JP7604218B2 - System for atomizing and propelling liquids for transdermal delivery - Patents.com - Google Patents

Description

The present invention relates to a system for atomizing and ejecting a liquid, e.g., water, oil, lotion, etc., for transdermal delivery, particularly shallow transdermal delivery. The present invention also relates to an apparatus for transdermal delivery of a liquid, including such a system. The present invention further relates to a method for atomizing and ejecting a liquid for transdermal delivery.

Cosmetic liquids, such as liquid lotions containing hyaluronic acid, are generally applied to certain parts of a user's body, such as the face, hands, and arms, by shallow transdermal delivery (i.e., shallow depth of transdermal delivery). For more effective transdermal delivery of such liquids, it is desirable to atomize the liquid into fine droplets on the order of micrometers and spray or squirt it onto the desired part of the user's body.

In the prior art, several devices for atomizing and spraying cosmetic liquids are known. Most of these prior devices use a high pressure gas (e.g., carbon dioxide gas) or compressed air for atomizing and spraying cosmetic liquids. Devices using high pressure gas require a replaceable gas cartridge. This gas cartridge method has the drawback that if the device is used frequently, the gas cartridge is quickly used up and therefore requires frequent replacement. On the other hand, devices using compressed air require an external source of compressed air, i.e., an external air compressor or an external air pump. This makes the device large overall. Such devices are difficult to move and transport and are not particularly suitable for easy handling. Therefore, there is a need for improvements in devices for atomizing and spraying liquids.

Examples of prior art that relate at least in part to the techniques disclosed herein are as follows: US Patent No. 5,399,633 (Marui) describes an electrically powered spring-piston-gear mechanism for generating compressed air. US Patent No. 5,399,633 (Gold NanoTech Inc.) describes a device for atomizing liquids by using a solenoid valve to control the release of a volume of pressurized air. In this device, the pressurized air passes through a venturi tube to atomize the liquid. However, Reference 1 is only intended to generate compressed air for a model air gun or air pistol to eject solid pellets/projectiles. On the other hand, the device disclosed in Reference 2 is merely configured to operate with externally supplied pressurized air.

Public Gazette No. 7-22635 US Patent Application Publication No. 2018/0099104

In view of the above, it is an object of the present invention to provide a novel system and method for atomizing and spraying liquids (especially liquid formulas having high molecular weight) for transdermal delivery, and a novel device for transdermal delivery of liquids, including such a system.

In particular, it is an object of the present invention to provide novel systems and devices for atomizing and propelling liquids for transdermal delivery that do not require a replaceable, i.e., single-use/disposable, power source, such as a high-pressure gas cartridge, and thus can atomize and propel liquids multiple times as needed by the user. Additionally, it is an object of the present invention to provide novel systems and devices for atomizing and propelling liquids for transdermal delivery that do not require an external source, such as an air compressor or air pump, and thus are generally compact (i.e., have a small physical footprint) and are easy to move, transport, and handle.

To achieve the above objects, the present invention provides a system for atomizing and spraying a liquid for transdermal delivery (particularly shallow transdermal delivery) as described below. That is, the system according to the present invention includes: (i) a tank for holding a liquid; (ii) a Venturi tube having a central longitudinal axis and an internal passage extending along the central longitudinal axis, the internal passage being fluidly connected to the tank through an orifice defined in the Venturi tube, the internal passage including a convergent portion, a divergent portion, and a throat portion located between the convergent portion and the divergent portion; and (iii) a cylinder including a central longitudinal axis, an end wall perpendicular to the central longitudinal axis, a circumferential wall extending from the end wall along the same central longitudinal axis, and an exit hole formed in the end wall, the exit hole being fluidly connected to an inlet of the convergent portion of the Venturi tube. (iv) a piston disposed within the cylinder so as to be displaceable within the cylinder along its longitudinal central axis, the piston cooperating with the cylinder to define an air intake space within the cylinder, the air intake space being in fluid communication with the inlet of the tapered portion of the Venturi tube through an outlet hole in the cylinder; (v) a drive unit for displacing the piston in a direction in which the volume of the air intake space within the cylinder increases; and (vi) an elastic member that deforms in accordance with the displacement of the piston and stores elastic energy therein while the piston is displaced in the direction in which the volume of the air intake space increases. In the present invention, the drive unit includes an elastic energy release mechanism that releases the elastic energy stored in the elastic member, thereby propelling the piston in a direction in which the volume of the air intake space decreases.

The present invention also provides a device for transdermal (particularly shallow transdermal) delivery of atomized liquid, the device comprising a system for atomizing and spraying the liquid for transdermal delivery as described above, and a casing at least partially housing the system.

The present invention further provides a method for atomizing and spraying a liquid for transdermal (particularly shallow transdermal) delivery, comprising the steps of (i) filling a reservoir with liquid, the reservoir being fluidly connected to an internal passage of a Venturi tube through an orifice defined in the Venturi tube, the internal passage of the Venturi tube having a convergent portion, a divergent portion, and a throat portion located between the convergent portion and the divergent portion, and (ii) displacing a piston in the cylinder in a direction that increases the volume of an air intake space in the cylinder, the air intake space being defined between the piston and an end wall of the cylinder, an exit hole formed in the end wall of the cylinder being fluidly connected to an inlet of the convergent portion of the Venturi tube. (iii) a step of deforming an elastic member that is arranged to deform according to the displacement of the piston and stores elastic energy therein while the piston is displaced in a direction in which the volume of the air intake space increases; (iv) a step of releasing the elastic energy stored in the elastic member, thereby thrusting the piston in a direction in which the volume of the air intake space decreases; and (v) a step of atomizing the liquid supplied from the tank into the internal passage of the Venturi tube and spraying it out by pushing air out of the cylinder through an outlet hole in the end wall of the cylinder as the piston thrusts.

