Multiple injection needle assembly

Abstract

Some embodiments are directed to a needle assembly including at least N injection needles where N is at least four and a multiple of two. The needle assembly also includes a first liquid port adapted to be connected to an injection device, and N second liquid ports connected to one of the N injection needles. N/2 main liquid pathways each have an entrance connected to the first liquid port and an exit, further including N/2 secondary liquid pathways that have two extremities each opening on one of the N second liquid ports, and a mid portion connected to the exit of one of the main liquid pathways. The main liquid pathways and the secondary liquid pathways define N liquid flow paths between the first liquid port and the N second liquid ports dimensioned so a pressure drop between them is similar.

Claims

1. An injection needle assembly, comprising: at least N injection needles where N is at least four and a multiple of two, a first liquid port adapted to be connected to an injection device, N second liquid ports, each connected to only one of the N injection needles, $\frac{N}{2}$ main liquid pathways each having an entrance connected to the first liquid port and having an exit, wherein the injection needle assembly further comprises $\frac{N}{2}$ secondary liquid pathways, further including: two extremities each opening on one of the N second liquid ports, and a mid portion connected to the exit of one of the main liquid pathways; and wherein the main liquid pathways and the secondary liquid pathways define N liquid flow paths between the first liquid port and the N second liquid ports and are dimensioned so that a pressure drop between the first liquid port and each of the N second liquid ports is between ±10%.

2. The injection needle assembly according to claim 1, wherein the pressure drop between the first liquid port and each of the second liquid ports is within 5%.

3. The injection needle assembly according to claim 1, wherein a length of any of the N liquid flow paths is between ±10%.

4. The injection needle assembly according to claim 1, wherein a length of any of the N liquid flow paths is within ±10% of each other.

5. The injection needle assembly according to claim 1, wherein a majority of the N injection needles are aligned in a straight line.

6. The injection needle assembly according to claim 5, wherein all the injection needles are aligned in a straight line.

7. The injection needle assembly according to claim 1, wherein: the main liquid pathways have a substantially constant cross-section surface between each others, and the secondary liquid pathways have a substantially constant cross-section surface between each others.

8. The injection needle assembly according to claim 7, wherein: the main liquid pathways have a cross section surface within ±10% between each others, and the secondary liquid pathways have a cross section surface within ±10% between each others.

9. The injection needle assembly according to claim 1, further comprising an additional second needle, an additional second liquid port connected to the additional second needle, and an additional second liquid flow path between the first liquid port and the additional second liquid port, wherein the additional liquid flow path is dimensioned so that a pressure drop between the first liquid port and the additional second liquid port is between ±10% to the pressure drop between the first liquid port and each of the N second liquid ports.

10. The injection needle assembly according to claim 1, wherein the main liquid pathways and the secondary liquid pathways are formed in a same piece of material.

11. The injection needle assembly according to claim 1, wherein the main liquid pathways and the secondary liquid pathways are arranged in a plane perpendicular to an injection axis.

12. An injection needle assembly, comprising: at least N injection needles where N is at least two and a multiple of two, a first liquid port adapted to be connected to an injection device, N second liquid ports, each connected to only one of the N injection needles, $\frac{N}{2}$ main liquid pathways each having an entrance connected to the first liquid port and having an exit, wherein the injection needle further comprises $\frac{N}{2}$ secondary liquid pathways, further including: two extremities each opening on one of the N second liquid ports, and a mid portion connected to the exit of one of the main liquid pathways; and wherein the main liquid pathways and the secondary liquid pathways define N liquid flow paths between the first liquid port and the N second liquid ports and are dimensioned so that a pressure drop between the first liquid port and each of the N second liquid ports is between ±10%.

13. An injection device comprising an injection needle assembly according to claim 1.

14. An injection device comprising an injection needle assembly according to claim 12.

15. The injection needle assembly according to claim 5, wherein: the main liquid pathways have a substantially constant cross-section surface between each others, and the secondary liquid pathways have a substantially constant cross-section surface between each others.

16. The injection needle assembly according to claim 5, further comprising an additional second needle, an additional second liquid port connected to the additional second needle, and an additional second liquid flow path between the first liquid port and the additional second liquid port, wherein the additional liquid flow path is dimensioned so that a pressure drop between the first liquid port and the additional second liquid port is between ±10% to the pressure drop between the first liquid port and each of the N second liquid ports.

