METHOD AND DEVICE FOR THE NEEDLE-FREE INJECTING OF FLUID INTO A SUBSTRATE, AND FLUID CONTAINER FOR USE IN THE METHOD AND THE DEVICE

Abstract

The invention proposes a method and a device for needleless injection of liquid into a substrate, in particular of a liquid pharmaceutical or cosmetic preparation into a biological tissue, making it possible in a particularly advantageous manner to reliably inject a liquid completely into the substrate without a needle. In accordance with the invention, this is achieved by a sequential injection, wherein a first partial quantity of the liquid first exits from an outlet nozzle at a very high outlet velocity as a fine liquid jet under high pressure generated in the liquid by means of a impulse shock and enters the substrate and creates an injection channel in the substrate, into which a second partial quantity of the liquid is then introduced at lower pressure and lower velocity. Preferably, the ejected liquid jet is set in rotation around its jet axis before it impinges on the substrate, so that the jet receives a helical movement and thus practically drills into the substrate without splashing away laterally.

Claims

1.-6. (canceled)

7. An injection device for the needleless injection of a liquid into a substrate, particularly for injection of liquid pharmaceutical or cosmetic product into a biological tissue, comprising a housing, a liquid supply accommodated or arrangeable in the housing, an outlet nozzle and an ejector device for ejecting liquid from the liquid supply through the outlet nozzle, wherein the ejector device has means for generating an impulse shock acting at least on a first quantity of liquid in the liquid supply.

8. The device according to claim 7, wherein the means of the ejector device for generating the impulse shock comprise an ejector plunger acceleratable to an impulse velocity, with whose mass accelerated to the impulse velocity the first quantity of liquid can be acted on.

9. The device according to claim 7, wherein the liquid supply is actable on by means of an ejector piston actuatable by the ejector device, which ejector piston in turn is actable on or formed by the ejector plunger.

10. The device according to claim 7, wherein the ejector device has an electromagnetic drive for the ejector plunger.

11. The device according to claim 7, wherein the ejector device has an acceleration section for the ejector plunger.

12. The device according to claim 10, wherein the electromagnetic drive is arranged at a rear end of the housing spaced from the outlet nozzle or approximately in the middle of the housing, wherein the acceleration section extends between the outlet nozzle and the rear end of the housing.

13. The device according to claim 10, wherein the electromagnetic drive has a magnetic coil formed on the ejector plunger itself as well as an iron cylinder and/or a stator coil surrounding the ejector plunger

14. The device according to claim 10, wherein the ejector plunger is provided with an electric power storage device to supply the electromagnetic drive with electric power.

15. The device according to claim 7, wherein the acceleration section in the area in front of and behind the ejector plunger is connected to pressure compensation openings.

16. The device according to claim 15, wherein the pressure compensation openings are connected to each other via an overflow line.

17. The device according to claim 7, wherein the ejector device comprises means for generating an increase in pressure in the liquid supply immediately following the exerted impulse shock.

18. The device according to claim 17, wherein means for generating a pressure increase are substantially formed by the ejector plunger which, after exerting the impulse shock, acts on the liquid supply by means of a force-exerting drive.

19. The device according to claim 18, wherein the force-exerting drive is the electromagnetic drive.

20. The device according to claim 7, wherein the liquid supply is accommodated in a liquid container which can be arranged replaceably in the housing.

21. The device according to claim 20, wherein the outlet nozzle is arranged on the liquid container.

22. The device according to claim 8, wherein the outlet nozzle comprises means for setting the liquid jet at least in its outer area in rotation before its impingement on the substrate.

23. The device according to claim 7, wherein the outlet nozzle has a nozzle outlet running substantially coaxial to the housing axis of the housing.

24. The device according to claim 7, wherein the outlet nozzle has a nozzle outlet running substantially in a plane normal to the housing axis of the housing.

25. The device according to claim 7, wherein the outlet nozzle and/or the front end of the housing is/are provided with a depth indicator or a depth stop.

26. The device according to claim 7, wherein the liquid container with the liquid contained therein together with the ejector plunger is movably accommodated or accommodatable in the housing or an acceleration section provided in the housing, respectively, and that the housing has at its front outlet end a stop for the liquid container.

