Multi-sectioned gas-actuated drug supplying device and method

Abstract

A multi-sectioned gas-actuated drug supplying device (100) and a method. The multi-sectioned gas-actuated drug supplying device (100) is connected to a drug injection container (10) and comprises: a gas supplying unit (1) for supplying gas; a push rod unit (2) composed of a plurality of hollow tubes (21, 22, 23), wherein one end of the push rod unit is connected to the gas supply unit (1), and the hollow tubes (21, 22, 23) can be extended by means of gas; a push rod top (3) connected to the other end of the push rod unit (2) and extending along the hollow tubes (21, 22, 23) to push a drug (13); a gas chamber (4) penetrating the push rod unit (2) and connected to the gas supply unit (1) for accommodating gas and making the hollow tubes (21, 22, 23) extend as the amount of gas increases, so as to further expand the gas chamber (4); limiting parts (5) located at connecting ends of the connected hollow tubes and limiting the extension and retraction length of the hollow tubes (21, 22, 23); and gas-tight members (9) located at the connecting ends of the connected hollow tubes, such that the gas chamber (4) is sealed.

Description

Multi-stage gas-actuated medicine supply device and method Technical Field

[0001] The present invention relates to a multi-stage gas-actuated medicine supply device, and in particular to an actuated medicine supply device and method which require a small volume and prevent gas leakage. Background Art

[0002] The treatment of many chronic diseases requires the subcutaneous administration of drugs or therapeutic agents in precisely controlled doses at continuous or specific time intervals. Subcutaneous injection is a common method of delivering drugs into the body, allowing the drug to be slowly absorbed in the body over a longer period of time (compared to direct injection into the blood vessels). Currently, pen-type or patch-type injectors using primary containers (prefilled syringes or prefilled cartridges) such as pen injectors, automatic injectors, and wearable injectors have been developed, enabling users to inject drugs into their own bodies. However, these traditional pen injectors use springs or micromotors to generate the driving force to deliver drugs, and the unstable driving force caused by the spring or motor may cause unexpected pain during the injection process.

[0003] Furthermore, some treatments require injection volumes greater than 1 mL, exceeding the injection volume limits of existing subcutaneous injection devices. Furthermore, the injection rate is either too fast (seconds) or too slow (hours). For example, conventional intravenous injections of protein drugs often exceed 30 mL or even 250 mL, with injection times ranging from 30 minutes to several hours. Therefore, increasing the concentration of protein drugs to reduce the injection volume (1-20 mL) and providing portable or wearable subcutaneous injection devices for home drug delivery would save patients time and improve treatment convenience. However, protein drugs cannot be concentrated indefinitely. Increasing the protein concentration beyond the solubility limit will result in crystallization and precipitation. Therefore, the volume of many subcutaneous protein drugs at the necessary therapeutic dose often exceeds 1 mL. Injecting protein volumes exceeding 1 mL at high flow rates can cause swelling at the injection site and pain for the patient, resulting in a maximum injection volume of 1 mL for existing pen-type or autoinjector subcutaneous injection devices on the market. Many wearable drug pump devices are driven by stepper motors (or similar components for rotating gears). However, their motion is discrete (one rotation per step) rather than continuous. Consequently, the basal delivery rate provided by the stepper motor is also discrete (one drop at a time). For example, a basal rate in the range of 5 to 5000 nl / min (a typical insulin dosage regimen) has discrete deliveries of 5 nl each, with rates ranging from one delivery per hour to one thousand deliveries per hour. Injecting 1 ml typically takes more than 3-6 hours at the fastest, which is too slow to meet patient needs (5-10 minutes).

[0004] Existing electrochemical pumps typically apply generated gas directly to a drug separation component (such as a diaphragm or movable barrier) to expel the drug from its container, completing the drug delivery process. During this drug delivery process, there is a risk of drug contamination due to the electrochemically generated high-pressure gas leaking through leaky areas of the separation component (such as defects in the diaphragm, container wall, or movable barrier).

