FI116451B - A method of controlling the action of a drug dispenser and a mechanism for its implementation - Google Patents

Description

116451 Method and mechanism for controlling the action of a drug dispenser

Background of the Invention

The invention relates to a method of controlling the action of a medicament dispenser comprising: operating a medicament dispensing actuator for releasing a dose of medicament so that the dispenser locking member moves from a first position to a second, locked position in which actuation of the actuating member it is possible to simulate said delay with a functional element having a dormant state and an armed state whose deformation of the element causes the locking member to move from the first position to the second position and vice versa.

The invention further relates to a mechanism for controlling the action of a medicament dispenser comprising a locking member having a first position in which a dose of medicament is dispensed by the actuation member, and a second position in which the medicament dispensing is prevented; the dispenser has metered a certain amount of drug.

A still further object of the invention is a medicament dispenser comprising a locking member having a first position for actuating the operating member, and a second position in which the drug delivery is prevented, which locking member is adapted to move from the first member. from one position to another when the dispenser has metered. · · ·, The amount of drug.

• *; t 25 With the aid of drug dispensers, the patient himself or a patient, with the assistance of a caregiver, delivers a predetermined volume of drug under the skin, circulatory system, respiratory tract, mucous membranes, or skin. The dosage form may be, for example, a powder, an aerosol, a liquid, a fixed dose of a compact or a combination thereof. Such drug dispensers include, but are not limited to, inhalers, intravenous dosing devices, and syringes.

The drug is most often fitted in a drug reservoir in the inhaler. In some inhalers, the drug reservoir contains a pre-dose dose of • • medicine, which is transported with the inhaled air to the user 's body; in this case, the inhaler has a plurality of discrete drug-containing drug containers 35 which are arranged in a magazine-like manner in a plurality of small discrete drug containers. In some other inhalers, the drug reservoir is dispensed with a certain amount of drug into a special chamber in the inhaler from which the drug is mixed with the inhalation air. Based on the operation of the inhaler on either of the above principles, the inhaler is provided with means for removing the drug from the 5 drug reservoirs and arranging the drug for mixing with the flow of air through the inhaler. The inhaler may be a single use disposable waste product or may be refilled with a drug substance upon expiration.

In order to achieve the desired 10 therapeutic response to the drug, it is essential for the dosing agent to follow the treatment guidelines which determine both the dose size and dosing intervals. As with drugs in general, overdosing of drugs administered via drug dispensers can, in certain diseases, lead to dangerous situations that require immediate medical attention.

Current drug dispensers may deliberately or unintentionally misdeliver drugs.

Drug dispensers are known for attempting to solve the above problem by attaching an electronic control unit to the timers and actuators controlled by them which prevent dosing if attempted too soon after the previous dosing. Such solutions are disclosed, for example, in U.S. Patent Nos. 4,934,358 and 5,284,133, and in WO application 00/78639. However, the problem with these arrangements is the complexity and; i * component price.

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BRIEF DESCRIPTION OF THE INVENTION It is an object of the present invention to provide a novel and improved method, a mechanism implementing the method, and a drug delivery device such that the above problems can be avoided.

The drug dispenser control method of the invention is characterized in that the functional element comprises a memory metal.

For a mechanism according to the invention, a dispenser control method. is characterized in that the mechanism further comprises a functional, ···, element which comprises a memory metal having a dormant state and an armed state, wherein said element has a different shape, and that the deformation of the memory metal is arranged to move the locking member from a first position. ; 35 to the other position and vice versa.

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The drug dispenser according to the invention is further characterized in that the drug dispenser further comprises a functional element comprising a memory metal having a dormant state and an excited state, wherein said element has a different shape, and that the deformation of the memory metal is arranged

An advantage of the invention is that too frequent dosing of the drug is prevented by simple solutions and in a cost-effective manner.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described in greater detail in connection with the preferred embodiments, with reference to the accompanying drawings, in which Fig. 1a schematically depicts one side of a drug dispenser and Fig. 1b schematically illustrates Fig. 3a and 3b show a third partially opened and top view of a third drug dispenser according to the invention, and Figs. 4a-4d show a fourth partially exploded locking mechanism according to the invention.

DETAILED DESCRIPTION OF THE INVENTION. Figures 1a and 1b show schematically an embodiment of the invention.

