Applicator, device and method for needleless injection of an active medium for injection

Abstract

For an applicator for needleless injection of an active medium (WM), which permits a high injection pressure and ensures a reliable and secure separation of the injectable active medium (WM) from the actuation of the device (1), an injection valve (20) is provided in the applicator (B) and a working medium (AM) with a working pressure (pA) can be applied at an inlet (27) of the injection valve, a pressure volume (21) is provided in the applicator (B), and the pressure volume (21) is filled with working medium (AM) at an initial pressure less than the working pressure (pA), the operational injection valve (20) is configured to inject into the pressure volume (21) a predefined injection quantity of the working medium (AM) with an injection pressure (pE) between the working pressure (pA) and the initial pressure, and there is provided in the applicator (B) a movably arranged plunger (22), which at a first end has a plunger piston (26) that at least partially delimits the pressure volume (21), and which, with an opposite second end, bears on the pressure piston (25) such that the operational plunger (22) is movable in the direction of the pressure piston (25) in order to move the pressure piston (25) so as to deliver an active-medium pulse from at least nozzle opening (29).

Description

[0001] Applicator, device and method for needleless injection of an active medium to be injected

[0002] The present invention relates to an applicator for the needleless injection of an active medium to be injected into a body surface, comprising a nozzle unit with a nozzle volume into which the active medium to be injected is filled. At least one nozzle opening connected to the nozzle volume is provided on the nozzle unit. A pressure piston is arranged in the nozzle unit, which at least partially defines the nozzle volume and is movably arranged in the nozzle unit. The invention also relates to a method and a device for the needleless injection of an active medium to be injected into a body surface using such an applicator.

[0003] WO 2012 / 139774 A1 describes a device for the needleless injection of a medium into or under the skin using a series of pressure pulses. The device defined therein is characterized by minimal construction effort to achieve the described purpose. Due to the minimally invasive needleless injection into or through the skin, this device falls into hazard class IIb according to EU Regulation 2017 / 745 on medical devices. Therefore, all surfaces in the device that come into contact with the medium to be injected must be biocompatible and sterilizable. Available off-the-shelf parts such as high-pressure pumps, valves, reservoirs, or hoses usually do not meet this requirement, which is why a market-ready implementation of such a device is difficult. Special developments would be necessary for individual components of such a device, which would make the device complex and expensive.

[0004] EP 2 957 309 B1 describes a cylinder-piston unit for a needleless injector. The medium to be injected is contained in a cylinder. The cylinder has a nozzle for dispensing the medium at one end and a piston at the opposite end, which is moved in a pulsed manner toward the nozzle by an unspecified actuating means, thereby delivering the medium through the nozzle and into the patient's skin.

[0005] EP 2 035 065 B1 describes a device for the needle-free injection of an aqueous medium into a patient's skin. A piston is moved back and forth by a pneumatic cylinder in a nozzle filled with the medium to be injected. During the piston's return stroke, the aqueous medium is pumped into the nozzle via a dosing unit, and is then dispensed through the nozzle during the piston's forward stroke. However, this device can only handle pressures of approximately 150 bar, which is too low for many applications, particularly with higher-viscosity media. Furthermore, air can also be sucked in through the nozzle during the piston's return stroke, which can impair the dispensing of the medium during the next forward stroke of the piston. KR 20140054812 A also shows such a device.

[0006] It is an object of the present invention to provide an applicator for the needle-free injection of an active medium, which enables a high injection pressure and ensures a reliable and safe separation of the active medium to be injected from the actuation of the device.

[0007] This object is achieved in that an injection valve is provided in the applicator, to which a working medium with a working pressure can be applied on the inlet side, a pressure volume is also provided in the applicator and the pressure volume is filled with working medium with an initial pressure less than the working pressure, the injection valve is set up to inject a predetermined injection quantity of the working medium into the pressure volume at an injection pressure between the working pressure and the initial pressure, and a movably arranged plunger is provided in the applicator, which has a plunger piston at a first end which at least partially limits the pressure volume and rests against the pressure piston with an opposite second end, so that the plunger can be moved in the direction of the pressure piston during operation in order to move the pressure piston in order to deliver an active medium pulse from the at least one nozzle opening.

[0008] The active medium and the working medium are physically and spatially separated by the plunger. In addition, the pressure in the pressure volume is very low compared to the working pressure (usually atmospheric pressure). Contamination of the active medium by the working medium is impossible if the applicator is used properly. This also reliably separates the active medium in the nozzle unit from the actuation, because the active medium is not accessible at any point outside the nozzle unit, and especially not inside the applicator.

[0009] It is also advantageous if the working pressure of the working medium is generated separately from the applicator. For this purpose, a base unit can be provided that provides the working medium at the working pressure. The base unit is connected to the applicator via a pressure hose to supply the working medium at the working pressure to the applicator. All components of the base unit do not come into contact with the active medium, thus eliminating any special requirements for these components; in particular, they do not need to be biocompatible or sterilizable.

[0010] Preferably, the nozzle unit is detachably mounted on the applicator. This allows for easy and quick replacement of the active medium.

[0011] Advantageously, the nozzle unit is designed with a cartridge holder having an internal recess, and an active medium cartridge is replaceably inserted into the internal recess. The at least one nozzle opening is provided on the active medium cartridge, and the pressure piston is movably arranged in the active medium cartridge. The active medium cartridge, containing various active media and also with various active medium volumes, can be provided as operating media for the applicator. The active medium cartridge can be easily and safely replaced in the applicator.

[0012] To ensure the applicator can be positioned precisely on the body surface, a tubular spacer is advantageously provided on the active agent cartridge near the nozzle opening. This spacer extends axially from the active agent cartridge by a predetermined length and surrounds the nozzle opening, allowing the active agent pulse to exit through the tubular spacer. This reliably adjusts and maintains the distance between the nozzle opening and the body surface. Furthermore, the tubular spacer prevents splashing of the active agent.