[0005] Therefore, it is urgent to develop an actuated drug delivery device that can promote drug delivery by generating gas at a moderate speed without the risk of gas contamination of the drug and has a small size.

[0006] Summary of the Invention

[0007] In view of this, the present invention provides a multi-stage gas-actuated medicine supply device and method to solve the background technical problems, which can be used in conjunction with different medicine supply equipment.

[0008] A multi-stage gas-actuated medicine supply device of the present invention includes: an air supply unit for supplying gas to the device; a push rod unit composed of several hollow tubes, one end of which is connected to the air supply unit; a push rod top connected to the other end of the push rod unit; an air chamber that passes through the push rod unit and is connected to the air supply unit; a limiting portion located at the connecting end of the connected hollow tubes, used to limit the telescopic length of the several hollow tubes; and an airtight member located at the connecting end of the connected hollow tubes, which serves to seal the air chamber.

[0009] The gas supply unit of the present invention includes an electrochemical pump, which can release gas at a linear or nonlinear speed, or slowly release gas to push the push rod unit; it is worth noting that the present invention can administer drugs in accordance with the injection site and / or the delivery speed requirements of different drugs, so that the person being injected will not feel uncomfortable.

[0010] A multi-stage gas-actuated drug delivery method of the present invention includes: a gas supply unit continuously provides a gas with a linear or nonlinear speed increase within a time period; the gas is filled into an air chamber covered by a push rod unit; as the gas pressure received by the air chamber increases, several hollow tubes of the push rod unit simultaneously extend at a linear or nonlinear speed; the push rod unit extends, thereby pushing a push block structure; if the gas supply unit continues to supply gas, a limit portion on the several hollow tubes can limit a certain extension length of the push rod unit; and the push block structure can push a medicine.

[0011] In addition, the airtight member of the present invention is located at the connecting end of the connected hollow tubes, and the airtight member prevents the gas from leaking from the gas chamber, which can effectively prevent the gas from contaminating the supplied medicine. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIG1 is a schematic diagram of a multi-stage gas-actuated drug supply device;

[0013] FIG2 is a schematic flow chart of a multi-stage gas-actuated drug supply method;

[0014] FIG3 is a schematic diagram of a buffer gas chamber and a separate gas supply;

[0015] FIG4 is a schematic diagram of a push rod unit of a hollow tube from small to large;

[0016] FIG5 is a schematic diagram of a push rod unit of a hollow tube of different forms;

[0017] FIG6 is a schematic diagram of a push rod unit in the form of a multi-segment hollow tube;

[0018] FIG7 is a schematic diagram of different airtight components and concave design forms;

[0019] FIG8 is a schematic diagram of the change of the force-bearing area of ​​the push rod unit;

[0020] FIG9 is a schematic diagram of a column assembly and a capillary hollow tube;

[0021] Figure 10 is a schematic diagram of large and small spiral patterns;

[0022] Figure 11 is a schematic diagram of the structure of the top joint of the push rod and the buffer sheet;

[0023] FIG12 is a schematic diagram of a push rod unit with variations;

[0024] Figure 13 is a schematic diagram of the injection needle of the drug supply actuator;

[0025] FIG14 is a schematic diagram of an injection needle of a drug supply actuator device and a general injection needle;

[0026] FIG15 is a schematic diagram of different drug supply speed curves;

[0027] Explanation of the accompanying drawings: 1-air supply unit; 2-push rod unit; 3-push rod top; 4-air chamber; 5-limiting part; 6-push block structure; 7-buffer air chamber; 8-column assembly; 9-air-tightening part; 10-drug injection container; 11-small spiral pattern; 12-large spiral pattern; 13-medicine; 14-capillary hollow tube; 15-movable barrier; 20-hollow tube; 21-first hollow tube; 22-second hollow tube; 23-third hollow tube; 24-fourth hollow tube; 31-joint; 91-back support ring; 92-buffer plate; 100-multi-stage gas-actuated drug supply device; 200-drug supply actuating device injection needle; 300-general injection needle; A1~A4-multi-stage gas-actuated drug supply method process. DETAILED DESCRIPTION

[0028] The following is a more detailed description of the embodiments of the present invention in conjunction with the accompanying drawings. It should be understood that the sizes, proportions, and gaps of the components in the specific embodiments of the present invention are only for illustration and are not intended to limit the present invention.