27.-28. (canceled)

Description

DRAWINGS

[0038] The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

[0039] Further features and advantages of the invention result from the following description and figure, in which preferred embodiments of the invention are presented and explained in more detail by means of examples. These show:

[0040] FIG. 1 a general representation of an injection device according to the invention in perspective view;

[0041] FIG. 2a-c the handling part of the injection device according to FIG. 1 in longitudinal section in different operating positions of the ejector device;

[0042] FIG. 3 the ejector device with a first version of an outlet nozzle used in the invention, in longitudinal section;

[0043] FIG. 4 a second embodiment of an outlet nozzle for use with the device according to the invention in section;

[0044] FIG. 5 a third embodiment of an outlet nozzle for use with the device according to the invention in section;

[0045] FIG. 6 a fourth embodiment of an outlet nozzle for use with the device according to the invention in section;

[0046] FIG. 7 the orifice plates of the orifice plate stack used in the embodiment according to FIG. 6 in a perspective, expanded representation (exploded view); and

[0047] FIG. 8 a fifth embodiment of an outlet nozzle for use with the device according to the invention in section.

DETAILED DESCRIPTION

[0048] Example embodiments will now be described more fully with reference to the accompanying drawings.

[0049] In FIG. 1, 10 refers to an injection device as a whole according to the invention, which has a handling part 11, which is connected via a cable connection 12 to an external power supply 13, a battery pack in the embodiment shown.

[0050] The handling part 11 of the injection device 10 can be conveniently handled by its user with a single hand. The more detailed structure of the handling part 11 is clearly visible in the sectional view according to FIG. 2a to c. Accordingly, it has a housing 14 which is provided with a recess 15 on its outer circumference in which a magnetic coil 16 is accommodated. The magnetic coil 16 is protected by a circumferential cover 17.

[0051] The magnetic coil 16 is part of an ejector device referred to as 18 in its entirety, which further comprises an ejector tube 19 made of plastic material inserted into the housing and passing through it essentially from its rear end (right in the figure) to the front (left) outlet end, and an ejector plunger 20 guided therein in a longitudinally displaceable manner, which in the embodiment shown has a rear section 21 and a front section 22. While the rear section with a larger diameter is adapted to the internal cross-section of the ejector tube 19 and can slide in it with as little play and friction as possible, the front section 22 has a smaller diameter. It forms a pressure piece 23 which can be inserted or is insertable from behind into a cylindrical liquid container 24 in the form of a liquid round or cartridge containing a liquid 25 to be injected into a substrate, for example into or under the skin of a human or animal. This liquid container 24, similar to the rear section 21 of the ejector plunger 20, is accommodated in the ejector tube 19 substantially without play, so that it can also slide easily in the latter. At the rear (i.e. on the right in the figure), the liquid container 24 is closed by a piston 26, which holds the liquid 25 in the container 24 and is pushed into the cylinder space 27 defined by the container 24 to such an extent that the pressure piece 23 also fits a little into this cylinder space at its rear. On its left outlet side, as shown in the figure, the liquid container 24 is closed with a membrane 28.

[0052] The ejector tube 19 is fitted with a cap 29 at its front end, left-hand side in FIG. 2, which has a central opening in which a piercing cannula 30 projecting inwards towards the liquid container 24 is accommodated. An elastic buffer element 31 surrounding the piercing cannula 30 is arranged inside the cap.

[0053] The piercing cannula 30 protrudes with its outlet side end opposite its piercing tip 32 somewhat beyond the cap 30 and thus forms a centering for an outlet nozzle 33, which is fitted onto this outlet side end of the cannula 31 and fixed to the housing 14 by means of a union nut 34.

[0054] In order to prepare the device for use, the ejector plunger 20 with its front section 22, which forms the pressure piece 23, is first inserted from behind into the cartridge-like liquid container 24, wherein the front side of the pressure piece 23 contacts the piston 26 in the cylindrical opening of the liquid container. This assembly of liquid cartridge and ejector plunger can then be inserted with the membrane 28 in front, which closes the liquid cartridge at the front, from behind into the ejector tube 19 in the housing 16, for which purpose a cover cap 35 arranged at the rear of the housing can be opened. After closing the cover cap the device is ready for operation. This operating state is shown in FIG. 2a.