[0013] Particularly advantageously, the inner recess in the cartridge holder and the active medium cartridge are designed to converge conically toward the at least one nozzle opening. The active medium cartridge can be shaped in the opposite direction. In this way, the active medium cartridge can be pressed into the cartridge holder during use, so that the active medium cartridge rests securely and, above all, over its entire surface against the cartridge holder. This prevents the active medium cartridge from expanding or deforming during applicator operation, which could impair the pressure buildup in the nozzle volume of the active medium cartridge and thus the generation of the active medium pulse.

[0014] To ensure safe and easy filling of the nozzle volume with active medium, the pressure piston can be designed with an axially continuous recess. This allows filling to occur through the pressure piston, preventing air from being trapped in the nozzle volume during filling. For this purpose, a filling connection is advantageously provided on the side of the pressure piston facing away from the at least one nozzle opening. This allows active medium to be filled into the nozzle volume via the filling connection and the axially continuous recess. A filling device can be connected to the filling connection for filling.

[0015] Preferably, a control button is provided on the applicator to actuate the injection valve. The control button can be actuated by an applicator.

[0016] The applicator can also be used to repeatedly inject a specified amount of working medium into the pressure volume via the injection valve during operation, at an injection pressure between the working pressure and the initial pressure. This delivers several consecutive active medium pulses. The multiple injections can be controlled by the applicator, but can also occur at specified intervals.

[0017] It is advantageous if the injection valve varies the injection pressure during the delivery of at least one active medium pulse. This makes it possible to achieve pressure modulation and to control the injection of the active medium into the body surface more flexibly, which also enables gentler application. In this context, it is particularly advantageous if the injection valve first injects for a first period of time at a first injection pressure and then injects for a second period of time at a second injection pressure, wherein the second injection pressure is lower than the first injection pressure. In this case, the body surface can be penetrated with the first high pressure in order to then inject a desired amount of active medium into the body surface at a lower, gentler pressure.

[0018] To generate the working pressure, a pump is advantageously provided in the basic unit, which increases the pressure of a working medium from a storage container to the working pressure, wherein the pump delivers into a pressure line which is connected to the pressure hose.

[0019] In the base unit, a return line branches off from the pressure line, preferably downstream of the pump. A controllable return valve is arranged in the return line to depressurize the pressure line via the return line when the return valve is open. This allows the device and applicator to be easily depressurized, for example, to remove the nozzle unit, for example, to replace an active medium cartridge. When depressurized, the plunger can also be easily pushed back to its original position, preferably automatically by a compression spring acting on the plunger.

[0020] The compression spring preferably engages with a first end on the side of the plunger piston facing away from the pressure volume and a second end of the compression spring preferably lies on a part of the applicator that is immovable relative to the plunger, which enables a structurally simple design.

[0021] To increase operational safety, the device is preferably equipped with a safety switch to enable or disable the applicator. Only when the safety switch is activated can the device be operated using a control button. This prevents the accidental release of active medium pulses from the applicator.

[0022] The present invention will be explained in more detail below with reference to Figures 1 to 7, which show exemplary, schematic, and non-limiting advantageous embodiments of the invention. Figure 1 shows a schematic representation of the device according to the invention with a base unit and applicator.

[0023] Fig.2 shows an embodiment of an applicator according to the invention,

[0024] Fig.3 shows a further embodiment of an applicator according to the invention,

[0025] Fig.4 shows an embodiment of a nozzle unit for an applicator according to the invention, Fig.5 shows a further embodiment of a nozzle unit for an applicator according to the invention,

[0026] Fig.6 an example relationship between working pressure and injection quantity for different active media and

[0027] Fig.7 an example of pressure modulation of the pressure in the pressure volume.

[0028] The device 1 according to the invention is used for the needleless injection of various active media (WM) into a body surface of a patient (human or animal), for example, the skin or a fingernail or toenail. Examples of active media (WM) used include aqueous solutions of disinfectants, antibiotics, botulinum toxin, and anesthetics, as well as highly viscous hyaluronic acids with kinematic viscosities of up to 1 m 2 / s (1 million cSt), platelet-rich plasma (PRP), suspensions with particles with maximum particle dimensions less than half the cross-sectional area of ​​the nozzle or antifungal agents (e.g. against nail fungus).

[0029] The device 1 according to the invention separates the generation and control of the working pressure PA of the working medium AM required for the described function in a base unit A from the components required for the intermittent, needleless injection of the active medium WM to be injected in an applicator B. This allows mainly standard components to be used for the working medium AM in the base unit A and the applicator B. Furthermore, compliance with EU Regulation 2017 / 745 is also ensured.

[0030] The device 1 thus consists of a base unit A and an applicator B. The base unit A serves to generate and regulate the working pressure PA of the working medium AM. The applicator B is used for needle-free injection and is held or guided by the applicator (e.g., a doctor). The applicator B is connected to the base unit A via a pressure hose 18. For this purpose, a suitable media coupling 11, for example, a quick-release coupling, can be provided on the base unit A and / or on the applicator B in order to detachably connect the pressure hose 18.

[0031] Likewise, an electrical control line 12 is provided between the base unit A and the applicator B in order to enable a communication connection between the applicator B and the base unit A, for example for data exchange or for controlling the functions of the applicator B. For this purpose, a suitable connector 13, for example a socket plug connection, can also be provided on the base unit A and / or on the applicator B in order to detachably connect the control line 12.

[0032] The basic unit A can therefore also be used with different applicators B.

[0033] In a preferred embodiment, the control line 12 and / or the pressure hose 18 are permanently connected to the applicator B. A media coupling 11 and / or a connector 13 are provided on the base unit A to connect the pressure hose 18 and / or the control line 12. This allows the applicator B to be easily separated from the base unit A or replaced.

[0034] The control line 12 and the pressure hose 18 can also be routed in a common hose package, which can facilitate the handling of the applicator B.

[0035] The base unit A is supplied with electrical energy by a power supply C, for example via a mains connection as in Fig.1 or via a battery in the base unit A or a battery that can be connected to the base unit A.

[0036] The base unit A may have a main switch 14 for switching the device 1 on and off and an electrical fuse 15.

