KR20090080983A - Ophthalmic injection device including dosage control device - Google Patents

Abstract

An injection device includes a dispensing chamber, a plunger, a controller, a temperature control device, and a memory device. The dispensing chamber has an inner surface and an outer surface. The inner surface defines a cavity for receiving a quantity of a substance. The plunger is engaged with the inner surface of the dispensing chamber, is capable of sliding in the cavity of the dispensing chamber, and is fluidly sealed to the inner surface of the dispensing chamber. The controller controls the operation of the injection device. The temperature control device at least partially surrounds the dispensing chamber. The memory device has a parameter stored on it. The controller uses the parameter from the memory device to operate the injection device.

Description

Ophthalmic infusion device with dosage control device {OPHTHALMIC INJECTION DEVICE INCLUDING DOSAGE CONTROL DEVICE}

Related Applications

The present invention is a partial continuing application of US Patent Application 11 / 581,629, filed October 16, 2006, US Patent Application 11 / 688,573, filed March 20, 2007, US Patent, filed October 16, 2006 Application 11 / 581,630, filed on October 16, 2006, US Patent Application 11 / 581,591, filed on May 17, 2006, is part of US Patent Application 11 / 453,906.

The present invention relates to an apparatus for injecting a drug into the eye, and more particularly to an ophthalmic drug delivery device having a dosage control mechanism and a method of operating the system.

Several diseases and conditions of the back part of the eye threaten vision. Some examples include age related macular degeneration (ARMD), choroidal neovascularization (CNV), retinopathy (eg diabetic retinopathy, vitreoretinopathy, retinitis) (Eg, cytomegalovirus (CMV) retinitis), uveitis, macular edema, glaucoma, and neuropathies.

These and other diseases can be treated by injecting drugs into the eye. Such injections are typically made manually using conventional syringes and needles. 1 shows a perspective view of a prior art syringe used to inject medication into the eye. In FIG. 1, the syringe includes a needle 105, a luer hub 110, a chamber 115, a plunger 120, a plunger shaft 125, and a thumb support 130. As is generally known, the drug to be injected is located in the chamber 115. When the thumb support 130 is pressed, the plunger 120 sprays the medicine through the needle 105.

In using such syringes, the surgeon (with or without the help of a nurse) pierces the tissue of the eye with a needle, keeps the syringe stable, and activates the syringe plunger to inject the drug into the eye. The flow rate of the fluid is not controlled. Since the parallax error is affected in the reading of the vernier, the injected volume is usually not controlled in a precise manner. Tissue damage can occur due to "unsteady" injections.

Efforts have been made to control the delivery of small amounts of liquid. Commercially available fluid distributors are available from EFD Inc. of Rhode Island, Providence. ULTRA ^™ positive displacement dispenser available from. ULTRA dispensers are generally used to dispense small volumes of industrial adhesives. This utilizes conventional syringes and customized dispensing tips. The syringe plunger operates using an electric stepper motor and working fluid. For this type of dispenser, the volume delivered is highly dependent on the viscosity of the fluid, the surface tension, and the particular dispensing tip. Paker Hannifin Corporation of Ohio, Cleveland distributes small volume liquid distributors for drug discovery applications manufactured by Aurora Instruments LLC of San Diego, California. Parker / Aurora distributors use a piezoelectric distribution mechanism. Such distributors, although accurate, are expensive and require electrical signals to be delivered to the distribution mechanism.

U. S. Patent 6,290, 690 discloses a second viscous fluid (e.g., perfluorocarbon liquid) from the eye in a fluid / fluid exchanger during the surgical procedure to treat retinal detachment or tear and simultaneously into the eye. An ophthalmic system for injecting a viscous fluid (eg silicone oil) is disclosed. Such a system includes a conventional syringe with a plunger. One end of the syringe couples fluidly to a pneumatic source that provides a constant pneumatic pressure to actuate the plunger. The other end of the syringe couples in fluid communication with an infusion cannula through a tube to deliver the viscous fluid to be injected.

It would be desirable for the ophthalmic infusion system to have a dosage control device so that the correct dosage is delivered during each infusion process. Such a device would eliminate dosing errors on the part of the medical practitioner and would be desirable to ensure accurate dosing during the course of the clinical trial of the drug.

In one embodiment according to the principles of the present invention, the present invention is an injection device having a dosage chamber, a plunger, a controller, a temperature control device, and a memory device. The dosage chamber has an inner surface and an outer surface. The inner surface defines a cavity to receive a certain amount of material. The plunger engages the inner surface of the dosing chamber, is slidable within the cavity of the dosing chamber, and is fluidly sealed to the inner surface of the dosing chamber. The controller controls the operation of the injection device. The temperature control device at least partially surrounds the dosage chamber housing. The memory device stores the parameters. The controller uses these parameters from the memory device to operate the injection device.

In another embodiment according to the principles of the present invention, the present invention includes the steps of recognizing a connection between a tip segment and a finite reuse assembly; Reading a parameter from a memory device in the tip segment; Operating the finite reuse assembly and the tip segment based on the parameter to deliver material to the eye; Including, the method of injecting the material into the eye.