According to the present invention, the system includes a compressed air source, mainly consisting of a cylinder, a piston, an elastic member, and a drive unit, as well as a Venturi tube in fluid communication with a fluid tank. In the present invention, the drive unit displaces the piston in the cylinder by deformation of the elastic member, thereby taking in a predetermined amount of air into the cylinder. Then, by instantly releasing the elastic energy stored in the elastic member, the piston is pushed back to its original position in the cylinder, compressing the air in the cylinder. As a result, high-pressure air is expelled at high speed from the outlet hole of the cylinder and introduced into the internal passage of the Venturi tube. When the high-speed air passes through the Venturi tube, the pressure inside it decreases, and thus a small amount of liquid in the tank is taken into the internal passage of the Venturi tube. The small amount of liquid thus taken in is atomized inside the Venturi tube by the action of the high-speed air and is ejected out of the Venturi tube together with the air. According to the present invention, it is thus possible to provide a jet of finely atomized liquid, i.e., high-speed atomized liquid particles, suitable for transdermal delivery, in particular shallow transdermal delivery. As is well known to those skilled in the art, liquids having high molecular weights do not effectively penetrate the skin by simple superficial application. In accordance with the present invention, the liquid is sufficiently finely divided so that even liquids having high molecular weights can effectively penetrate the skin. As used herein, shallow transdermal delivery refers to delivery to the upper epidermis of the skin.

Furthermore, the systems, devices, and methods according to the present invention do not require a replaceable or single-use/disposable power source, such as a high-pressure gas cartridge, to atomize and propel the liquid for transdermal delivery. Thus, the systems, devices, and methods according to the present invention can atomize and propel the liquid over and over again. In addition, the systems, devices, and methods according to the present invention do not require an external source, such as an air compressor or air pump. That is, the high-velocity air jets for atomizing and propelling the liquid can be generated internally. Thus, the systems and devices can be generally compact enough to be handheld, making them easy to move, transport, and handle.

According to a preferred embodiment of the present invention, the piston may have a longitudinal central axis, an end wall facing the end wall of the cylinder, and a circumferential wall extending from the end wall along the longitudinal central axis. In this embodiment, a rack extending along the longitudinal central axis may be formed on the outer surface of the circumferential wall of the piston. Also, in this embodiment, the drive unit may have a sector gear having teeth only in a certain angular range, and the sector gear meshes with the rack of the piston to move the piston linearly. Furthermore, in this embodiment, the combination of the sector gear and the rack may form an elastic energy release mechanism. According to this embodiment, the mechanism for releasing the elastic energy stored in the elastic member may be made particularly simple and robust. However, other mechanisms/means operating mechanically, electrically, electromagnetically, or fluidically to release the elastic energy stored in the elastic member may be appropriately adopted.

According to a preferred aspect of the invention, when the drive unit comprises a sector gear, the drive unit may further comprise a power supply and a power motor electrically connected to the power supply and directly or indirectly driving the sector gear to rotate. According to this aspect, the drive unit is particularly easy to operate.

According to a preferred embodiment of the present invention, when the drive unit comprises an electric motor, the drive unit may further comprise a pinion coupled to the output shaft of the electric motor and one or more gears for transmitting the rotational motion of the pinion to the sector gear to move it in rotation. In particular, the one or more gears may comprise a bevel gear meshing with the pinion and a spur gear meshing with both the bevel gear and the sector gear. According to this embodiment, the output shaft of the motor and the axis of rotation of the sector gear may be arranged perpendicular to each other so that the system can be made as compact as possible. In addition, the use of such a combination of gears helps to properly position the electric motor depending on the desired overall shape of the device including the system.

According to a preferred embodiment of the present invention, when the drive unit includes a bevel gear and a spur gear, the drive unit may further include a latch that meshes with the spur gear, and the latch adjusts the direction of rotation of the spur gear so that the spur gear rotates in only one direction. According to this embodiment, the latch can prevent the spur gear from rotating in the opposite direction, and therefore can prevent the piston from returning due to the restoring force of the deformed elastic member. As a result, it is possible to prevent the piston from unintentionally operating to fire the air trapped in the cylinder before the sector gear rotates to its final position where it is disengaged from the rack of the piston (i.e., before the elastic member stores sufficient elastic energy).

According to a preferred aspect of the invention, when the drive unit includes a sector gear, the circumferential wall of the cylinder may be formed with a linear notch for exposing at least a portion of the rack of the piston, and the sector gear may mesh with the rack through the notch in the circumferential wall of the cylinder. According to this aspect, the system can be made more compact in the direction of displacement of the piston compared to a case in which there is no notch in the circumferential wall of the cylinder for exposing at least a portion of the rack of the piston.

According to a preferred embodiment of the present invention, when the piston has an end wall facing the end wall of the cylinder and a circumferential wall extending from the end wall, the elastic member may be a coil spring at least partially housed inside the piston. In this manner, the system can also be made compact with respect to the displacement direction of the piston. Furthermore, according to a preferred embodiment of the present invention, the system may further include an elongated guide rod arranged to be surrounded by an elastic member such as a coil spring. In this case, the guide rod may at least partially enter the piston when the piston is displaced in a direction in which the volume of the air intake space increases. According to this embodiment, it is possible to reliably compress the elastic member, i.e., the coil spring, when the piston is displaced, while making the system compact with respect to the displacement direction of the piston.

According to a preferred embodiment of the invention, the tank may be fluidly connected to the throat of the Venturi tube, in particular via an orifice defined in the Venturi tube. This embodiment allows for a particularly efficient atomization of the liquid. According to a preferred embodiment of the invention, the Venturi tube may be directly connected to the cylinder, such that the inlet of the tapered portion of the Venturi tube and the outlet hole of the cylinder are aligned with each other. This embodiment allows for a particularly efficient injection of the atomized liquid, as compared to when the inlet of the tapered portion of the Venturi tube and the outlet hole of the cylinder are connected, for example, by a separate pipeline or separate conduit.