[0037] A control unit 16 is provided in the base unit A. An input / output unit 17, such as a touchscreen, a display, lamps, lights, buttons, handwheels, sliders, etc., can also be provided on the base unit A to display information to the applicator and / or to enable the applicator to input information to control functions of the device 1.

[0038] The control unit 16 is typically a microprocessor-based hardware device running control software. However, the control unit 16 can also be implemented as an integrated circuit, such as a field-programmable gate array (FPGA) or an application-specific integrated circuit (ASIC). Combinations are also conceivable.

[0039] To generate pressure for the working medium AM, preferably a synthetic fluid or medical silicone oil, a reservoir 2 is provided in the base unit A, from which a pump 3 draws working medium AM to increase the pressure of the working medium AM to the desired working pressure PA. The pump 3 conveys the working medium AM into a pressure line 7. A filter 4 can be provided between the pump 3 and the reservoir 2. The pump 3 can be driven by an electric motor 5, which can be controlled by the control unit 16.

[0040] The pump 3 can be designed as a speed-controlled pump in order to set a specific working pressure PA of the working medium AM in the pressure line 7. To set the working pressure PA of the working medium AM, a pressure regulating valve 6 can also be provided downstream of the pump 3, as in the embodiment shown in Fig. 1. The pressure regulating valve 6 can be actuated electrically, for example controlled by the control unit 16, or can be actuated mechanically, for example via a handwheel on the base unit A. A desired working pressure PA is set on the pressure regulating valve 6 by actuation. A current working pressure PA in the pressure line 7 could also be displayed on a pressure indicator, for example on a manometer or on the input / output unit 17.

[0041] A pressure sensor 19 can also be provided in the pressure line 7 to detect a current working pressure PA ZU. The detected working pressure PA can be signaled to the control unit 16 and / or can be displayed on the input / output unit 17.

[0042] A return line 8 can also be provided in the base unit A, which branches off from the pressure line 7 and leads into the storage tank 2 via a return valve 9. The return valve 9 can be controlled by the control unit 16 (as in Fig. 1) to open the return line 8 into the storage tank 2, for example, to depressurize the device 1. Alternatively, the return valve 9 can also be operated manually. To also depressurize the pressure volume 21, the injection valve 20 can be opened, for example, by controlling it via the control unit 16. This facilitates the removal of the nozzle unit 23.

[0043] Furthermore, a pressure accumulator 10 connected to the pressure line 7 can also be provided in the base unit A. The pressure accumulator 10 ensures a working pressure PA in the pressure line 7 that is as constant as possible and is intended to suppress pressure fluctuations.

[0044] The pressure line 7 is connected to the pressure hose 18 in order to supply the working medium AM with the set working pressure PA to the applicator B.

[0045] At least some of the components and parts described above are preferably arranged in a closed housing of the base unit A.

[0046] The design of the basic unit A according to Fig. 1 is merely exemplary and can be modified as desired. Essential to the invention is only that the basic unit A provides a working medium AM with a desired working pressure PA, which is fed to the applicator B via the pressure hose 18. The working pressure PA of the working medium AM can typically be up to 500 bar, which is sufficient for most treatments.

[0047] The design of applicator B ensures the reliable and safe separation of the working medium AM and the active medium WM to be injected. Figure 2 shows the design of applicator B schematically. The applicator B according to the invention comprises a controlled injection valve 20, a pressure volume 21, a plunger 22, and a nozzle unit 23.

[0048] An injection valve 20 is a controlled valve that, when actuated, conveys a working medium AM present at an inlet 27 of the injection valve 20 at a working pressure PA to an outlet 28 of the injection valve 20. Using applicator B, the pressure hose 18 carrying the working medium AM at the working pressure PA is connected to the inlet 27 of the injection valve 20. If the injection valve 20 is not actuated, no working medium AM is conveyed from the inlet 27 to the outlet 28.

[0049] The injection valve 20 is preferably electrically actuated and can be connected to the control line 12, via which the injection valve 20 can be controlled for actuation, for example by the control unit 16 in the base unit A.

[0050] A nozzle chamber 24 is provided in the nozzle unit 23, in which the active medium WM to be injected is arranged. The nozzle chamber 24 communicates with a nozzle opening 29 of the nozzle unit 23 in order to spray the active medium WM to be injected through the nozzle opening 29 during operation. The nozzle chamber 24 is delimited, preferably on the opposite side of the nozzle opening 29, by a pressure piston 25. The pressure piston 25 is movably arranged in the nozzle chamber 24. A sealing element 33, for example an O-ring, is provided between the pressure piston 25 and the wall of the nozzle unit 23 surrounding the nozzle chamber 24, or the active medium cartridge 40 (see, for example, Fig. 4 or Fig. 5), to prevent the active medium WM from escaping between the pressure piston 25 and the wall of the nozzle unit 23, or the active medium cartridge 40 (see, for example, Fig. 4 or Fig. 5). When the device 1 is actuated, the pressure piston 25 reduces the size of the nozzle chamber 24 in order to eject the active medium WM to be injected from the nozzle opening 29.

[0051] The nozzle opening 27 typically has a diameter of 0.1 to 0.3 mm, depending on the viscosity of the active medium WM.

[0052] The nozzle unit 23 with the pressure piston 25 is preferably arranged detachably and replaceably on the applicator B. For example, the nozzle unit 23 can be screwed onto the applicator B via a screw thread or screwed into the applicator B.

[0053] The applicator B may have an applicator housing 32 in which the injection valve 20, the pressure volume 21, and the tappet 22 are arranged. The nozzle unit 23 is detachably arranged on the applicator housing 32, for example, screwed into the applicator housing 32.

[0054] The plunger 22 rests at one end on the pressure piston 25 or is connected to the pressure piston 25 at this end in order to move the pressure piston 25 during operation of the applicator B. At the other end of the plunger 22, a plunger piston 26 is provided, which borders the pressure volume 21 and at least partially delimits the pressure volume 21. A sealing element 34, for example an O-ring, is provided between the plunger piston 26 and the wall of the applicator B surrounding the pressure volume 21 in order to prevent the working medium AM from escaping between the plunger piston 26 and the wall of the applicator B.