[0029] A multi-stage gas-actuated drug delivery device 100 of the present invention is shown in FIG1 and FIG13 and can be connected to a drug injection container 10 for use. The device 100 comprises:

[0030] A gas supply unit 1, providing a gas;

[0031] A push rod unit 2, consisting of a plurality of hollow tubes, one end of which is connected to the air supply unit 1, and the hollow tubes can be stretched by gas;

[0032] A push rod top 3, connected to the other end of the push rod unit 2, extends along the plurality of hollow tubes to push a movable barrier 15, further pushing a medicine 13;

[0033] An air chamber 4, which passes through the push rod unit 2 and is connected to the air supply unit 1, is used to contain gas and extends several hollow tubes as the gas increases, further expanding the air chamber 4;

[0034] When the gas supply unit 1 is not in operation, the push rod unit 2 is in the shortest unextended state; after the gas supply unit 1 provides gas, the extended length of the push rod unit 2 is less than the total length of the plurality of hollow tubes.

[0035] The gas supply unit 1 of the present invention includes an electrochemical pump, which can release gas at a linear or nonlinear rate, or slowly release gas to push the push rod unit 2. It is worth noting that the present invention can provide medication in accordance with the injection site and / or the delivery speed requirements of different medications without causing discomfort to the person being injected.

[0036] In one embodiment of the present invention, a multi-stage gas-actuated drug delivery method is shown in FIG2 , comprising:

[0037] A1. A gas supply unit 1 continuously provides a linear or nonlinear rate increase of a gas over a period of time;

[0038] A2. Gas is filled into a chamber 4 enclosed by a push rod unit 2;

[0039] A3. As the gas pressure received by the air chamber 4 increases, the plurality of hollow tubes of the push rod unit 2 simultaneously stretch at a linear or nonlinear speed; and

[0040] A4. The push rod unit 2 extends, thereby pushing a movable barrier 15 of a drug injection container to push out a medicine 13.

[0041] Preferably, the movable blocking member 15 includes a rubber stopper and a piston.

[0042] In one embodiment of the present invention, a multi-stage gas-actuated drug supply device 100 as shown in Figure 3, the several hollow tubes of the push rod unit 2 have an airtight member 9 and a limit portion 5 at the connecting ends of the connected hollow tubes. The airtight member 9 prevents gas from leaking from the gas chamber 4, which can effectively prevent the gas from contaminating the supplied medicine; the limit portion 5 limits the extension length of the several hollow tubes.

[0043] In one embodiment of the present invention, a multi-stage gas-actuated drug supply device 100, as shown in FIG3 , the gas supply unit 1 is further connected to a buffer gas chamber 7 and then connected to the push rod unit 2; the buffer gas chamber 7 prevents the gas generated by the gas supply unit from directly impacting the push rod unit 2, thereby achieving a smooth extension of the push rod unit 2; the shape of the buffer gas chamber 7 shown in the figure is only an embodiment, and the present invention is not limited to this shape.

[0044] In one embodiment of the present invention, a multi-stage gas-actuated medicine supply device 100 is shown in FIG3 . The gas supply unit 1 can be a separate design and connected to the push rod unit 2 via a connecting pipe.

[0045] In one embodiment of the present invention, the push rod unit 2 is composed of hollow tubes of decreasing diameter, and the inner diameter of the Nth hollow tube is slightly larger than the outer diameter of the N+1th hollow tube, so that the N+1th hollow tube can slide inside the Nth hollow tube; N is the number of sections of the hollow tube 20, which is an integer greater than 0.