According to a preferred embodiment of the present invention, the ratio of the maximum inner diameter of the convergent portion of the Venturi tube to the inner diameter of the throat portion of the Venturi tube to the maximum inner diameter of the divergent portion of the Venturi tube may be 1:0.1-0.7:1-1.5 based on the maximum inner diameter of the convergent portion. According to this embodiment, a particularly sufficient injection rate and amount of atomized liquid can be achieved.

According to a preferred embodiment of the present invention, the liquid may be a cosmetic liquid to be delivered transdermally, in particular shallowly. However, according to the present invention, various liquids, including cosmetic liquids, may be atomized and sprayed. Suitable liquids for the present invention have, for example, a viscosity of 1×10 ⁻⁴ Pa·s to 200 Pa·s, more preferably a viscosity of less than 70 Pa·s.

Non-limiting representative embodiments of the present invention will now be described in detail below with reference to the accompanying drawings.

FIG. 1 is a schematic block diagram of an apparatus for shallow transdermal delivery of atomized liquid in accordance with one embodiment of the present invention. FIG. 2 is a schematic diagram of a system for atomizing and spraying liquid for shallow transdermal delivery that may be incorporated into the device shown in FIG. 1, showing cross-sections of its components: a venturi tube, a piston, and a cylinder. FIG. 3 is an enlarged cross-sectional view of the tank and Venturi tube that are components of the system shown in FIG. FIG. 3 is a perspective view showing, in exploded form, various gears forming the drive transmission mechanism of the drive unit of the system shown in FIG. 2; 3 is a schematic diagram similar to FIG. 2 of a system for atomizing and spraying a liquid for shallow transdermal delivery, showing the piston displaced distally (i.e., to the left in the figure) by the drive unit. 3 is a schematic diagram similar to FIG. 2 of a system for atomizing and spraying a liquid for shallow transdermal delivery, with the piston displaced distally by the drive unit to its final position. FIG. 3 is a schematic diagram similar to FIG. 2 of a system for atomizing and spraying liquid for shallow transdermal delivery, with the elastic energy stored in the coil spring being released, pushing the piston back proximally (i.e., to the right in the figure). FIG. 3 is a schematic diagram similar to FIG. 2 of a system for atomizing and propelling a liquid for shallow transdermal delivery, in which a piston collides with the end wall of a cylinder, causing high-velocity air forced out of the cylinder to eject a mist of liquid from the outlet of a Venturi tube.

Next, some exemplary embodiments of the present invention will be described with reference to Figures 1 to 8. In each figure, the width, length, height, diameter, etc. of each element may not be to scale and may differ from the actual one. Please note that in some figures, some elements or features are drawn larger or smaller than they are in reality for emphasis.

As used herein, directional terms such as "up," "down," "up," "down," "upper," "lower," "top," "bottom," "right," "left," and the like, should be understood in relation to the orientation of the systems and devices in the figures, which may or may not correspond to their actual orientation in use. Additionally, as will be apparent to one of ordinary skill in the art, the terms "distal" or "distally" herein refer to a direction away from the venturi tube that ejects or ejects the atomized liquid, whereas the terms "proximal" or "proximally" refer to a direction closer to the venturi tube.

1 shows a schematic diagram of an exemplary embodiment of the present invention, a device for shallow transdermal delivery of atomized liquid. The device, generally designated by reference numeral 1, mainly comprises a system, generally designated by reference numeral 10, for atomizing and spraying liquid for transdermal delivery (described in detail below), and a casing 20 for housing the system 10 therein. While the casing 20 may simply house at least a portion of the system 10, in the illustrated embodiment the casing 20 substantially encloses the entire system 10 (except for the outlet of the venturi tube for discharging the atomized liquid). The liquid targeted for atomization and spraying by the device 1 is specifically a cosmetic liquid, such as a liquid lotion containing hyaluronic acid to be delivered transdermally. However, the device 1 and system 10 may be used for atomizing and spraying water, oil, various lotions, and the like.

As can be better seen from FIG. 2 in addition to FIG. 1, the system 10 comprises a tank 100 for holding a certain amount of liquid L, for example a few milliliters to a few hundred milliliters of liquid L. The tank 100 is preferably made of, for example, transparent plastic or glass so that the contents and/or the amount of the contents are visible from the outside. Translucent or opaque materials can be used to make the tank 100. The system 10 also comprises a Venturi tube 200, a cylinder 300 arranged adjacent to the Venturi tube 200, and a piston 400 slidably disposed within the cylinder 300. The Venturi tube 200 can be made of a plastic material having sufficient rigidity, for example, acrylonitrile butadiene styrene (ABS), polypropylene (PP), polycarbonate (PC), etc. The cylinder 300 and the piston 400 can also be made of the same material. Alternatively, both the cylinder 300 and the piston 400 can be made of a suitable metal (or metal alloy) material.

With further reference to Figures 1 and 2, the system 10 additionally includes a drive unit 500 operatively (i.e., mechanically) associated with the piston 400, a resilient member 600 (a coil spring in this embodiment) also mechanically associated with the piston 400, and an elongated guide rod 700 arranged to be surrounded by the coil spring 600.

In detail, as shown in FIG. 1, the drive unit 500 mainly includes a gear train 500a and a power source assembly 500b, which will be described in detail below. In this embodiment, the power source assembly 500b includes a battery (power supply) 520, an electric motor 530, and a switch 580 disposed therebetween. Please note that the battery 520 and the switch 580 are not shown in any figures other than FIG. 1 for convenience.

