Abstract: An enema has liquid amount controlling component, namely a rotary valve, having an outer tube with a cylindrical concave part at its center and is provided with an insertion opening fitting a connecting tube and a discharge opening fitting a conduit on a side wall of the concave part of the outer tube. A rotator is provided with opening parts corresponding to the positions of the insertion opening and the discharge opening of the outer tube, and a knob part on an upper part of the rotator. Two fitting spring are integrally formed to extend on both sides of a fixture (8), and the fixture has a penetration hole for inserting a beak tube. The fixture slides on the said beak tube for controlling the length of the beak tube to be inserted into an anus.

Abstract: The applicator (10) for depositing a one- or multi-component fluid, particularly a tissue adhesive, comprises a housing (12) arranged for attachment of at least one supply container (16) for the fluid. The supply container (16) comprises a discharge opening (28) and a piston (20) for sliding displacement in the direction of said discharge opening (28). A tensioning lever (58) is pivotally supported on the housing (12), which, when manually operated, causes movement of a spring tensioning element (54) by which a spring (46) for storage of mechanical energy can be tensioned. Coupled to the spring tensioning element (54) is a drive element (66) being adapted to be driven, by the stored mechanical energy of said spring (46), in increments and which is arranged to move a press-on element (84) acting on said piston (20) for displacing it in the direction of said discharge opening (28) of said supply container (16).

Abstract: A seal adapted to be fitted over the open end of the barrel of a hypodermic syringe has a cap of a non-latex elastomer having a central aperture which is sufficiently small as ordinarily to retain liquid therebehind but which can be deformably expanded to allow passage of the rearward end of a needle hub for engagement with the barrel.

Abstract: Device for withdrawing Blood for Diagnostic Purposes. A lancet holder (8) for holding a lancet (7) and a lancet drive (12) having a loadable elastic drive spring (15) are provided within an elongated housing (2). The relaxing motion of the drive spring (15) is converted into a puncturing motion, after release of a locking device, to move the lancet (7), held by the lancet holder (8), at high speed in the puncturing direction until its tip exists out of an exit opening (5) of the housing (2). An improved handling and simultaneous minimization of pain is achieved by providing a two-sided rotary/translatory transmission (25) in the housing (2), wherein a) the input side (24) of the rotary/translatory transmission (25) transforms the motion of a loading button (17), protruding out of the rear end (16) of the housing.

Abstract: This device comprises: a syringe body equipped with an access which may be connected in succession to a filling member, such as a needle, and to an infusion line fitted with a non-return valve to allow liquid to pass from the syringe into the line; a housing mounted so that it can slide in leaktight fashion inside the body so as to vary the volume of a chamber which it delimits with the body of the syringe; an element which, forming a piston, mounted on the housing and in contact with the chamber, is able, according to its position, to create a raised pressure or reduced pressure in the chamber; means for moving the piston-forming element back and forth.

Abstract: A syringe has a sensor for sensing physical contact between a syringe needle and the syringe. As the sensor detects that a syringe needle has just been installed into the syringe, a counter is set to “zero”, indicating the number of injections given with the installed needle. The counter automatically and cumulatively counts each injection given to the animal during a period of continuous physical contact between the syringe and the syringe needle. When the number of cumulatively counted injections equals a predetermined maximum number of injections, a syringe needle change warning mechanism delivers a needle change warning to the operator of the syringe.

Abstract: The present invention relates to syringes comprising a housing (1), a dose setting mechanism in the housing, an injection button (6), and a needle receiving member. By this syringe doses of a medicine can be set by the dose setting mechanism and by operating the injection button (6) the set dose can be pressed out from an ampoule accommodated in the housing (1) through a needle (5) mounted on the needle receiving member. The housing further comprises an accessible compartment covered by a lid (10) or a cap (8) in which compartment accessories (11) are stored.

Abstract: An injector of the present invention comprises:

Abstract: A resettable display of a device for metered administration of a fluid drug, comprising a housing, a fluid container containing the fluid and provided in or on said housing, an actuating device shiftably mounted by a length in or on said housing, which, upon actuation, shifts a piston in the fluid container in order to displace from the fluid container a fluid dose adjusted by the actuating device, a display provided in or on said housing displaying a measure for the adjusted fluid dose, and a resetting means shifted with the actuating device and thus resetting the display. The display comprises a minimum of one counter ring rotated from a zero position when adjusting the fluid dose by means of the actuating device in relation to the housing. The resetting means mechanically transfers the shift movement of the actuating device into a reverse rotary movement of the counter ring towards its zero position (FIG. 1).