It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are intended to provide a description of the claimed subject matter. The following description and examples of the present invention illustrate and present additional advantages and objects of the present invention.

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several embodiments of the present invention and together with the description serve to explain the principles of the invention.

1 is a perspective view of a syringe of the prior art.

2 is an illustration of an ophthalmic hand piece that includes a drug delivery tip segment and a finite reuse assembly according to one embodiment of the invention.

3 is a diagram of a memory device circuit for use in a drug delivery tip segment, according to one embodiment of the invention.

4 is an exploded cross-sectional view of a drug delivery tip segment for an ophthalmic hand piece in accordance with one embodiment of the present invention.

5 is a cross-sectional view of the drug delivery tip segment and finite reuse assembly according to one embodiment of the present invention.

6 is a perspective view of a medication control card according to an embodiment of the present invention.

7 is a perspective view of a console, a drug delivery device, and a medication control card according to one embodiment of the present invention.

8 is a circuit diagram of a wired memory circuit according to an embodiment of the present invention.

Reference is now made in detail to exemplary embodiments of the present invention. Examples of such embodiments are shown in the accompanying drawings. Wherever possible, the same reference numbers have been used for the same or similar parts throughout the figures.

2 illustrates an ophthalmic hand piece that includes a finite reusable assembly and a drug delivery tip segment in accordance with an embodiment of the present invention. In FIG. 2, this hand piece includes a tip segment 205 and a finite reuse assembly 250. Tip segment 205 includes a needle 210, a housing 215, a plunger connection 225 and an optional light source 275. The finite reuse assembly 250 includes a housing 255, a switch 270, a locking device 265, and a threaded portion 260.

Tip segment 205 may be connected to and removed from finite reuse assembly 250. In this embodiment, the tip segment 205 has a thread on the inner surface of the housing 215 that is screwed onto the thread 260 of the finite reuse assembly 250. Lock device 265 also secures tip segment 205 to finite reuse assembly 250. The locking device 265 may be in the form of a button, a sliding switch, or a cantilevered mechanism. Other mechanisms for connecting tip segment 205 to finite reuse assembly 250, such as those involving structural features that match each other, are well known to those of ordinary skill in the art to which the present invention pertains. It falls within the scope of the present invention.

Needle 210 is configured to deliver a substance, such as a drug, to the eye. Needle 210 may be of a generally known shape. Preferably, the needle 210 is configured such that its thermal properties are advantageous for use in certain drug delivery. For example, if a heated medication is to be delivered, the needle 210 may be relatively short (a few millimeters) long to aid in the correct delivery of the medication.

The switch 270 is configured to provide an input to the system. For example, switch 270 may be used to operate the system or turn on the heater. Other switches, buttons, or control inputs for the user are generally known and may be used with the finite reuse assembly 250 and / or tip segment 205.

When tip segment 205 is ready for use, optional light source 275 is illuminated. The optional light source 275 may protrude from the housing 215 or may be embedded within the housing 215 in which case the optional light source 275 may be identified through the transparent portion of the housing 215. In other embodiments, the optional light source 275 may be replaced with an indicator, such as a liquid crystal display, a segmented display, or other device indicating the condition or condition of the tip segment. For example, optional light source 275 may be in other states such as, but not limited to, system error, full charge of the battery, low charge of the battery, or poor connection between tip segment 205 and finite reuse assembly 250. It may be pulse on or pulse off to indicate.

3 is a diagram of a memory device circuit for use in a drug delivery tip segment, according to one embodiment of the invention. In FIG. 3, the circuit includes an optional light source 275, a fuse 375, a controller 305, a power source 310, and a memory device 315. The controller 305 controls the operation of the power source 310 and reads the data stored in the memory device 315.

In the embodiment of FIG. 3, optional light source 275 is any suitable colored light emitting diode. In other embodiments, optional light source 275 may be a lamp, fluorescent light, or other similar electrical or electronic light source. In another embodiment, the optional light source 275 is any type of indicator, such as a liquid crystal display or segmented display.

The fuse 375 is a fuse having a current rating that is greater than the operating current of the optional light source 275. Fuse 375 may be a typical glass encapsulated fuse, a trace fuse on a printed circuit board, or other similar structure that provides the function of a fuse. For example, a switch or switching circuit can be used to provide the function of the fuse 375. The fuse 375 may be blown after use to prevent reuse of the tip segment.

Power source 310 is typically a rechargeable battery with associated circuitry. In other cases, the power source 310 is a single-use battery or a connection to an independent power source such as only a switch mode power supply. In this embodiment, the power source 310 also includes charging and current driving electronics associated therewith.

Controller 305 is typically an integrated circuit having power, input, and output pins capable of performing logic functions. In various embodiments, the controller 305 is a targeted device controller. In such a case, the controller 305 performs specific control functions targeting specific components or parts, such as heaters or power supplies. For example, the heater controller has a basic function of controlling the heater. In another embodiment, the controller 305 is a microprocessor. In such a case, the controller 305 may be programmed to function to control more than one component of the autonomy. In other cases, the controller 305 is not a programmable microprocessor, but instead is a purpose-built controller configured to control different components that perform different functions. In the embodiment of FIG. 3, controller 305 controls power source 310 and reads data from memory device 315. Although illustrated as one component in FIG. 3, the controller 305 may be manufactured from various components or integrated circuits.

