Applicator, device and method for needle-free injection of active medium to be injected

Abstract

In order to provide an applicator for needle-free injection of an active medium (WM), which provides a high injection pressure and ensures a reliable and safe separation of the active medium (WM) to be injected from the operation of the device (1), provision is made for an injection valve (20) to be arranged in the applicator (B), on which a working medium (AM) with a working pressure (pA) can be applied at an inlet (27), a pressure volume region (21) is arranged in the applicator (B) and is filled with a working medium (AM) having a starting pressure which is lower than the working pressure (pA), and an injection valve (20) is provided for injecting a predetermined injection amount of the working medium (AM) into the pressure volume region (21) during operation at an injection pressure (pE) which is between the working pressure (pA) and the starting pressure, a pressure piston (25) is arranged in the applicator (B), and a displaceably arranged tappet (22) is arranged in the applicator (B), which tappet has a tappet piston (26) at a first end, which tappet piston at least partially delimits the pressure volume (21) and which bears with an opposite second end against the pressure piston (25) such that the tappet (22) can be moved in the direction of the pressure piston (25) during operation in order to move the pressure piston (25), in order to output a pulse of active medium from the at least one nozzle opening (29).

Description

Technical Field

[0001] The present invention relates to an applicator for needle - free injection of an active medium to be injected into the body surface. The applicator has a nozzle unit with a nozzle volume region into which the active medium to be injected is filled. At least one nozzle opening connected to the nozzle volume region is provided on the nozzle unit, and a pressure piston is provided in the nozzle unit. The pressure piston at least partially defines the nozzle volume region and is movably arranged in the nozzle unit. The present invention also relates to a method and a device for needle - free injection of an active medium to be injected into the body surface using such an applicator. Background Art

[0002] WO 2012 / 139774 A1 describes a device for needle - free injection of a medium into the skin or under the skin by a series of pressure pulses. The device defined there is characterized by the lowest structural complexity required to achieve the said purpose. Since it is a minimally invasive needle - free injection into the skin, according to EU Regulation No. 2017 / 745 on medical devices, this device belongs to class IIb risk devices. Therefore, all surfaces in the device that come into contact with the medium to be injected must be biocompatible and sterilizable. Most existing standard components, such as high - pressure pumps, valves, reservoirs or pipes, cannot meet this requirement, which makes it difficult to commercialize such a device. For individual components of such a device, specialized development is required, which makes the device costly and expensive.

[0003] EP 2 957 309 B1 describes a cylinder - piston unit for a needle - free syringe. A medium to be injected is contained in a cylinder. The cylinder has a nozzle for discharging the medium at one end and a piston at the opposite end. By an operating device not described in detail, the piston is pulsed in the direction of the nozzle, so that the medium enters the patient's skin through the nozzle.

[0004] EP 2 035 065 B1 describes a device for needle - free injection of an aqueous medium into a patient's skin. In a nozzle filled with the medium to be injected, a piston is driven back and forth by a pneumatic cylinder. When the piston moves backward, the aqueous medium is conveyed into the nozzle through a dosing unit, and when the piston moves forward, the medium is discharged through the nozzle. However, this device can only reach a pressure of about 150 bar, which is too low for many applications, especially for high - viscosity media. In addition, when the piston moves backward, air may also be sucked in through the nozzle, which may affect the discharge of the medium when the piston moves forward the next time. KR 20140054812A also shows such a device. Summary of the Invention

[0005] The object of the present invention is to provide an applicator for the needle-free injection of active media, which can achieve a high injection pressure and ensure a reliable and safe separation of the active media to be injected from the operation of the device.

[0006] This object is solved in that an injection valve is provided in the applicator, on which a working medium with a working pressure can be applied on the inlet side, a pressure volume region is also provided in the applicator and this pressure volume region is filled with a working medium having an initial pressure less than the working pressure, the injection valve is arranged to inject a predetermined injection volume of the working medium into the pressure volume region during operation at an injection pressure between the working pressure and the initial pressure, a movable push rod is provided in the applicator, which has a push rod piston at its first end, the push rod piston at least partially defines the pressure volume region and abuts with its opposite second end against a pressure piston, such that the push rod can move in the direction of the pressure piston during operation to move the pressure piston in order to output an active media pulse from the at least one nozzle opening.

[0007] The active media and the working media are physically and spatially separated by the push rod. Furthermore, only a very low pressure relative to the working pressure (usually atmospheric pressure) acts in the pressure volume region. In the case of correct use of the applicator, contamination of the active media by the working media is excluded. Thereby, the active media can also be reliably separated from the operation in the nozzle unit, since the active media cannot come into contact anywhere except in the nozzle unit and in particular not inside the applicator.

[0008] Here, it is also advantageous that the generation of the working pressure of the working media is carried out separately from the applicator. For this purpose, a basic unit can be provided, which provides a working media with a working pressure, and this basic unit is connected to the applicator via a pressure pipe in order to convey the working media with the working pressure to the applicator. None of the components of the basic unit come into contact with the active media, so there are no special requirements for these components, in particular they do not have to be biocompatible and sterilizable.

[0009] Preferably, the nozzle unit is detachably arranged on the applicator. This enables a simple and quick replacement of the active media.

[0010] Advantageously, the nozzle unit is designed to have a cartridge holder with internal grooves, and an active media cartridge is replaceably mounted in the internal grooves, wherein the at least one nozzle opening is arranged on the active media cartridge, and the pressure piston is movably arranged in the active media cartridge. Active media cartridges with different active media and different active media volumes can be provided as consumables for the operation of the applicator. The active media cartridge can be replaced simply and safely in the applicator.

[0011] In order to be able to place the applicator at a defined position on the body surface, a tubular spacer is advantageously provided on the active medium cartridge in the region of the nozzle opening. The tubular spacer projects axially from the active medium cartridge by a predetermined length and the tubular spacer surrounds the nozzle opening such that the active medium pulses are output through the tubular spacer. Thereby, the distance between the nozzle opening and the body surface is reliably set and maintained. In addition, splashing of the active medium is avoided by the tubular spacer.

