal axis 131. In the illustrated configuration, the connecting portions 156 are positioned on either side of the longitudinal axis 131 such that the compressible region 150 provides greater flexibility in one direction transverse to the longitudinal axis 131 than in another direction transverse to the longitudinal axis 131. Although other configurations are envisioned, the illustrated connecting portions 156 are aligned with the tip portions 142 such that the compressible region 150 is more flexible in a direction defined by a first transverse axis 146 (i.e., an axis extending between the tips 142) and less flexible in a direction defined by a second transverse axis 148 (i.e., an axis extending between the recesses 144). Such selective flexibility can assist in guiding distal portion 130 during insertion into patient tissue.

[0020] In the illustrated embodiment, the slits 152 are positioned to provide compressible region 150 with varying degrees of flexibility in different directions transverse to longitudinal axis 131. It is also envisioned that slits 152 may be positioned to provide uniform flexibility in different directions transverse to longitudinal axis 131. For example, an array of ten slits equally spaced apart about longitudinal axis 131 may provide uniform flexibility in all directions transverse to longitudinal axis 131. However, providing less flexibility along certain directions may facilitate insertion of needle 100, as discussed above.

[0021] The compressible region 150 of the distal portion 130 is operable to transition between an extended state ( FIG. 3 ) and a compressed state ( FIG. 4 ). More specifically, upon insertion of the distal portion 130 into patient tissue, the serpentine structure 154 at least partially collapses, thereby at least partially closing one or more slits 152 as the compressible region 150 is in a compressed state. When such compressed, the stiffness of the compressible region 150 increases, thereby facilitating further insertion of the distal portion 130 into tissue. When the insertion force is removed and / or reversed, the compressible region 150 returns to its extended state, thereby at least partially opening the slits 152 and the second port 113 defined thereby. As a result, the therapeutic agent is operable to flow through the port 113 defined by the slits 152, thereby increasing the diffusion area of ​​the therapeutic agent into the patient tissue.

[0022] In addition to facilitating the distribution of therapeutic agent into the patient tissue, the compressible region 150 helps prevent the tip portion 140 from causing excessive damage to the patient tissue. When a conventional stiff needle is inserted into patient tissue, various types of forces (e.g., movement of the patient or a device attached to the needle) can cause the tip of the stiff needle to penetrate unexplored tissue or scrape against surrounding tissue. However, the compressible region 150 can at least partially absorb these forces, thereby preventing the sharpened tip 142 from causing further damage to the patient tissue.

[0023] 5 and 6, the illustrated tab 160 is cut from the outer wall of the distal portion 130 with a proximal end 161 of the tab 160 remaining connected to the remainder of the distal portion 130. The tab 160 defines a ramp 162 that is deformed into the interior of the needle 100 to at least partially occlude the lumen 110 and result in an opening 164 defined in the space previously occupied by the tab 160. In certain configurations, the tab 160 may include one or more slits 166 that increase the flexibility of the tab 160 and / or facilitate flow of therapeutic agent through the ramp 164. Additionally or alternatively, a distal tip 168 of the tab 160 is received within a slot 169 formed opposite the opening 164 to at least selectively retain the tab 160 in its angled position.

[0024] During insertion of the tip portion 140 into patient tissue, plugs of patient tissue may enter the port 113 defined by the tip portion 140 in a manner similar to that which occurs during a traditional biopsy procedure. One skilled in the art will readily recognize that such tissue plugs, particularly tissue plugs including dermal tissue, may occlude the lumen 110 and prevent the flow of therapeutic agents to the patient tissue. The tab 160 may assist in removing such plugs by causing the dermal tissue to ride along the ramp 162 upon insertion of the distal portion 130 into the patient tissue, such that the dermal plug may exit the lumen 110 via the opening 164. Although the illustrated tab 160 is provided on a flexible needle 100, it is envisioned that the ramps and openings, as described in connection with the tab 160, may find use in other forms of needles, such as rigid needles.

[0025] The proximal compressible region 170 is substantially similar to the distal compressible region 150 and generally includes one or more slits 172 that allow the proximal compressible region 170 to expand and compress in a manner similar to that described above with respect to the distal compressible region 150. Thus, similar to the distal compressible region 150, the proximal compressible region 170 can absorb forces to assist in preventing the tip portion 140 from causing further damage to the patient tissue.