The memory device 315 is a hard wired memory device as shown in FIG. 8. Unlike conventional semiconductor memory, such as EEPROM or flash memory, which cannot tolerate gamma sterilization without data loss, memory device 315 withstands gamma sterilization without data loss. Memory device 315 is typically packaged with a drug delivery device or disposable tip segment. These packages are sterilized before leaving the manufacturing plant. In order to preserve the data stored in the memory device 315, the memory device 315 is constructed or wired resistant to commonly used sterilization techniques such as gamma sterilization.

4 is an exploded cross-sectional view of a drug delivery tip segment for an ophthalmic hand piece in accordance with one embodiment of the present invention. In FIG. 4, the drug delivery tip segment includes a housing 215, a needle 210, an optional light source 275, a fuse 375, a memory device 315, a plunger shaft 410, a plunger tip (or fluid seal). seal) 415, a mechanical link interface 420, a dosage chamber 405, a dosage chamber housing 425, a temperature control device 450, a thermal sensor 460, and an optional luer 430.

In the embodiment of FIG. 4, the mechanical link interface is located on one end of the plunger shaft 410. Plunger tip 415 is located on the other end of plunger shaft 410. Plunger shaft 410 and plunger tip 415 together form a plunger. Dosing chamber 405 is surrounded by plunger tip 415 and dosing chamber housing 425. The plunger tip 415 forms a fluid seal with the inner surface of the dosage chamber housing 425. The needle 210 couples in fluid communication with the dosing chamber 405. In this manner, material located within the dosage chamber 405 is pushed out of the needle 210 in contact with the plunger 415. The needle 210 may be secured or permanently attached to the drug delivery tip segment by an optional luer 430. The temperature control device 450 is disposed on the dosage chamber housing 425 and at least partially surrounds the dosage chamber 405. The housing 215 forms an outer skin on the drug delivery tip segment and at least partially surrounds the plunger shaft 410, the plunger tip 415, the dosing chamber 405, and the dosing chamber housing 425. .

The substance to be delivered to the eye, typically the medication, is located in the dosing chamber 405. In this manner, the material contacts one surface of the plunger tip 415 and the inner surface of the dosage chamber housing 425. Typically, the dosing chamber 405 is cylindrical in shape. The temperature control device 450 is in thermal contact with the dosage chamber housing 425. In this manner the temperature control device 450 is configured to heat and / or cool the contents of the dosing chamber 405. Current is applied to the temperature control device 450 via an electrical interface (not shown). The thermal sensor 460 provides temperature information to assist in controlling the operation of the temperature control device 450.

In one embodiment of the invention, the substance in the dosing chamber 405 is a drug that is preloaded into the dosing chamber. In this case, the drug delivery tip segment is suitable as a single use consumable product. Such disposable products may be assembled at the factory with a single dose of drug. The exact volume of material can be preloaded into the delivery device.

When the medication is pre-injected into the dosing chamber 405, a set amount of medication may be pre-injected. For example, 100 microliters of medication may be introduced into the dosing chamber 405 and any amount up to 100 microliters may be dosed. In this case, the plunger (plunger shaft 410 and plunger tip 415) may move at the correct distance to deliver the correct dose of medication from the dosing chamber 405 through the needle 210 to the eye. This will provide flexibility in dosage and ease of assembly.

In other embodiments, different dosages may be pre-injected into different tip segments. For example, dosages increased by 1 microliter up to 10 microliters in the dosing chamber 405 of different tip segments may be pre-injected. An appropriate dosage may be selected by selecting a tip segment preloaded with an appropriate amount of drug in the dosage chamber 405.

In operation, the drug delivery tip segment of FIG. 4 is attached to a finite reuse assembly (not shown). The finite reuse assembly provides power to the tip segment and illuminates the optional light source 275. In this case, current passes through optional light source 275 and fuse 375. The mechanical link interface 420 mates with the mechanical interface of the finite reuse assembly. Dosing information such as drug type, dosage volume, operating temperature, infusion rate, thermal expansion coefficient, density and other information can be read from the memory device 315. This dosage information allows the controller to operate the plunger to deliver the correct dosage. When a force is applied to the plunger shaft 410, the plunger tip 415 moves. Movement of the plunger tip 415 will continue to move material stored in the dosing chamber 405. The material is pushed out of the needle 210. After the dose is delivered, a controller (not shown) causes the increased current to be sent to fuse 375. The increased current indicates that the tip segment burned out fuse 375 was used and should therefore be discarded. Since the tip segment of the illustrated embodiment is a single use tip segment, once the fuse 375 is blown, the tip segment can no longer operate. In addition, once the fuse 375 is blown, reading from the memory device 315 is also impossible.