As mentioned above, and as shown in more detail in FIG. 3, which shows a cross-sectional view of the tank 100 and the venturi tube 200, the system 10 comprises a tank 100 for holding a liquid L. In this embodiment, the tank 100 is removably connected in a liquid-tight manner to the venturi tube 200 by screwing. The tank 100 has a flange 110 at its open side. The venturi tube 200 also has a flange 260 that corresponds to the flange 110 of the tank 100. The tank 100 is placed on the venturi tube 200 with its flange 110 in contact with the flange 260 of the venturi tube 200. This arrangement is particularly preferred, since the action of gravity facilitates the supply of the liquid L to the venturi tube 200 during operation of the system 10. However, the orientation of the tank 100 with respect to the venturi tube 200 is not limited to this exemplary embodiment and can be appropriately changed as needed.

With further reference to FIG. 3, the Venturi tube 200 comprises a central longitudinal axis _X1 and an internal passage 210 extending continuously along the central longitudinal axis _X1 . The internal passage 210 is fluidly connected to the tank 100 via an orifice 220 defined in the Venturi tube 200. As shown in FIG. 3, the internal passage 210 comprises a convergent portion 230, a divergent portion 240, and a throat portion 250, which are continuously connected along the central longitudinal axis _X1 . The throat portion 250 is located between the convergent portion 230 and the divergent portion 240. The tank 100 is specifically fluidly connected to the throat portion 250 of the Venturi tube 200 via the orifice 220, as described above. The inner diameter of the orifice 220 is such that when the pressure in the Venturi tube 200 is equal to atmospheric pressure, the liquid L does not fall naturally into the Venturi tube 200 due to the viscosity of the liquid L.

The convergent portion 230 has an inlet 232 and an outlet 234 located at each of its two ends. The throat portion 250 also has an inlet 252 and an outlet 254 located at each of its two ends. Furthermore, the divergent portion 240 has an inlet 242 and an outlet 244 located at each of its two ends. The outlet 234 of the convergent portion 230 and the inlet 252 of the throat portion 250 smoothly and continuously connect with each other. Similarly, the outlet 254 of the throat portion 250 and the inlet 242 of the divergent portion 240 smoothly and continuously connect with each other.

In this embodiment, the inner diameter _D3 of the throat section 250 is constant. The inner diameter (smallest inner diameter) _D4 of the outlet 234 of the convergent section 230 is the same as the inner diameter _D3 of the throat section 250, and the inner diameter (smallest inner diameter) _D5 of the inlet 242 of the divergent section 240 is also the same as the inner diameter _D3 of the throat section 250. The inner diameter of the convergent section 230 decreases monotonically (linearly) toward the throat section 250, and the inner diameter of the divergent section 240 increases monotonically (linearly) away from the throat section 250. However, the inner diameters of the convergent section 230 and the divergent section 240 may decrease and increase curvilinearly, respectively.

Also, in this embodiment, the ratio of the maximum inner diameter D ₁ of the convergent portion 230 (i.e., the inner diameter of the inlet 232), the inner diameter D ₃ of the throat portion 250, and the maximum inner diameter D ₂ of the divergent portion 240 (i.e., the inner diameter of the outlet 244), i.e., D ₁ :D ₃ :D ₂ , is 1:0.1-0.7:1-1.5. This is based on the maximum inner diameter D ₁ of the convergent portion 230. However, this ratio is merely an example, and various other ratios can be adopted as needed.

2, the cylinder 300, which is one component of the system 1, comprises a longitudinal central axis _X2 , an end (proximal end) wall 310 facing the Venturi tube 200 and perpendicular to the longitudinal central axis _X2 , and a circumferential wall 320 extending from the end wall 310 along the longitudinal central axis _X2 . That is, the cylinder 300 is a hollow body open at one end. Although not shown, the cylinder 300 is fixedly supported by a frame of the system 10 (e.g., a subcase (not shown) of the device 1). The cylinder 300 further comprises an outlet hole 330 formed in its end wall 310. The outlet hole 330 is fluidly connected to the inlet 232 of the tapered portion 230 of the Venturi tube 200. In this embodiment, the Venturi tube 200 is directly connected to the cylinder 300 such that the inlet 232 of the convergent section 230 of the Venturi tube 200 and the outlet hole 330 of the cylinder 300 are aligned with one another. However, if desired, it is also possible to employ a configuration in which the inlet 232 of the convergent section 230 and the outlet hole 330 of the cylinder 300 are connected via a pipeline or conduit.

In the cylinder 300, the piston 400, which is one component of the system 1, is arranged so as to be smoothly displaceable along the longitudinal central axis _X2 of the cylinder 300. The piston 400 has a longitudinal central axis _X3 , an end (proximal end) wall 410 facing the end wall 310 of the cylinder 300, and a circumferential wall 420 extending from the end wall 410 along the longitudinal central axis _X3 . The piston 400 further has a rack 430 extending along the longitudinal central axis _X3 . The rack 430 is integrally formed on the outer surface of the circumferential wall 420 of the piston 400, specifically, in an area of approximately half of the distal end side of the circumferential wall 420. Although not shown in FIG. 2, the piston 400 cooperates with the cylinder 300 to define an air intake space V within the cylinder 300 (see FIGS. 5, 6, and 7). The air intake space V is in fluid communication with the inlet 232 of the convergent section 230 of the Venturi tube 200 via an exit hole 330 in the cylinder 300 .

The piston 400 further includes an O-ring (packing) 440, for example made of an elastomeric material. The O-ring 440 fits into a circular groove 450 formed in the end wall 410 of the piston 400. The O-ring 440 serves to maintain air tightness between the piston 400 and the inner surface of the cylinder 300. In this embodiment, the cross section of the piston 400 is a complete circle at the end wall portion of the piston 400 where the O-ring 440 is located. However, at the circumferential wall portion, the cross section of the piston 400 is a partial circle where a portion of the circle is cut along a straight line parallel to its diameter. This is to ensure a flat surface on the outer periphery of the piston for positioning the rack 430 as explained above. Of course, in other embodiments, other shapes may be adopted as the cross section of the circumferential wall portion of the piston 400. Although not shown, in this embodiment, the system 10 further includes a mechanism or function for preventing the piston 400 from rotating relative to the cylinder 300.