[0026] Those skilled in the art will readily recognize that the slits 172 in the proximal compressible region 170 can provide a passageway through which therapeutic agent can exit the portion of the needle 100 that is internal to the injection device, which is generally undesirable. To prevent such leakage, the proximal portion 120 may be provided with a sheath 180 that covers the proximal compressible region 170 to prevent fluid from exiting the slits 172 in the compressible region 170. The sheath 180 can be provided of a material suitable for sealing the compressible region 170, such as, for example, a soft polymer, polyurethane, or elastomer.

[0027] It is apparent from the above that the compressible regions 150, 170 can provide one or more advantages to the needle 100. For example, the compressible regions 150 / 170 can be stacked during insertion, as shown in FIG. 4, to form a rigid, pushable, compact structure. Once the needle 100 is positioned at a desired location in tissue, the force can be removed by a built-in expansion force caused by the serpentine structure 154 / 174 or by a small active rearward unloading of the needle 100. In the distal compressible region 150, this can open the slits 152 to act as an array of ports or outlets 113 and as a pathway for therapeutic agents to reach the patient tissue over a large contact area. Additionally, the compressible regions 150, 170 can act as a damping mechanism to retard or absorb motion imparted by the motion of the injection device, thereby preventing or reducing undesired movement of the sharp needle tip 142 in the tissue during the procedure.

[0028] As noted above, the illustrated needle 100 is a flexible needle, being flexible at least in the compressible regions 150, 170. In certain embodiments, the needle 100 may also be flexible in regions other than the compressible regions 150, 170. To provide such flexibility, the needle 100 may be formed, for example, from a superelastic material. In the illustrated form, the needle 100 is formed from Nitinol, which is at least primarily austenitic at body temperature (approximately 37° C.).

[0029] With further reference to FIG. 7, a graph is shown illustrating the behavior of Nitinol upon heating and cooling. At relatively low temperatures, Nitinol is fully martensite. When Nitinol is heated above its austenite start temperature, As, it transitions to the austenite phase, and above its austenite finish temperature, Af, Nitinol is fully austenitic. When Nitinol is cooled from the fully austenitic phase, above its martensite start temperature, Ms, it transitions to the martensite phase, and below its martensite finish temperature, Mf, Nitinol is fully martensite.

[0030] One property of Nitinol that may be advantageous for certain implementations of needle 100 is the superelasticity of austenitic Nitinol. More specifically, when Nitinol is nearly fully austenitic (e.g., greater than 95% austenitic), Nitinol exhibits a relatively large superelastic range. This superelasticity allows Nitinol to be elastically deformed through a relatively wide range of stresses, such that needle 100 formed of Nitinol can bend elastically without incurring permanent deformation in needle 100.

[0031] 8, a stress-strain diagram is shown comparing the behavior of a needle formed from 316 stainless steel with a needle 100 formed from Nitinol. As can be seen, the Nitinol needle 100 has a wide range of elastic deformation and does not significantly increase the stress in the needle as the strain increases. In the illustrated configuration, the stress begins to rise at a strain of about 8%. Thus, in order for the needle 100 to remain within its elastic deformation range, it would be desirable to keep the strain associated with the needle 100 below about 6%.

[0032] From the above, it is apparent that needle 100 formed from superelastic Nitinol can exhibit greater flexibility than similarly constructed needles formed from more traditional materials, such as, for example, stainless steel. Those skilled in the art will also readily appreciate that the extent of superelasticity for a particular formulation of Nitinol is highly dependent on its nickel / titanium ratio. As described herein, certain embodiments of needle 100 can be formed from Nitinol alloys with nickel / titanium ratios specifically selected to impart particular properties to needle 100.

[0033] As discussed above, a reduction in the austenite fraction of Nitinol can occur when Nitinol is cooled below its martensite start temperature, Ms, which correlates with the nickel / titanium ratio of Nitinol. This correlation is shown in Figure 9. With this knowledge, one skilled in the art will readily appreciate that a particular martensite start temperature, Ms, can be achieved by providing Nitinol with an appropriately selected nickel / titanium ratio.