[0046] In one embodiment of the present invention, as shown in Figure 1, the push rod unit 2 is composed of three hollow tubes, one end of the first hollow tube 21 is connected to the air supply unit 1, and the other end is connected to a second hollow tube 22, the outer diameter of the second hollow tube 22 is slightly smaller than the inner diameter of the first hollow tube 21, so that the second hollow tube 22 can slide in the first hollow tube 21; the third hollow tube 23 is connected to the second hollow tube 22, the outer diameter of the third hollow tube 23 is slightly smaller than the inner diameter of the second hollow tube 22, so that the third hollow tube 23 can slide in the second hollow tube 22, and the other end of the third hollow tube 23 is connected to a push rod top 3.

[0047] In one embodiment of the present invention, the push rod unit 2 is composed of hollow tubes with increasing diameters, and the outer diameter of the Nth hollow tube is slightly smaller than the inner diameter of the N+1th hollow tube, so that the Nth hollow tube can slide in the N+1th hollow tube; N is the number of sections of the hollow tube 20, which is an integer greater than 0.

[0048] In one embodiment of the present invention, as shown in Figure 4, the push rod unit 2 is composed of three hollow tubes, one end of the first hollow tube 21 is connected to the air supply unit 1, and the other end is connected to the second hollow tube 22. The outer diameter of the first hollow tube 21 is slightly smaller than the inner diameter of the second hollow tube 22, so that the first hollow tube 21 can slide in the second hollow tube 22; the third hollow tube 23 is connected to the second hollow tube 22, and the outer diameter of the second hollow tube 22 is slightly smaller than the inner diameter of the third hollow tube 23, so that the second hollow tube 22 can slide in the third hollow tube 23, and the other end of the third hollow tube 23 is connected to a push rod top 3.

[0049] In one embodiment of the present invention, push rod units of hollow tubes of different forms are shown in the right figure of Figure 5. The push rod unit 2 is composed of three sections of hollow tubes. One end of the first hollow tube 21 is connected to the air supply unit 1, and the other end is connected to the second hollow tube 22. The outer diameter of the first hollow tube 21 is slightly smaller than the inner diameter of the second hollow tube 22, so that the first hollow tube 21 can slide in the second hollow tube 22; the third hollow tube 23 is connected to the second hollow tube 22, and the inner diameter of the second hollow tube 22 is slightly larger than the outer diameter of the third hollow tube 23, so that the third hollow tube 23 can slide in the second hollow tube 22. The other end of the third hollow tube 23 is connected to a push rod top 3.

[0050] In one embodiment of the present invention, a push rod unit of a hollow tube of different forms is shown in the left figure of Figure 5. The push rod unit 2 is composed of three sections of hollow tubes. One end of the first hollow tube 21 is connected to the air supply unit 1, and the other end is connected to the second hollow tube 22. The inner diameter of the first hollow tube 21 is slightly larger than the outer diameter of the second hollow tube 22, so that the second hollow tube 22 can slide in the first hollow tube 21; the third hollow tube 23 is connected to the second hollow tube 22, and the outer diameter of the second hollow tube 22 is slightly smaller than the inner diameter of the third hollow tube 23, so that the second hollow tube 22 can slide in the third hollow tube 23. The other end of the third hollow tube 23 is connected to a push rod top 3.

[0051] In one embodiment of the present invention, a push rod unit of a multi-section hollow tube is shown in FIG6 . The push rod unit 2 can be composed of several hollow tubes, including two sections of hollow tubes (as shown in the left figure of FIG6 ) and four sections of hollow tubes (as shown in the right figure of FIG6 ). When the two sections of hollow tubes are not extended, the length is half of the total length; when the four sections of hollow tubes are not extended, the length is one quarter of the total length. The present invention can effectively reduce the size of the device and save space.

[0052] Preferably, when the push rod unit 2 of the multi-stage gas-actuated drug feeding device 100 is not extended, its length can be reduced to 1 mm.

[0053] Preferably, the contact area of ​​the hollow tube changes according to the shape and material of the airtight member 9, further affecting the extension speed of the hollow tube; the airtight member 9 is tightly attached to the hollow tube to form a contact area, which is inversely proportional to the extension speed of the hollow tube.

