Assisted injection device for injecting a composition contained in a medical container
The present disclosure relates to an assisted injection device for injecting a composition contained in a medical container. The injection device includes a body configured to receive the medical container in a fixed position relative to the body. The injection device includes a spring-loaded piston rod translationally movable inside the body along a spring axis. The injection device includes a lever pivotably mounted on the body about a first pivot axis orthogonal to the spring axis at a first distance form the spring axis. The injection device includes a selective blocking system coupled to the lever by a second pivot axis orthogonal to the spring axis. The lever is pivotable between a rest position. The selective blocking system engages the piston rod to prevent any translation movement of the piston rod and a second position wherein the selective blocking system releases the piston rod.
1. An assisted injection device for injecting a composition contained in a medical container, comprising:
a body configured to receive the medical container in a fixed position relative to the body,
a spring-loaded piston rod translationally movable inside the body along a spring axis, between a proximal rest position and a distal operative position wherein the piston rod engages a stopper of the medical container and pushes the stopper in the medical container,
a lever pivotably mounted on the body about a first pivot axis orthogonal to the spring axis at a first distance from the spring axis, comprising an actuation zone configured to be directly pressed on by a user, said actuation zone being opposite the first pivot axis relative to the spring axis, at a second distance from the spring axis, and
a selective blocking system coupled to the lever by a second pivot axis orthogonal to the spring axis,
the lever being pivotable between a rest position wherein the selective blocking system engages the piston rod to prevent any translational movement of the piston rod and a second position wherein the selective blocking system releases the piston rod to allow the piston rod to move toward the distal operative position under the spring force.
2. The assisted injection device according to claim 1 ,
wherein the second distance is greater than the first distance.
3. The assisted injection device according to claim 1 , wherein the second pivot axis intersects the spring axis.
4. The assisted injection device according to claim 1 , wherein the piston rod is provided with a toothed rack that extends along its outer wall, and the selective blocking system comprises:
a rotatably movable wheel comprising:
a first part being a rotatably movable cogwheel, including teeth adapted to mesh with the toothed rack of the piston rod,
a second part coaxial with the first part and rotatably movable with the first part, comprising a curved surface, and
a connecting rod including a first end coupled to the lever by the second pivot axis and a second end provided with a hole that receives the second part of the wheel, the connecting rod being movable by the lever between a first position wherein the lever is in the rest position and the inner surface of the hole engages the curved surface of the second part of the wheel so as to block the wheel by friction thereby blocking the piston rod, and a second position wherein the lever is the operative position and the inner surface of the hole disengages the curved surface of the second part of the wheel so as to allow the rotation of the wheel thereby allowing the piston rod to move.
5. The assisted injection device according to claim 4 , wherein the ratio of the diameter of the first part of the wheel to the diameter of the second part of the wheel is between 2 and 3.
6. The assisted injection device according to claim 4 , wherein the curved surface of the second part of the wheel is made of a material selected from the group consisting of epoxy resin, plastic material, steel, aluminum, or rubber and the inner surface of the hole of the connecting rod is made of a material selected from the group consisting of epoxy resin, plastic material, steel, or rubber.
7. The assisted injection device of claim 4 , wherein the curved surface of the second part of the wheel is made of at least one of epoxy resin, plastic material, steel, aluminum, or rubber and the inner surface of the hole of the connecting rod is made of at least one of epoxy resin, plastic material, steel, or rubber.
8. The assisted injection device according to claim 1 , wherein the piston rod is provided with a toothed rack that extends along its outer wall, and the selective blocking system comprises:
a pawl comprising a surface provided with a at least one tooth, and
a connecting rod assembly including a first end coupled to the lever by the second pivot axis, and a second end coupled to the pawl, the connecting rod assembly being movable by the lever between a first position wherein the lever is in the rest position and the pawl meshes with the toothed rack of the piston rod so as to block the piston rod, and a second position wherein the lever is in the operative position and the pawl disengages the toothed rack of the piston rod so as to allow the piston rod to move.
9. The assisted injection device according to claim 1 , wherein the body comprises a container holder system configured to receive at least a portion of the medical container and to hold the medical container aligned with the movement direction of the piston rod so that when moving from the proximal rest position to the distal operative position, the piston rod engages the stopper of the medical container and pushes the stopper in the medical container to inject the composition.
10. The assisted injection device according to claim 9 , wherein the container holder system comprises:
an opening provided in the distal wall of the body that leads to a housing adapted to receive at least a portion of the medical container in a position aligned with the movement direction of the piston rod,
a slot provided in the outer wall of the body that leads to the housing, and
an insert adapted to be inserted in the slot to contact the medical container and to maintain the medical container in a fixed position in the housing.
11. The assisted injection device according to claim 9 , wherein the container holder system comprises:
a slot provided in the outer wall of the body that leads to a housing, configured to receive at least a portion of the medical container and to maintain the medical container in a fixed position aligned with the movement direction of the piston rod, and
a through groove provided in the distal wall of the body, continuous with the slot and extending in the distal wall from the slot, the groove being configured to guide the medical container inserted via the slot to the housing.
12. The assisted injection device of claim 1 , wherein said device is handheld.
13. The assisted injection device of claim 1 , wherein the second distance is at least two times greater than the first distance.