In the state shown in FIG. 2, i.e., in the state where the end wall 310 of the cylinder 300 and the end wall 410 of the piston 400 are in contact with each other, the distal end of the piston 400 protrudes slightly from the distal end of the cylinder 300. In other words, the length of the piston 400 along the longitudinal center axis _X3 is slightly greater than the length of the circumferential wall 320 of the cylinder 300 along the longitudinal center axis _X2 . Thus, in the state shown in FIG. 2, a part of the rack 430 integrally formed on the outer circumferential surface of the piston 400 protrudes from the distal end of the cylinder 400. In this embodiment, the circumferential wall 320 of the cylinder 300 is formed with a linear notch 340 for exposing at least a part of the rack 430 of the piston 400. As will be described in detail below, the sector gear 510 of the drive unit 500 meshes with the rack 430 by means of this notch 340 in the circumferential wall 320 of the cylinder 300.

As described above, the system 10 includes a drive unit 500 and an elastic member 600 mechanically associated with each other. The drive unit 500 can displace the piston 400 distally, i.e., in a direction in which the volume of the air intake space V in the cylinder 300 increases. Meanwhile, while the piston 400 is displaced distally, i.e., in a direction in which the volume of the air intake space V increases, the elastic member 600 is arranged to deform according to the displacement of the piston 400, and stores elastic energy (mechanical potential energy) therein. Therefore, the system 10 of this embodiment can be called a "spring-loaded system." In this embodiment, as described above, the elastic member 600 is a coil spring, and the coil spring is at least partially, for example, about half, housed inside the hollow piston 400.

The drive unit 500 further includes an elastic energy release mechanism M. In this embodiment, the elastic energy release mechanism M is configured to release the elastic energy stored in the elastic member 600 at regular intervals, thereby causing the piston 400 to dash proximally, i.e., in the direction in which the volume of the air intake space V decreases. More specifically, the drive unit 500 includes a sector gear 510 having teeth only in a certain angular range, for example, from 90° to 300°. The sector gear 510 is configured to mesh with the rack 430 of the piston 400, and moves the piston 400 linearly in one direction (i.e., to the left in the figure). In this embodiment, the combination of the sector gear 510 and the rack 430 forms an elastic energy release mechanism M for releasing the stored elastic energy at regular intervals. That is, at the moment when the last tooth of the sector gear 510 disengages from the last tooth of the rack 430, the constraint of the piston 400 is released, and therefore the elastic energy stored in the elastic member 600 is also instantly released. However, in another embodiment, another type of elastic energy release mechanism may be employed, and may be configured to release the elastic energy stored in the elastic member 600 only when desired.

As already explained, the drive unit 500 comprises a power supply 520, for example a rechargeable battery such as a lithium-ion battery. Also as explained above, the drive unit 500 comprises an electric motor 530 electrically connected to the power supply 520, which indirectly (i.e. via a gear train for power transmission) drives the sector gear 510 to rotate. The power supply 520, the electric motor 530 and the switch 580 placed between them constitute the power source assembly 500b of the drive unit 500 as explained above. In this embodiment, the sector gear 510 is rotated by the electric motor 530 via the gear set 500a only in one direction, i.e. counterclockwise in FIG. 2. In another embodiment, the sector gear 510 may be driven directly by the electric motor 530. However, in this case a motor with a large torque and therefore a large size is required, so it is preferable to drive the sector gear 510 via a suitable reduction mechanism consisting of a gear train, as described herein.

Now, referring to FIG. 4, the gear train constituting the reduction mechanism of the drive unit 500, i.e., the gear group 500a of the drive unit 500 as described above, will be described. The gear group 500a of the drive unit 500 includes a pinion 540 (bevel gear type) fixedly coupled to the output shaft 532 of the electric motor 530. Furthermore, the gear group 500a of the drive unit 500 includes two types of gears 550, 560 that transmit the rotational motion of the pinion 540 to the sector gear 510 to move the sector gear 510 to rotate. In this embodiment, these gears 550, 560 as well as the sector gear 510 are rotatably supported by the frame (not shown) of the system 10 (i.e., the subcase of the device 1). Since the electric motor 530 is fixedly supported by the frame (not shown) of the system 10, the pinion 540 is also rotatably supported by the frame (not shown) of the system 10. In another embodiment, gears 510, 550, and 560 may be rotatably supported by the casing 20 of device 1 itself.

With further reference to FIG. 4, the gear 550 meshing with the pinion 540 is a bevel gear. Meanwhile, the gear 560 meshing with both the bevel gear 550 and the sector gear 510 is a spur gear. Here, the spur gear 560 functions as an intermediate gear. In this embodiment, both the sector gear 510 and the bevel gear 550 have a structure in which two types of gearing portions are stacked along the direction of the rotation axis. The sector gear 510 includes a first portion 512 having teeth only in a certain angular range along its root circle. Furthermore, the sector gear 510 includes a second portion 514 integrally connected to the first portion 512. The second portion 514, i.e., the spur gear portion, of the sector gear 510 includes teeth along the entire circumference of its root circle. The diameter of the tip circle of the second portion 514 is smaller than the diameter of the tip circle of the first portion 512.