5 is a cross-sectional view of the drug delivery tip segment and finite reuse assembly according to one embodiment of the present invention. 5 shows how tip segment 205 connects to finite reuse assembly 250. In the embodiment of FIG. 5, tip segment 205 includes memory assembly 555, mechanical link interface 420, plunger 505, dosing chamber housing 425, tip segment housing 215, temperature control device 450. ), Thermal sensor 460, needle 210, dosing chamber 405, interface 530, and tip interface connector 520. The finite reuse assembly 250 includes a mechanical link interface 545, an actuator shaft 510, an actuator 515, a power source 310, a controller 305, a finite reuse assembly housing 255, an interface 535, and Finite reuse assembly interface connector 525.

In the tip segment 205, the mechanical link interface 420 is located on one end of the plunger 505. The other end of the plunger 505 forms one end of the dosage chamber 405. The plunger 505 is configured to slide in the dosing chamber 405. The outer surface of the plunger 505 is fluid seal to the inner surface of the dosage chamber housing 425. Dosing chamber housing 425 surrounds dosing chamber 405. Typically, the dosage chamber housing 425 has a cylindrical shape. Thus, the dosing chamber 405 also has a cylindrical shape.

The needle 210 couples in fluid communication with the dosing chamber 405. In such a case, material stored in the dosing chamber 405 may pass through the needle 210 and enter the eye. The temperature control device 450 at least partially surrounds the dosage chamber housing 425. In this case, temperature control device 450 is configured to cool and / or heat any material stored in dosing chamber housing 425 and dosing chamber 405. That is, the temperature control device 450 is in thermal contact with the dosing chamber housing 425. The interface 530 connects the temperature control device 450 to the tip interface connector 520.

The components of the tip segment 205 are at least partially surrounded by the tip segment housing 215, including the dosing chamber housing 425, the temperature control device 450, and the plunger 505. In one embodiment according to the principles of the present invention, a seal is present on the bottom surface of the tip segment housing 215. In this manner, the plunger 505 is sealed against the tip segment housing 215. This seal prevents contamination of any material stored in the dosing chamber 405. For medical purposes, such seals are preferred. Such a seal may be disposed at any position of the dosage chamber housing 425 or the plunger 505. In this case, the tip segment housing 215 is connected to the dosing chamber housing 425 to form an air tight or fluid tight seal. In other embodiments, tip segment housing 215 may be sealed against plunger 505 where mechanical link interface 420 is present at its end. In such a case, a gas seal or fluid seal may be formed between the tip segment housing 215 and the position on the plunger 505.

The tip segment 205 can also include a plunger stop mechanism. As shown in FIG. 5, the lower portion of the plunger 505 (the portion where the mechanical link interface 420 is present) is configured to contact the lower portion of the dosage chamber housing 425. In such a case, as the plunger 505 proceeds upward toward the needle 210, the mechanical link interface 420 also advances upward toward the needle 210. The upper surface of the mechanical link interface 420 is in contact with the lower surface of the dosage chamber housing 425. In this embodiment, the lower surface of the dosage chamber housing 425 and the protrusion on the lower end on the plunger 505 form a plunger stop mechanism. The plunger 505 may not travel further than the point where the top surface of the mechanical link interface 420 contacts the bottom surface of the plunger 505. This plunger stop mechanism may provide a safety feature, such as eliminating the possibility that the plunger 505 contacts and moves the needle 210. In another embodiment according to the principles of the present invention, such a plunger stop mechanism also includes a locking mechanism such that the plunger 505 cannot retract or move away from the needle 210 when the needle 210 is removed from the eye. . This plunger locking mechanism helps to prevent backflow of material when the needle 210 is removed.

In the finite reuse assembly 250, the power source 310 provides power to the actuator 515. An interface (not shown) connects the power source 310 to the actuator 515 through the controller 305. Actuator 515 is coupled to actuator shaft 510. When the actuator 515 is a stepper motor, the actuator shaft 510 is integral with the actuator 515. The mechanical link interface 545 is connected to the actuator shaft 510. In this configuration, as the actuator 515 moves the actuator shaft 510 upwards towards the needle 210, the mechanical link interface 545 also moves upward towards the needle 210.

The controller 305 is connected to the finite reuse assembly interface connector 525 via the interface 535. The finite reuse assembly interface connector 525 is located on the top surface of the finite reuse assembly housing 255 adjacent the mechanical link interface 545. In this manner, both the finite reuse assembly interface connector 525 and the mechanical link interface 545 are configured to be connected to the plunger interface 420 and the tip interface connector 453, respectively.

Controller 305 and actuator 515 are connected by an interface (not shown). This interface (not shown) allows the controller 305 to control the operation of the actuator 515. The controller 305 may connect with one of the rechargeable or non-rechargeable power sources 310. The controller 305 may control the current or voltage supplied to the memory assembly 555 to, for example, disconnect the fuse 375 included in the memory assembly 555 and / or illuminate the optional light source 275. Can be.