[0034] As discussed above, certain embodiments of the needle 100 are specifically configured for use with an injection device. Those skilled in the art will readily recognize that such an injection device can be worn by a patient, with at least a portion of the distal portion 130 remaining embedded in the patient's soft tissue. Due to the superelastic properties of austenitic nitinol and / or the provision of one or more compressible regions 150, 170, the needle 100 can reduce tissue damage by remaining flexible as discussed above. However, as the proportion of martensite in the distal portion 130 begins to increase, the distal portion 130 is exposed to stress and undergoes plastic deformation, resulting in irregular and uncontrollable shape changes. This can cause tissue damage for reasons similar to those discussed above with respect to stiff needles. Although the patient's body temperature can help maintain the nitinol in the austenitic phase, certain embodiments of the needle 100 can be embedded in tissue to a relatively low insertion depth, such as about 3 mm to about 4 mm. Thus, if the martensite start temperature Ms is too high, the lower temperatures experienced by the patient may cause the nitinol to transition to the martensite phase. Thus, in certain embodiments, the needle 100 may be formed from a nitinol alloy selected to remain nearly completely austenitic (e.g., at least 95% austenite) at the temperatures that will be experienced by the patient, thereby reducing the risk of the needle 100 becoming martensite.

[0035] In certain embodiments, the Nitinol can be selected such that the Nitinol exhibits selected properties for a particular temperature. In certain embodiments, the particular temperature may be a temperature below 10° C., a temperature below 0° C., a temperature below −10° C., and / or a temperature below −20° C. In certain embodiments, the Nitinol can be configured to maintain at least 95% austenite at a particular temperature. In certain embodiments, the Nitinol can be configured to maintain at least 95% austenite when cooled to a particular temperature from a temperature at which the Nitinol is fully austenitic. In certain embodiments, the martensite start temperature may be a particular temperature. In certain embodiments, the nickel / titanium ratio of the Nitinol can be selected to provide the Nitinol with one or more selected properties. In certain embodiments, the Nitinol has an atomic ratio of nickel to titanium between 1.01 and 1.05. In certain embodiments, the Nitinol has an atomic ratio of nickel to titanium between 1.02 and 1.04.

[0036] The superelasticity of the needle 100 can facilitate its use in injection devices, among other applications. For example, due to the superelasticity and flexibility provided by the concepts described herein, the needle 100 can change its geometry from circular (e.g., for storage in an injection device) to straight (e.g., for insertion into patient tissue), or vice versa, by loading or unloading a force on the needle 100. This allows the needle 100 to be advanced for insertion into soft tissue, or coiled into the housing of the injection device for transport back into the housing after use. This feature allows the needle 100 to require minimal volumetric space occupation during transport or storage, and further allows the needle 100 to momentarily form a straight line as it exits the housing and enters the soft tissue, while coiling upon retraction after use. This helps ensure that the patient never sees the needle 100, and prevents healthcare providers from being exposed to a sharp, unprotected needle. In certain configurations, the insertion device can be configured such that the strain experienced by the needle 100 during insertion and retraction remains less than 6%.

[0037] 10, a distal portion 230 of a needle 200 is shown according to certain embodiments. The needle 200 is substantially similar to the needle 100 described above, and like reference numbers are used to indicate like elements and features. For example, the needle 200 includes a lumen 210 that corresponds to the lumen 110 described above, and the distal portion 230 includes a tip portion 240 and a tab 260 that correspond to the tip portion 140 and tab 160 described above. The proximal end of the needle 200 may be substantially similar to the proximal end 120 of the needle 100 described above. For brevity, the following description of the needle 200 will focus primarily on features that differ from those described with respect to the needle 100.

[0038] Instead of the flexible region 150, the needle 200 includes a dispersion region 290 with a plurality of apertures 292, each aperture defining a corresponding port 213 in the lumen 210. The dispersion region 290 extends at least partially around the circumference of the needle 200 and also extends longitudinally. Although the dispersion region 290 does not necessarily assist in providing flexibility to the distal portion 230 beyond that provided by the properties of the material (e.g., Nitinol) from which the needle 200 is formed, the dispersion region 290 can still assist in the dispersion of a therapeutic agent in a manner similar to that described above with respect to the compressible region 150.

[0039] Apertures 292 can be designed to aid in the flow of therapeutic agents with various viscosities. In certain embodiments, apertures 292 can be designed as longitudinal slits, circular holes, arrays of holes or slits, and openings of increasing or decreasing size to equalize agent pressure over a greater distance and surface of needle 200. In certain embodiments, distribution region 290 can be tailored to vary according to tissue type and / or pressure, and / or structured for better stability and / or to maximize flow at a particular viscosity.