17. The injection needle assembly according to claim 7, further comprising an additional second needle, an additional second liquid port connected to the additional second needle, and an additional second liquid flow path between the first liquid port and the additional second liquid port, wherein the additional liquid flow path is dimensioned so that a pressure drop between the first liquid port and the additional second liquid port is between ±10% to the pressure drop between the first liquid port and each of the N second liquid ports.

18. The injection needle assembly according to claim 5, wherein the main liquid pathways and the secondary liquid pathways are formed in a same piece of material.

19. The injection needle assembly according to claim 7, wherein the main liquid pathways and the secondary liquid pathways are formed in a same piece of material.

20. The injection needle assembly according to claim 9, wherein the main liquid pathways and the secondary liquid pathways are formed in a same piece of material.

21. An injection needle assembly, comprising: at least N injection needles where N is at least four and a multiple of two, a first liquid port adapted to be connected to an injection device, N second liquid ports, each connected to one of the N injection needles, $\frac{N}{2}$ main liquid pathways each having an entrance connected to the first liquid port and having an exit, wherein the injection needle assembly further comprises $\frac{N}{2}$ secondary liquid pathways, further including: two extremities each opening on one of the N second liquid ports, and a mid portion connected to the exit of one of the main liquid pathways; wherein the main liquid pathways and the secondary liquid pathways define N liquid flow paths between the first liquid port and the N second liquid ports and are dimensioned so that a pressure drop between the first liquid port and each of the N second liquid ports is between ±10%, and wherein each of the N liquid flow paths are dimensioned at an angle with respect to an adjacent one of the N liquid flow paths.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further advantages of some embodiments of the presently disclosed subject matter will become apparent from the following detailed description and drawings, in which:

(2) FIG. 1 is an exploded view of an injection needle assembly according to an embodiment of the presently disclosed subject matter including four injection needles.

(3) FIG. 2 is a detailed view of a liquid circulation area of an injection needle assembly according to FIG. 1.

(4) FIG. 3 is an exploded view of an injection needle assembly according to another embodiment of the presently disclosed subject matter including six injection needles.

(5) FIG. 4 is a detailed view of a liquid circulation area of an injection needle assembly according to FIG. 3.

DETAILED DESCRIPTION

(6) The present injection needle assembly is intended to be used for the injection of an injection product in a patient or an animal by multiple injection point. The injection product may be a liquid or a gel and may include any therapeutic, diagnostic, cosmetic or prophylactic product, but is in some embodiments a cosmetic product such as hyaluronic acid. In addition, the injection could be intradermal, subcutaneous or intramuscular but is in some embodiments subcutaneous or intradermal.

(7) The injection needle assembly is intended to be used with an injection device, such as a syringe, an auto-injector or a reusable injector.

(8) Now referring to FIG. 1, and from proximal to distal or from bottom to top in the view of FIG. 1, an embodiment of an injection needle assembly 1 includes a base plate 10, a needles plate 20, a cover 30 and a needles shield 40.

(9) The base plate 10 includes on its proximal face an adaptor 11 in the form of a female luer lock adaptor intended to be connected to a male luer lock adaptor of a prefilled syringe (not shown). However, any other adaptor can be used in order to secure the injection needle assembly 1 to the injection device. For example, it can be fixed to the tip of a syringe by a luer slip connection and or be glued, clipped or welded. It can also be screwed in an adapted receiving part of an injector. The adaptor 11 can be hollow so as to allow a fluid communication between the injection device and the base plate 10.

(10) The base plate 10 is further provided on its distal face with an embossed design 12 defining a liquid circulation area as explained later, two protruding tabs 13 and a centring stud 14.

(11) The needles plate 20 includes on its distal face four aligned injection needles 21 which are glued to the needles plate 20. The needles plate 20 further includes four protruding tabs 22 (three are visible in FIG. 1), two circumferential recesses 23 and an axial hole (not visible). The circumferential recesses 23 are intended to accommodate the protruding tabs 13 of the base plate 10 and the axial hole is intended to accommodate the centring stud 14 of the base plate 10, when the needles plate 20 is assembled to the base plate 10, as detailed below.

(12) On its proximal face, the needles plate 20 can have an embossed design (not visible) corresponding or complementary to the embossed design 12 of the base plate 10. The needles 21 can be open on the proximal face of the needles plate 20 so as to allow a fluid communication with the base plate 10 when the injection needle assembly 1 is assembled.

(13) The cover 30 includes a hollow body in the form of a crest, four distal openings 31 with a cylindrical shape, aligned with the injection needles 21 and four circumferential recesses 32 aligned with the protruding tabs 22 of the needles plate 20 and having a geometry complementary to the geometry of the protruding tabs 22.