Abstract: Measurements of insulin quantities in a syringe are performed capacitively in an integrated insulin dose recorder/blood glucose meter. The syringe is placed in a holder before and after the administration of the dose. Capacitor electrodes may be situated within the syringe and/or outside the syringe in various geometries. Liquid quantities in the syringe are determined by comparing capacitive response patterns of the syringe with calibration data stored. in the device. Dose histories are downloaded to a patient computer for transfer to a clinician's computer. Standard or customized syringes may be used.

Abstract: A system for automatically metering a predetermined dosage of a medicament from a cartridge. The system includes a tubular cartridge containing the medicament and a plunger which is movable in the cartridge to dispense the medicament through one end. The cartridge further includes an interior tab (e.g. a ring) for stopping forward movement of a detent carried by the trigger of a syringe body in which the cartridge is positioned. By limiting forward movement of the detent, forward movement of the plunger rod is also stopped, thereby controlling the amount of medicament dispensed from the cartridge.

Abstract: An injection device made up from a housing, a dose setting and injection mechanism, a dose setting member and an injection button is described. The dose setting and injection mechanism is made as a preassembled unit insertable into the housing. Both the dose setting member and the injection button is thereafter connected to the preassembled dose setting and injection mechanism inside the boundaries of the housing, while being accessible for a user from outside the housing. The same preassembled dose setting and injection mechanism can fit into a large variety of different houses making production of different variants of an injection device somewhat easier.

Abstract: An injection device for injecting set doses from an ampoule (2) mounted in the device, which doses are set by operation of a dose setting button (7) by which operation elastic torsion rods (14) positioned parallel with the longitudinal axis of the device are twisted. By the dose setting a torque is transmitted from the dose setting button (7) to the rods (14) through gear transmissions comprising a toothing (11) carried by a tubular (8) part coupled to the dose setting button (7) to rotate with this button. The toothing (11) engages pinions (13) fixed to the proximal ends of the torsion rods (14), which are made from a super elastic material, which can stand a deformation larger than 2% without being permanently deformed.

Abstract: A method for holding an epidural needle together with a syringe and controlling the depth and advancement of penetration of the epidural needle during the epidural needle insertion into the human epidural space through the multiple layers of the tissues with the apparatus of the invention.

Abstract: Embodiments of an injector, syringe, syringe interface, and piston/plunger assembly for an injector (of contrast medium, for example) are described. Preferably, the syringe is adapted to engage a syringe interface mechanism such that the syringe may be connected to an injector without regard to any particular orientation of the syringe to the injector or to the piston/plunger assembly.

Abstract: A modular drug delivery system for use by cardiothoracic surgeons and interventional cardiologists for delivery of molecular and cellular therapies that target genes, molecules and peptides. The regulated drug delivery devices comprise a modular mechanically actuated drug delivery module (DDM) that can be attached to either a surgical viewing endoscope hand-piece or specialized catheter for interventional procedures. The DDM provides metering of drugs to treatment sites and allows for quick interchangeability with other component parts such as a viewing scope end portion for MIS or other surgical procedures or a flexible catheter shaft for percutaneous procedures.

Abstract: Apparatuses for sharing information on syringe configuration between syringes and injector systems comprise a storage system to store encoded information on syringe configuration. The encoded information is readable by a detection circuit in an injector. In one embodiment, the storage system is an electronic storage system in which information relevant to the syringe configuration is encoded. A method comprises the step of conveying syringe configuration information to a detector in an injector for use with the syringe.

Abstract: The invention concerns an apparatus for the registration of the setting of a medical device, the setting of which implies a mechanical adjustment of at least two relatively moveable elements of the device. The invention is characterized in that the apparatus is intended for disconnectible engagement with the medical device, and that it has detector means for detecting the mechanical adjustment and has information means arranged for providing information related to said mechanical adjustment.