[0012] Particularly advantageously, the inner groove in the cartridge holder and the active medium cartridge are designed to converge in a conical shape in the direction of the at least one nozzle opening. For this purpose, the active medium cartridge can be shaped accordingly. In this way, during use, the active medium cartridge can be pressed into the cartridge holder such that the active medium cartridge can reliably and in particular completely fit against the cartridge holder. This prevents the active medium cartridge from expanding or deforming during operation of the applicator, as this could affect the pressure build-up in the nozzle volume region of the active medium cartridge and thus the generation of the active medium pulses.

[0013] In order to be able to safely and simply fill the nozzle volume region with the active medium, the pressure piston can be designed with an axially through groove. Thereby, filling can be carried out through the pressure piston and air can be prevented from remaining in the nozzle volume region during filling. For this purpose, a filling interface is advantageously provided on the side of the pressure piston remote from the at least one nozzle opening, so that the active medium can be filled into the nozzle volume region through the filling interface and the axially through groove. A filling mechanism can be connected at the filling interface for filling.

[0014] Preferably, a control button is provided on the applicator for operating the injection valve. The control button can be operated by the operator.

[0015] The applicator can also be used to inject a predetermined injection volume of the working medium into the pressure volume region through the injection valve multiple times at an injection pressure between the working pressure and the starting pressure during operation. Thereby, a plurality of active medium pulses are output successively in time. The multiple injections can be controlled by the operator, but can also be carried out at predetermined time intervals.

[0016] Advantageously, the injection valve changes the injection pressure during the output of at least one active medium pulse. Thereby, pressure modulation can be achieved and the injection of the active medium onto the body surface can be controlled more flexibly, which also makes the application gentler. In this regard, it is particularly advantageous that the injection valve first injects at a first injection pressure during a first time period and then injects at a second injection pressure during a second time period, wherein the second injection pressure is lower than the first injection pressure. Here, the high first pressure can penetrate the body surface so that subsequently the lower, gentler pressure can inject the required amount of the active medium into the body surface.

[0017] To generate the working pressure, a pump is advantageously provided in the basic unit, which raises the pressure of the working medium from the storage container to the working pressure, and the pump conveys the working medium into a pressure pipeline connected to the pressure tube.

[0018] In the basic unit, preferably downstream of the pump, a return pipeline branches off from the pressure pipeline, and a controllable return valve is provided in the return pipeline so that when the return valve is opened, the pressure pipeline can be depressurized through the return pipeline. In this way, the device and the applicator can be simply depressurized, for example, for disassembling the nozzle unit, for example, for replacing the active medium cartridge. In the depressurized state, the push rod can also be simply pushed back into its initial position, preferably automatically returned by the pressure spring acting on the push rod.

[0019] The pressure spring preferably acts with its first end on the side of the piston of the push rod away from the pressure volume region, and the second end of the pressure spring preferably abuts against a component of the applicator that is immovable relative to the push rod, which makes the structural design simple.

[0020] To improve the operating safety, a safety switch is advantageously provided on the device for releasing or locking the operation of the applicator. Only when the safety switch is activated can the device be operated through the control button. This can prevent the accidental output of active medium pulses on the applicator. Description of the Drawings

[0021] The following will refer to Figures 1 to 7 to describe the present invention in more detail. These figures show the advantageous embodiments of the present invention in an exemplary, schematic and non-limiting manner. In the drawings:

[0022] Figure 1 A schematic diagram of the device of the present invention is shown, which includes a basic unit and an applicator;

[0023] Figure 2 An embodiment of the applicator of the present invention is shown;

[0024] Figure 3 Another embodiment of the applicator of the present invention is shown;

[0025] Figure 4 An embodiment of the nozzle unit for the applicator of the present invention is shown;

[0026] Figure 5 Another embodiment of the nozzle unit for the applicator of the present invention is shown;

[0027] Figure 6 An example relationship between the working pressure and the injection volume for different active media is shown; and

[0028] Figure 7Shows an example of pressure modulation in the pressure - volume region. Detailed Description

[0029] The device 1 of the present invention is used to inject different active media WM into the body surface of a patient (human or animal) without a needle, such as the skin or fingernails or toenails. As the active medium WM, for example, a disinfectant, an antibiotic, botulinum toxin, an aqueous solution of an anesthetic, and a high - viscosity hyaluronic acid with a kinematic viscosity up to 1 square meter per second (1 million centistokes), platelet - rich plasma (PRP), a particle suspension with a maximum particle size less than half of the nozzle cross - section, or an antifungal agent (for example, for treating onychomycosis) can be used.

[0030] The device 1 of the present invention generates and regulates the working pressure p of the working medium AM required for the above - mentioned functions in the basic unit A A Separate from the components required for intermittent needle - free injection of the active medium WM to be injected in the applicator B. Thus, in the basic unit A and the applicator B, mainly standard components can be used for the working medium AM. In addition, compliance with EU Regulation No. 2017 / 745 is also ensured thereby.

[0031] Therefore, the device 1 consists of a basic unit A and an applicator B. The basic unit A is used to generate and regulate the working pressure p of the working medium AM A . The applicator B is used for needle - free injection and is held or operated by an operator (such as a doctor). The applicator B is connected to the basic unit A through a pressure tube 18. For this purpose, a suitable medium coupler 11, such as a quick - locking coupler, can be provided on the basic unit A and / or the applicator B to detachably connect the pressure tube 18.

[0032] Similarly, an electrical control line 12 is provided between the basic unit A and the applicator B to achieve a communication connection between the applicator B and the basic unit A, for example, for data exchange or for controlling the functions of the applicator B. For this purpose, suitable connectors 13, such as socket - plug connection devices, can also be provided on the basic unit A and / or the applicator B to detachably connect the control line 12.

[0033] Therefore, the basic unit A can also be used with different applicators B.

[0034] In a preferred embodiment, the control line 12 and / or the pressure tube 18 are fixedly connected to the applicator B. The medium coupler 11 and / or the connector 13 are provided on the basic unit A for connecting the pressure tube 18 and / or the control line 12. Thus, the applicator B can be simply separated from or replaced with the basic unit A.

[0035] The control line 12 and the pressure line 18 can also be guided in a common pipe assembly, which can simplify the operation of the applicator B.

[0036] The basic unit A is supplied with electrical energy by a power supply C, for example, through a power grid connection as Figure 1 shown, or by a battery in the basic unit A, or by a battery connectable to the basic unit A.

[0037] The basic unit A can have a main switch 14 for turning on and off the device 1 and an electrical fuse device 15.