[0055] Pressure volume 21 is filled with the working medium AM, preferably without any air pockets that could dampen pressure. The pressure volume 21 can be filled with the working medium AM before applicator B is put into operation.

[0056] The injector 20 is supplied with working medium AM at the working pressure PA via the pressure hose 18 at the inlet 27. The outlet 28 of the injector 20 is connected to the pressure volume 21. When the injector 20 is actuated and thus opened, a defined injection quantity of the working medium AM is injected into the pressure volume 21 at the working pressure PA.

[0057] By injecting the working medium AM at high working pressure PA into the pressure volume 21, a short pressure pulse is created in the pressure volume 21. This causes the plunger 22 to move in a pulse-like manner towards the pressure piston 25 via the plunger piston 26 (indicated by a dashed line and greatly exaggerated in Fig. 2), which in turn moves the pressure piston 25, which is freely movable in the nozzle chamber 24, and the active medium WM to be injected is sprayed out of the nozzle opening 29 in a pulse-like manner, at high pressure and at high speed in the form of an active medium pulse with a specific injection quantity E. Due to the movement of the plunger 22, the pressure volume 21 increases by the injection quantity, whereby the pressure pulse in the pressure volume 21 is quickly reduced due to the incompressibility of the working medium AM and the pressure in the pressure volume 21 quickly reaches the initial pressure acting in the pressure volume 21, so that the movement of the pressure piston 25 is also quickly ended.In any case, the initial pressure in the pressure volume 21 is smaller, usually by several orders of magnitude smaller, than the working pressure p. A The initial pressure is usually atmospheric pressure and the working pressure PA is in the range of several tens to several hundred bar.

[0058] The working pressure PA of the working medium AM present in front of the injection valve 20 thus propagates via the open injection valve 20 to the tappet piston 26 and presses the tappet 22 with the tappet piston 26 by the amount resulting from the injection quantity in the direction of the nozzle unit 23. The tappet 22 transmits this movement to the pressure piston 25 in the nozzle unit 23 and presses the active medium WM filled in the nozzle volume 24 out of at least one nozzle opening 29 at a speed of up to 250 m / s. Upon exiting the nozzle opening 29, the active medium WM forms a micro-jet with high kinetic energy that penetrates the body surface and penetrates to a certain depth.

[0059] The outlet pressure of the active medium WM from the nozzle unit 23 is naturally dependent on the working pressure PA and essentially also depends on pressure losses in the applicator B, for example in the injection valve 20, friction losses, flow losses, etc. However, the outlet pressure can also be influenced by the ratio of the piston areas of the tappet piston 26 and the pressure piston 25.

[0060] The injection quantity E is essentially determined by the working pressure p A , the viscosity v of the active medium WM, the flow area when the injection valve 20 is open, and the opening duration t during which the injection valve 20 is open. This relationship can be determined empirically for a specific applicator B and can be assumed to be known.

[0061] Fig.6 shows an example of a relationship between working pressure p Aand injection quantity E, for example in microliters, at different viscosities v of the active medium WM and for a specific opening time t of the injection valve 20. The curves show the course of the injection quantity E at different viscosities v of the active medium WM as a function of the working pressure p A In this example, the viscosity increases from v1 to v3. Such relationships can be determined for different opening times t. Interpolation can be performed between these times as needed. Such relationships can also be established for different skin types.

[0062] This relationship, or such relationships, can be stored in the control unit 16, for example in table form. This allows for a specific active medium WM and a specific working pressure p A, the opening duration t of the injection valve 20 can be determined, with which the injection valve 20 must be controlled in order to deliver a certain injection quantity E with the applicator B. Likewise, an advantageous working pressure p A for a specific active medium WM for specific skin types.

[0063] Typical opening times of the injection valve 20 are in the range of 2 to 80 ms, advantageously between 5 and 40 ms.

[0064] The injection of the working medium AM into the pressure volume 21 by means of the injection valve 20 can be carried out once, resulting in a single delivered "shot" (active medium pulse) of the active medium WM to be injected via the nozzle unit 23. The active medium pulses can be repeated if necessary, with an active medium pulse being delivered each time the device 1 is actuated. This can be controlled by the applicator. However, the injection of the working medium AM can be carried out in a "burst mode" when the device 1 is actuated at predetermined time intervals in order to cause several consecutive "shots" (active medium pulses) of the active medium WM to be injected. This achieves intermittent operation with consecutive active medium pulses. In burst mode, time intervals in the range of one hundred milliseconds to one second, for example, between 0.5 and 2 seconds, are typical.This can be controlled via the control unit 16, for example, in response to the applicator's input via the input and output unit 17. The burst mode can be maintained as long as the device 1 is operated by the applicator. However, it can also be provided that the number of consecutive active medium pulses is predetermined or adjustable.

[0065] In particular, the working pressure PA can be adjusted on device 1. In burst mode, the number of times the injection valve 20 injects the working medium AM into the pressure volume 21 can also be adjusted. The working pressure PA (in relation to the initial pressure in the pressure volume 21) influences in particular the pressure and speed of the active medium WM sprayed out of the nozzle unit 23, but also the injection quantity E. The time interval between successive injection processes with the injection valve 20 could also be adjusted in burst mode. In burst mode, therefore, preferably the length and frequency of the active medium pulses, but if necessary also the quantity of the delivered active medium WM, can be adjusted. The settings can also be made depending on a desired injection volume. Patient characteristics, such as skin type, age, or injection site, could also be taken into account.

[0066] The device 1 can also be operated in burst mode so that active medium WM is released from the nozzle unit 23 at predetermined time intervals, for example, as long as a control button 30 is actuated, for example via a control button 30 and / or a safety switch 31. It is thus up to the applicator to decide how long the active medium WM is injected into the treated body surface. In the preferred normal mode, however, only one active medium pulse is triggered at a time when the device 1 is actuated, for example via a control button 30 and / or a safety switch 31.