[0040] As discussed above, at least some embodiments of the needles 100, 200 described herein are flexible. Certain embodiments of the needles described herein can bend at least 90° along their length without exhibiting significant plastic deformation. Certain embodiments of the needles described herein can be coiled without exhibiting significant plastic deformation. Certain embodiments of the needles described herein exhibit superelasticity during normal use. Certain embodiments of the needles described herein exhibit superelasticity at temperatures between a lower threshold and an upper threshold. In certain embodiments, the upper threshold is at least 40° C., at least 45° C., or at least 50° C. In certain embodiments, the lower threshold is 10° C. or less, 0° C. or less, −10° C. or less, or −20° C. or less.

[0041] 11, a graph is shown illustrating certain characteristics of an exemplary embodiment of needle 100 compared to a conventional cannula. More specifically, FIG. 11 illustrates the cross-sectional flow area, dead space, and drug transfer area provided by two embodiments of needle 100 compared to a 100% benchmark provided by a conventional cannula having an outer diameter (OD) of 0.68 mm.

[0042] The top burr set shows the characteristics of the needle 100 having the same outer diameter of 0.68 mm. Such larger needles 100 and cannulas can be utilized, for example, in non-diabetic infusion devices (e.g., for use in chemotherapy infusion devices). Due to the reduced wall thickness of the needle 100 compared to conventional cannulas, the needle 100 provides more than twice the cross-sectional flow area compared to conventional cannulas, thereby enhancing the flow of therapeutic agents. This correlates with an increase in the dead space of the needle 100, but the drug transfer area provided by the needle 100 is more than 12 times that of conventional cannulas, resulting in improved drug diffusion characteristics.

[0043] The middle burr set shows a needle 100 having a smaller outer diameter of 0.4 mm. Such a smaller needle 100 can be utilized, for example, in diabetic infusion devices (e.g., for use in insulin infusion devices). The flow cross-sectional area is more than half that of a conventional cannula, while the dead space is reduced by about 25%. Furthermore, the drug transfer area provided by the smaller diameter needle 100 is more than seven times that of a conventional cannula, resulting in improved drug diffusion characteristics.

[0044] Certain embodiments of the present application relate to a flexible needle 100 that defines a lumen 110, the flexible needle 100 including a proximal portion 120 that defines a first port 112 of the lumen 110, a distal portion 130 that defines at least one second port 113 of the lumen 110, the lumen 110 extending between and connecting the first port 112 and the at least one second port 112, the distal portion 130 including a small tubular member 140 configured to facilitate insertion of the distal portion 130 into patient tissue. The distal portion 130 includes a tip portion 140 having at least one sharpened tip 142 and a compressible region 150 having at least one slit 152, each slit 152 defining a corresponding second port 113 of the at least one second port 113, the compressible region 150 being configured to compress upon insertion of the distal portion 130 into patient tissue, thereby closing one or more second ports 113 of the at least one second port 113, and then expand to open the one or more second ports 113.

[0045] In certain embodiments, one or more of the at least one slit 152 extend transversely to the longitudinal axis 131 of the distal portion 130 .

[0046] In certain embodiments, the at least one second port 113 includes a plurality of second ports 113 , with the tip portion 140 further defining additional second ports 113 of the plurality of second ports 113 .

[0047] In certain embodiments, the at least one sharpened tip 142 includes multiple sharpened tips 142 .

[0048] In certain embodiments, the multiple sharpened tips 142 are equally spaced apart about the longitudinal axis 141 of the tip portion 140 .

[0049] In certain embodiments, the compressible region 150 is more flexible in a first direction transverse to the longitudinal axis 131 of the distal portion 130 and less flexible in a second direction transverse to the longitudinal axis 131 of the distal portion 130.

[0050] In certain embodiments, the proximal portion 120 further comprises a second compressible region 170 including at least one second slit 172 and a sheath 180 covering the second compressible region 170 to prevent fluid from exiting through the at least one second slit 172.

[0051] Certain embodiments of the present application relate to a needle 100 defining a lumen 110, the needle 100 comprising a proximal portion 120 defining a first port 112 of the lumen 110, and a distal portion 130 defining a second port 113 of the lumen 110, the lumen 110 extending between and connecting the first port 112 and the second port 112, the distal portion 130 comprising an open tip portion 140 defining the second port 113, the open tip portion 140 including at least one sharpened tip 142 configured to facilitate insertion of the distal portion 130 into patient tissue, an opening 164 connected to the lumen 110, and a ramp (162) configured to at least partially occlude the lumen 110 and urge patient tissue within the distal portion toward the opening 164 upon insertion of the distal portion 130 into the patient tissue.