[0038] A control unit 16 is provided in the basic unit A. Similarly, an input / output unit 17, such as a touch screen, a display screen, a light, an indicator light, a button, a knob, a slider, etc., can be provided on the basic unit A to display information to the operator and / or allow the operator to input to control the functions of the device 1.

[0039] The control unit 16 is generally hardware based on a microprocessor, and software runs on this hardware. However, the control unit 16 can also be designed as an integrated circuit, such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC). Of course, a combined approach can also be envisaged.

[0040] In order to generate pressure for the working medium AM (preferably a synthetic fluid or medical silicone oil), a storage container 2 is provided in the basic unit A, and a pump 3 draws the working medium AM from the storage container to raise the pressure of the working medium AM to the required working pressure p A . The pump 3 transports the working medium AM into the pressure line 7. A filter 4 can be provided between the pump 3 and the storage container 2. The pump 3 can be driven by an electric motor 5, and the electric motor can be controlled by the control unit 16.

[0041] The pump 3 can be designed as a pump with controllable rotational speed so as to set a definite working pressure p of the working medium AM in the pressure line 7 A .

[0042] In order to set the working pressure p of the working medium AM A , a pressure regulating valve 6 can also be provided downstream of the pump 3, as in the Figure 1 embodiment shown. The pressure regulating valve 6 can be electrically operated, for example, controlled by the control unit 16, or mechanically operated, for example, by a knob on the basic unit A. By operating the pressure regulating valve 6, the required working pressure p can be set A . The current working pressure p in the pressure line 7 A can also be displayed on a pressure display, such as a pressure gauge or on the input / output unit 17.

[0043] A pressure sensor 19 can also be provided in the pressure pipeline 7 for detecting the current working pressure p A . The detected working pressure p A can be sent as a signal to the control unit 16 and / or can be displayed on the input / output unit 17

[0044] A return pipeline 8 can also be provided in the basic unit A. The return pipeline branches off from the pressure pipeline 7 and is guided to the storage container 2 through a return valve 9. The return valve 9 can be controlled by the control unit 16 (as Figure 1 shown) to open the return pipeline 8 leading to the storage container 2, for example, to depressurize the device 1. Alternatively, the return valve 9 can also be manually operated. To also depressurize the pressure volume area 21, the injection valve 20 can be opened, for example, through the control of the control unit 16. Thereby, it is convenient to remove the nozzle unit 23

[0045] In addition, a pressure accumulator 10 can also be provided in the basic unit A. The pressure accumulator is connected to the pressure pipeline 7. The pressure accumulator 10 ensures that the working pressure p in the pressure pipeline 7 A is as constant as possible and should suppress pressure fluctuations

[0046] When the pressure pipe 18 is connected, the pressure pipeline 7 is connected to the pressure pipe to guide the working medium AM with a set working pressure p A to the applicator B

[0047] At least some of the above-mentioned components and members are preferably arranged in the closed housing of the basic unit A

[0048] However, the embodiment of the basic unit A according to Figure 1 is only an example and can be any other. The key of the present invention is to provide, by means of the basic unit A, the working medium AM with the required working pressure p A , and the working medium AM is guided to the applicator B through the pressure pipe 18. The working pressure p of the working medium AM A can generally reach 500 bar here, which is sufficient for most treatments

[0049] The applicator B ensures reliable and safe separation of the working medium AM and the active medium WM to be injected through its structure Figure 2 The structure of the applicator B is shown in a schematic diagram

[0050] The applicator B of the present invention includes a controllable injection valve 20, a pressure volume area 21, a push rod 22, and a nozzle unit 23

[0051] The injection valve 20 is a controllable valve. During operation, it will act on the working pressure p at the inlet 27 of the injection valve 20A The working medium AM is conveyed to the outlet 28 of the injection valve 20. When using the applicator B, the pressure line 18 conveying the working medium AM with the working pressure p A is connected to the inlet 27 of the injection valve 20. If the injection valve 20 is not operated, the working medium AM is not conveyed from the inlet 27 to the outlet 28.

[0052] The injection valve 20 is preferably electrically operated and can be connected to the control line 12 for this purpose, and the injection valve 20 can be controlled to operate through the control line, for example, controlled by the control unit 16 in the basic unit A.

[0053] A nozzle chamber 24 is provided in the nozzle unit 23, and the active medium WM to be injected is arranged in the nozzle chamber. The nozzle chamber 24 is connected to the nozzle opening 29 of the nozzle unit 23 so that the active medium WM to be injected is ejected through the nozzle opening 29 during operation. The nozzle chamber 24 is preferably delimited by a pressure piston 25 on the opposite side of the nozzle opening 29. The pressure piston 25 is movably arranged in the nozzle chamber 24. Between the pressure piston 25 and the wall of the nozzle unit 23 surrounding the nozzle chamber 24 or between the pressure piston and the active medium cartridge 40 (for example, see Figure 4 or Figure 5 ), a sealing element 33, such as an O-ring, is provided to prevent the leakage of the active medium WM between the pressure piston 25 and the wall of the nozzle unit 23 or between the pressure piston and the active medium cartridge 40 (for example, see Figure 4 or Figure 5 ). During operation of the device 1, the pressure piston 25 reduces the size of the nozzle chamber 24 so that the active medium WM to be injected is ejected from the nozzle opening 29.

[0054] The diameter of the nozzle opening 27 is generally 0.1 mm to 0.3 mm, depending on the viscosity of the active medium WM.

[0055] The nozzle unit 23 with the pressure piston 25 is preferably detachably and replaceably arranged on the applicator B. For example, the nozzle unit 23 can be screwed onto the applicator B or screwed into the applicator B.

[0056] The applicator B can have an applicator housing 32, and the injection valve 20, the pressure volume area 21 and the push rod 22 are arranged in the applicator housing. The nozzle unit 23 is detachably arranged on the applicator housing 32, for example, screwed into the applicator housing 32.

[0057] The push rod 22 abuts against the pressure piston 25 at one end or is connected to the pressure piston 25 at this end, so as to move the pressure piston 25 when the applicator B is operating. A push rod piston 26 is provided on the other end of the push rod 22. The push rod piston is adjacent to the pressure volume region 21 and at least partially defines the pressure volume region 21. A sealing element 34, such as an O-ring, is provided between the push rod piston 26 and the wall of the applicator B surrounding the pressure volume region 21 to prevent the working medium AM from leaking between the push rod piston 26 and the wall of the applicator B.