[0067] An active medium pulse can also be delivered with a modulated pressure, as explained with reference to Fig. 7. Fig. 7 shows, as an example, the pressure curve in the pressure volume 21 for an active medium pulse over time T, starting with the initial pressure in the pressure volume 21. The pressure curve corresponds to the injection pressure PE, i.e. the pressure with which the working medium AM is injected by the injection valve 20 into the pressure volume 21. The dashed line shows the pressure curve without pressure modulation as an example. With pressure modulation, the pressure in the pressure volume 21 is varied during the active medium pulse. The pressure modulation naturally also modulates the injection quantity E delivered by the nozzle unit 23 during an active medium pulse and the pressure of the active medium pulse.

[0068] In the embodiment of Fig.7, working medium AM is first injected into the pressure volume 21 for a first time period T1, for example 2 to 5 ms, with a first injection pressure p EiThis is followed by a second time period T2, for example 2 to 40 ms, in which the working medium AM is injected with a second injection pressure p E 2 is injected, whereby the second injection pressure p E 2 is lower than the first injection pressure p E i. With such a pressure modulation, for example, the first high injection pressure p Ai to penetrate the body surface, for example the epidermis. With the lower second injection pressure p A 2 a depot of the active medium WM can then be created under the body surface, for example in the deeper layer of the skin.

[0069] With pressure modulation, other pressure profiles are of course also conceivable and possible. A desired pressure profile can be set for each active medium pulse, for example, in burst mode, or only at specific intervals if required. A combination of different pressure profiles in consecutive active medium pulses is also possible. A combination of active medium pulses with and without pressure modulation is also possible.

[0070] The pressure modulation can be realized with the injection valve 20. The applicator B is supplied with working medium AM at a specific working pressure p A This pressure is present at the inlet 27 of the injection valve 20. This is the maximum injection pressure p E, which can be reached in the pressure volume 21 (apart from losses). This maximum pressure occurs when the injection valve 20 is fully opened. The inlet pressure at the injection valve 20 is present at the outlet of the injection valve 20 in a short time, typically in the range of a millisecond, which is indicated by the ramp-like flanks in Fig.7. If, however, the injection valve 20 is not fully opened, but only partially, throttling is caused, which leads to a lower pressure at the outlet 28 of the injection valve 20 (apart from additional losses in the injection valve 20 for throttling) than at the inlet 27 and thus the injection pressure p E into the pressure volume 21 is lower. This relationship between this throttling of the injection pressure p Eand the extent of the opening (for example, in percent of the maximum opening) can again be determined experimentally and can be assumed to be known and can also be stored in the device 1, for example, in the control unit 16. A desired injection pressure p E can thus be adjusted via the degree of opening of the injection valve 20, for example, by the control unit 16 depending on a desired pressure curve. Pressure modulation is characterized by the fact that the injection pressure PE of the working medium AM into the pressure volume 21 is varied during an active medium pulse. This is advantageously achieved with the injection valve 20 by controlling the opening position of the injection valve 20.

[0071] The described design of the applicator B ensures a complete separation of the working medium AM and the active medium WM in the nozzle unit 23. Any contamination of the active medium WM in the nozzle unit 23 by the high-pressure side of the device 1 with the working medium AM is physically excluded.

[0072] For needle-free injection of the active medium WM, the nozzle unit 23 with at least one nozzle opening 29 can be placed directly on the patient's body surface to be treated, or at a freely selectable distance from the treated body surface. In the latter case, to prevent media splashes, it is advantageous to provide a tubular spacer 41 on the nozzle unit 23, which encompasses the media jet emitted by the nozzle unit 23 (see Fig. 4 for an exemplary design of such a spacer 41). The spacer 41 can also serve to maintain a specific distance from the patient's body surface.

[0073] For a single-hole nozzle with a nozzle opening 29, it has proven advantageous if the distance between the nozzle opening 29 and the patient's body surface is between 2 and 25 mm, preferably 5 and 15 mm. This can be easily ensured by a spacer 41. In this case, the spacer 41 is placed directly on the patient's body surface.

[0074] When using a multi-hole nozzle with multiple nozzle openings 29, a spacer 41 with a conical inner bore has proven advantageous. Cone angles of the inner bore between 25° and 35° have proven effective in studies. The distance from the nozzle opening 29 to the patient's body surface preferably varies between 15 and 40 mm, depending on the cone angle.

[0075] Even in the case of a single-hole nozzle, the spacer 41 can have a conical inner bore, whereby a cone angle of less than 5° is sufficient.

[0076] To simulate microneedling (mesotherapy), a nozzle unit 23 with multiple nozzle openings 29 is used, with small nozzle bores (0.10 to 0.15 mm) and a reduced working pressure PA (100-200 bar). The active medium WM is injected simultaneously at multiple locations into the superficial skin layers. The applicator can move the applicator B slowly over the skin area to be treated, with the active medium WM being released in burst mode at intervals of preferably 0.25 to 0.5 seconds. For this treatment, a spacer 41 with a length between 2 and 60 mm, preferably 15 and 50 mm, is preferably used.

[0077] A control button 30 can be arranged on the device 1, for example on the applicator B as indicated by dashed lines in Fig. 2, for example on an applicator housing 32, with which the applicator B is actuated. The control button 30 can be connected to the control unit 16 via the control line 12. If the applicator presses the control button 30 on the applicator B, the generation of at least one active medium pulse begins.

[0078] The control button 30 can also be provided on the base unit A (as in Fig.1).

[0079] For safety reasons, an additional safety switch 31, for example a foot switch, can be provided on the device 1, preferably on the base unit A. Such a switch 31 can be used to ensure that the applicator B only generates active medium pulses when the safety switch 31 is actuated. Actuation of a control button 30 would thus be ineffective as long as the safety switch 31 is not actuated. During operation of the applicator B, the generation of active medium pulses can be stopped immediately if the safety switch 31 is no longer actuated.

[0080] A lamp 30a, 31a, for example a bi-color LED, can also be installed in the control button 30 and / or the safety switch 31 (as in the embodiment according to Fig. 1) to indicate the system status of the device 1. This lamp 30a, 31a lights up, for example, when the device 1 is ready for operation. If the device 1 is not ready for operation, the lamp 30a, 31a can be provided not to light up or to light up in a different color.