Abstract: The present invention provides an auto-injection device including a housing, a container from which a product is dispensed by advancing a piston, the container shiftably accommodated by the housing and carrying a needle, and a drive unit including a driven member, wherein the driven member is shiftably accommodated by the housing and, during an auto-injection, is adapted for inserting the needle and advancing the container to a predetermined frontal position in relation to the housing and advancing the piston within the container for dispensing of the product, wherein the driven member remains uncoupled with the piston until the container reaches its frontal position, and upon the container reaching its frontal position, the driven member detaches from the container and couples with the piston for advancing the piston within the container.

Abstract: A medication delivery pen includes a housing having an actuator disposed in the proximal end of the housing for setting and administering a dosage of medication, a medication-containing cartridge assembly having a cartridge with a pierceably sealed distal end, an open proximal end removably attachable to the distal end of the housing, and a piston in sliding, fluid tight engagement within the cartridge. A drive mechanism is coupled between the actuator and the cartridge to exert an axial force on the piston to inject the set dosage of medication. The actuator triggers the drive mechanism to administer the injection of medication held in the cartridge and a processor is coupled to the actuator to determine a value equal to the dosage set by the actuator.

Abstract: An injection device has signal generators (11, 12, 13, 14) which are connected to operative elements (8, 3, 5, 4) of the device and which give off signals which represents the operative condition of the device. The signals are sent to an electronic circuit which controls a presentation of the operational condition of the device and presents operational conditions, which are defined as not allowed, as error indications by switching off the display presenting the operational condition of the device. The number of signals from each generator is counted and a number of operations exceeding a pre-set number for the signal generator in question is interpreted as representing a not allowed operational condition.

Abstract: Multipurpose fluid applicators, particularly suitable for surgical purposes, are disclosed. The applicators are specifically designed for dispensing various combinations of sterile pressurized gas, suction, irrigation and sealant agents, including a mixed liquid sealant agent. Preferred embodiments employ a dual-acting valve selectively to control the flow of gas or suction which valve is capable of simultaneously varying flow from a source and the venting of that flow to atmosphere.

Abstract: A medication delivery pen having very few parts allowing it to be manufactured at a very low-cost. The medication delivery pen also includes an automatic release mechanism to allow the user to easily reset the dose on the medication delivery pen and a mechanism for allowing the lead screw to easily retract back into the body of the medication delivery pen when the vial retainer has been removed to receive a new vial.

Abstract: A syringe having a dose setting mechanism, a button which can be operated to inject a set dose, a switch operated at a time between the start and completion of injection, and an electronic presentation of parameters such as the size of a set dose and the size of the last dose administered. The syringe also has a stop watch which is reset and started responsive to operation of the switch. The electronic presentation includes an indication of the number of hours elapsed from the activation of the switch, and may also include, for a predetermined period initially following the activation of the switch, a presentation of the number of seconds elapsed. The latter presentation can provide a visual indication to the patient of the length of time, after the injection button has been actuated to inject the dose, that the needle should remain inserted in the skin.

Abstract: The invention relates to an injection device (10) having a housing (15) and an injection fluid container (12) which can move, in relation to this housing, between a distal and proximal end position, and also having a pushrod (14) to act on a plunger (23) in this container (12) for the purpose of expelling fluid from the container. A drive connection (27) is provided between the pushrod (14) and the container (12) and, in the distal end position of the container, this drive connection is effective in both the proximal and the distal direction, but in the proximal end position of the container (12), it is only effective when the pushrod (14) is moved in the distal direction.

Abstract: The present invention provides an injection syringe comprises a housing including a holder for containing a cartridge of medicine, a piston rod with a non-circular cross-section having an outer thread, a piston rod drive, a one way coupling having an annular ring of internal ratchet notches, which annular ring can be integral with the housing, and a pawl having at least a pair of resilient arms each having a free end.

Abstract: An injection device has a housing (112,116) wherein there is a longitudinally movable expressing member (186) for expressing an injection fluid from a fluid container (118). In order to displace the expressing member (186) longitudinally within the housing, an actuating member (170, 172) is associated therewith. The actuating member is displaceable between a proximal end position and a distal end position. Between the actuating member (170, 172) and the expressing member (186), a position-dependent connecting device (166″, 167″, 198, 210, 212) is provided, which is disabled in the distal end position of the actuating member (170, 172) and is enabled in a position range adjacent to the distal end position of the actuating member (170, 172) including its proximal end position. One thus obtains an injection device which is simple to operate, and which is especially adapted to permit a patient to repeatedly administer the same constant injection dose.