[0058] The pressure volume region 21 is filled with the working medium AM, preferably without air that may play a role in buffering pressure being mixed in. Before the applicator B is put into use, the pressure volume region 21 can be filled with the working medium AM.

[0059] The injection valve 20 is supplied with the working medium AM having the working pressure p at the inlet side at the inlet 27 through the pressure pipe 18. A The outlet 28 of the injection valve 20 is connected to the pressure volume region 21. When the injection valve 20 is operated and thus opened, the working medium AM having the determined injection volume with the working pressure p A is injected into the pressure volume region 21.

[0060] By injecting the working medium AM having the high working pressure p A into the pressure volume region 21, a short pressure pulse will be generated in the pressure volume region 21. Thereby, the push rod 22 moves pulsatingly in the direction of the pressure piston 25 through the push rod piston 26 (shown in dashed lines and greatly exaggerated in Figure 2 ), thereby moving the pressure piston 25 that can move freely in the nozzle chamber 24, and the active medium WM to be injected is pulsed out of the nozzle opening 29 in the form of an active medium pulse with high pressure and high speed and having a determined injection volume E. Due to the movement of the push rod 22, the pressure volume region 21 will increase due to the injection volume. Thus, due to the incompressibility of the working medium AM, the pressure pulse in the pressure volume region 21 will rapidly decay, and the pressure in the pressure volume region 21 will rapidly reach the starting pressure acting on the pressure volume region 21, so that the movement of the pressure piston 25 will also rapidly stop. The starting pressure in the pressure volume region 21 is less than the working pressure p A anyway, usually several orders of magnitude smaller. The starting pressure is usually atmospheric pressure, while the working pressure p A is in the range of several tens to several hundreds of bar.

[0061] Therefore, the working pressure p of the working medium AM existing in front of the injection valve 20 AIt will be transmitted to the push rod piston 26 through the open injection valve 20, and the push rod 22 with the push rod piston 26 will be extruded in the direction of the nozzle unit 23, and the degree of extrusion is determined by the injection volume. The push rod 22 transmits this movement to the pressure piston 25 in the nozzle unit 23, and the active medium WM filled in the nozzle volume area 24 is extruded from the at least one nozzle opening 29 at a speed of up to 250 m / s. When discharged from the nozzle opening 29, the active medium WM forms a microjet with high kinetic energy, and this microjet penetrates the body surface and penetrates to a certain depth.

[0062] The outlet pressure of the active medium WM from the nozzle unit 23 naturally depends on the working pressure p A , and to a large extent also depends on the pressure loss in the applicator B, such as the pressure loss in the injection valve 20, frictional loss, flow loss, etc. However, the outlet pressure can also be affected by the piston area ratio of the push rod piston 26 and the pressure piston 25.

[0063] The injection volume E is mainly determined by the working pressure p A , the viscosity ν of the active medium WM, the flow area when the injection valve 20 is opened, and the opening duration t when the injection valve 20 is opened. For a determined applicator B, this relationship can be determined through experiments and can be regarded as known conditions.

[0064] Figure 6 Exemplarily shows the relationship between the working pressure p A and the injection volume E (for example in microliters) under different viscosities ν of the active medium WM and at a determined opening duration t of the injection valve 20. These curves show the variation of the injection volume E with the working pressure p A under different viscosities ν of the active medium WM. In this example, the viscosity increases from ν1 to ν3. This relationship can be determined for different opening durations t. If necessary, interpolation can also be performed therein. This relationship can also be established for different skin types.

[0065] This relationship or these relationships can be stored in the control unit 16, for example, in tabular form. In this way, 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, and the opening duration of the injection valve 20 must be controlled to output a determined injection volume E using the applicator B. Similarly, according to this relationship, the appropriate working pressure p of a specific active medium WM can also be determined for a specific skin type A .

[0066] The typical opening duration of the injection valve 20 is between 2 milliseconds and 80 milliseconds, advantageously between 5 milliseconds and 40 milliseconds.

[0067] The operation of injecting the working medium AM into the pressure volume region 21 via the injection valve 20 can be carried out once, so that a "jet" (active medium pulse) of the separate output of the active medium WM to be injected can be achieved via the nozzle unit 23. If necessary, the active medium pulse can be repeated, and an active medium pulse is output each time the device 1 is operated. This can be controlled by the operator. However, when operating the device 1, the working medium AM can also be injected in a "pulse mode" at a predetermined time interval in order to achieve a plurality of temporally successive "jets" (active medium pulses) of the active medium WM to be injected. Thereby, an intermittent operation with successive active medium pulses is achieved. In the pulse mode, the time interval is generally in the order of several hundred milliseconds to one second, for example, between 0.5 seconds and 2 seconds. This can be controlled by the control unit 16, for example, in response to an input operation by the operator via the input / output unit 17. As long as the operator operates the device 1, the pulse mode can be maintained all the time. However, it can also be stipulated that the number of temporally successive active medium pulses is preset or adjustable.

[0068] Therefore, the working pressure p can be adjusted particularly on the device 1 A . In the pulse mode, the frequency of injecting the working medium AM into the pressure volume region 21 by the injection valve 20 can also be adjusted. The working pressure p A (relative to the starting pressure in the pressure volume region 21) particularly affects the pressure and speed of the active medium WM ejected from the nozzle unit 23, as well as the injection volume E. In the pulse mode, the time interval between successive injection processes of the injection valve 20 can also be adjusted. Therefore, in the pulse mode, preferably, the time length and frequency of the active medium pulse and, if necessary, the amount of the active medium WM output can be adjusted. These settings can also be adjusted according to the required injection volume. Some characteristics of the patient, such as skin type, age or injection site, can also be taken into account.

[0069] The device 1 can operate in the pulse mode such that as long as the active medium WM is output from the nozzle unit 23 within a predetermined time interval, for example, as long as the operation control button 30 is operated (for example, via the control button 30 and / or the safety switch 31). Thereby, the operator can decide by himself / herself the duration of injecting the active medium WM into the treated body surface. In the preferably used normal operation, each operation of the device 1 (for example, via the control button 30 and / or the safety switch 31) only triggers one active medium pulse.