The bevel gear 550 also comprises a first part 552 including a row of teeth arranged circumferentially on a conical surface, and a second part 554 integrally connected to the first part 552 and consisting of a spur gear having a diameter smaller than the smallest diameter of the first part 552. A pinion 540 fixedly mounted on the output shaft 532 of the electric motor 530 meshes with the first part 552 of the bevel gear 550, and a second part 554 of the bevel gear 550, which rotates integrally with the bevel gear 550, meshes with a spur gear 560. The spur gear 560 further meshes with a second part 514 of the sector gear 510. As a result, the high speed rotation of the pinion 540 rotates the sector gear 510 at a predetermined low speed, for example, a few revolutions per second. The piston 400 is displaced distally at regular intervals by the rotation of the sector gear 510 thus produced. In this embodiment, the number of teeth on the rack 430 of the piston 400 is approximately equal to the number of teeth on the first portion 512 of the sector gear 510, but the invention is not limited thereto.

Now, referring again to FIG. 2, the drive unit 500 further comprises a latch 570 that meshes with the spur gear 560. The latch 570 is arranged to adjust the direction of rotation of the spur gear 560 such that the spur gear 560 rotates in only one direction (i.e., clockwise in FIG. 2). In alternative embodiments, it is contemplated that the latch 570 may mesh with any other gear other than the spur gear 560. The latch 570 is not a required component of this system 10.

With further reference to FIG. 2, the system 10 further comprises an elongated spring guide rod 700 arranged to be surrounded by the coil spring 600. In this embodiment, a base end 710 of the guide rod 700 is supported by a frame (not shown) of the system 10 (i.e., the sub-case of the device 1). In another embodiment, the spring guide rod 700 may be supported by the casing 20 of the device 1 itself. The spring guide rod 700 is arranged to at least partially enter the piston 400 when the piston 400 is displaced distally, i.e., in a direction in which the volume of the air intake space V increases.

The operation of the system 10 for atomizing and spraying a liquid configured as described above, and therefore the method for atomizing and spraying a liquid for transdermal delivery, will now be described with reference to Figures 2, 5-8 (assuming initially that the tank 100 is empty).

Prior to the atomization and injection of the liquid, the tank 100 is filled with the liquid L. This process can be performed with the tank 100 removed from the Venturi tube 200. The system 10, and therefore the device 1, is then turned upside down and the tank 100 is screwed onto the Venturi tube 200, connecting them to each other. The system 10, and therefore the device 1, is then returned to its normal use position with the tank 100 located above the Venturi tube 200. As a result of this process, the tank 100 is fluidly connected to the internal passage 210 of the Venturi tube 200 via the orifice 220 defined in the Venturi tube 200. This completes the preparation for atomizing and ejecting the liquid (see FIG. 2). If a tank with a retractable lid (in this case the lid is provided opposite the flange 110 of the tank 100) is used, the tank 100 can be filled with liquid without removing it from the Venturi tube 200.

The piston 400 is then displaced distally within the cylinder 300, i.e. in a direction that increases the volume of the air intake space V defined within the cylinder 300. This process is performed automatically by turning on the switch 580. That is, as explained above, when the switch 580 is turned on, the electric motor 530 rotates, and its rotational force is transmitted to the sector gear 510 via a gear train consisting of gears 550, 560. Since the sector gear 510 meshes with the rack 430 of the piston 400, the rotation of the sector gear 510 displaces the piston 400 distally, as explained above. Figure 5 shows the state in which the piston 400 is displaced a short distance in the distal direction by the drive unit 500.

While the piston 400 is displaced in a direction in which the volume of the air intake space V increases, the elastic member 600, i.e., the coil spring, is simultaneously gradually deformed. As described above, the elastic member 600 is arranged to deform linearly according to the displacement of the piston 400. Thus, during this process, the elastic member 600 stores elastic energy therein. FIG. 6 shows the state in which the piston 400 has been displaced distally by the drive unit 500 to its final position. This state is just before the last tooth (seen from the direction of rotation) in the tooth row of the sector gear 510 and the last tooth (seen from the direction of displacement) of the rack 430 are disengaged, and the elastic energy stored in the coil spring 600 is maximized.

When the sector gear 510 rotates further by a small angle from the state shown in FIG. 6, the sector gear 510 and the rack 430, more specifically the last tooth of the sector gear 510 and the last tooth of the rack 430, disengage. As a result, the piston 400 is now free to move. Thus, the elastic energy stored in the elastic member 600 is instantly released, thereby plunging the piston 400 proximally, i.e., in the direction in which the volume of the air intake space V decreases. FIG. 7 shows the state in which the piston 400 has been pushed proximally a short distance within the cylinder 300.

In the situation shown in FIG. 7, the air present in the air intake space V in the cylinder 300 is compressed by the piston 400 and moves at high speed from the outlet hole 330 of the cylinder 300 to the Venturi tube 200. As the air travels through the Venturi tube 200, the flow rate of the air increases, especially at its throat portion 250. As a result, the pressure in the throat portion 250 drops and a small amount of liquid L in the tank 100 is drawn into the passage 210 through the orifice 220 of the Venturi tube 200. This small amount of liquid L is pushed out of the cylinder 300 by the piston 400, atomized inside the Venturi tube 200 by the fast moving air, and discharged out through the outlet 244 of the Venturi tube 200. FIG. 8 shows a state in which the piston 400 collides with the end wall 310 of the cylinder 300 and the high speed air pushed out of the cylinder 300 causes the discharge of a mist of liquid L from the outlet of the Venturi tube 200.

In this embodiment, the electric motor 530 continues to rotate, and therefore the sector gear 510 also continues to rotate, unless the switch 580 is turned off. Thus, shortly after reaching the state shown in FIG. 8, the sector gear 510 re-engages with the rack 430 of the piston 400. As a result, the system 10 returns to the initial state shown in FIG. 2. Thus, while the switch 580 is on, the system 10 intermittently atomizes the liquid L in the tank 100 (at intervals corresponding to the rotational speed of the sector gear 510) and expels it out through the venturi tube 200 as atomized liquid particles.

