Plunger Linkage and Seal For Ophthalmic Medical Device
A disposable injection device has a dispensing chamber housing and a plunger. The dispensing chamber housing has an inner surface and an outer surface. The inner surface partially defines a dispensing chamber for receiving a quantity of a substance. The plunger is engaged with the inner surface of the dispensing chamber housing, is capable of sliding in the dispensing chamber housing, and is fluidly sealed to the inner surface of the dispensing chamber housing. The plunger has a plunger interface. The plunger interface mates with a mating surface on a mechanical linkage interface such that force is transferred from the mechanical linkage interface to the plunger along a first direction towards the plunger when the plunger interface is in contact with the mating surface of the mechanical linkage interface, and force is not substantially transferred from the mechanical linkage interface to the plunger along a second direction away from the plunger.
1 . A disposable injection device comprising:
a dispensing chamber housing having an inner surface and an outer surface, the inner surface partially defining a dispensing chamber for receiving a quantity of a substance; and
a plunger engaged with the inner surface of the dispensing chamber housing, the plunger capable of sliding in the dispensing chamber housing, the plunger fluidly sealed to the inner surface of the dispensing chamber housing, the plunger having a plunger interface;
wherein the plunger interface mates with a mating surface on a mechanical linkage interface such that force is transferred from the mechanical linkage interface to the plunger along a first direction towards the plunger when the plunger interface is in contact with the mating surface of the mechanical linkage interface, and force is not substantially transferred from the mechanical linkage interface to the plunger along a second direction away from the plunger.
2 . The device of claim 1 further comprising:
a housing at least partially enclosing the dispensing chamber housing and the plunger.
3 . The device of claim 1 further comprising:
a needle fluidly coupled to the dispensing chamber.
4 . The device of claim 1 further comprising:
a temperature control device in thermal contact with the dispensing chamber, the temperature control device for altering the temperature of the substance.
5 . The device of claim 4 further comprising:
a thermal sensor in thermal contact with the dispensing chamber.
6 . The device of claim 1 wherein the substance is a drug for treating a condition of the eye.
7 . The device of claim 1 wherein the plunger further comprises:
an o-ring located around the plunger, the o-ring for fluidly sealing the plunger to the inner surface of the dispensing chamber housing.
8 . The device of claim 7 wherein the plunger is made of a material selected from the group consisting of stainless steel, elastomer, and polymer.
9 . The device of claim 1 wherein the plunger further comprises:
an annular ring located around the plunger, the annular ring for fluidly sealing the plunger to the inner surface of the dispensing chamber housing.
10 . The device of claim 1 wherein the plunger is over molded onto a rigid shaft, and the plunger interface is located on a proximal end of the shaft.
11 . The device of claim 1 wherein the plunger is press-fitted onto a rigid shaft, and the plunger interface is located on a proximal end of the shaft.
12 . The device of claim 1 wherein the plunger interface is substantially concave and the mating surface is substantially convex.
13 . The device of claim 1 wherein the plunger interface is substantially convex and the mating surface is substantially concave.
14 . The device of claim 1 wherein the plunger interface and the mating surface are both substantially flat.
15 . The device of claim 1 further comprising:
the mechanical linkage interface and an actuator for driving the mechanical linkage interface.
16 . An ophthalmic injection system comprising:
a tip segment and a limited reuse assembly;
the tip segment comprising:
a dispensing chamber housing having an inner surface and an outer surface, the inner surface partially defining a dispensing chamber for receiving a quantity of a substance; and
a plunger engaged with the inner surface of the dispensing chamber housing, the plunger capable of sliding in the dispensing chamber housing, the plunger fluidly sealed to the inner surface of the dispensing chamber housing, the plunger having a plunger interface;
the limited reuse assembly comprising:
a power source;
an actuator having a shaft;
a controller for controlling the actuator; and
a mechanical linkage interface coupled to the shaft, the mechanical linkage interface having a mating surface on an end;
wherein the plunger interface mates with the mating surface on the mechanical linkage interface such that force is transferred from the mechanical linkage interface to the plunger along a first direction towards the plunger when the plunger interface is in contact with the mating surface of the mechanical linkage interface, and force is not substantially transferred from the mechanical linkage interface to the plunger along a second direction away from the plunger.
17 . The ophthalmic injection system of claim 16 wherein the tip segment further comprises:
a needle fluidly coupled to the dispensing chamber.
18 . The ophthalmic injection system of claim 16 wherein the tip segment further comprises:
a temperature control device in thermal contact with the dispensing chamber, the temperature control device for altering the temperature of the substance.
19 . The ophthalmic injection system of claim 18 wherein the tip segment further comprises:
a thermal sensor in thermal contact with the dispensing chamber.
20 . The ophthalmic injection system of claim 16 wherein the substance is a drug for treating a condition of the eye.