[0070] The active medium pulse can also be output at a modulated pressure, as explained according to Figure 7 what has been explained. Figure 7Exemplarily shown is the pressure change in the pressure volume region 21 within an active medium pulse at time T, starting from the initial pressure in the pressure volume region 21. This pressure change curve corresponds to the injection pressure p E i.e., the pressure when the working medium AM is injected into the pressure volume region 21 through the injection valve 20. The dashed line shows the pressure change, for example, when there is no pressure modulation. When pressure modulation is carried out, the pressure in the pressure volume region 21 changes during the active medium pulse. Through pressure modulation, naturally, the injection amount E output from the nozzle unit 23 during an active medium pulse and the pressure of the active medium pulse are also modulated.

[0071] In Figure 7 the embodiment of, first, within a first time period T1 (e.g., 2 to 5 milliseconds), the working medium AM is injected into the pressure volume region 21 at a first injection pressure p E1 Subsequently is a second time period T2 (e.g., 2 to 40 milliseconds), during which the working medium AM is injected at a second injection pressure p E2 wherein the second injection pressure p E2 is lower than the first injection pressure p E1 . Through such pressure modulation, for example, the high first injection pressure p A1 can be used to penetrate the body surface, such as the epidermis. Then, the lower second injection pressure p A2 can form an accumulation of the active medium WM beneath the body surface, in, for example, a deeper skin layer.

[0072] When carrying out pressure modulation, of course, other pressure change curves can also be conceived and implemented. The required pressure change curve can be set for each active medium pulse, for example, in a pulse mode or only at determined intervals as needed. Different pressure change curves can also be combined in successive active medium pulses. Similarly, active medium pulses with pressure modulation and without pressure modulation can also be combined.

[0073] Pressure modulation can be achieved through the injection valve 20. The applicator B is supplied with the working medium AM having a determined working pressure p A . This pressure acts at the inlet 27 of the injection valve 20. This is the maximum injection pressure p E that can be achieved in the pressure volume region 21 (neglecting losses). When the injection valve 20 is fully open, this maximum pressure is reached. The inlet pressure at the injection valve 20 acts on the outlet of the injection valve 20 within a short time (usually in the range of one millisecond), Figure 7The sloped edge therein indicates this. Conversely, if the injection valve 20 is not fully opened but only partially opened, a throttling effect will occur, which will cause the pressure at the outlet 28 of the injection valve 20 (disregarding the additional losses generated within the injection valve 20 for throttling) to be lower than the pressure at the inlet 27, thereby causing the injection pressure p of the injection pressure volume region 21 E to decrease. This relationship between the throttling of the injection pressure p E and the opening degree (e.g., the percentage relative to the maximum opening) can be determined experimentally again and can be regarded as a known condition, or can also be stored in the device 1, for example, stored in the control unit 16. Therefore, the required injection pressure p can be set by adjusting the opening degree of the injection valve 20 (e.g., by the control unit 16 according to the required pressure variation curve) E .

[0074] Therefore, the characteristic of pressure modulation is to change the injection pressure p of the working medium AM in the injection pressure volume region 21 during the active medium pulse E . This is advantageously achieved by means of the injection valve 20 by controlling the opening position of the injection valve 20

[0075] The above structure of the applicator B ensures 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 working medium AM on the high-pressure side of the device 1 is physically excluded

[0076] For needleless injection of the active medium WM, the nozzle unit 23 with the at least one nozzle opening 29 can be placed directly on the body surface of the patient to be treated, or placed at a freely selectable distance from the body surface to be treated. In the latter case, in order to avoid medium splashing, it is advantageous to provide a tubular spacer 41 on the nozzle unit 23, which surrounds the medium jet output from the nozzle unit 23 (see Figure 4 , which shows an example design of such a spacer 41). The spacer 41 can simultaneously be used to maintain a defined distance from the patient's body surface

[0077] For a single-hole nozzle with one nozzle opening 29, it has been proven advantageous that the distance between the nozzle opening 29 and the patient's body surface is between 2 millimeters and 25 millimeters, preferably between 5 millimeters and 15 millimeters. This can be easily ensured by the spacer 41. In this case, the spacer 41 is placed directly on the patient's body surface

[0078] When using a porous nozzle with multiple nozzle openings 29, a spacer 41 with a conical inner bore has proven to be advantageous. Studies have shown that it is advantageous for the cone angle of the inner bore to be between 25° and 35°. The distance from the nozzle opening 29 to the patient's body surface preferably varies between 15 mm and 40 mm depending on the cone angle.

[0079] Even for a single-hole nozzle, the spacer 41 can have a conical inner bore, where the cone angle can be less than 5°.

[0080] To simulate microneedle therapy (mesotherapy), a nozzle unit 23 with multiple nozzle openings 29 can be used, which has small nozzle holes (0.10 mm to 0.15 mm) and a reduced working pressure p A (100 - 200 bar), and the active medium WM is injected only into the superficial skin layer simultaneously at multiple locations. The operator can guide the applicator B to move slowly on the skin surface to be treated, and in pulse mode, output the active medium WM at a time interval preferably between 0.25 s and 0.5 s. In this treatment, a spacer 41 with a length between 2 mm and 60 mm, more preferably between 15 mm and 50 mm, is preferably used.

[0081] On the device 1, for example, on the applicator B shown in dashed lines as in Figure 2 a control button 30 can be provided, for example, on the applicator housing 32, and the applicator B is operated through this control button. The control button 30 can be connected to the control unit 16 through a control line 12. When the operator presses the control button 30 on the applicator B, the at least one active medium pulse is generated.

[0082] But the control button 30 can also be provided on the basic unit A (as shown in Figure 1 ).

[0083] For safety reasons, on the device 1, preferably on the basic unit A, an additional safety switch 31, such as a foot switch, can also be provided. Through such a switch 31, it can be specified that the applicator B will generate an active medium pulse only when the safety switch 31 is operated. Therefore, as long as the safety switch 31 is not operated, operating the control button 30 is ineffective. During the operation of the applicator B, if the safety switch 31 is no longer operated, the generation of the active medium pulse will stop immediately.