[0054] In one embodiment of the present invention, a multi-stage gas-actuated drug supply device 100 is shown in FIG7 , wherein the airtight member 9 includes circular, quadrilateral, elliptical, polygonal, X-shaped, etc.; each shape causes the hollow tube to expand at a different speed.

[0055] In the above embodiment, the airtight member 9 can be used interchangeably, for example, as shown in FIG7 , a variety of forms can be used in combination; the extension speed of the several hollow tubes in each combination form is determined by the form of the airtight member 9; it is worth noting that this combination design can be designed according to the different properties of the drug or / and the characteristics of the tissues of different subcutaneous areas to design a time speed curve for drug delivery that will minimize the discomfort felt by the recipient.

[0056] Preferably, as shown in FIG. 7 , the airtight member 9 can be used in conjunction with one or more backing rings 91 to improve the deformation of the airtight member 9 when the hollow tube expands and contracts under high pressure.

[0057] Preferably, as shown in FIG. 7 , the limiting portion 5 is concave in design, and the height of the concave side is lower than the height of the airtight member 9 , so as to strengthen the positioning of the airtight member 9 and ensure airtightness.

[0058] In one embodiment of the present invention, as shown in FIG8 , the plurality of hollow tubes of the push rod unit can be directly designed with different diameters and / or wall thicknesses, thereby indirectly changing the relationship between the force area (A) and the normal force (F) of the gas pressure (P) released by the gas supply unit 1; the formula is as follows:

[0059] Pressure (P) = normal force (F) / force area (A), P = F / A

[0060] Under the fixed pressure (P) provided by the air supply unit 1, the force-bearing area (A) is proportional to the positive force (F) of the extension speed. The larger the force-bearing area (A), the faster the extension speed. Furthermore, by changing the ratio of the inner diameter and the wall thickness of the multiple hollow tubes, the extension sequence and speed of the multiple hollow tubes can be changed and controlled to achieve a variable and controllable drug supply rate curve.

[0061] In one embodiment of the present invention, a four-stage gas-actuated drug supply device, as shown in Figure 8, consists of a push rod unit 2 and a drug injection container 10, which can achieve different drug supply speed curves; the first hollow tube 21 is fixedly connected to the gas supply unit 1, and the gas supply unit 1 provides a fixed pressure (P); in the first stage, when the push rod unit is not extended, the maximum positive force (F1) of the force area (A1) is the highest (A1 = the area of ​​the top 3 of the push rod + the wall thickness of the second and third hollow tubes 22 and 23 * 2), and the flow rate is the highest 2st; in the second stage, when the second hollow tube 22 is extended, the force area (A2 = the area of ​​the top 3 of the push rod + the wall thickness of the third hollow tube 23 * 2) is the second, and the flow rate is the second; in the third stage, when the third hollow tube 22 is extended, the force area (A3 = the area of ​​the top 3 of the push rod) is the smallest 4rd; Figure 15 shows the relationship between time and the flow rate of the drug.

[0062] In one embodiment of the present invention, the inner surface roughness of the plurality of hollow tubes of the push rod unit can be designed according to the actual stretching sequence and stretching speed; since the roughness of the inner surfaces of the plurality of hollow tubes is inversely proportional to the stretching speed of the plurality of hollow tubes (the greater the roughness, the slower the stretching speed), the stretching sequence and speed of the hollow tubes can be changed and controlled by changing the ratio of the roughness of the inner surfaces of the hollow tubes to achieve a variable and controllable drug supply rate curve.

[0063] In one embodiment of the present invention, a multi-stage gas-actuated drug supply device 100 is shown in the left figure of Figure 9. The end section of the push rod unit 2 is a columnar assembly 8. The columnar assembly 8 does not have an air chamber 4. The gas directly pushes one end of the columnar assembly 8, and the other end is the push rod top 3.

[0064] In one embodiment of the present invention, a multi-stage gas-actuated drug supply device 100 is shown in the right figure of FIG. 9 , in which the first hollow tube 21 may be a capillary hollow tube 14 structure.