Tip segment 205 is configured to attach to or mate with finite reuse assembly 250 as described above. In the embodiment of FIG. 5, the plunger interface 420 located on the bottom surface of the plunger 505 is configured to mate with the mechanical link interface 545 located near the top surface of the finite reuse assembly housing 255. Tip interface connector 520 is also configured to be coupled with finite reuse assembly interface connector 525. When tip segment 205 is connected to finite reuse assembly 250 in this manner, actuator 515 and actuator shaft 510 are adjusted to drive plunger 505 upward toward needle 210. In addition, an interface is formed between the controller 305 and the temperature control device 450. Signals can be communicated from the controller 305 to the temperature control device 450 via the interface 535, finite reuse assembly interface connector 525, tip interface connector 520, and interface 530.

In operation, when tip segment 205 is connected to finite reuse assembly 250, controller 305 controls operation of actuator 515. When the actuator 515 is actuated, the actuator shaft 510 moves up towards the needle 210. Subsequently, a mechanical link interface 545 that mates with the mechanical link interface 420 moves the plunger 505 upward toward the needle 210. Subsequently, material located in the dosing chamber 405 is released through the needle 210.

The controller 305 also controls the operation of the temperature control device 450. The temperature control device 450 is configured to cool and / or heat the outer surface of the dosage chamber housing 425. Since the dosing chamber housing 425 is at least partially thermally conductive, heating the dosing chamber housing 425 will heat the material located within the dosing chamber 405. Temperature information may be communicated from the thermal sensor 460 back to the controller 305 via the interface 530, the tip interface connector 520, the finite reuse assembly interface connector 525, and the interface 535. This temperature information can be used to control the operation of the temperature control device 450. Typically, the controller 305 controls the amount of current entering the temperature control device 450. When the temperature control device 450 is a heater, the more current enters the temperature control device 450, the hotter the temperature control device becomes. In this manner, the controller 305 may use a feedback loop that utilizes information from the thermal sensor 460 to control the operation of the temperature control device 450. Any suitable control algorithm, such as a proportional integral derivative (PID) algorithm, can be used to control the operation of the temperature control device 450.

The memory assembly 555 is connected to the interface 530 in the tip segment 205. In an embodiment of the present invention, as described with reference to FIGS. 3 and 4, the memory assembly 555 includes an optional light source 275, a fuse 375, and a memory device 315. The memory device 315 in the memory assembly 555 is typically a hard wired memory circuit as shown in FIG. 8. The memory device 315 in the memory assembly 555 is configured to store medication information for the medication stored in the medication chamber 405.

The controller 305 is also configured to connect with the memory assembly 555. In this manner, the controller 305 allows current to flow from the power source 310 to the memory assembly 555. The controller 305 also reads data from the memory device included in the memory assembly 555. Current passing through the optional light source 275 and the fuse 375 illuminates the optional light source 275. After the tip segment 205 is used (after material is dosed), the controller 305 causes the power source 310 to deliver increased current to blow the fuse 375 and turn off the optional light source 275. . This indicates that tip segment 205 has been used and should therefore be discarded. The controller also checks the fuse to see if the fuse 375 is blown. If the fuse is blown, the controller 305 defines the tip segment 205 as inoperative. Alternatively, the fuse 375 may be arranged such that no power is delivered to the tip segment when it is blown. In this case, once the fuse 375 is blown, no more data is read from the memory device in the memory assembly 555.

In the embodiment of FIG. 5, interface 530, tip interface connector 520, finite reuse assembly interface connector 525, and interface 535 are all data interfaces between tip segment 205 and finite reuse assembly 250. To form. In this manner, information from thermal sensor 460 may return to finite reuse assembly 250 through this series of interfaces and interface connectors. In addition, data stored on the memory device in the memory assembly 555 may also be read by the controller 305 through this series of interfaces and interface connectors. When the tip segment 205 is connected to the finite reuse assembly 250, the mechanical link interface 545 is connected to the mechanical link interface 420 and the tip interface connector 520 is connected to the finite reuse assembly interface connector 525. . The connection of the tip interface connector 520 to the finite reuse assembly interface connector 525 allows data or information from the memory device and thermal sensor 460 in the memory assembly 555 to be transferred to the controller 305.

In one embodiment in accordance with the principles of the present invention, a memory device in memory assembly 555 stores drug type, dosage volume, operating temperature, injection rate, thermal expansion coefficient, density, and other information. Information about the medication stored in the medication chamber 405 is stored in a memory device within the memory assembly 555. In such a case, the controller 305 reads the drug information from the memory device in the memory assembly 555 and, in a manner suitable for checking if possible the type of drug introduced for delivery, operating temperature, infusion rate, etc. And injection volume. For example, 100 microliters can be stored in the dosing chamber 405. Information specifying that a dosage of 20 microliters should be delivered to the eye, heated to 70C, and having a coefficient of thermal expansion of 1.10 may be stored in the memory device within memory assembly 555. In this case, the controller 305 reads drug information (ie, 20 microliters must be delivered to the eye, the operating temperature is 70C, and the thermal expansion coefficient is 1.10) from the memory device in the memory assembly 555. . Controller 305 may then operate temperature control device 450 to heat the drug to 70C and actuator 515 to deliver a dosage of 20 microliters. The controller 305 causes the actuator 515 to move the actuator axis 510 and the mechanical link interface 545 at a set distance associated with a thermal expansion coefficient of 1.10 and a dosage of 20 microliters. In this case, the plunger 505 moves by this set distance such that only 20 microliters of medication are released from the needle 210 into the eye.