[0055] Based on the FIGS. 2a to 2c, the operation of the device according to the invention can be easily understood during injection: FIG. 2a shows the initial position of the ejector device, in which the rear section 21 of the ejector plunger 20 is in the rearmost position (in the figure on the right) (rear end position). The free space in the ejector tube 19 which extends in this position of the ejector plunger and the liquid container placed on the front of the ejector plunger up to the end cap 29 forms an acceleration section S, over the length of which the assembly consisting of plunger and liquid container 24 can be accelerated. In order to trigger an injection from the position shown in FIG. 2a, the magnetic coil 16 is supplied with electric energy from the battery pack 13 and thereby accelerates the ejector plunger 20 with the liquid cartridge 24 attached to the front of it over the acceleration section S in a direction of movement towards the outlet nozzle (to the left in the figure). The accelerated assembly reaches a very high velocity in a very short time, which in practice can be over 500 m/s, and even over 800 m/s with a suitably longer acceleration section. The liquid container 24 with the liquid 25 contained in it first follows this movement until it is decelerated by the buffer element 31, which is compressed between the front cap 29 of the ejector tube 19 and the assembly of ejector plunger 20 and liquid container 24 moved at high velocity by the magnetic coil 16 towards the outlet nozzle 33. The main purpose of the buffer element 31 is to prevent the liquid container striking against the front cap 29 from jumping back from it. The position of the ejector device in this operating state is shown in FIG. 2b.

[0056] As is only schematically indicated by dotted lines in the illustration according to FIG. 2a, the free space 36, which is present inside the ejector tube 19 between its front cap 29 and the front end of the liquid container 24 closed by the membrane, is connected to the space 38 behind the rear plunger end 21 by means of an overflow line 37. Through the overflow line, air can be displaced from the front free space 36 or actually actively sucked out by the negative pressure in space 38 which forms behind the plunger during its forward movement, thus ensuring that the ejector plunger 20 with the liquid container 24 is not slowed down due to increased air resistance. In the practical implementation of this feature, the overflow line can be integrated into the wall of the housing so that it is actually not noticeable from the outside.

[0057] As soon as the piercing tip 32 of the piercing cannula 30 pierces the membrane 28 provided at the front end of the liquid container 24, the liquid 25 contained in the container can emerge from the front end of the container and pass through the cannula 31 into the outlet nozzle 33. Since at the moment of piercing, the liquid container 24 with the liquid 25 contained in it is still moving at high velocity and this movement stops very abruptly as soon as the buffer element 29 is compressed as much as possible, there is a brief strong pressure increase in the liquid volume contained in container 24 (pressure shock), because the ejector plunger 20 pressing on the rear of piston 26 in the liquid container 24 with its pressure piece 23 is decelerated just as suddenly and transmits its own dynamic energy as an impulse shock into the initially co-accelerated liquid, which triggers the strong pressure increase in the latter. Due to this briefly, very high pressure in the liquid, a first partial quantity of the liquid is pushed at a correspondingly high pressure through the cannula and the subsequent outlet nozzle 33 and exits the outlet nozzle at the outlet side of the outlet nozzle at a high orifice velocity corresponding to the high static pressure, ambient pressure being imposed on the liquid at the outlet side of the outlet nozzle and the inherent pressure energy being converted into kinetic energy (velocity). In practice, the outlet nozzle used, which is preferably designed as described below, can have a passage 36 for liquid 25 with a diameter of 80 to 300 m, so that the first partial quantity of liquid ejected as a result of the impulse shock impinges as a very fine liquid jet with a correspondingly small cross-section on the substrate at a very high velocity. The exit velocity of the liquid as a result of the pressure shock can easily reach 1000 m/s. With this extremely fast and thin liquid jet, an injection channel is created (shot) in the substrate to a depth that depends on the jet velocity and its diameter and thus ultimately on the strength of the impulse shock generated by the ejector plunger in the liquid supply.