[0081] Also for safety reasons, it can be provided that applicator B only generates active medium pulses after the control button 30 has been pressed continuously for a predetermined period of time, for example, in the range of seconds. This prevents the generation of active medium pulses if the control button 30 is accidentally pressed.

[0082] The device 1 can be operated in such a way that the pump 3, optionally with the pressure control valve 6, generates the set working pressure PA. Once the working pressure PA is reached, the pump 3 switches off. The pressure accumulator 10 keeps the working pressure PA approximately constant. Only when the applicator B is actuated for a specific period of time, for example 1 to 5 s, to generate the active medium pulses, does the pump 3 start up again and generate the set working pressure pA for a set period of time, for example 20 to 60 s, before the pump 3 is switched off again. Each further actuation of the applicator B for the specified period of time causes the pump 3 to start up again. This mode of operation serves to save energy and reduces wear in the pump 3. Further advantageous embodiments of an applicator B according to the invention are explained below with reference to Fig. 3.Only those components and functions that have not already been described above with reference to Figs. 1 and 2 are explained here.

[0083] In applicator B of Fig. 3, a compression spring 39 is arranged, which acts on the plunger 22, specifically on the plunger piston 26 of the plunger 22. The plunger 22 with the plunger piston 26, and during operation also the pressure piston 25, are moved against the spring action of the compression spring 39. The compression spring 39 also ensures that the plunger 22 is pushed back to its initial position (at minimal pressure volume 21) when the applicator B is depressurized, for example, to release the nozzle unit 23 from the applicator B. The compression spring 39 is tensioned when the applicator B is actuated, i.e. when working medium AM is injected into the pressure volume 21 by the injection valve 20.

[0084] The compression spring 39 as shown in Fig.3 can of course also be provided in a design as in Fig.2.

[0085] In the illustrated embodiment, the compression spring 39 engages the side of the plunger piston 26 facing away from the pressure volume 21. The other end of the compression spring 39 rests against a part of the applicator B that is immovable relative to the plunger 22 and pressure piston 25, for example, against a part of the applicator housing 32 or against an abutment 47, as in Fig. 3. The abutment 47 in Fig. 3 is designed as a ring that is screwed into the same internal thread into which the nozzle unit 23 is screwed. This allows the compression spring 39 and the plunger 22 to be easily removed after the ring has been removed.

[0086] To move the plunger 22 back to a starting position with minimal pressure volume 21, for example by means of the compression spring 39 or manually, it can be provided to depressurize the applicator B. This can be done via the non-return valve 9 and the return line 8. If the injection valve 20 is opened with the applicator B depressurized and the plunger 22 is pushed towards the starting position, working medium AM is fed back into the base unit A via the pressure hose 18 and flows there, with the pump 3 switched off, via the non-return valve 9 and the return line 8 into the storage container 2. During this procedure, the injection valve 20 is preferably opened in burst mode in order to reduce the risk of overheating of the injection valve 20 due to a long opening time and thus constant current supply.

[0087] A drainage opening 38 can be provided in the applicator housing 32 in order to easily drain any leakage of working medium AM from the applicator B. This drainage opening 38 also serves to immediately indicate a leak in the applicator B. In the event of a leak, the applicator B can be replaced immediately. A vent opening 36 can also be provided in the applicator B, which is connected to the pressure volume 21 and can be closed by a vent screw 35. The pressure volume 21 can, for example, be filled with working medium AM via the vent opening 36, whereby it is preferably ensured that the pressure volume 21 is completely vented during the filling process. The vent opening 36 with the vent screw 35, as shown in Fig. 3, can of course also be provided in a design as in Fig. 2.

[0088] In the area of ​​the inlet 27 of the injection valve 20, an additional storage volume 37 for working medium AM can be provided, which is filled with working medium AM at working pressure PA during operation of the applicator B. For example, the pressure hose 18 can be connected to the storage volume 37, and the inlet 27 can be connected to the storage volume 37. The storage volume 37 ensures that when the injection valve 20 is opened, the working pressure PA does not drop, but remains as constant as possible. It has proven sufficient if the storage volume 37 corresponds to between ten and one hundred times the injection quantity of the injection valve 20. The storage volume 37 as shown in Fig. 3 can of course also be provided in a design as shown in Fig. 2.

[0089] Fig. 4 shows a nozzle unit 23 in detail. In this embodiment, the active medium WM is filled into an active medium cartridge 40, which is inserted into an internal recess 42 of a cartridge holder 43. This enables rapid replacement of the active medium WM by replacing the active medium cartridge 40. To do this, the nozzle unit 23 is detached from the applicator B, for example, via a thread 44 on the cartridge holder 43, and the active medium cartridge 40 is replaced. The nozzle unit 23 can then be reattached to the applicator B.

[0090] In this embodiment, the active medium cartridge 40 forms the nozzle chamber 24 of the nozzle unit 23, in which the pressure piston 25 is arranged. The spacer 41 is also provided on the active medium cartridge 40 in this embodiment. Alternatively, it could also be provided on the cartridge holder 43.

[0091] It can also be seen that the pressure piston 25, at the end facing the nozzle opening 29, is shaped in the opposite direction to the inner contour of the active medium cartridge 40. This enables the active medium cartridge 40 to be emptied as completely as possible. This is, of course, also advantageous in a design of the nozzle unit 23 as shown in Fig. 2.

[0092] The active medium cartridge 40 can be closed at the end facing away from the nozzle opening 29 (which, in use, faces the plunger 22) with a non-removable plug 45 having a central recess for the plunger 22.

[0093] To effectively prevent unwanted multiple filling of the active medium cartridge 40, the pressure piston 25 can be provided with at least one sharp-edged, radially protruding nose on its surface. If necessary, the nose can also be arranged on the pressure piston 25 only after the filling process. When the pressure piston 25 moves during operation, such a nose creates a deep groove in the axial direction on the inside of the active medium cartridge 40, effectively preventing a subsequent pressure buildup in the active medium cartridge 40 and reuse of the active medium cartridge 40. Such an active medium cartridge 40 would be unusable for further use.