In one embodiment according to the principles of the present invention, the controller 305 stores various plunger distances along with operating temperature, thermal expansion coefficient, drug type and other appropriate information. Each of these plunger distances is associated with a different dosage. For example, one plunger distance may be associated with a dose of 20 microliters and a second, larger plunger distance may be associated with a dose of 40 microliters. In this manner, the controller 305 is configured to control the actuator 515, the actuator shaft 510, the mechanical link interface 545, the mechanical link interface 420 to move the plunger 505 to this set distance. Plunger distances are available. That is, the controller 305 reads the dosage information from the memory device in the memory assembly 555, finds the plunger distance associated with this dosage, and sets this distance that the plunger 505 must travel to deliver a given dosage of medication. I use it. Since the actuator shaft 510 and the mechanical link interface 545 are connected to the mechanical link interface 420, movement of the actuator shaft 510 causes a corresponding movement of the plunger 505. If the actuator 515 is a stepper motor, the controller 305 moves the actuator so that the plunger 505 moves a suitable distance to deliver the required dosage from the dosing chamber 405 to the eye through the needle 210. Control the movement of 515.

In another embodiment in accordance with the principles of the present invention, the controller 305 may calculate the distance that the plunger 505 must travel to deliver the desired dosage. For example, if controller 305 reads dosage information regarding a drug dosage of 20 microliters from the memory device along with the coefficient of thermal expansion and operating temperature in memory assembly 555, controller 305 uses this information. Calculate the proper distance the plunger 505 should travel. Knowing the volume of the dosing chamber 405 and the volume of the drug introduced into the dosing chamber 405, the distance at which the plunger 505 must travel to deliver the required dose can be calculated at the controller 305. If the dosing chamber 405 has a cylindrical shape, the volume of the dosing chamber can be calculated by multiplying the cross-sectional area (circle area) of the cylinder by the height of the dosing chamber. This simple mathematical formula can be used to calculate the total volume of the dosage chamber 405. Since the cross-sectional area of the dosage chamber 405 is constant for any given situation, a height corresponding to the distance the plunger 505 travels can be calculated for any dosage.

For example, 100 mg of drug, which expands to 1.1 (coefficient of thermal expansion) when heated to a given operating temperature to generate 100 microliters of medicine, is introduced into the dosing chamber 405 and the cross-sectional area of the dosing chamber 405 is 10. Suppose If the dosage chamber 405 is cylindrical, the height of the cylinder is also 10. In order to deliver a dose of 20 microliters corresponding to 20% of the total volume of the dosing chamber 405, the plunger 505 must be moved upwards 2 toward the needle 210. That is, a dosage of 20 microliters corresponds to 20% of the total volume of the dosage chamber 405 after the drug is inflated. In this case, the plunger 505 must move up towards the needle 210 by a distance corresponding to 20% of the total height of the dosing chamber 405. The controller 305 thus controls the actuator 515 such that the actuator shaft 510 moves the plunger 505 over a distance of 20% of the overall height of the dosing chamber 405.

In addition, the controller 305 can read information about the speed at which the plunger 505 must move to properly deliver the single dose. In such a case, the controller 305 reads information about the drug delivery rate from the memory assembly 555 and uses this information to operate the actuator 515 to drive the plunger 505 at that speed. The speed at which the plunger 505 moves can be fixed or variable. In some cases, it may be necessary to move the plunger 505 faster than in other cases. For example, if the drug stored in the dosing chamber 405 is a drug that needs to be heated before being injected into the eye, the plunger 505 may be driven at a rate such that the heated drug is not cooled and does not clog the needle 210. It would be desirable. In other cases, it may be necessary to move the plunger 505 slowly to improve delivery of the medication stored in the dosing chamber 405.

It may be desirable to include dosage information in the memory device within memory assembly 555 to avoid dosage errors. In such a case, a number of different drug delivery tip segments 205 will be manufactured with the drug injected at the factory. Dosage information may be loaded on the memory device in memory assembly 555 at the factory. A number of different tip segments may be manufactured and shipped, each having the same amount of medication stored in the dosing chamber 405 while different dosing information stored in the memory device in the memory assembly 555. Alternatively, a number of different tip segments may be manufactured and shipped, each storing a different amount of medication in the dosing chamber 405 and the corresponding dosing information stored in a memory device within the memory assembly 555. The physician can then order the disposable tip segment 205 with the necessary dosage information on the memory device in the memory assembly 555. Packaging may be clearly classified to confirm dosage information so that an appropriate dosage is taken to a patient. If the memory assembly 555 is disposed on a separate card 600, this card 600 may be included in the drug delivery device 405.