[0084] In the control button 30 and / or the safety switch 31, a light 30a, 31a, such as a two-color LED (as in accordance with Figure 1In the embodiment), it is used to display the system status of the device 1. For example, when the device 1 is ready to run, the lights 30a, 31a will light up. It can be stipulated that in the case of not being ready to run, the lights 30a, 31a do not light up, or light up in another color.

[0085] Also for safety reasons, it can be stipulated that only when the control button 30 has been continuously pressed for a predetermined period (for example, in the range of seconds) in advance, the applicator B will generate an active medium pulse. This prevents the generation of an active medium pulse when the control button 30 is misoperated.

[0086] The device 1 can operate in such a way that the pump 3 (optionally together with the pressure regulating valve 6) generates a set working pressure p A . After reaching the working pressure p A , the pump 3 is turned off. The pressure accumulator 10 keeps the working pressure p A substantially constant. Only when the applicator B is operated for a certain period (for example, 1 to 5 seconds) to generate an active medium pulse, the pump 3 will start again and generate a set working pressure p A within a set period (for example, 20 to 60 seconds), and then the pump 3 is turned off again. Each time the applicator B is re-operated for a predetermined period, the pump 3 will start again. This working method helps to save energy and reduce the wear of the pump 3.

[0087] The following will refer to Figure 3 to describe other advantageous embodiments of the applicator B of the present invention. Only those components and functions that have not been described above with reference to Figure 1 and Figure 2 will be explained here.

[0088] In Figure 3 's applicator B, a pressure spring 39 is provided, which acts on the push rod 22, specifically on the push rod piston 26 of the push rod 22. The push rod 22 together with the push rod piston 26 and the pressure piston 25 during operation will move against the spring action of the pressure spring 39. The pressure spring 39 also ensures that when the applicator B is depressurized, for example, in order to remove the nozzle unit 23 from the applicator B, the push rod 22 returns to its initial position (at this time the pressure volume area 21 is the smallest). When the applicator B is operated, that is, when the working medium AM is injected into the pressure volume area 21 by the injection valve 20, the pressure spring 39 will be tensioned.

[0089] As shown in Figure 3 The pressure spring 39 can of course also be arranged as in the embodiment shown in Figure 2 .

[0090] In the illustrated embodiment, the compression spring 39 acts on the side of the push rod piston 26 remote from the pressure volume region 21. The other end of the compression spring 39 abuts against a component of the applicator B that is immovable relative to the push rod 22 and the pressure piston 25, for example against a component of the applicator housing 32 or, as Figure 3 shown, against a support 47. Figure 3 The support 47 of Figure 3 is designed as an annular part that is screwed into an internal thread that is the same as the internal thread into which the nozzle unit 23 is screwed. Thereby, after removing the annular part, the compression spring 39 and the push rod 22 can be easily removed.

[0091] In order to move the push rod 22 back to the smallest initial position of the pressure volume region 21 (for example by the compression spring 39 or manually), it can be provided that the applicator B is depressurized. This can be achieved by the non-return valve 9 and the return line 8. If the injection valve 20 is opened while the applicator B is depressurized and the push rod 22 is pressed towards the initial position in this case, the working medium AM is fed back into the basic unit A through the pressure line 18 and flows from there through the non-return valve 9 and the return line 8 into the storage container 2 when the pump 3 is switched off. In this process, the injection valve 20 is preferably opened in a pulsed mode in order to reduce the risk of overheating of the injection valve 20 due to a long opening time and thus continuous power supply.

[0092] A drain opening 38 can be provided in the applicator housing 32 in order to be able to easily drain any leaking working medium AM from the applicator B. This drain opening 38 can also be used to immediately indicate a lack of tightness in the applicator B. In the case of a lack of tightness, the applicator B can be replaced immediately.

[0093] An exhaust opening 36 can also be provided in the applicator B, which is connected to the pressure volume region 21 and can be closed by an exhaust bolt 35. For example, the pressure volume region 21 can be filled with the working medium AM through the exhaust opening 36, preferably taking care to completely exhaust the pressure volume region 21 during the filling process. As Figure 3 shown, the exhaust opening 36 with the exhaust bolt 35 can of course also be provided in the embodiment as Figure 2 shown.

[0094] An additional storage volume 37 for the working medium AM can be provided in the region of the inlet 27 of the injection valve 20, which is filled with the working medium AM having the working pressure p A during operation of the applicator B. For example, the pressure line 18 can be connected to the storage volume 37 and the inlet 27 is connected to the storage volume 37. The storage volume 37 ensures that the working pressure p AInstead of decreasing, it remains as stable as possible. It has been proven that a storage volume 37 in the range of 10 to 100 times the injection volume of the injection valve 20 is sufficient. As Figure 3 The storage volume 37 shown can of course also be provided in the embodiment as Figure 2 shown.

[0095] Figure 4 A nozzle unit 23 is shown in detail. In this embodiment, the active medium WM is filled in an active medium cartridge 40, which is inserted into an inner groove 42 of a cartridge holder 43. This enables the rapid replacement of the active medium WM by replacing the active medium cartridge 40. For this purpose, the nozzle unit 23 is removed from the applicator B, for example by means of a thread 44 on the cartridge holder 43, and the active medium cartridge 40 is replaced. After that, the nozzle unit 23 can be installed on the applicator B again.

[0096] In this embodiment, the active medium cartridge 40 forms the nozzle chamber 24 of the nozzle unit 23, and a pressure piston 25 is arranged in this nozzle chamber. In this embodiment, a spacer 41 is also provided on the active medium cartridge 40. Alternatively, it can also be provided on the cartridge holder 43.

[0097] It can also be seen that the pressure piston 25 is shaped complementary to the inner contour of the active medium cartridge 40 at one end facing the nozzle opening 29. This enables the active medium cartridge 40 to be emptied as completely as possible. Of course, this is also advantageous in the embodiment of the nozzle unit 23 as Figure 2 shown.

[0098] The active medium cartridge 40 can be closed at one end remote from the nozzle opening 29 (which faces the push rod 22 during use) with a non-removable plug 45 having a central groove for the push rod 22.

[0099] To effectively prevent the active medium cartridge 40 from being accidentally filled multiple times, at least one radially protruding flange with a sharp edge can be provided on the surface of the pressure piston 25. Here, if necessary, this flange can also be provided on the pressure piston 25 only after the filling process. During operation, when the pressure piston 25 moves, such a flange will axially pull a deep groove on the inner side of the active medium cartridge 40, which effectively prevents subsequent pressure build-up in the active medium cartridge 40 and the reuse of the active medium cartridge 40. Such an active medium cartridge 40 will no longer be usable.