[0094] It is also advantageous if the active medium cartridge 40 is arranged in the cartridge holder 43 with as little gap as possible. If there is a gap between the active medium cartridge 40 and the cartridge holder 43, the active medium cartridge 40 could radially expand or deform during pressure buildup due to actuation of the pressure piston 25, which would adversely counteract the pressure buildup.

[0095] Therefore, it is advantageous if the inner recess 42 of the cartridge holder 43 is designed to taper slightly toward the nozzle opening 26 (as shown, for example, in Fig. 5). A cone angle between 0.1° and 2°, preferably between 0.15 and 1°, can be provided. The active medium cartridge 40 has the same cone angle over its outer diameter. This ensures that the active medium cartridge 40 rests against the inner recess 42 of the cartridge holder 43 over its entire surface. Expansion under the internal pressure generated by the pressure piston 25 can thus be prevented.

[0096] In addition, the active medium cartridge 40 advantageously protrudes axially from the cartridge holder 43 at the end opposite the nozzle opening 29. In one possible embodiment, the active medium cartridge 40 has a protruding collar 46 at this end. If the nozzle unit 23 with the active medium cartridge 40 arranged therein is attached to the applicator B, for example, screwed in, the cartridge is pressed into the cartridge holder 43 with a slight interference fit and without play via the axially protruding end, which, for example, comes into contact with the abutment 47 in the applicator B. Expansion under the internal pressure generated by the pressure piston 25 can thus be prevented.

[0097] The pressed-in active medium cartridge 40 can be ejected from the cartridge holder 43 after use using a special ejection tool.

[0098] Fig. 5 shows a further advantageous embodiment of a nozzle unit 23 with a cartridge holder 43 and an active medium cartridge 40. However, the embodiment described below is equally applicable if the active medium WM is used without an active medium cartridge 40 (for example, as in Fig. 2). This design is particularly advantageous for highly viscous active media WM. With highly viscous active media WM, it is possible that trapped air does not escape through the nozzle opening 29 during the filling process, but remains in the nozzle chamber 24. Trapped air in the nozzle chamber 24 can adversely affect the pressure buildup in the nozzle unit 23 and should therefore be avoided.

[0099] Therefore, a pressure piston 25 with an axially continuous recess 54 is used. Before the filling process, the pressure piston 25 is pressed all the way down so that the end of the pressure piston 25 facing the nozzle opening 29 rests axially in the active medium cartridge 40. At the opposite axial end, a filling connection 51 is provided on the pressure piston 25, to which a filling device (not shown) can be connected for filling. The filling connection 51 can be designed as a fastening thread or, preferably, as a male Lüer-Lock connection. For filling, the filling device can be connected to the recess 54 via the filling connection 51, for example by placing a female Lüer-Lock connection of the filling device onto the male Lüer-Lock connection, or by screwing a connection of the filling device onto the fastening thread.Through this (Lüer-Lock connection of the filling device), the (highly viscous) active medium WM is pressed through the recess 54 into the active medium cartridge 40, whereby the pressure piston 25 in the active medium cartridge 40 is raised. After reaching the intended filling volume, the (Lüer-Lock connection of the filling device is removed. The recess 54 can then be closed, for example with a plug 53 made of biocompatible elastomer. The nozzle opening 29 can be closed if necessary during filling.

[0100] In this design of the pressure piston 25, the radially projecting nose described above can be placed on the pressure piston 25 after the filling process.

[0101] In the embodiment according to Fig. 5, the recess 54 is widened at the end of the pressure piston 25 facing the plunger 22. A plug 53, preferably made of a biocompatible elastomer, is inserted into this widened part of the recess 54, and the recess 54 is closed. The plunger 22 is stepped at the end facing the pressure piston 25, whereby the reduced end 55 of the plunger 22, when the nozzle unit 23 is used, moves into the widened part of the recess 54 and presses the plug 53 into the recess 54 until the formed shoulder 56 of the plunger 22 rests against the pressure piston 25. The recess 54 is thus securely closed in a liquid-tight manner, which increases operational reliability.

[0102] To ensure the sterility of the active medium WM filled into the active medium cartridge 40, the active medium cartridge 40 can be covered and sealed on the nozzle side with a sterile closure, for example, a peel-off film. The nozzle side of the active medium cartridge 40, for example, in the area of ​​the spacer 41, can also be designed as a male Luer-Lock connection on which a female Luer-Lock plug is arranged. The closure, for example, the peel-off film or the Luer-Lock plug, must be removed before inserting the active medium cartridge 40 into the cartridge holder 43. If the active medium cartridge 40 is properly inserted into the cartridge holder 43, contact of the active medium cartridge 40, in particular the nozzle tip, with the non-sterile inner wall of the cartridge holder 43 is excluded by the guidance of the active medium cartridge 40 in the cartridge holder 43.

[0103] An active medium cartridge 40 with pressure piston 25 as described with reference to Figs. 4 and 5 is considered to be an independent invention.

[0104] Likewise, a nozzle unit 23 with a cartridge holder 43 and an active medium cartridge 40, as described with reference to Figs. 4 and 5, is considered an independent invention. Such a nozzle unit 23 is characterized in particular by the fact that the active medium cartridge 40 is inserted with a press fit into the cartridge holder 43, specifically into the inner recess 42 of the cartridge holder 43, in order to prevent any play between the active medium cartridge 40 and the inner recess 42 in the cartridge holder 43.