[0058] According to the invention, it is possible to inject the entire amount of liquid contained in the liquid container or, anyway, a second partial quantity of liquid in addition to the first partial quantity injected forming an injection channel, as explained above, into the substrate at this injection point. For this purpose, the magnetic coil 16 can continue to be powered after reaching the front end position of the liquid container 24 (FIG. 2b). This causes the ejector plunger 20 with its front section 22 (pressure piece 23) to be pressed further from behind against the piston 26 in the liquid container so that at least a part of the liquid (second partial quantity) still remaining in the container after the pressure shock has decayed is pressed through the cannula 31 as with a conventional syringe and then ejected through the outlet nozzle 33. Surprisingly, it has been found that despite the significantly lower pressure with which the second partial quantity is then ejected and the lower exit speed of the second partial quantity liquid from the outlet nozzle resulting therefrom, also the second partial quantity reliably and completely penetrates into the injection channel created in the substrate previously by means of the first partial quantity and thus reaches into the substrate, i.e. in the embodiment into or under the skin. This generally leads to a depot formation at the end of the injection channel, i.e. the second partial quantity of liquid is distributed substantially evenly in the tissue in a spherical shape around the end of the injection channel. The injection can be continued until plunger 26 is fully inserted from pressure piece 23 to the front end of the liquid container (FIG. 2c).

[0059] If desired, a sequence of more or less closely positioned injections of comparatively small amounts of liquid can be made at short intervals with the device. For this purpose, the ejector plunger 20 is pulled back into its initial position (i.e. to the right in the figure) by suitable control (changing the direction of electrical current) of the magnetic coil 16 directly after generating a pulse shock in the liquid contained in the container. Since the liquid container 24 for the embodiment described here is already open from the piercing tip 32 of the cannula 30 at the membrane after the very first injection carried out as described above, in this mode of operation it remains expediently in its left-hand end position as shown in the figure according to FIG. 2c, which can be ensured by a suitable retaining element not shown. For example, for this purpose, a locking bar pretensioned radially inwards transversely to the longitudinal axis of the ejector tube 19 by means of a spring can be accommodated in a recess in the ejector tube, which locking bar, after the liquid cartridge has passed after the first injection has been triggered, moves radially inwards under the spring pressure, gripping behind the rear edge (in the figure at the right end of the liquid container) of the liquid container and thus preventing it from moving back again. The ejector plunger 20, which has been pulled back again by momentarily reversing the polarity of the magnetic coil, can be held in its retracted position by means of a small permanent magnet or an electromagnet on the rear cover cap 35 of the housing so that it does not drop again unintentionally and/or prematurely against the shock inducer element (piston 26) on the liquid container solely due to its own weight. The ejector plunger can then, optionally by overcoming the magnetic holding force of the aforementioned (not shown) permanent magnet or electromagnet, be accelerated again to high velocity via the acceleration section lying in front of it, wherein it slides to the end of its movement with the front pressure piece back into the cylinder space at the rear end of the liquid container and there hits the piston 26 and thus again generates a pressure shock for ejecting a further (small) partial quantity of liquid. The repeated triggering of the electromagnet and the resulting ejection of liquid from the device (after its repositioning at the next, desired injection point) can be done manually, i.e. by actuating a (not shown) triggering mechanism, or automatically at pre-determined time intervals, which can also be very short, for example when using the device as a tattoo machine. An operation of the device with a triggering frequency in the range of 35 to 200 Hz is easily possible with suitable dimensioning of the plunger and the acceleration section.

[0060] In FIG. 3, a first preferred embodiment of the outlet nozzle 33 to be used is shown in its mounted state on the housing of the device according to the invention. It can be seen that this outlet nozzle 33 has a central passage 39, running coaxially to the cannula 30, for the liquid 25 to be injected, which passage has on its passage wall 40 at least one screw-shaped or helical fluid channel 41, which extends from the nozzle inlet 42 on the side of the cannula 30 to the nozzle outlet 43, from which the liquid 25 exits for injection. This helical fluid channel 41 causes a swirl or rotational movement to be imposed on the liquid flowing through the outlet nozzle 33 so that the liquid jet 44 is set in rotation around its jet axis 45 when it exits the nozzle and thus impinges on the substrate 46, in the embodiment the skin of a human or animal, as a rotating liquid jet.

[0061] The superposition of the translatory movement of the liquid with the rotation imposed on it causes the liquid jet 44 to practically screw or drill itself into the substrate 46 when it impinges on the substrate, wherein the helical movement of the liquid apparently holds the jet together, so that when the liquid impinges on the surface of the skin or substrate, it does not mushroom and splash off sideways, but rather enters the substrate with as little loss as possible and creates an injection channel 47 with a depth T, which depends essentially on the nature of the substrate, the velocity of the liquid jet in the axial direction and its cross-section. In the embodiment shown, the passage 39 in the outlet nozzle has a diameter of approx. 80 to 100 m on the outlet side and the (first) partial flow exiting this passage as a result of the pressure shock in the liquid supply exits the nozzle at a velocity in the order of 100 to 1000 m/s. The depth of the resulting injection channel in (human or animal) tissue can thus be adjusted between a few millimetres and a few centimetres.