[0100] Furthermore, it is advantageous that the active medium cartridge 40 is arranged in the cartridge holder 43 with as little clearance as possible. In the case where there is a clearance between the active medium cartridge 40 and the cartridge holder 43, when the pressure increases due to operating the pressure piston 25, the active medium cartridge 40 may expand or deform radially, which will have an adverse effect on the pressure increase.

[0101] Therefore, it is advantageous that the inner groove 42 of the cartridge holder 43 converges slightly conically in the direction of the nozzle opening 26 (as Figure 5 shown). At this time, the cone angle can be set between 0.1° and 2°, preferably between 0.15° and 1°. The outer diameter of the active medium cartridge 40 has the same cone angle. In this way, the active medium cartridge 40 can fit perfectly into the inner groove 42 of the cartridge holder 43. This prevents expansion under the internal pressure generated by the pressure piston 25.

[0102] In addition, it is advantageous that the active medium cartridge 40 axially protrudes from the cartridge holder 43 at the end opposite to the nozzle opening 29. In a feasible embodiment, the active medium cartridge 40 has a protruding flange 46 at this end. When the nozzle unit 23 with the active medium cartridge 40 disposed therein is mounted on the applicator B (for example, screwed in), the cartridge is pressed into the cartridge holder 43 without clearance with a slight interference fit through the axially protruding end (which, for example, abuts against the support 47 in the applicator B). This prevents expansion under the internal pressure generated by the pressure piston 25.

[0103] After use, the pressed-in active medium cartridge 40 can be pushed out of the cartridge holder 43 by a special pushing tool.

[0104] Figure 5 Another advantageous embodiment of the nozzle unit 23 is shown, which includes a cartridge holder 43 and an active medium cartridge 40. However, the following-described embodiment is also applicable to the case where the active medium WM does not use the active medium cartridge 40 (as Figure 2 shown). This embodiment is particularly advantageous for highly viscous active media WM.

[0105] For highly viscous active media WM, during the filling process, there may be trapped air that cannot be discharged through the nozzle opening 29 but remains in the nozzle chamber 24. The trapped air in the nozzle chamber 24 has an adverse effect on the pressure build-up in the nozzle unit 23 and should therefore be avoided as much as possible.

[0106] Therefore, a pressure piston 25 with an axially through-going groove 54 is used. Before the filling process, the pressure piston 25 is fully pushed downwards so that one end of the pressure piston 25 facing the nozzle opening 29 abuts axially against the inside of the active medium cartridge 40. At opposite axial ends of the pressure piston 25, filling interfaces 51 are provided, to which a filling mechanism (not shown in the figure) can be connected for filling. The filling interface 51 can be designed as a fixed thread or preferably as a Luer lock male connector. For filling, the filling mechanism can be connected to the groove 54 via the filling interface 51, for example in such a way that the Luer lock female connector of the filling mechanism is slipped over the Luer lock male connector, or the interface of the filling mechanism is screwed onto the fixed thread. Through the (Luer lock) interface of the filling mechanism, the (high-viscosity) active medium WM is pressed through the groove 54 into the active medium cartridge 40, and the pressure piston 25 rises within the active medium cartridge 40. After the desired filling volume is reached, the (Luer lock) interface of the filling mechanism is removed. The groove 54 can then be closed, for example, using a plug 53 made of a biocompatible elastomer. When filling, the nozzle opening 29 can be closed if necessary.

[0107] In this embodiment of the pressure piston 25, the above-mentioned radially protruding flange can be placed on the pressure piston 25 after the filling process.

[0108] In an embodiment according to Figure 5 , the groove 54 at the end of the pressure piston 25 facing the push rod 22 is widened. A plug 53, preferably made of a biocompatible elastomer, is inserted into the widened portion of the groove 54 and closes the groove 54. The push rod 22 is designed in a stepped manner at the end facing the pressure piston 25. When using the nozzle unit 23, the reduced end 55 of the push rod 22 enters the widened portion of the groove 54 and presses the plug 53 into the groove 54 until the shoulder 56 formed by the push rod 22 abuts against the pressure piston 25. This ensures that the groove 54 is reliably sealed against liquid, which improves the operating safety.

[0109] To ensure the sterility of the active medium WM loaded into the active medium cartridge 40, it can be provided that the nozzle side of the active medium cartridge 40 is sterilely covered and closed by means of a closure, for example by a peelable film. The nozzle side of the active medium cartridge 40 (for example in the region of the spacer 41) can also be designed as a Luer lock male connector, on which a matching Luer lock plug is provided. Before inserting the active medium cartridge 40 into the cartridge holder 43, the closure (such as a peelable film or a Luer lock plug) needs to be removed. When the active medium cartridge 40 is correctly inserted into the cartridge holder 43, by guiding the active medium cartridge 40 within the cartridge holder 43, contact between the active medium cartridge 40 (especially the nozzle tip) and the non-sterile inner wall of the cartridge holder 43 can be avoided.

[0110] Having reference to Figure 4 andFigure 5 The active medium cylinder 40 of the described pressure piston 25 is regarded as an independent invention.

[0111] Similarly, the cylinder holder 43 and the nozzle unit 23 of the active medium cylinder 40 described with reference to Figure 4 and Figure 5 are also regarded as an independent invention. The nozzle unit 23 is particularly characterized in that the active medium cylinder 40 is installed in the cylinder holder 43 in an interference fit manner, specifically in the inner groove 42 of the cylinder holder 43, to prevent a gap from occurring between the active medium cylinder 40 and the inner groove 42 in the cylinder holder 43.