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;:; medicament dispenser and the function of its locking mechanism. Drug Dispenser 1, *; *; * hereinafter, the dispenser 1, the outline is shown in the figure by dotted lines.

The components of the dispenser 1 are preferably made mainly of polymeric materials by casting or injection molding or the like. Dispenser 1 may comprise a plurality of reservoirs of drugs each contain one dose of drug. Alternatively, the drug substance is disposed in a single drug container from which only a certain amount of 30 drugs is dispensed per drug dose, i.e., the drug container is filled with more than one drug dose. Notes- '·; · 'That the drug containers are not shown in the figures.

The dispenser 1 shown in Figures 1a, 1b has a rotationally symmetrical center axis 9 as the axis of symmetry. The dispenser 1 comprises a 35 cylindrical actuator 2 rotatably disposed about the central axis 9 of the dispenser 1 4 116451. When the dispenser 1 is to be administered in the dose of drug has been prescribed the use of two rotary member of the dispenser 3 relative to the body portion of the angle of rotation of arrow A direction.

The actuator 2 is provided with a locking member 4 comprising a lock 5 piece 5 and a functional element 6 attached thereto. In Figs. 1a, 1b, the lock piece 5 is a cylindrical hollow shaped piece with one end closed; it can be different, of course. The functional element 6 is formed of a metal wire twisted into a helical spring-like shape. The yarn comprises reversibly deformable memory material that changes its shape in a controlled manner when its energy state changes, i.e., when it moves from a dormant state to an armed state or vice versa. The memory material, both in the dormant state and the armed state, has a particular shape which the memory material tends to enter when entering that state. The change in energy state in the embodiment disclosed herein is caused by a change in temperature, but may also be caused by a change in electric field or a change in magnetic field. The memory material is, for example, nitinol, an alloy of which about half is nickel and half titanium, or other alloy such as Cu-Zn-Al or Cu-Al-Ni. The function of a memory metal is based on a change in the crystal structure of the metal. In a change in structure, the atoms of the crystal structure repackage because a given stiffness has the lowest energy at a given temperature and the structure always strives for energy minima. The temperature or range of temperature at which the change occurs is called the transition temperature. t j · The body part 3 is fitted with a locking member 7 which is now '! a recess having a diameter of some locking piece 5: * '; greater and with a depth substantially less than the height of the locking member.

. ···. The counter part 7 is arranged such that when rotating the actuator 2 to perform the dosing: v, the locking member 5 slides over the counter part 7.

'..! Further, the dispenser 1 comprises electrical contacts 8 'and 8' connected to a power supply 10. The power supply 10 is a disposable battery or rechargeable battery known per se. The electrical contacts 8 ', 8 "are arranged such that: when the actuator 2 is rotated to effect metering, the functional element 6 at some point switches the electrical contacts 8' and 8" electrically! rope to a closed circuit. The electric current then passes through the functional element 6 and its temperature increases substantially due to the electrical resistance generated by the element 6. Thus, the temperature of the functional element 6 '' 35 rises above the transition temperature, whereby the memory material enters an excited state. In the present embodiment, the excitation occurs so that the functional element 6 tends to increase its length.

As the locking member 4 rotates to the counterpart 7 of the lock body, the elongate functional element 6 pushes the lock body 5 into the counterpart 7.

5 The locking member 5 in the counterpart 7 prevents rotation of the actuator member 2 for re-dispensing the drug. The dispensed drug may be taken by the user, but the locking member 4 prevents rotation of the actuator 2 immediately to dispense a second dose.

As the functional element 6 is rotated with respect to the electrical contacts 8 ', 8 "10 so that the circuit opens, it begins to cool. When the temperature drops below the transition temperature, the excitation state of the memory material is triggered and the locking piece 5 rises out of the counterpart 7, whereby the dispenser 1 can again dispense the drug. The time it takes for the tuning state to be triggered, i.e. the delay, depends on the properties of the memory material itself, mainly the transition temperature, and its rate of change of temperature. A lower transition temperature gives a longer delay under the same environmental conditions than a higher transition temperature. The locking time can be, for example, 5-30 minutes.