In another embodiment of the present invention, memory assembly 555 stores information about the nature of the drug itself and / or tip segment. For example, the memory assembly 555 may include a drug identifier. This determiner is used to correctly determine the medication stored in the tip segment. If a large number of different drugs are stored in a number of different tip segments, the drug determiner is useful for determining the type of drug in a particular tip segment. The drug determiner may be provided with information regarding the best mode of drug delivery. For example, if a drug is suspended in a phase shift compound, the drug determiner may include information about the best way to deliver the drug. Such additional information may include dosage information, delivery rate information, thermal expansion coefficient, and temperature control information. For example, the drug and phase shift compounds are preferably delivered at a fixed rate after reaching a fixed temperature. In this case, the information stored in the memory assembly 555 can be used as input to the controller 305 to optimally control the delivery of medication.

In this manner, a particular drug may be associated with a set of optimal delivery settings. Such delivery settings include temperature settings and delivery rate settings. The drug can be thermally altered at a fixed or variable speed and can reach one or more temperatures. For example, the phase shift compound / drug mixture may be heated from room temperature to a temperature of 55 ° C. over a period of 30 seconds. The rate of heating can be steady (approximately linear) or non-linear. Once the steady state temperature is reached, the controller 305 actuates the actuator 515 to move the plunger 415 at that speed due to the information about the delivery rate. For example, it may be desirable to deliver a phase shift compound / drug mixture at a relatively fast rate (eg, deliver the entire dosage in less than one second) to form an approximately spherical bolus in the eye. Such agglomerates can erode over time at known rates to deliver the drug over a long time. In other cases, the plunger 415 operates slowly such that the phase shift compound / drug mixture can be delivered over a longer period of time (eg, several seconds). In this case, the mixture cools as it enters the eye to form a cylinder. This cylindrical shape provides a larger surface area, resulting in a higher rate of drug release over time (ie, the cylinder melts faster than the sphere).

In another embodiment of the present invention, memory assembly 555 stores information regarding the characteristics of the tip segment. For example, information regarding the length and gauge of the needle 210 may be stored in the memory assembly 555. Information regarding the type of temperature control device (eg, heater and its power or current consumption) may also be stored in the memory assembly 555. When delivering the medication to the eye, the length of the needle 210 and the gauge can be important inputs to the controller 305 so that the medication can be delivered correctly. For example, larger gauges or longer needles enclose the larger volume that must be released through the drug to reach the eye. Various volumes of different needles can affect the amount of drug delivered. Compensation for different needle sizes may be needed by controlling the motion of the plunger 415. For example, using a 25 or 27 gauge needle with a length of a few millimeters requires moving the plunger 415 to a set distance to deliver a set amount of medication. Using a 23 gauge needle with a length of one centimeter or longer, the plunger 415 must be moved a different distance to deliver the same set amount of medication. Similarly, the shape of the needle 210 can also affect how the temperature control device 450 operates. Using longer or larger needles may require slightly more heating of the phase change material than using smaller or shorter needles.

In this manner, any number of different parameters can be stored in the memory assembly 555. These parameters can be used in the controller 305 to optimally control the system to accurately deliver medication to the eye. These parameters can also be used to implement safety features. For example, if the type of medication is stored in the memory assembly 555, this information can be examined for the infusion procedure. A checksum or CRC may be included in the memory assembly 555 to verify the accuracy or integrity of the data stored in the memory assembly 555.

The parameters stored in memory assembly 555 can be used to operate the system to perform optimal implantation. In one method, the connection between the tip segment and the finite reuse assembly can be recognized. One or more parameters may be read from memory assembly 555. Injection is controlled based on this parameter. As noted above, such parameters include, but are not limited to, medication information, delivery rate information, needle gauge, needle length, temperature control device information, drug information, thermal expansion information, and checksum.

6 is a perspective view of a medication control card according to one embodiment of the invention. In the embodiment of FIG. 6, the medication control device 600 is implemented in a memory card type device. The same structure and function as the structure and function described above in connection with the memory assembly 555 of FIG. 5 is performed in the dosage control device 600. The medication control device 600 includes a fuse, a light source, and a memory device (not shown) as described above. The medication control device 600 has a connector end 605, a body 610, and a lighted end 615. In this embodiment, the connector end 605 is configured to be able to communicate with the console box 700 even when connected to it. The light source 275 is incorporated into the light end 615.

7 is a perspective view of a console, a drug delivery device, and a dosage control card in accordance with one embodiment of the present invention. In FIG. 7, the console box 700 includes a slot 715, a port 700, a button 725, and an indicator 730. Slot 715 is configured to receive the connector end 605 of medication control card 600. Injection device 705 has a connector 710. Port 720 is configured to receive connector 710. Console box 700 has a controller (not shown) that controls the operation of injection device 705. Injection device 705 includes components of the embodiment shown in FIG. 5 except for a power source, a controller, and possibly some indicators or light sources. The components enter the console box 700. The heater is also optional as it was optional in the device described above.

In operation, the medical professional removes the infusion device 705 and the dosage control device 600 from the sterile packaging (not shown). Injection device 705 is connected to console box 700 by connecting connector 710 to port 720. The medication control device 600 is inserted into the slot 715. A controller (not shown) in console box 700 reads medication information from a memory device on medication control device 600. The controller in console box 700 then operates the injection device 700 to deliver the appropriate dosage in the manner described above.