Claims

1. An applicator for needle - free injection of an active medium (WM) to be injected into the body surface, the applicator (B) having a nozzle unit (23), the nozzle unit having a nozzle volume region (24) into which the active medium (WM) to be injected is filled, at least one nozzle opening (29) connected to the nozzle volume region (24) is provided on the nozzle unit (23), and a pressure piston (25) is provided within the nozzle unit (23), the pressure piston at least partially defining the nozzle volume region (24) and being movably arranged within the nozzle unit (23). Characterized in that, An injection valve (20) is provided in the applicator (B), and a working medium (AM) having a working pressure (p A ) can be applied at an inlet (27) of the injection valve. A pressure volume region (21) is provided in the applicator (B), and the pressure volume region (21) is filled with a working medium (AM) having an initial pressure less than the working pressure (p A ). The injection valve (20) is arranged to inject a predetermined injection volume of the working medium (AM) into the pressure volume region (21) during operation at an injection pressure (p A ) between the working pressure (p E ) and the initial pressure. A push rod (22) movably arranged is provided in the applicator (B). The push rod has a push rod piston (26) at a first end. The push rod piston at least partially defines the pressure volume region (21) and abuts against a pressure piston (25) with an opposite second end, such that the push rod (22) can move in the direction of the pressure piston (25) during operation to move the pressure piston (25) so as to output an active medium pulse from the at least one nozzle opening (29).

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

3. The applicator according to claim 2, Characterized in that, The nozzle unit (23) is designed to have a cartridge holder (43), the cartridge holder having an internal groove (42), and an active medium cartridge (40) is replaceably mounted in the internal groove (42), the at least one nozzle opening (29) is provided on the active medium cartridge (40), and the pressure piston (25) is movably arranged within the active medium cartridge (40).

4. The 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), the tubular spacer axially projects from the active medium cartridge (40) by a predetermined length and at least partially surrounds the nozzle opening (29) such that the active medium pulse is output through the tubular spacer (41).

5. The applicator according to claim 3, Characterized in that, The internal groove (42) within the cartridge holder (43) and the active medium cartridge (40) are designed to converge in a conical shape towards the direction of the at least one nozzle opening (29).

6. The applicator according to any one of claims 1 to 5, Characterized in that, The pressure piston (25) is designed to have an axial through - groove (54).

7. The applicator according to claim 6, Characterized in that, A filling interface (51) is provided on a side of the pressure piston (25) remote from the at least one nozzle opening (29) so as to fill the active medium (WM) into the nozzle volume region (24) through the filling interface (51) and the axial through - groove (54).

8. The applicator according to claim 6, Characterized in that, When the active medium cartridge (40) is filled, the axial through - groove (54) is closed.

9. The applicator according to any one of claims 1 to 8, Characterized in that, A control button (30) is provided on the applicator (B) for operating an injection valve (20).

10. The applicator according to any one of claims 1 to 9, Characterized in that, The injection valve (20) is configured to inject a predetermined injection volume of the working medium (AM) into the pressure volume region (21) multiple times during operation at an injection pressure (p A ) that lies between the operating pressure (p E ) and the starting pressure.

11. The applicator according to claim 10, Characterized in that, Multiple injections are performed at a predetermined time interval.

12. The applicator according to any one of claims 1 to 11, Characterized in that, The injection valve (20) changes the injection pressure (p E ) during the output of at least one active medium pulse.

13. The applicator according to claim 12, characterized in that, The injection valve (20) injects first at a first injection pressure (p E1 ) during a first time period (T1) and then at a second injection pressure (p E2 ) during a second time period (T2), wherein the second injection pressure (p E2 ) is lower than the first injection pressure (p E1 ).

14. The applicator according to any one of claims 1 to 13, characterized in that, a pressure spring (39) is provided in the applicator (B), and the pressure spring acts on the push rod (22), preferably on the push rod piston (26) of the push rod (22).

15. The applicator according to claim 14, characterized in that, the pressure spring (39) acts on one side of the push rod piston (26) away from the pressure volume region (21) with a first end portion, and the second end portion of the pressure spring (39) abuts against a component of the applicator (B) that is immovable relative to the push rod (22).

16. A device for needle - free injection of an active medium (WM) to be injected into the body surface, the device comprising an applicator (B) according to any one of claims 1 to 15, wherein, A basic unit (A) is provided, which supplies a working medium (AM) having an operating pressure (p A ). The basic unit (A) is connected to an applicator (B) via a pressure pipe (18) in order to convey the working medium (AM) having the operating pressure (p A ) to the applicator (B).

17. The device according to claim 16, characterized in that, A pump (5) is provided within the basic unit (A), which raises the pressure of the working medium (AM) from the storage container (2) to the working pressure (p A ), and the pump (5) conveys it into a pressure pipeline (7) connected to a pressure pipe (18).

18. The device according to claim 17, characterized in that, a return pipeline (8) branches out downstream of the pump (5) in the pressure pipeline (7), and a controllable return valve (9) is provided in the return pipeline so as to relieve the pressure of the pressure pipeline (7) through the return pipeline (8) when the return valve (9) is opened.

19. The device according to any one of claims 16 to 18, characterized in that, a safety switch (31) is provided on the device (1) for releasing or locking the operation of the applicator (B).

20. A method for needle - free injection of an active medium (WM) to be injected into the body surface by using an applicator (B), the applicator having a nozzle unit (23), the nozzle unit having a nozzle volume region (24) containing the active medium (WM), and in the nozzle unit (23), at least a part of the pressure piston (25) defining the nozzle volume region (24) is moved in order to discharge the active medium (WM) through at least one nozzle opening (29) of the nozzle unit (23), characterized in that, The injection valve (20) is supplied with a fluid having a working pressure (p A ) of the working medium (AM), and the injection valve (20) is at an injection pressure (p E ) injects a predetermined injection amount of the working medium (AM) into a pressure volume area (24) filled with the working medium (AM) in the applicator (B), in which the initial pressure is less than the working pressure (p A ) acts, and the injection pressure (p E ) is selected between the working pressure (p A ) and a starting pressure, and by injecting a working medium (AM) into the pressure volume area (24), a push rod (22) movably arranged in the applicator (B) is moved in the direction of a pressure piston (25), wherein the push rod at least partially defines the pressure volume area (24) by means of a push rod piston (26) arranged on a first end and abuts against the pressure piston (25) with an opposite second end, thereby outputting an active medium pulse from the at least one nozzle opening (29) based on the movement of the pressure piston (25).

21. The method according to claim 20, characterized in that, the pressure volume region (21) is injected multiple times through an injection valve (20) to output multiple active medium pulses.

22. The method according to claim 20 or 21, characterized in that, The injection valve (20) changes the injection pressure (p E ) during at least one active medium pulse.

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