Figures 2a to 2d schematically show another locking mechanism according to the invention, partially in section and sideways. Dispenses-20 instead provides drug by moving the operating member 2 in the direction of arrow A. The actuator 2 is provided with a protruding actuator switch 11 which; - facilitates operation of the actuator 2. The mechanism further includes a dispensing member 12 which is adapted to contact with the actuating member, but such that the components may slide relative to one another. The dispensing member 12 is still. ** ·, 25 fitted with a sliding contact with the dispenser body 3; The sliding surfaces between the v part 12 and the actuator member 2 and the dispensing member 12 and the body member 3 are parallel, so that the dosing member 12 can move between the actuator member 2 '' and the body member 3 in the direction of the arrows A and R.

The dosing element 12 will sufficiently far in the direction of arrow A to take ί administration for 30, as a result of the drug can be released from the dispenser ,, the body. After dosing, the actuator returns to the initial: 1 shown in Figure 2a. moved by a force member fitted to the dispenser such as a return spring in the direction R: the force member is not shown in the figures to simplify the presentation.

The dispenser has a locking member 4 having a functional element 6 and a locking member 5 attached thereto adapted to be movable with the dispensing part 12 6 116451, while the counter part 7 is arranged on the actuating member 2. The functional element 6 applicable here is manufactured below the transition temperature than at higher temperatures. Thus, as the functional element 6 is tuned, its length is reduced.

The dispenser locking mechanism is in the resting state of the functional element 6 in the state shown in Figure 2a. If desired, the medicinal substance is transferred to the operating member 2 of the arrow A in the direction of travel determined. Since the locking piece 5 of the locking part 4 is in the counterpart 7, the dispensing part 12 moves with the actuating member 2 in the direction A, shown in Fig. 2b. The movement of the dispensing member 12 implements 10 or allows a procedure and design dependent on the dispenser: for example, piercing a hole in the pre-dispensed drug capsule, dispensing the drug from the non-dispensed drug reservoir, or opening the propellant reservoir valve, or

As the dispensing member 12 moves in the direction A required for dispensing, the functional element 6 contacts the electrical contacts 8 'and 8', closing the electrical circuit therebetween. The electric element 10 heats the functional element 6 so that its temperature rises above the transition temperature of its material. As a result, the locking member 5 20, guided by the guide surfaces 13, retracts from the counter part 7 into the dispensing part 12, Fig. 2c. If a new dosing is now attempted, such as in Fig. 2d, the dosing member 12 will not move with the actuating member 2 in the A direction, and it will not be possible to take the drug I. The locking member 5 is within the dispensing member 12 when the temperature of the functional element 6 drops below the transition temperature.

The temperature lowering rate can be slowed down and the drug dose prolonged in the blocking time by fitting a thermal insulating element 11 in the locking part 4 around the functional element 6.

Fig. 3a shows a third medicament dispenser according to the invention in the first tuning mode and 3b in the second tuning mode, partially: 30 in sectional and top view. The medicament dispenser 1 has a first body portion 13a of circular cylindrical shape and a second body portion 13b coaxially disposed within it. The body members 13a, 13b may slide relative to one another along the sliding surfaces 20. The body members 13a, 13b are connected to one another via a "return spring 18 which is secured to the second body: the central shaft 19 is rotatably attached to the first body member 13a and the other end to the second body member 13b. frame member 13b with respect to the first frame member 13a in a direction of rotation opposite to the direction of rotation T shown in the figure. Instead of the return spring 18, any other force element which provides the necessary rotation movement can be used.

A locking member 4 is attached to the second body portion 13b, which includes a locking member 5 and a functional element 6. The functional element 6 is formed of a reversible deformable memory material in the form of a helical spring. The functional element 6 in the dormant state is substantially shorter than in the excited state 10, thereby allowing the locking member 5 to move in the sliding groove 17. The sliding groove 17 is formed with the sliding surface 20 on the first body part 13a side.

Further, the dispenser 1 comprises a power supply 10 and a first and a second capacitor 22a, 22b each connected to a power supply 10. In addition, the electrical system of the dispenser 1 comprises an activation switch 21 having two modes of operation. 22b and in the other it opens a circuit whereby capacitors 22a, 22b are not charged. In other words, in the first state of the Akti-20 power switch 21, the power supply fully charges the capacitors 22a, 22b while in the second state, the power supply and the capacitor circuit are open and no charging occurs. While the dispenser 1 is in the unset state, the locking member 5 presses against the Akti butter switch 21 and the functional element 6 placed at the other end of the sliding groove 17. When the locking pin 25 is pressed against the activation switch 21, this is in the first mode, i.e. the power supply 10 fully charges the capacitors 22a, 22b.

