Distal bevel-tip needle control device and algorithm
Disclosed is a system for percutaneously steering a surgical needle. Needle steering is accomplished by taking advantage of a deflection force imparted on the bevel tip of the needle by the tissue medium as the needle is pushed through the tissue. By controlling the translation speed and rotation angle of the bevel, a flexible needle may be steered substantially without deflecting or distorting the tissue. The control inputs (translation speed and rotation angle) are computed based on a “bicycle” non-holonomic kinematic model that is a function of mechanical properties of the tissue medium. The system may be used with image-based feedback, which may provide for feedback-based refinement of the model as the needle propagates through the tissue.
1. A device for controlling a needle having a bevel, comprising:
a translation actuator;
a rotation actuator; and
a processor connected to the translation actuator and the rotation actuator, wherein the processor includes a memory encoded with a program for computing a needle path based on a desired end position of the needle, estimated properties of the needle and a tissue, a rotation angle of the bevel, and a translation speed of the needle.
2. The device of claim 1 , wherein the program for computing the needle path comprises instructions for computing the needle path based on a mechanical property of the tissue.
3. The device of claim 1 , wherein the memory is further encoded with a program for computing a first control input and a second control input, wherein the first control input and the second control input correspond to the computed needle path.
4. The device of claim 1 , further comprising a translation encoder connected to the processor.
5. The device of claim 1 , further comprising a rotation encoder connected to the processor.
6. The device of claim 1 , further comprising a needle having a bevel, wherein the bevel has an angle of about 5°.
7. The device of claim 1 , further comprising a needle, wherein the needle is flexible.
8. A device for controlling a needle having a bevel, comprising:
a translation actuator;
a translation encoder;
a rotation actuator;
a rotation encoder; and
a processor connected to the translation actuator, the translation encoder, the rotation actuator, and the rotation encoder, wherein the processor includes a memory encoded with a program for computing a needle path based on a first signal from the translation encoder that represents a translation speed of the needle, and a second signal from the rotation encoder that represents a rotation angle of the bevel.
9. The device of claim 8 , wherein the translation actuator is manually controlled.
10. The device of claim 8 , wherein the rotation actuator is manually controlled.
11. The device of claim 1 , further comprising a needle, wherein the needle comprises Nitinol.
12. The device of claim 8 , further comprising a needle, wherein the needle comprises Nitinol.