Abstract: A fluid delivery device for delivering fluid from a fluid reservoir to a patient. The device includes an inlet channel in communication with a fluid reservoir and a dosing chamber, and an outlet channel disposed in communication with the dosing chamber. A reciprocating dosing actuator is moveable in a reciprocating motion between first and second positions for alternately (i) transporting a dose of fluid conveyed by the inlet channel into the intermediate dosing chamber, and (ii) ejecting the dose from the dosing chamber through the outlet channel to the patient, respectively.

Abstract: A multi-use medication dispensing pen made of a plastic material that is recyclable after the contents of the medication cartridge have been exhausted. The pen is made of a minimal number of parts, which include a housing, a dial mechanism, a generally cylindrical button assembly located within the proximal end of the dial mechanism, an internally threaded nut, and an externally threaded leadscrew. The pen is arranged so that the dial mechanism must be rotated to the zero-dose position prior to setting a dose. The pen includes a lockout mechanism that prevents the dial mechanism from being inadvertently depressed during dosing. The pen further includes a mechanism that limits the maximum dosage that can be dialed up and a mechanism that prevents the user from dialing up a dosage greater than that remaining in the cartridge.

Abstract: A cartridge and system are described for automatically metering a predetemined dosage of a medicament. The cartridge includes a tab on its exterior, and a dispensing gun which receives the cartridge has a detent for stopping forward movement of the upper end of a trigger when the detent contacts the tab on the cartridge. When the detent contacts the tab on the cartridge, no further medicament can be dispensed on that stroke of the trigger.

Abstract: An auto-injection device is provided for mounting a standard medical syringe which enables the user to automatically inject the contents of the syringe to a desired penetration depth. The auto-injection device includes a barrel sized for receiving the syringe therein, a driver shiftably received in the barrel for moving the syringe and causing injection of its contents, and a trigger accessible from outside the syringe, the trigger requiring movement across the exterior surface of the barrel prior to depression for releasing the plunger as a safety against inadvertent needle exposure and discharge. The barrel may include a window for enabling the user to ascertain whether the device is cocked or not. The barrel may be provided in two separate sections with one of the sections receivable into the other to permit cocking. The barrel also may include a slot for receiving a button to permit exposure of the needle to remove a protective cap when the device is cocked and the syringe is withdrawn into the barrel.

Abstract: The present invention relates to a system for locking a dosing button in a device for the administration of a product to be injected in predetermined doses. This device comprises a body (1) with a housing (2) for the product, wherein a selected dose for injection is transported from said body out of a container (3) through a transport member (4). This device also comprises a drive member (5,7) for the transport member (4) as well as a dosing button (9) coupled to the drive member (5, 7) which is mounted so as to be capable of sliding within the body (1). The button ensures the transport of the selected dose when it is displaced from a first position into a second by actuating the drive member (5, 7). The dose is selected in the first position by rotating the dosing button (9) so that is can be moved from a first rotation position indicating that no transport is possible into a second rotation position.

Abstract: A modular drug delivery system for use by cardiothoracic surgeons and interventional cardiologists for delivery of molecular and cellular therapies that target genes, molecules and peptides. The regulated drug delivery devices comprise a modular mechanically actuated drug delivery module (DDM) that can be attached to either a surgical viewing endoscope hand-piece or specialized catheter for interventional procedures. The DDM provides metering of drugs to treatment sites and allows for quick interchangeability with other component parts such as a viewing scope end portion for MIS or other surgical procedures or a flexible catheter shaft for percutaneous procedures.

Abstract: A compact, patient controlled fluid dispenser for use in controllably dispensing fluid medicament at a selected uniform rate. The device is of an all mechanical construction and is ideally suited for the reliable patient administration of pain killing drugs in the home care environment. To positively regulate the patient administration of the medicament, the intervals at which a selected medicament can be administered, as well as the volume of the dose of the medicament to be administered, is preset by the treating physician and, once set, cannot be altered by the patient. More particularly, the device setting can only be operated by a small physician's key that remains in the possession and control of the treating physician or health care worker.