(14) The needles shield 40 includes four sheaths 41 on its proximal surface, the four sheaths 41 being aligned with the four distal openings 31 of the cover 30 and having similar dimensions.

(15) The base plate 10, the needles plate 20 and the cover 30 are in some embodiments made of a rigid plastic material of medical grade such as Poly(methyl methacrylate) (PMMA) or alternatively Polycarbonate (PC). They are produced by injection moulding and the injection needles 21 are glued to the needles plate 30. Alternatively, the needles 21 may be overmoulded, staked or screwed to the needles plate 20. The needle shield 40 is made of a plastic material as mentioned above or an elastomer such as natural rubber, butyl rubber, halo butyl rubber or silicon rubber.

(16) The injection needle assembly 1 according to some embodiments embodiments is assembled as follows: the needles plate 20 is fitted on the base plate 10 such that the protruding tabs 13 of the base plate 10 are accommodated in the circumferential recesses 23 of the needles plate 20 and the centring stud 14 is accommodated in the axial hole of the needles plate 20. The needles plate 20 and the base plate 10 now fitted together can then be welded by ultrasonic welding, in order to close and seal the liquid circulation area defined at least by the embossed design 12 of the base plate 10.

(17) The cover 30 is then fitted onto the needles plate 20 and the protruding tabs 22 of the needles plate 20 interlock the circumferential recesses 32 of the cover 30 such as to secure the cover 30 to the needles plate 20. In addition, the injection needles 21 of the needles plate 20 are accommodated through the distal opening 31 in order to protrude in the distal direction beyond the cover 30.

(18) The needle shield 40 is finally placed onto the cover 30: the sheaths 41 are force-fitted onto the distal openings 31 of the cover 30 and at least the tips of the injection needles 21 are accommodated and protected inside the sheaths 41.

(19) The injection needle assembly 1 is then ready for the next applicable phases, such as sterilization, packaging, shipping, storage and use.

(20) Now referring to FIG. 2, the embossed design 12 defines a liquid circulation area 50 including a first liquid port 51 connected to the adaptor 11, four second liquid ports 52 connected or opening to the needles 21 when the injection needle assembly 1 is assembled, two main liquid pathways 53 extending from the first liquid port 51 in opposite radial directions and two secondary liquid pathways 54. The second liquid ports 52 are aligned and may represent the location of the injection needle opening on the proximal face of the needles plate 21.

(21) The main liquid pathways 53 include a first extremity or entrance connected to the first liquid port 51 and a second extremity or exit connected to a 20 mid-portion of a secondary liquid pathway 54. Each secondary liquid pathway 54 has two extremities, each of them accommodating or opening on a second liquid port 52. In the liquid circulation area 50 according to some embodiments, the main liquid pathways 53 and the second liquid pathways 54 are symmetric around an axis formed by the first liquid port 51.

(22) Both couples of a main liquid pathway 53 and a secondary liquid pathway 54 of the injection needle assembly define a liquid flow path allowing an injection product to flow from an injection device to an injection needle. Each liquid flow path has a similar profile and a similar length, and thus shows a similar pressure loss when an injection product circulates through it.

(23) The use of an injection needle assembly 1 according some embodiments is now explained with reference to FIGS. 1 & 2. The injection needle assembly 1 is first extracted from its packaging for example by a medical staff member and is fixed or screwed by the adaptor 11 to the luer lock connector of a syringe filled or prefilled with an injection product. The needle shield 40 is then removed to reveal at least the tip of the injection needles 21. The injection needle assembly is then primed by the medical staff member: the plunger rod of the syringe is moved distally in order to fill-up the liquid circulation area 50 with the injection product, thus removing air from the liquid circulation area 50.

(24) The skin of the patient is then punctured by the injection needles 21 which penetrate in or under the skin to an injection area. The plunger rod is distally moved again, and the injection product flows equally, from the first liquid port 51 toward the main liquid pathways 53 and reaches the secondary liquid pathways 54 by their mid-portion. The injection fluid is then distributed equally, i.e. with a similar flow rate and in similar quantities between the two second liquid ports 52 through each secondary liquid pathway 54, thanks to the two similar flow paths with similar pressure loss. As a result, a similar flow rate of the injection product is achieved in each needle 21 and a homogeneous quantity of injection fluid is injected in the injection area of a patient. As a result, the cosmetic, therapeutic, diagnostic or prophylactic effect of the injection fluid is maximized and a specific injection area of a patient can be treated in a single injection, which saves time and injection material.