[0065] In one embodiment of the present invention, a multi-stage gas-actuated drug supply device 100 is shown in the hollow tube cross-sectional view of Figure 10. The inner wall of a hollow tube 20 of the push rod unit 2 has multiple spiral patterns, allowing the hollow tube of the push rod unit 2 to extend in a spiral manner; the spiral patterns include small spiral patterns 11 and large spiral patterns 12.

[0066] In one embodiment of the present invention, as shown in FIG11 , the top of the push rod 3 is connected to a joint 31 for installing a plurality of push block structures 6 to lock the movable barrier 15 to assist in pushing the medicine. The push block structure 6 includes a movable barrier lock, a push rod top lock, and a movable barrier push rod top lock.

[0067] In one embodiment of the present invention, as shown in FIG11 , a buffer sheet 92 is installed at one end of the hollow tube. The buffer sheet 92 may have one or more holes extending therethrough. By installing buffer sheets 92 with different numbers of holes in each section of the hollow tube, the stretching sequence and speed of each section of the hollow tube may be changed. The holes may be micro-nano- to micron-sized holes to provide different gas passage speed controls.

[0068] As shown in an embodiment of the present invention shown in FIG12, the buffer sheet 92 is matched with different forms of airtight parts 9 and hollow tubes 20 of different lengths to achieve a variable drug supply curve. The push rod unit 2 of an embodiment of the present invention is composed of a second hollow tube 22 having a length greater than that of the third hollow tube 23. The first hollow tube 21 and the second hollow tube 22 use a circular airtight part 9, and the second hollow tube 22 and the third hollow tube 23 use a rectangular airtight part 9. A buffer sheet 92 is installed at one end of the second hollow tube 22; because the buffer sheet 92 acts to make the gas generated by the gas supply unit 1 fill first. The second hollow tube 22 section of the air chamber 4 is filled, and because the contact area between the circular air-tight member 9 and the first hollow tube 21 is smaller than the contact area between the rectangular air-tight member 9 and the third hollow tube 23, the second hollow tube 22 is first extended to the length of the first hollow tube 21; the gas further fills the third hollow tube 23 section of the air chamber 4, and because of the rectangular air-tight member 9, the extension speed is slower than the extension speed of the second hollow tube 22; the present invention achieves the goal of first pushing a relatively large amount of the medicine 13 at a relatively fast speed, and then pushing a relatively small amount of the medicine 13 at a relatively slow speed.

[0069] As mentioned above, by changing the length, diameter, and roughness of the hollow tube and matching the shape of the airtight member 9 with different combinations of the buffer sheet 92, different drug supply speed curves can be achieved.

[0070] As shown in FIG13 , an embodiment of the present invention includes a multi-stage gas-actuated drug supply device 100 that can be used in conjunction with a drug injection container 10 containing a movable barrier to form a drug supply actuation device injection needle 200 . Furthermore, the gas supply unit 1 is an electrochemical pump, and the device can be installed on an automatic injection device.

[0071] In the above embodiment, the electrochemical pump slowly generates gas and gently pushes the medicine in the injection needle 200, so that patients who need long-term and continuous small-volume subcutaneous injections will not feel discomfort due to the injection process. Currently, long-term and continuous small-volume subcutaneous injections are all controlled by nurses. This problem can be solved by using the present invention.

[0072] As shown in FIG14 , an embodiment of the present invention comprises a multi-stage gas-actuated drug supply device 100 and a drug injection container 10 to form a drug supply activation device injection needle 200. Compared with a conventional injection needle 300, the present invention can effectively shorten the injection needle length.

[0073] The above descriptions are merely embodiments of the present invention and are not intended to limit the scope of protection of the present invention. All equivalent implementations based on the contents, features and spirit of the claims of the present invention should be included in the scope of protection of the present invention.