Abstract: A device for sample collection, sample separation and for aseptically, controllably and precisely transferring at least one of the separated portions is disclosed. The device utilizes a metering syringe to collect a sample, such as blood, the metering syringe with the sample therein is centrifuged, the metering syringe is connected to a sterile syringe contained within sterile packaging, the metering syringe is used to controllably, precisely and aseptically meter a separated portion into the sterile syringe, the sterile syringe with the separated portion therein is then given to appropriate personnel within a sterile field without performing any further transferring steps.

Abstract: Measurements of insulin quantities in a syringe are performed optically in an integrated insulin dose recorder/blood glucose meter. The syringe is placed in a holder before and after the administration of the dose. Liquid quantities in the syringe are determined by comparing optical response patterns of the syringe with calibration data stored in the device. Dose histories are downloaded to a patient computer for transfer to a clinician's computer. Standard or customized syringes (e.g. with marked plungers) may be used. Other wave energy carriers such as sound waves may also be used.

Abstract: Measurements of insulin quantities in a syringe are performed capacitively in an integrated insulin dose recorder/blood glucose meter. The syringe is placed in a holder before and after the administration of the dose. Capacitor electrodes may be situated within the syringe and/or outside the syringe in various geometries. Liquid quantities in the syringe are determined by comparing capacitive response patterns of the syringe with calibration data stored in the device. Dose histories are downloaded to a patient computer for transfer to a clinician's computer. Standard or customized syringes may be used.

Abstract: A cartridge for containing a fluid and for use with an electronic delivery device, includes a cartridge housing for holding the fluid, and information providing source. The information providing source is coupled to the cartridge housing to operatively couple with the electronic delivery device to provide predetermined information regarding the cartridge to the electronic delivery device. For example, the information providing source may be a set of wires and contacts, or contact bands, that provide the predetermined information to electronic delivery device by producing a binary code. Alternatively, the information providing source is a bar code that provides the predetermined information to electronic delivery device by reading of the bar code. The cartridge may be used in a system that includes an electronic delivery device, such as an electronic pen-type injector and/or infusion pump.

Abstract: The present invention relates to syringes for apportioning set doses from an ampoule has a dose setting and injection mechanism comprising a dose setting member which may be moved in one direction to set a dose and in the opposite direction to inject the set dose. A piston advancing mechanism comprises a piston rod and a piston rod drive, and the dose setting and injection mechanism is coupled to the piston advancing mechanism through a unidirectional coupling transmitting only movement of the dose setting member in the dose injecting direction to the piston rod drive. Operation of an air shot button enables influence on the piston advancing mechanism to advance the piston to expel an adjustable fixed volume. The air shot button is either coupled to the piston rod drive through a unidirectional coupling through which the piston rod is advanced when the air shot button is pressed, or it moves the end stop for an injection button so that this button may be pressed beyond its normal depressed end position.

Abstract: The balloon inflating device comprises a syringe (12) the plunger (28) of which has a screw thread (36). It further comprises a mechanism for retaining the plunger comprising a first half nut (40A) movable between a position separated from the screw thread (36) and a position of engagement with the screw thread (36), and a slidable control element (42) which comprises first coupling means (54A) adapted to displace the first movable half nut (40A). The retaining mechanism (14) further comprises a second movable half nut (40B) movable between a position spaced away from the screw thread (36) and a position of engagement with the screw thread (36). The control element (42) further comprises second coupling means (54B) associated with the second half nut (40B) and adapted to move the second half nut. The first and second coupling means (54A, 54B) are mechanically connected to each other in the region in which the control element (42) is coupled to the first and second half nuts (40A, 40B).

Abstract: A digital fluid delivery and aspiration apparatus with a mechanical de-amplifier for the delivery or removal of discrete volumes of fluidic material from a surgical site. The apparatus has a syringe with a plunger designed to be powered by a pneumatic air supply system. A ratcheting mechanism attached to a pneumatic piston by a mechanical linkage causes the plunger of the syringe to inject discrete doses of the fluidic material into the surgical site or remove discrete amounts of fluidic material from the surgical site. The mechanical linkage increases the force provided to the plunger by the movement of the piston and also de-amplifies the movement of the piston into a lesser movement of the plunger.

Abstract: A medication delivery pen having a repeat-dose feature that is performed by using a pull-push operation. In particular, the medication delivery pen includes means for whether the medication delivery pen is armed and a variety of novel drive mechanisms. In addition, the medication delivery pen also includes a priming control mechanism that allows the user to easily prime medication delivery pen prior to arming the pen.