Claims

Patent claims 1. Applicator for the needleless injection of an active medium (WM) to be injected into a body surface, comprising a nozzle unit (23) with a nozzle volume (24) into which the active medium (WM) to be injected is filled, wherein at least one nozzle opening (29) is provided on the nozzle unit (23) and is connected to the nozzle volume (24), and wherein a pressure piston (25) is arranged in the nozzle unit (23), which at least partially delimits the nozzle volume (24) and is movably arranged in the nozzle unit (23), characterized in that an injection valve (20) is provided in the applicator (B), to which a working medium (AM) with a working pressure (PA) can be applied at an inlet (27), that a pressure volume (21) is provided in the applicator (B), and the pressure volume (21) is filled with working medium (AM) with an initial pressure less than the working pressure (PA). is filled, that the injection valve (20) is set up,during operation, to inject a predetermined injection quantity of the working medium (AM) into the pressure volume (21) at an injection pressure (PE) between the working pressure (PA) and the initial pressure, and in that a movably arranged plunger (22) is provided in the applicator (B), which has a plunger piston (26) at a first end which at least partially limits the pressure volume (21) and rests with an opposite second end on the pressure piston (25), so that the plunger (22) is movable in the direction of the pressure piston (25) during operation in order to move the pressure piston (25) in order to deliver an active medium pulse from the at least one nozzle opening (29).

2. Applicator according to claim 1, characterized in that the nozzle unit (23) is detachably arranged on the applicator (B).

3. Applicator according to claim 2, characterized in that the nozzle unit (23) is designed with a cartridge holder (43) with an inner recess (42) and an active medium cartridge (40) is replaceably inserted in the inner recess (42), wherein the at least one nozzle opening (29) is provided on the active medium cartridge (40) and the pressure piston (25) is movably arranged in the active medium cartridge (40).

4. Applicator according to claim 2 or 3, characterized in that a tubular spacer (41) is provided on the active medium cartridge (40) in the region of the nozzle opening (29), which protrudes axially from the active medium cartridge (40) by a predetermined length and which at least partially surrounds the nozzle opening (29) so that the active medium pulse exits through the tubular spacer (41).

5. Applicator according to claim 3, characterized in that the inner recess (42) in the cartridge holder (43) and the active medium cartridge (40) are designed to converge in a conical manner in the direction of the at least one nozzle opening (29).

6. Applicator according to one of claims 1 to 5, characterized in that the pressure piston (25) is designed with an axially continuous recess (54).

7. Applicator according to claim 6, characterized in that a filling connection (51) is provided on the side of the pressure piston (25) facing away from the at least one nozzle opening (29) in order to fill the active medium (WM) into the nozzle volume (24) via the filling connection (51) and the axially continuous recess (54).

8. Applicator according to claim 6, characterized in that the axially continuous recess (54) is closed when the active medium cartridge (40) is filled.

9. Applicator according to one of claims 1 to 8, characterized in that a control button (30) is provided on the applicator (B) to actuate the injection valve (20).

10. Applicator according to one of claims 1 to 9, characterized in that the injection valve (20) is designed to inject a predetermined injection quantity of the working medium (AM) into the pressure volume (21) several times during operation at an injection pressure (PE) between the working pressure (PA) and the initial pressure. 11 . Applicator according to claim 10, characterized in that the repeated injections take place at predetermined time intervals.

12. Applicator according to one of claims 1 to 11, characterized in that the injection valve (20) varies the injection pressure (PE) during the delivery of at least one active medium pulse.

13. Applicator according to claim 12, characterized in that the injection valve (20) is firstly operated for a first time period (T1) with a first injection pressure (p E i) and then injects for a second period of time (T2) at a second injection pressure (pE2), wherein the second injection pressure (pE2) is lower than the first injection pressure (p E i).

14. Applicator according to one of claims 1 to 13, characterized in that a compression spring (39) is arranged in the applicator (B), which acts on the plunger (22), preferably on the plunger piston (26) of the plunger (22).

15. Applicator according to claim 14, characterized in that the compression spring (39) engages with a first end on the side of the plunger piston (26) facing away from the pressure volume (21) and a second end of the compression spring (39) bears against a part of the applicator (B) which is immovable relative to the plunger (22).

16. Device for needleless injection of an active medium (WM) to be injected into a body surface with an applicator (B) according to one of claims 1 to 15, wherein a base unit (A) is provided which provides the working medium (AM) with the working pressure (PA) and the base unit (A) is connected to the applicator (B) via a pressure hose (18) in order to supply the working medium (AM) with the working pressure (PA) to the applicator (B).

17. Device according to claim 16, characterized in that a pump (5) is provided in the base unit (A) which increases the pressure of a working medium (AM) from a storage container (2) to the working pressure (PA), wherein the pump (5) delivers into a pressure line (7) which is connected to the pressure hose (18).

18. Device according to claim 17, characterized in that downstream of the pump (5) in the pressure line (7) branches off a return line (8), in which a controllable return valve (9) is arranged in order to depressurize the pressure line (7) via the return line (8) when the return valve (9) is open.

19. Device according to one of claims 16 to 18, characterized in that a safety switch (31) is provided on the device (1) to enable or disable the operation of the applicator (B).

20. Method for the needleless injection of an active medium (WM) to be injected into a body surface, with an applicator (B) having a nozzle unit (23) with a nozzle volume (24) containing the active medium (WM), wherein in the nozzle unit (23) for dispensing the active medium (WM) via at least one nozzle opening (29) of the nozzle unit (23) a pressure piston (25) which at least partially delimits the nozzle volume (24) is moved, characterized in that an injection valve (20) is supplied with a working medium (AM) at a working pressure (PA), and the injection valve (20) injects a predetermined injection quantity of the working medium (AM) at an injection pressure (PE) into a pressure volume (24) in the applicator (B) filled with working medium (AM), in which an initial pressure less than the working pressure (PA) acts, and the injection pressure (PE) is between the working pressure (PA) and the initial pressure is selected,and that by injecting the working medium (AM) into the pressure volume (24), a plunger (22) which is movably arranged in the applicator (B) and which at least partially limits the pressure volume (24) with a plunger piston (26) arranged at a first end and rests against the pressure piston (25) with an opposite second end is moved in the direction of the pressure piston (25), so that due to the movement of the pressure piston (25) an active medium pulse is emitted from the at least one nozzle opening (29).

21. Method according to claim 20, characterized in that the injection valve (20) is used to inject several times into the pressure volume (21) in order to deliver several active medium pulses.

22. Method according to claim 20 or 21, characterized in that the injection valve (20) varies the injection pressure (PE) during at least one active medium pulse.

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