As described above, the system 10, and therefore the device 1, includes a compressed air source, mainly consisting of a cylinder 300, a piston 400, an elastic member 600, and a drive unit 500, as well as a Venturi tube 200 in fluid communication with the fluid tank 100. The drive unit 500 displaces the piston 400 in the cylinder 300 with the deformation of the elastic member 600, thereby drawing in a predetermined amount of air into the cylinder 300. Thereafter, by releasing the elastic energy stored in the elastic member 600, the piston 400 is pushed back to its original position in the cylinder 300, compressing the air in the cylinder 300. As a result, the high-pressure air is expelled at high speed from the outlet hole 330 of the cylinder 300 and supplied to the internal passage 210 of the Venturi tube 200. When the high-speed air passes through the Venturi tube 200, specifically the throat portion 250 (i.e., the narrowed portion), the pressure inside it drops, and thus a small amount of liquid L in the tank 100 is drawn into the internal passage 210 of the Venturi tube 200. The small amount of liquid L thus drawn is atomized inside the Venturi tube 200 by the action of the high-speed air, and is ejected from the Venturi tube 200 together with the air. In this way, it is possible to provide a jet of finely atomized liquid, i.e., high-velocity atomized liquid particles (droplets of extremely fine size), suitable for shallow transdermal delivery to the upper epidermal layer of the skin.

Furthermore, system 10, and thus device 1, does not require a replaceable, i.e., single-use/disposable, power source, such as a high-pressure gas cartridge, to atomize and propel the liquid for transdermal delivery. Therefore, system 10, and thus device 1, can repeatedly atomize and propel liquid L. In addition to this, system 10, and thus device 1, does not require an external source, such as an air compressor or air pump. That is, a high-velocity air jet is generated internally to atomize and propel the liquid. Therefore, system 10, and thus device 1, as a whole, can be compact and easy to move, transport, and carry.

The specific data of an example of a system according to the embodiment described above are given below, however the invention is not limited to these values.
- Inner diameter of cylinder: 10-30mm,
- Spring constant of elastic member: 20 to 70N/m,
- Natural length of elastic member: 10-30cm,
- Outer diameter of elastic member: 5-15mm;
- Cylinder outlet hole diameter: 1-10mm, specifically 5mm;
- Maximum inner diameter of the tapered part of the Venturi tube: 1-10 mm, specifically 5 mm;
- The maximum inner diameter of the divergent part of the Venturi tube: 7 mm when the maximum inner diameter of the convergent part of the Venturi tube is 5 mm;
- Inside diameter of the Venturi throat: 3.4 mm when the maximum inside diameter of the Venturi tapered part is 5 mm;
- inner diameter of the Venturi orifice: 0.6-1.2 mm, in particular 0.6 mm, when the maximum inner diameter of the tapered part of the Venturi is 5 mm;
- Maximum pressure of air compressed in the cylinder: 0.55MPa;
- Atomized liquid droplet size: less than 10μm;
- the velocity of the atomized liquid droplets at the outlet of the Venturi tube: at least 150 m/s, regardless of the molecular weight of the liquid;
- Amount of liquid that can be delivered: 20ml/delivery(shot),
- Maximum frequency of liquid delivery (shots): 2 per second.

Preferred embodiments of the present invention have been described above in detail with reference to the drawings. However, the present invention is not limited to these embodiments, and various modifications and changes may be made to the above-described embodiments without departing from the scope of the present invention, and such modifications and changes are also included in the scope of the present invention.

10. System
100 Tank
110 Flange
200 Venturi tube
210 Internal Passage
220 Orifice
230 Tapered section
232 Entrance
Exit 234
240 End of the road
242 Entrance
Exit 244
250 Throat part
252 Entrance
Exit 254
260 Flange
300 cylinders
310 End Wall
320 Circumferential Wall
330 Exit Hole
340 Notch
400 piston
410 End Wall
420 Circumferential Wall
430 Rack
440 O-ring
450 circular groove
500 Drive Unit
510 Sector Gear
512 First Part
514 Second Part
520 Power Supply Unit
530 Electric Motor
532 Output shaft
540 Pinion
550 Bevel Gear
552 First Part
554 Second Part
560 Spur Gear
570 Latch
580 Switch
600 Elastic members, coil springs
700 Guide Rod
710 Base end

Claims (14)