21 . The ophthalmic injection system of claim 16 wherein the tip segment further comprises:
an o-ring located around the plunger, the o-ring for fluidly sealing the plunger to the inner surface of the dispensing chamber housing.
22 . The ophthalmic injection system of claim 21 wherein the plunger is made of a material selected from the group consisting of stainless steel, elastomer, and polymer.
23 . The ophthalmic injection system of claim 16 wherein the tip segment further comprises:
an annular ring located around the plunger, the annular ring for fluidly sealing the plunger to the inner surface of the dispensing chamber housing.
24 . The ophthalmic injection system of claim 16 wherein the plunger is over molded onto a rigid shaft, and the plunger interface is located on a proximal end of the shaft.
25 . The ophthalmic injection system of claim 16 wherein the plunger is press-fitted onto a rigid shaft, and the plunger interface is located on a proximal end of the shaft.
26 . The ophthalmic injection system of claim 16 wherein the plunger interface is substantially concave and the mating surface is substantially convex.
27 . The ophthalmic injection system of claim 16 wherein the plunger interface is substantially convex and the mating surface is substantially concave.
28 . The ophthalmic injection system of claim 16 wherein the plunger interface and the mating surface are both substantially flat.
29 . The ophthalmic injection system of claim 19 further comprising:
an electrical interface for coupling the temperature control device to the limited reuse assembly.
30 . The ophthalmic injection system of claim 16 wherein the controller operates the actuator such that the shaft is moved a calculated distance thereby displacing the plunger and causing a fixed amount of the substance to exit the dispensing chamber.
31 . The ophthalmic injection system of claim 16 wherein the power source is a battery.
32 . The ophthalmic injection system of claim 16 wherein the mechanical linkage interface is rigidly coupled to the shaft.
33 . The ophthalmic injection system of claim 16 wherein the mechanical linkage interface is coupled to the shaft with a ball joint.
34 . The ophthalmic injection system of claim 16 wherein the mechanical linkage interface is tapered near the end on which the mating surface is located.
35 . A dispensing mechanism for use in an ophthalmic drug delivery device comprising:
a dispensing chamber housing having an inner surface and an outer surface, the inner surface partially defining a dispensing chamber for receiving a quantity of a substance;
a plunger engaged with the inner surface of the dispensing chamber housing, the plunger capable of sliding in the dispensing chamber housing, the plunger fluidly sealed to the inner surface of the dispensing chamber housing, the plunger having a plunger interface; and
a mechanical linkage interface having a mating surface on one end;
wherein the plunger interface mates with the mating surface on the mechanical linkage interface such that force is transferred from the mechanical linkage interface to the plunger along a first direction towards the plunger when the plunger interface is in contact with the mating surface of the mechanical linkage interface, and force is not substantially transferred from the mechanical linkage interface to the plunger along a second direction away from the plunger.
36 . The dispensing mechanism of claim 35 further comprising:
a temperature control device in thermal contact with the dispensing chamber, the temperature control device for altering the temperature of the substance.
37 . The dispensing mechanism of claim 35 further comprising:
an o-ring located around the plunger, the o-ring for fluidly sealing the plunger to the inner surface of the dispensing chamber housing.
38 . The dispensing mechanism of claim 35 further comprising:
an annular ring located around the plunger, the annular ring for fluidly sealing the plunger to the inner surface of the dispensing chamber housing.
39 . The dispensing mechanism of claim 35 wherein the plunger is over molded onto a rigid shaft, and the plunger interface is located on a proximal end of the shaft.
40 . The dispensing mechanism of claim 35 wherein the plunger is press-fitted onto a rigid shaft, and the plunger interface is located on a proximal end of the shaft.
41 . The dispensing mechanism of claim 35 wherein the plunger interface is substantially concave and the mating surface is substantially convex.
42 . The dispensing mechanism of claim 35 wherein the plunger interface is substantially convex and the mating surface is substantially concave.
43 . The dispensing mechanism of claim 35 wherein the plunger interface and the mating surface are both substantially flat.
44 . The dispensing mechanism of claim 35 further comprising:
an actuator with a shaft, the shaft connected to the mechanical linkage interface.
45 . The dispensing mechanism of claim 44 wherein the mechanical linkage interface is rigidly coupled to the shaft.
46 . The dispensing mechanism of claim 44 wherein the mechanical linkage interface is coupled to the shaft with a ball joint.
47 . The dispensing mechanism of claim 35 wherein the mechanical linkage interface is tapered near the end on which the mating surface is located.
48 . The dispensing mechanism of claim 35 wherein the plunger interface and the mating surface permit transfer of motion only in a single direction.
49 . The dispensing mechanism of claim 35 wherein when the mechanical linkage interface is retracted, the plunger remains in substantially the same position.