The first capacitor 22a is further connected to the first electrical contact 8 'by the first electrical conductor 14 and to the functional one. element 6 by a second electric conductor 15; respectively, the second capacitor 22b; 30 in the second electrical contact 8 "and the functional element 6. The electrical contacts 8 ',; * 8" are arranged in the slider groove 17 so that the locking piece 5 made of electrically conductive material slides in the slider groove 17. with.

In order to administer the drug, a first dose of drug is obtained by rotating the second body portion 13b with respect to the first body portion 13a in the direction of rotation T by an angle ai. As the locking piece 5 detaches from the activation switch 116 116, this moves to another state where the circuit between the capacitors 22a, 22b and the power supply 10 is open and the power supply cannot charge the capacitors. The locking piece 5 slides along the sliding groove 17 and the first electrical contact 8 'fitted thereto. Hereby, the first capacitor 22a is discharged 5 through a circuit closed by the first electrical contact 8 'and heats the functional element 6 so that its temperature rises above the transition temperature of the material in question. As a result, the functional element 6 tends to increase its length. As the rotation continues, the locking member 4 rotates to the first counterpart 7a, whereby the locking member is pushed by the functional element 10 into the first counterpart 7a and locks the body members 13a, 13b in this position. The first dose of the drug can now be administered.

As the functional element 6 cools, it shortens, so that the locking member 5 is gradually withdrawn from the first counterpart 7a. The first counterpart 7a is shaped such that in the direction of rotation T the mouth 15 of the rear face has a bevelled surface 16 and only a portion of the rear face is substantially perpendicular to the rotation T. The perpendicular portion 23 prevents the rotation from continuing when the locking piece 5 is within this portion. After about five minutes, the locking piece 5 has withdrawn from the perpendicular portion 23 of the first counterpart 7a. Now the locking member 5 can be rotated forward in the rotation direction T of the angle a2, although the locking member 5 has not completely retracted from the first counterpart 7a. The bevelled surface 16 forces the functional element 6 ... V to collapse so that the locking member 5 rotates along the sliding groove 17 in the forward direction T. During this rotary movement, the locking member 5 slides over one of the "electrical contacts 8", thereby discharging the second capacitor 22 " the functional element 6 heats up again. It should be noted that Fig. 3b does not show the power supply 10, the capacitors 22a, 22b and the conductors required.

. ···. As the rotation continues, the locking member 4 rotates to the second counterpart 7b, whereupon a heated and tending functional gesture. the insert 6 inserts the locking piece 5 into the second counterpart 7b. It is now possible to administer a second dose of drug. In other words, dispenser 1; 'The first dose of the drug may be administered first, and at the earliest after five! *: Minutes, the second dose. The second drug dose may be different or equal to the first drug dose.

'. The depth of the second counter piece 7b is dimensioned such that it takes about half an hour for the locking piece 5 to retract from it. During this time, dispenser 1 will not be able to deliver the next dose. When the locking member 5 9 116451 has retracted into the sliding groove 17, the return spring 18 rotates in the opposite direction of rotation T of the second body part 13b until the locking member 5 rotates against the activation switch 21 located at one end of the sliding groove 17. 5 capacitors 22a, 22b again full. Capacitors 22a, 22b may also be charged with an external power source for the drug dispenser, which is mounted, for example, on a tablet dispenser stand. It should also be noted that the capacitor can also be applied to the locking arrangements shown in Figures 1a, 1b and 2a to 2d.

Figures 4a to 4d show a fourth locking mechanism according to the invention, partially in section. The locking member 4 comprises a locking member 5 secured by a support member 29 to the first portion 13a of the drug dispenser. The locking member 5, supported by the support member 29, can move to its position shown in Fig. 4a closer to the first part 13a. This may be accomplished, for example, by providing a groove or channel in the first portion 13a within which the support member 29 can slide.

A helical spring 24 is disposed between the lock body 5 and the first body member 13a. This can be compressed from its space shown in Figure 4a, whereby the lock body 5 moves closer to the first body member 13a.