[0052] In certain embodiments, the distal portion 130 further comprises at least one additional port 113 positioned near the opening 164 .

[0053] In certain embodiments, the distal portion 130 further comprises a plurality of slits 152 positioned near the opening 164 .

[0054] In certain embodiments, the plurality of slits 152 extend transversely to the longitudinal axis 131 of the distal portion 130 .

[0055] In certain embodiments, the needle 100 comprises an outer surface 102 and an inner surface 104 , where the outer surface 102 is more hydrophilic than the inner surface 104 .

[0056] In certain embodiments, at least one of the exterior surface 102 or the interior surface 104 includes a surface treatment 103, 105 that alters the hydrophilicity of at least one of the exterior surface 102 or the interior surface 104.

[0057] In certain embodiments, distal portion 130 includes a tab 160 that is inwardly deformed to thereby define a ramp 162 and an opening 164 .

[0058] Certain embodiments of the present application relate to a flexible needle 100 defining a lumen 110, the needle 100 having a proximal portion 120 defining a first port 112 of the lumen 110 and a distal portion 130 defining a second port 113 of the lumen 110, the lumen 110 extending between and connecting the first port 112 and the second port 112, the distal portion 130 having a tip portion 140 including at least one sharpened tip 142 configured to facilitate insertion of the distal portion 130 into patient tissue, the flexible needle 100 being formed of Nitinol, which is at least 95% austenitic at temperatures below 0°C.

[0059] In certain embodiments, the Nitinol is configured to retain at least 95% austenite when cooled to a temperature of 0° C. or below from a temperature at which the Nitinol is fully austenitic.

[0060] In certain embodiments, the martensite start temperature of the nitinol is below 0°C.

[0061] In certain embodiments, the nitinol is at least 95% austenitic at temperatures below -10°C.

[0062] In certain embodiments, the nitinol is at least 95% austenitic at temperatures below -20°C.

[0063] In certain embodiments, the outer surface 102 of the distal portion 130 has a higher hydrophilicity than the inner surface 104 of the distal portion 130 .

[0064] In certain embodiments, the Nitinol has an atomic ratio of nickel to titanium between 1.01 and 1.05.

[0065] In certain embodiments, the nickel to titanium atomic ratio of the nitinol is between 1.02 and 1.04.

[0066] In certain embodiments, the distal portion 130 further comprises a flexible region 150 that includes a plurality of slits 152 .

[0067] In certain embodiments, the tip portion 140 includes a plurality of sharpened tips 142 that are spaced apart from one another about the longitudinal axis 141 of the tip portion 140 .

[0068] While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in nature, it being understood that only the preferred embodiments have been illustrated and described and that all changes and modifications which come within the spirit of the invention are desired to be protected.

[0069] As used in the above description, the use of terms such as preferred, preferably, preferred, or more preferred indicates that the feature so described may be more desirable, but it should nevertheless be understood that it may not be necessary, and that embodiments lacking it may be envisioned as being within the scope of the invention as defined by the claims that follow. In interpreting the claims, the use of words such as "a," "an," "at least one," or "at least a portion" is not intended to limit the claim to only one item, unless specifically stated to the contrary in the claim. When the terms "at least a portion" and / or "a portion" are used, unless specifically stated to the contrary, the item may include a portion and / or the entire item.

Claims

1. A flexible needle (100) defining a lumen (110), a proximal portion (120) defining a first port (112) of the lumen (110); a distal portion (130) defining at least one second port (113) of the lumen (110); a lumen (110) extending between and connecting a first port (112) and the at least one second port (113); The distal portion (130) comprises: a distal portion (140) including at least one sharpened tip (142) configured to facilitate insertion of the distal portion (130) into patient tissue; a compressible region (150) including at least one slit (152); Each slit (152) defines a corresponding one of the at least one second port (113); The compressible region (150) of the flexible needle (100) is configured to compress upon insertion of the distal portion (130) into patient tissue, thereby closing one or more of the at least one second port (113), and then expand to open the one or more second ports (113).

2. The flexible needle (100) of claim 1, wherein one or more of the at least one slit (152) extends transversely to the longitudinal axis (131) of the distal portion (130).