[0062] FIG. 4 shows a further embodiment of an outlet nozzle according to the invention, wherein corresponding features are provided with the same reference signs as for the first embodiment. The outlet nozzle 33 shown in FIG. 4 is fixed to the housing by means of a union nut 34a, which also forms a spacer or depth gauge. The outlet nozzle shown in FIG. 4 can be pressed a little bit into the substrate 46, namely from its upper side 48 into the skin of a patient, so that it forms a trough-like depression 49 therein. A radially outwardly projecting ring area 50 on the union nut 34a limits the depth of depression of the nozzle or indicates when a desired depth has been reached, which is the case when the outer edge of the ring area 50 also comes into contact with the skin surface 48. The outlet nozzle 33 has a passage 39 with an approximately cup-shaped nozzle chamber 51 on the inlet side, on the wall of which two (or more) fluid channels 41 are formed, which wrap around each other helically in the manner of a double (or multiple) helix and which, as described, impose the swirl (spiral movement) according to the invention on the liquid flowing through the nozzle. The nozzle has two (or also several) laterally e.g. radially outwardly open nozzle outlets 43, through which, in contrast to the first embodiment of the device, jets of liquid 44 do not leave the nozzle coaxially to its longitudinal direction, but in directions which are essentially perpendicular to the longitudinal axis of the device orin the embodiment showneven an angle , which can be slightly greater than 90. In this way it is easily possible to inject the liquid not perpendicularly to the substrate surface, but to distribute it under the uppermost skin layer 52 essentially parallel to the surface in the substrate.

[0063] The embodiment of an outlet nozzle 33 shown in FIG. 5 largely corresponds to that shown in FIG. 3. However, the passage 39 here does not have a constant cross-section over its entire length, but on the inlet side it initially has a converging section 53, whose cross-section decreases in the flow direction 54 of the liquid 25 ejected through the nozzle, and then continues into a section of constant cross-section 55. In both sections 53 and 55, helically spiraling fluid channels 41 are provided on their walls, in the embodiment shown two channels, which are arranged in the manner of a double helix. The converging section firstly ensures an acceleration of the fluid passing from the fluid container into the nozzle.

[0064] FIG. 6 shows an embodiment of the outlet nozzle for the invention, in which the or a fluid channel 41 extends through the outlet nozzle 33 in the form of a helical pipe 56 from the inlet side 42 to the outlet side 43 of the outlet nozzle 33. The arrangement is such that the pipe 56 has a helical radius R decreasing from the inlet side 42 to the outlet side 43. Thereby a cyclone effect is achieved, i.e. an acceleration of the rotational velocity of the liquid flowing through the pipe helix 56 around itself, so that the liquid rotates around itself at high velocity when it exits the nozzle outlet.

[0065] In the embodiment shown in FIGS. 7 and 8, the outlet nozzle 33 has a plurality of orifice plates 58 which are arranged one behind the other in the direction of passage 54 of the liquid in the form of an orifice plate stack 57, which orifice plates each have a slot opening 59 extending over a part of the plate diameter d, the slot openings 59 of successive orifice plates 58 in the orifice plate stack 57 being arranged offset to one another in the circumferential direction by an angular amount . The amount of this angular offset in the circumferential direction is smaller at the radially outer ends of the slot openings 59 than the width of the slot openings. This results in a spiral staircase-like fluid channel 41 with a central passage opening. The embodiment with the stacked orifice plates can be manufactured particularly easily and cost-effectively, even having the smallest dimensions with an aperture cross section in the micrometer range.

[0066] In the outlet nozzle 33 shown in FIG. 8, four fluid channels 41 are formed on the wall 40 of the passage 39 passing through it, which run in a straight line parallel to the flow direction over the length of the section with constant cross-section 55 and are separated from each other by webs 60. In this embodiment, the entire nozzle is rotatably mounted on the housing of the device and can be driven by an electric motor using a coil. When it is set in rotation during the ejection, the webs on the passage wall transfer this rotational movement to the outer circumferential area of the liquid jet flowing through the nozzle, thus imposing the rotational movement according to the invention on the jet.

[0067] The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.