(25) The injection needle assembly 101 according to another embodiment is similar to the injection needle assembly 1 according to the previously described embodiment with the differences that it includes six needles instead of four and that the embossed design of the base plate defines a different and more complex liquid circulation area. With reference to FIGS. 3 and 4, similar parts of the injection needle assembly 2 are numbered with the same reference numbers plus 100. For example, the base plate according to this embodiment is 110.

(26) Now regarding FIG. 4, the embossed design 112 defines a liquid circulation area 150 including a first liquid port 151 connected to the adaptor 111, six second liquid ports 152 connected to the needles 121 when the injection needle assembly 101 is assembled.

(27) On a top portion, as viewed in FIG. 4, it further includes two main liquid pathways 153a and 153b with a stepped profile which is symmetric according to a planar symmetry and connected by an extremity or entrance to the first liquid port 151. These main liquid pathways 153a-153b are each connected by another extremity or exit to one of the two similar secondary liquid pathways 154a-154b. These secondary liquid pathways have an identical profile in the form of an arc of a circle, with a second injection port 152 located or accessible at each extremity of the arc of a circle. The secondary liquid pathways 154a-154b are connected to the main liquid paths 153a-153b by a mid-portion or a tangent point on the most upper portion of the arc of a circle as viewed in FIG. 4. Consequently, each couple of a main liquid pathway 153a-153b and a secondary liquid pathway 154a-154b defines a symmetric and similar liquid flow path, with a similar profile, a similar length, a similar cross-section and a similar pressure loss.

(28) On a bottom portion, as viewed in FIG. 4, the liquid circulation area 150 defines a third main liquid pathway 153c showing a different, linear profile. It extends from the first injection port by one extremity or entrance and is connected by another extremity or exit to a third secondary liquid pathway 153c having the profile of a fork, namely with two extremities pointing toward the top portion of the base plate 110 and in particular toward the arcs of a circle of the first two secondary liquid pathways 154a-154b. Each extremity is provided with or opens to a second injection port 152. The third main liquid pathway 153c is on a plane crossing the base plate 110 in the middle and the third secondary liquid pathway is symmetric in view of this plane.

(29) As a result of the specific profile of the third main liquid pathway 153c and the third secondary liquid pathway 154c, all or most of the second injection points 152 are aligned. In addition, the couple of the third main liquid pathway 153c and the third secondary liquid pathway 154c defines a third liquid flow path with a different profile than the first two liquid flow paths of the top portion of the base plate 110. However, the length, the cross-section and the pressure loss of this third liquid flow path are similar to the two other liquid flow paths of the top portion of the liquid circulation area 150. This ensures a similar injection flow rate for all or most of the aligned injection needles 121 when the injection needle assembly 101 is used to inject an injection product to a patient or an animal.

(30) Computer Simulation

(31) In order to demonstrate that the presently disclosed subject matter allows a similar injection flow rate for all or most of the injection needles, a computerized mock-up of the injection needle assembly according to the some embodiments of the presently disclosed subject matter and FIGS. 3 and 4 has been performed. The different pathways of the liquid circulation area 150 have a rectangular section and a total length of 21.061 mm and a total volume of 17.45 mm.sup.3.

(32) A fluid simulating an injection product such as a non Newtonian fluid with a consistency index smaller than 1 was used.

(33) The liquid circulation area is initially filled with air. The above detailed fluid is inserted in a syringe as an injection device. When the injection is simulated or performed, some time is desired before the fluid reaches the different second liquid ports. These time periods between the start of the injection (the distal movement of a plunger rod) and the entrance of the fluid into an injection needle are summarized in table 1 below.

(34) TABLE-US-00001 Time difference w.r.t. Corresponding Outlet no Time [s] largest time [s] volume [×10.sup.−3 ml] 1 2.171 0.117 0.972 2 2.288 0.000 0.000 3 2.137 0.151 1.256 4 2.128 0.160 1.329 5 2.280 0.008 0.067 6 2.168 0.120 0.996

(35) These results demonstrate a very limited time shift between each second liquid port and thus between each injection needle. Consequently, it can be deduced that the flow rate between each injection needle is similar or almost identical.

(36) Although the presently disclosed subject matter has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example and is not to be taken by way of limitations, the scope of the presently disclosed subject matter being limited only by the terms of the appended claims.