3. The at least one second port (113) includes a plurality of second ports (113); The flexible needle (100) of claim 1 or 2, wherein the tip portion (140) further defines an additional second port (113) of the plurality of second ports (113).

4. The flexible needle (100) of claim 1, wherein the at least one sharpened tip (142) comprises a plurality of sharpened tips (142).

5. The flexible needle (100) of claim 4, wherein the plurality of sharpened tips (142) are equally spaced apart about the longitudinal axis (141) of the tip portion (140).

6. 2. The flexible needle (100) of claim 1, wherein the compressible region (150) is more flexible in a first direction transverse to the longitudinal axis (131) of the distal portion (130) and less flexible in a second direction transverse to the longitudinal axis (131) of the distal portion (130).

7. The proximal portion (120) further comprises a second compressible region (170) including at least one second slit (172); and a sheath (180) covering the second compressible region (170) to prevent fluid from exiting the at least one second slit (172).

8. A needle (100) defining a lumen (110), a proximal portion (120) defining a first port (112) of the lumen (110); a distal portion (130) defining a second port (113) of the lumen (110); The lumen (110) extends between and connects the first port (112) and the second port (112); The distal portion (130) comprises: an open tip portion (140) defining a second port (113), the open tip portion (140) including at least one sharpened tip (142) configured to facilitate insertion of the distal portion (130) into patient tissue; an opening (164) connected to the lumen (110); a ramp (162) configured to at least partially occlude the lumen (110) and urge patient tissue within the distal portion (130) toward the opening (164) upon insertion of the distal portion (130) into the patient tissue.

9. The needle (100) of claim 8, wherein the distal portion (130) further comprises at least one additional port (113) positioned near the opening (164).

10. The needle (100) of claim 8 or 9, wherein the distal portion (130) further comprises a plurality of slits (152) positioned proximate the opening (164).

11. The needle (100) of claim 10, wherein the plurality of slits (152) extend transversely to the longitudinal axis (131) of the distal portion (130).

12. The needle (100) has an outer surface (102) and an inner surface (104); The needle (100) of claim 8, wherein the outer surface (102) is more hydrophilic than the inner surface (104).

13. The needle (100) of claim 12, wherein at least one of the outer surface (102) or the inner surface (104) includes a surface treatment (103, 105) that alters the hydrophilicity of at least one of the outer surface (102) or the inner surface (104).

14. 9. The needle (100) of claim 8, wherein the distal portion (130) comprises a tab (160) that is inwardly deformed thereby defining a ramp (162) and an opening (164).

15. A flexible needle (100) defining a lumen (110), a proximal portion (120) defining a first port (112) of the lumen (110); a distal portion (130) defining a second port (113) of the lumen (110); The lumen (110) extends between and connects the first port (112) and the second port (112); The distal portion (130) comprises: a distal portion (140) including at least one sharpened tip (142) configured to facilitate insertion of the distal portion (130) into patient tissue; The flexible needle (100) is made of Nitinol; The flexible needle (100), wherein the nitinol is at least 95% austenitic at temperatures below 0°C.

16. 16. The flexible needle (100) of claim 15, wherein the nitinol is configured to retain at least 95% austenite when cooled to a temperature of 0° C. or below from a temperature at which the nitinol is fully austenitic.

17. The flexible needle (100) of claim 15 or 16, wherein the martensite start temperature of Nitinol is below 0°C.

18. The flexible needle (100) of claim 15, wherein the Nitinol is at least 95% austenitic at temperatures below -10°C.

19. The flexible needle (100) of claim 15, wherein the Nitinol is at least 95% austenitic at temperatures below -20°C.

20. The flexible needle (100) of claim 15, wherein an outer surface (102) of the distal portion (130) has a higher hydrophilicity than an inner surface (104) of the distal portion (130).

21. The flexible needle (100) of claim 15, wherein the Nitinol has a nickel to titanium atomic ratio between 1.01 and 1.

05.

22. The flexible needle (100) of claim 20, wherein the Nitinol has an atomic ratio of nickel to titanium between 1.02 and 1.

04.

23. The flexible needle (100) of claim 15, wherein the distal portion (130) further comprises a flexible region (150) including a plurality of slits (152).

24. The tip portion (140) comprises a plurality of sharpened tips (142); The flexible needle (100) of claim 15, wherein the plurality of sharpened tips (142) are spaced apart from one another about the longitudinal axis (141) of the tip portion (140).

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