A system (10) for atomizing and propelling a liquid (L) for transdermal delivery, comprising:
A tank (100) for holding the liquid (L);
a Venturi tube (200) having a central longitudinal axis ( _X1 ) and an internal passage (210) extending along said central longitudinal axis ( _X1 ), said internal passage (210) being fluidly connected to said tank (100) via an orifice (220) defined in said Venturi tube (200), said internal passage (210) comprising a convergent portion (230), a divergent portion (240), and a throat portion (250) located between said convergent portion (230) and said divergent portion (240);
a cylinder (300) having a central longitudinal axis ( _X2 ) and an end wall (310) perpendicular to said central longitudinal axis ( _X2 ), a circumferential wall ( ₃₂₀ ) extending from said end wall (310) along said central longitudinal axis (X2), and an exit hole (330) formed in said end wall (310), said exit hole (330) fluidly connected to an inlet (232) of said convergent portion (230) of said Venturi tube (200);
a piston (400) disposed within the cylinder (300) so as to be displaceable within the cylinder (300) along the longitudinal central axis ( _X2 ) thereof, the piston (400) cooperating with the cylinder (300) to define an air intake space (V) within the cylinder (300), the air intake space (V) being in fluid communication with the inlet (232) of the tapered portion (230) of the Venturi tube (200) via the outlet hole (330) of the cylinder (300);
a drive unit (500) for displacing the piston (400) in a direction in which the volume of the air intake space (V) in the cylinder (300) increases;
an elastic member (600) that deforms in accordance with the displacement of the piston (400) and stores elastic energy therein while the piston (400) is displaced in the direction in which the volume of the air intake space (V) increases,
the drive unit (500) includes an elastic energy release mechanism (M) for releasing the elastic energy stored in the elastic member (600) and thereby thrusting the piston (400) in a direction in which the volume of the air intake space (V) decreases ;
The system ( ₁₀ ) includes a piston (400) having a longitudinal central axis (X3 ₎ , an end wall (410) facing the end wall (310) of the cylinder (300), and a circumferential wall (420) extending from the end wall (410) along the longitudinal central axis (X3), a rack (430) extending along the longitudinal central axis (X3 ₎ is formed on an outer surface of the circumferential wall (420) of the piston (400), and the drive unit (500) includes a sector gear (510) having teeth only within a certain angular range that meshes with the rack (430) of the piston (400) and moves the piston (400) linearly, and the combination of the sector gear (510) and the rack (430) forms the elastic energy release mechanism (M) . 2. The system (10) of claim 1, wherein the drive unit (500) further comprises a power supply (520) and an electric motor (530) electrically connected to the power supply (520) and configured to directly or indirectly move the sector gear (510) in rotation . 3. The system (10) of claim 2, wherein the drive unit (500) further comprises a pinion (540) coupled to an output shaft (532) of the electric motor (530) and one or more gears (550, 560) that transmit rotational motion of the pinion (540) to the sector gear (510) to move it in rotation. 4. The system (10) of claim 3, wherein the one or more gears (550, 560) include a bevel gear (550) meshing with the pinion (540) and a spur gear (560) meshing with both the bevel gear (550) and the sector gear (510). 5. The system (10) of claim 4, wherein the drive unit (500) further comprises a latch (570) that meshes with the spur gear (560), the latch (570) controlling a direction of rotation of the spur gear (560) such that the spur gear (560) rotates in only one direction. 6. The system (10) of claim 1, wherein the circumferential wall (320) of the cylinder (300) is formed with a linear notch (340) for exposing at least a portion of the rack (430) of the piston (400), and the sector gear (510) engages with the rack (430) through the notch (340) in the circumferential wall ( 320 ) of the cylinder (300). 7. The system (10) of any one of claims 1 to 6 , wherein the elastic member (600) is a coil spring housed at least partially inside the piston (400). 8. The system (10) of claim 7, further comprising an elongated guide rod (700) arranged to be surrounded by the elastic member (600), wherein the guide rod (700) at least partially enters the piston (400) when the piston (400) is displaced in a direction in which the volume of the air intake space ( V ) increases. 9. The system (10) of any one of claims 1 to 8 , wherein the tank (100) is fluidly connected to the throat portion (250) of the Venturi tube (200). 10. The system (10) of any one of claims 1 to 9, wherein the Venturi tube (200) is directly connected to the cylinder (300) such that the inlet (232) of the tapered portion (230) of the Venturi tube (200) and the outlet hole (330) of the cylinder (300) are aligned with one another . 11. The system (10) of any one of claims 1 to 10, wherein a ratio of a maximum inner diameter (D ₁ ) of the convergent portion (230) of the Venturi tube (200), an inner diameter (D ₃ ) of the throat portion (250) of the Venturi tube (200), and a maximum inner diameter (D ₂ ) of the divergent portion (240) of the Venturi tube (200) is 1:0.1-0.7:1-1.5, based on the maximum inner diameter (D ₁ ) of the convergent portion (230). 12. The system (10) according to any one of claims 1 to 11 , wherein the liquid (L) is a cosmetic liquid delivered transdermally. A device (1) for transdermal delivery of atomized liquid, comprising:
A system (10) according to any one of claims 1 to 12 ,
and a casing (20) that at least partially houses the system (10). A method for atomizing and propelling a liquid (L) for transdermal delivery, comprising:
filling a tank (100) with the liquid (L), the tank (100) being fluidly connected to an internal passage (210) of a Venturi tube (200) via an orifice (220) defined in the Venturi tube (200), the internal passage (210) of the Venturi tube (200) comprising a convergent portion (230), a divergent portion (240), and a throat portion (250) located between the convergent portion (230) and the divergent portion (240);
displacing a piston (400) in a cylinder (300) in a direction that increases a volume of an air intake space (V) in the cylinder (300), the air intake space (V) being defined between the piston (400) and an end wall (310) of the cylinder (300), an outlet hole (330) formed in the end wall (310) of the cylinder (300) being fluidly connected to an inlet (232) of the tapered portion (230) of the Venturi tube (200);
deforming an elastic member (600) arranged to deform in accordance with the displacement of the piston (400) and storing elastic energy therein while the piston (400) is displaced in the direction in which the volume of the air intake space (V) increases;
releasing the elastic energy stored in the elastic member (600), thereby causing the piston (400) to move in a direction in which the volume of the air intake space (V) decreases;
and a step of forcing air out of the cylinder (300) through the outlet hole (330) of the end wall (310) of the cylinder (300) by the thrust of the piston (400), thereby atomizing the liquid (L) supplied from the tank (100) into the internal passage (210) of the Venturi tube (200) and spraying it out ;
The piston (400) has a longitudinal central axis (X3 ₎ , an end wall (410) facing the end wall (310) of the cylinder (300), and a circumferential wall (420) extending from the end wall (410) along the longitudinal central axis (X3 _{) .} a rack (430) extending along a circumferential wall (420) of the piston (400) is formed on an outer surface of the circumferential wall (420) of the piston (400), the rack (430) extending along a circumferential wall (420) of the piston (400) is formed on an outer surface of the circumferential wall (420) of the piston (400), a drive unit (500) for displacing the piston (400) in a direction in which the volume of the air intake space (V) in the cylinder (300) increases includes a sector gear (510) having teeth only in a certain angular range that meshes with the rack (430) of the piston (400) and moves the piston (400) linearly, and a combination of the sector gear (510) and the rack (430) forms an elastic energy release mechanism (M) .

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