Claims

1. A multistage gas-actuated drug supply device, connected to a drug injection container, comprising:a gas supply unit, the gas supply unit including an electrochemical pump, operable to generate a gas;a plunger unit connected to the gas supply unit, comprising:a plurality of hollow tubes telescopically and slidably connected to one another, an outermost hollow tube forming a plunger top, the plunger top being configured to displace a movable barrier for dispensing a medicament from the drug injection container, wherein the plurality of hollow tubes include a first hollow tube disposed innermost, and a second hollow tube connected thereto, the plunger unit being connected to the gas supply unit via the first hollow tube; anda gas chamber defined by the plurality of hollow tubes and configured to receive the gas generated by the electrochemical pump;wherein, as the gas pressure increases, the plurality of hollow tubes are actuated by the gas to move the plunger top, thereby displacing the movable barrier and dispensing the medicament, andwherein the outermost hollow tube has a uniform, continuous outer diameter throughout its entire longitudinal length.2021383119   27 Aug 20262. The multistage gas-actuated drug supply device defined in claim 1, wherein the second hollow tube of the plunger unit is connected to a third hollow tube, the outside diameter of the third hollow tube is slightly smaller than the inside diameter of the second hollow tube, so that the third hollow tube can slide inside the second hollow tube.

3. The multistage gas-actuated drug supply device defined in claim 1 or claim 2, wherein the gas supply unit is first connected to a buffer gas chamber before being connected to the plunger unit, the buffer gas chamber functions to prevent the gas generated by the gas supply unit from directly impacting the plunger unit.

4. The multistage gas-actuated drug supply device defined in any one of the preceding claims, wherein a cushion sheet is installed between the plunger top and an adjacent hollow tube of the plunger unit, the cushion sheet having one or more holes penetrating therethrough.

5. The multistage gas-actuated drug supply device defined in any one of the preceding claims, wherein the roughness of a surface inside the hollow tubes of the plunger unit is inversely proportional to the rate of stretch of the hollow tubes, the higher the roughness is, the lower is the rate of stretch.

6. The multistage gas-actuated drug supply device defined in any one of the preceding claims, wherein the hollow tubes have an airtight piece and a limit part at a coupling end of the connected hollow tubes, the limit part is2021383119   27 Aug 2026designed in a concave form, a side edge height of the concave form is lower than the height of the airtight piece, so as to guarantee airtightness.

7. The multistage gas-actuated drug supply device defined in any one of the preceding claims, wherein the hollow tubes have a plurality of helices, so that the hollow tubes of the plunger unit can stretch in a direction of spiral.

8. The multistage gas-actuated drug supply device defined in any one of the preceding claims, wherein the plunger top is secured to the movable barrier of a syringe by a coupling section.

9. A multistage gas-actuated drug supply device, connected to a drug injection container, comprising:a gas supply unit, the gas supply unit including an electrochemical pump, operable to generate a gas;a plunger unit connected to the gas supply unit, comprising:a plurality of hollow tubes telescopically and slidably connected to one another, wherein the plurality of hollow tubes include a first hollow tube disposed outermost and a second hollow tube connected thereto, the plunger unit being connected to the gas supply unit via the first hollow tube;an end section telescopically and slidably connected to an innermost hollow tube of the plurality of hollow tubes and forming a plunger top, the2021383119   27 Aug 2026plunger top being configured to displace a movable barrier for dispensing a medicament from the drug injection container; anda gas chamber defined by the plurality of hollow tubes and the end section and configured to receive the gas generated by the electrochemical pump;wherein, as the gas pressure increases, the plurality of hollow tubes are actuated by the gas to move the plunger top, thereby displacing the movable barrier and dispensing the medicament, andwherein the outermost hollow tube has a uniform, continuous outer diameter throughout its entire longitudinal length.

10. The multistage gas-actuated drug supply device defined in Claim 9, wherein the second hollow tube of the plunger unit is connected to a third hollow tube, the inside diameter of the third hollow tube is slightly larger than the outside diameter of the second hollow tube, so that the second hollow tube can slide inside the third hollow tube.

