Self controlled image guided device and method for inserting a needle in an animal body for effecting radiation therapy in said body
The invention relates to a device and method for inserting a needle in an animal body for effecting radiation therapy in the body, including a template for positioning the needles to be inserted, needle drive structure for drive a needle through said template towards a desired location in the body, and real-time imaging structure for creating and presenting an image of the desired location and the position of said needle during the insertion of said needle. Due to the fact that the bevelled tip of a hollow needle cause the needle to diverge away from the “line of insertion or movement” and away from the actual desired position in the animal body adversely affecting the dosimetry quality of the implanted seeds a more accurate insertion of the needle is required. According to the invention the device is provided with adjusting structure for adjusting a movement of said needle towards said desired location during insertion.
1. Device for inserting at least one hollow needle to a desired location in an animal body for effecting radiation therapy in said body, comprising:
a template for positioning at least one needle to be inserted,
needle drive means for driving a needle through said template towards the desired location in the body,
real-time imaging means for creating and presenting an image of the desired location and the position of said needle during the insertion of said needle, and
means for adjusting a movement of said needle towards said desired location during insertion based on signals delivered by said imaging means.
2. Device according to claim 1 , wherein said adjusting means are capable of exerting correction forces on said needle almost perpendicular to the direction of insertion.
3. Device according to claim 1 , wherein said adjusting means are capable of moving said needle in a direction perpendicular to the direction of insertion.
4. Device according to claim 1 , wherein said adjusting means can move said needle in two orthogonal directions.
5. Device according to claim 4 , wherein said adjusting means comprises at least one drive means for moving said needle in at least one of said directions.
6. Device according to claim 5 , wherein said adjusting means comprises a shaft connected to at least one drive means, which shaft is provided at its free end with a guide ring through which the needle to be inserted is guided.
7. Device according to claim 6 , wherein said guide ring comprises at least two ring parts, which parts can be moved in order to be released from or to be placed around the needle to be inserted.
8. Device according to claim 7 , wherein said shaft has a hollow, longitudinal bore through which an actuator rod is movably mounted for actuating said at least two ring parts.
9. Device according to claim 8 , wherein said actuator rod is connected with one end of each of said at least two ring parts.
10. Device according to claim 8 , wherein when said actuator rod is moved in a direction towards the needle, the free ends of said ring parts are moved away from each other.
11. Device according to claim 8 , wherein when said actuator rod is moved in a direction away from the needle, the free ends the ring parts are moved towards each other.
12. Device according to claim 11 , wherein said at least two ring parts abut against a cam mounted near the free end of said shaft.
13. Device according to claim 1 , wherein said template is made of a flexible rubber material.
14. Device according to claim 13 , wherein a metal plate is positioned near at least one side of said template and provided with a plurality of holes.
15. Device according to claim 1 , wherein said needle drive means comprises a plate with a motor and at least one pair of opposing drive wheels.
16. Device according to claim 15 , wherein at least one of said drive wheels is movable between a position where it is free from the needle and a position where it is in frictional contact with the needle to be inserted.
17. Device according to claim 15 , wherein said needle drive means furthermore comprises sensing means for establishing a first reference position of the needle to be inserted.
18. Device according to claim 17 , wherein said sensing means comprise at least one pair of optical sensors.
19. Device according to claim 1 , wherein the insertion of the needle is terminated once the needle is inserted at the desired location in the body.
20. Method for inserting at least one hollow needle to a desired location in an animal for effecting radiation therapy in said body, comprising the steps of:
positioning a needle near the animal body,
inserting said needle towards the desired location in the body,
imaging the desired location and the position of said needle during the insertion of said needle using real-time imaging means, and
adjusting the insertion of said needle towards said desired location during insertion using signals delivered by said imaging means.