Abstract: Injection device for injecting fluid from a fluid container equipped with a piston, comprising an actuating device having a rod-shaped driven member having a structured surface, a control button being movable in axial direction, and a hollow cylindrical counter component having a structured internal sleeve, said counter component matching the rod-shaped driven member and being coaxially arranged in relation to said driven member.

Abstract: A sale unit for the parenteral application of liquid pharmaceutical products by the user is described, whereby the unit comprises at least one cannula, a device to emit a given liquid amount of the pharmaceutical product in single doses, as well as at least one vessel filled with the pharmaceutical product, the vessel being arranged within the device and emptied in single doses by means of the device, and whereby each single dose corresponds to the given liquid amount of the pharmaceutical product.

Abstract: The invention relates to an injection device for injecting a selectable dose of a liquid substance from an ampoule, located in an ampoule holder, comprising a piston and a sleeve-shaped mechanism holder, in the interior of which a longitudinally shiftable shaft is provided, the shaft being surrounded by an also longitudinally shiftable advancing sleeve coupled thereto. For selecting a dose of the liquid substance to be injected, a dosing sleeve with a stepped member is provided, the dose to be respectively administered being adjustable by a rotation of the dosing sleeve with the stepped member. The adjusted dose is readable via a dose imprint on the dosing sleeve.

Abstract: Disclosed is a needle assembly to be used with a pen-type injector and a percutaneously placed catheter device for intravenous infusion or a subcutaneously inserted cannula that is part of an injection set. Unlike all prior art needle assemblies which have a sharp point at the needle's distal end, the needle assembly described herein has a blunt tip so as to avoid any inadvertent needle sticks. This invention envisions using such a blunt tipped needle assembly connected to a pen-type injector and used with an injection set that has a cannula placed in the subcutaneous tissue. This invention also envisions using such a blunt tipped needle assembly with a pen-type injector for intravenous injections of medication through any intravenous catheter that has a septum through which the blunt needle of the pen-type injector can be placed.

Abstract: Measurements of insulin quantities in a syringe are performed inductively in an integrated insulin dose recorder/blood glucose meter. The syringe is placed in a holder before the administration of the dose, and the liquid quantity in the syringe is recorded. Inductors may be situated within the syringe and/or outside the syringe in various geometries. Standard or customized syringes may be used. Liquid quantities in the syringe are determined by comparing inductive response patterns of the syringe with calibration data stored in the device. Insulin dose and blood glucose histories are downloaded to a patient computer for transfer to a clinician's computer.

Abstract: The present invention provides an injection system including a disposable lower part and a reusable upper part wherein the lower part includes an ampoule holder for accommodating a container containing a liquid medicament and having an axially movable plug having a cross-section F for ejecting the liquid medicament from the container and a kinematic device for axially driving the plug forward by a number N of individual steps x, N being a natural number, and the reusable upper part includes a casing detachably connectable to the ampoule holder, and a dosing button for selecting the number N of individual steps x and for actuating the kinematic device of the lower part which thereby effects selectable ejection of a Volume V=NxF of the liquid medicament from the container.

Abstract: The invention is directed to a device (V) for the output of a liquid (2) in partitioned amounts (2') from a store room (3), preferably in form of a cartridge (K), over an output mouth piece (4), preferably in form of an injection needle (5), and has the object the application of exactly reproducible amounts from a reserve amount and its safe application. This is obtained by an intermediate reservoir (17) taking up the partitioned amount (2') from the store room (3), whereby for the intermediate reservoir (17) an output piston (19) is provided with a penetration canal (18) to fill the intermediate reservoir (17).

Abstract: An injection device has a housing (112,116) wherein there is a longitudinally movable expressing member (186) for expressing an injection fluid from a fluid container (118). In order to displace the expressing member (186) longitudinally within the housing, an actuating member (170, 172) is associated therewith. The actuating member is displaceable between a proximal end position and a distal end position. Between the actuating member (170, 172) and the expressing member (186), a position-dependent connecting device (166", 167", 198, 210, 212) is provided, which is disabled in the distal end position of the actuating member (170, 172) and is enabled in a position range adjacent to the distal end position of the actuating member (170, 172) including its proximal end position. One thus obtains an injection device which is simple to operate, and which is especially adapted to permit a patient to repeatedly administer the same constant injection dose.