The locking mechanism further comprises a functional element 6 which acts as a counterpart to the lock body 5 and is secured to the second body portion 13b of the drug dispenser. The functional element 6 is made of a magnetostrictive material which changes its shape as the magnetic field affecting it changes.

Still further, the mechanism 4 includes a return spring 25 which tends to hold the first frame 13a in the position shown in Fig. 4a. · * ·. a second body portion 13b.

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When dispensing the drug, the first body portion 13a is transplanted. TO A as shown by arrow A relative to the second body portion 13b.

At the same time, the oblique upper surface of the locking member 5 and the oblique lower surface of the functional element • · ·; * '6 force the locking member 5 closer to the first frame: part 13a so that the locking member 5 overrides the functional member 6. 24 forces it behind the functional element 6 such that, despite the spring force of the resilient spring 25 acting on the first body member 13a, the first body member 13a cannot return to the position shown in Fig. 4a relative to the second body member 13b. The mechanism is then in the state shown in Figure 4b. A single dose of drug can be administered in this condition.

To deliver the next dose of drug, the mechanism must be returned to the state shown in Figure 4a. This is done by introducing the drug dispenser 5 1 into the drug dispenser holder 26 shown in Fig. 4c. The holder 26 has means 27 for generating a magnetic field. The magnetic element 28 acts on the functional element 6 of the locking member 4 so that it deforms as shown in Fig. 4d. In other words, the functional element 6 withdraws from the front of the lock part 5, whereby the return spring 25 to push as first 10 of the body portion in the direction of arrow R shown in Figure 4a space 13a. By selecting the material and design of the functional element 6 and by varying the properties of the magnetic field 28, the recovery time can be adjusted. It will be obvious to a person skilled in the art that as technology advances, the basic idea of the invention can be implemented in many different ways. The invention and its embodiments are thus not limited to the examples described above, but may vary within the scope of the claims.

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Claims (11)

116451 A method of controlling the action of a drug dispenser, comprising: operating a drive member (2) of the drug dispenser (1) to release a dose of drug so that the dispenser locking member (4) moves from the first 5 to a second locked position returning the locking member (4) with a delay to a first position in which drug delivery is possible, followed by said delay by a functional element (6) having a resting state and an excited state and whose deformation of the element (6) causes the locking member to move from the first position to the second position; , characterized in that the functional element (6) comprises a memory metal. Method according to claim 1, characterized in that the deformation of the functional element (6) is achieved by changing its temperature. Method according to Claim 1, characterized in that the deformation of the functional element (6) is achieved by changing the magnetic field applied to the functional element (6). A mechanism for controlling the action of a medicament dispenser comprising a locking member (4) having a first position for dispensing a dose of medicament by means of the actuating member (2) and a second position in which the medicament dispensing is prevented; to move from the first position to the second position when the dispenser (1) has been dispensed with a predetermined amount of medicament, characterized in that the mechanism further comprises a functional element (6) comprising a memory metal having a sleep state and an excited state, states that said element (6) is of different shape and that the deformation of the memory metal is arranged to move the locking part (4) from the first position to the second position and vice versa. »> The mechanism according to claim 4, characterized in that; that the deformation of the functional element (6) is arranged to occur by changing its temperature. Mechanism according to claim 4 or 5, characterized in that the memory metal is nitinol, Cu-Zn-Al or Cu-Al-Ni. 116451 The mechanism according to claim 4, characterized in that the deformation of the functional element (6) is arranged to take place by changing the magnetic field acting on it. A medicament dispenser comprising a locking member (4) having a first position for dispensing a dose of a medicament using the operating member (2), and a second position in which the medicament delivery is prevented, which locking member (4) is adapted to move from a first position to a second position when a predetermined amount of drug is dispensed by the dispenser (1), characterized in that the drug dispenser further comprises a functional 10 element (6) comprising a memory metal having a dormant state and an armed state; of different shape, and that the deformation of the memory metal is arranged to move the locking member (4) from the first position to the second position and vice versa. Medicament dispenser according to claim 8, characterized in that the deformation of the functional element (6) is imaged by changing its temperature. Drug dispenser according to claim 8 or 9, characterized in that the memory metal is nitinol, Cu-Zn-Al or Cu-Al-Ni. Medicament dispenser according to Claim 8, characterized in that the deformation of the functional element (6) is arranged by changing the magnetic field acting on it. 116451