11. The multistage gas-actuated drug supply device defined in claim 9 or claim 10, wherein the gas supply unit is first connected to a buffer gas chamber before being connected to the plunger unit, the buffer gas chamber functions to prevent the gas generated by the gas supply unit from directly impacting the plunger unit.2021383119   27 Aug 202612. The multistage gas-actuated drug supply device defined in any one of claims 9 to 11, wherein a caliber size and a tube wall thickness of the hollow tubes of the plunger unit form a stressed area, the stressed area is proportional to the rate of stretch, the larger the stressed area is, the higher is the rate of stretch.

13. The multistage gas-actuated drug supply device defined in any one of claims 9 to 12, wherein the roughness of a surface inside the hollow tubes of the plunger unit is inversely proportional to the rate of stretch of the hollow tubes, the higher the roughness is, the lower is the rate of stretch.

14. The multistage gas-actuated drug supply device defined in any one of claims 9 to 13, wherein the hollow tubes have an airtight piece and a limit part at a coupling end of the connected hollow tubes, the limit part is designed in a concave form, the side edge height of the concave form is lower than the height of the airtight piece, so as to guarantee airtightness.

15. The multistage gas-actuated drug supply device defined in any one of claims 9 to 14, wherein the hollow tubes have a plurality of helices, so that the hollow tubes of the plunger unit can stretch in a direction of spiral.

16. The multistage gas-actuated drug supply device defined in any one of claims 9 to 15, wherein the end section of the plunger unit is a solid cylinder component, the gas directly pushes this solid cylinder component2021383119   27 Aug 202617. The multistage gas-actuated drug supply device defined in any one of claims 9 to 16, wherein the plunger top is secured to the movable barrier by a coupling section.

18. A method for multistage gas-actuated drug supply comprising:an electrochemical pump of a gas supply unit generating a gas;a plunger unit, connected to the gas supply unit, receiving the gas,wherein the plunger unit comprises: telescopically and slidably connected to one another, an outermost hollow tube forming a plunger top, the plunger top being configured to displace a movable barrier for dispensing a medicament from a drug injection container; and a gas chamber defined by the plurality of hollow tubes and configured to receive the gas generated by the electrochemical pump;as the gas pressure increases, the gas actuating the plurality of hollow tubes to move the plunger top, thereby displacing the movable barrier and dispensing the medicament, andwherein the outermost hollow tube has a uniform, continuous outer diameter throughout its entire longitudinal length.

19. The method defined in claim 18, wherein the gas supply unit is connected to a buffer gas chamber, and connected to the plunger unit, so as to avoid the gas directly impacting the gas chamber.2021383119   27 Aug 202620. The method defined in claim 18 or claim 19, wherein a cushion sheet is installed between the plunger top and an adjacent hollow tube, the cushion sheet having one or more holes penetrating therethrough.

21. The method defined in any one of claims 18 to 20, wherein a tube diameter size and a tube wall thickness of the hollow tubes of the plunger unit form a stressed area, the stressed area is proportional to the rate of stretch, the larger the stressed area is, the higher is the rate of stretch.

22. The method defined in any one of claims 18 to 21, wherein the rate of stretch of the hollow tubes can be adjusted by changing the roughness of inner surface of the hollow tubes of the plunger unit, the inner surface roughness of the hollow tubes is inversely proportional to the rate of stretch of the hollow tubes, the higher the roughness is, the lower is the rate of stretch.

23. The method defined in any one of claims 18 to 22, wherein the hollow tubes have an airtight piece at the coupling end of the connected hollow tubes, a contact area of the airtight piece and the hollow tubes is inversely proportional to the rate of stretch of the hollow tube.

24. The method defined in any one of claims 18 to 23, wherein the hollow tubes have a plurality of helices, so that the hollow tubes of the plunger unit can stretch in a direction of spiral.2021383119   27 Aug 202625. The method defined in any one of claims 18 to 24, wherein the plunger top is connected to a coupling section, multiple push block structures can be installed to assist in pushing.

26. The method defined in any one of claims 18 to 25, wherein the drug injection container is incorporated within an auto-injection device.MicroMed Co., Ltd.Patent Attorneys for the Applicant / Nominated Person SPRUSON & FERGUSON

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