8 is a circuit diagram of a wired memory circuit according to an embodiment of the present invention. In this embodiment, seven fuses (F1, F2, F3, F4, F5, F6, F7), six resistors (R1, R2, R3, R4, R5, R6), and one LED (L7) Used to store medication data. The embodiment of FIG. 8 also includes six terminals T1, T2, T3, T4, T5, T6, voltage line 810, and ground line 820. Fuse F7 and LED L7 correspond to fuse 375 and optional light source 275 of FIGS. 3 and 4.

The embodiment of FIG. 8 may store 5-bit numbers and checksums. As is generally known, the voltage applied to the voltage line 810 can be read across each of the six resistors. If a fuse in series with a particular resistor is blown, the voltage across this resistor will not be read. These two states (the presence or absence of voltage across the resistor) correspond to ones or zeros in binary. In the embodiment of FIG. 8, five resistors store medication data. This dosage data is one of 32 different numbers. The sixth resistor holds the checksum information.

For example, if fuse F2 and fuse F3 are blown and fuse F1, fuse F4, fuse F5, and fuse F6 are not blown, resistor R2 and resistor R3 are not blown. There will be no voltage across (i.e. zero voltage) and across the resistors R1, R4, R5, and R6 the total voltage (+5 volts) will appear. In this example, 5 bits corresponds to the first five resistors (R1-R5), and the checksum corresponds to the sixth resistor (R6). The voltage across each resistor is read between each terminal T1-T6 and ground line 820. In this case, the 5-bit binary number is 10011 or 19 and the checksum is one. The controller reads these numbers and checksums to determine if the numbers are correct in light of the checksums and then determines the dosage based on these numbers. In this case, the dosage control device defines 32 different dosage levels. The number 19 may correspond to a dosage of 48 microliters. In such a case, dosages in increments of 10 to 72 microliters by 2 microliters can be defined by the dosage control device. The controller can then operate the plunger to deliver 48 microliters. As described above, after the dose is delivered the fuse may be blown and the card may become inoperable.

From the above, it will be appreciated that the present invention provides an improved system for delivering the correct volume of material to the eye. The present invention provides a drug delivery device capable of delivering an accurate dosage. The tip segment connects with a universal finite reuse hand piece assembly. The information in the dosage control device instructs the injection device to deliver the correct dosage. The invention is illustrated by way of example herein, and various modifications may be made by those skilled in the art to which the invention pertains.

Other embodiments of the present invention will be apparent to those of ordinary skill in the art in view of the practice and description of the invention disclosed herein. The description and examples of the present invention are intended to be considered by way of example only, and the true scope and spirit of the present invention will be indicated by the following claims.

Claims (14)

As an injection device, A dosing chamber having an inner surface and an outer surface, the inner surface defining a cavity for receiving a predetermined amount of material; A plunger engaged with an inner surface of the dosing chamber, the plunger being slidable in a cavity of the dosing chamber and sealed in fluid communication with the inner surface of the dosing chamber; A controller for controlling the operation of the injection device; A temperature control device for at least partially surrounding the dosing chamber; And A memory device for storing parameters; Including, The controller operates the injection device using parameters from the memory device, Injection device. The method of claim 1, Further comprising a fuse that is broken after the material has been delivered from the dosing chamber to render the injection device inoperable. Injection device. The method of claim 1, Further comprising a needle coupled in fluid communication with the dosing chamber, Injection device. The method of claim 2, Further comprising a light source arranged in series with the fuse, Injection device. The method of claim 1, Further comprising an actuator for driving the plunger, Injection device. The method of claim 1, Wherein the memory device comprises one or more resistors and one or more fuses connected in series, Injection device. The method of claim 1, The parameter is an input to the controller for controlling the injection device to deliver the substance in a predefined manner, Injection device. As a method for injecting a substance into the eye, Recognizing a connection between the tip segment and the finite reuse assembly; Reading a parameter from a memory device in the tip segment; Operating the finite reuse assembly and tip segment based on the parameter to deliver material to the eye; Including, Method for injecting substance into the eye. The method of claim 8, The parameter is selected from a group of parameters consisting of medication information, delivery rate information, needle gauge, needle length, temperature controller information, drug information, thermal information, and checksum, Method for injecting substance into the eye. The method of claim 8, Reading drug information; Using the drug information to determine an optimal delivery algorithm; And Delivering the drug using the optimal delivery algorithm; Further comprising, Method for injecting substance into the eye. The method of claim 8, Reading medication information and medication rate information; And Controlling an actuator to move the plunger to deliver a suitable medication dose in accordance with the medication information and the medication rate information; Further comprising, Method for injecting substance into the eye. The method of claim 8, Reading needle gauge information and needle length information; And Controlling an actuator to move the plunger to deliver a suitable drug dosage in accordance with the needle gauge information and the needle length information; Further comprising, Method for injecting substance into the eye. The method of claim 8, Reading thermal information; And Controlling the temperature control device to thermally change the material; Further comprising, Method for injecting substance into the eye. The method of claim 8, Reading a checksum; And Evaluating the checksum to verify the integrity of the information read from the memory device; Further comprising, Method for injecting substance into the eye.

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