Device for brain biopsy

A surgical device for guiding a biopsy surgical tool, the surgical device comprising:

• a first rotational mechanism configured to provide a first rotational degree of freedom about a yaw axis to the surgical device, the first rotational mechanism including:
• a connector connected movably to a distal end of a coarse-tuning section in a configuration rotatable about a roll axis, the yaw axis, and a pitch axis,
• a base, fixedly attached to a distal end of the connector,
• a ring-type member movably connected to a distal end of the base in a configuration rotatable about a yaw axis,
• a plurality of restraining cylinders attached to the distal end of the base, the ring-type member disposed rotationally and slidably between the plurality of restraining cylinders in a configuration limiting motion of the ring-type member to a rotation about the yaw axis,
• a pipe-shaped section provided at a distal end of the ring-type member, and
• a first frictional gripper attached to the base with a first lock screw mounted on the first frictional gripper, the first frictional gripper configured to minimize movements of the ring-type member in response to the first lock screw being tightened on the first frictional gripper;
• a translational mechanism configured to provide a translational degree of freedom along the roll axis to the surgical device, the translational mechanism including:
• a main rod disposed slidably, from a proximal end thereof, along a distal end of the pipe-shaped section of the ring-type member in a configuration limiting the movements of the main rod to a translational movement along the roll axis,
• a c-type connector fitted securely, from a proximal end thereof, to a distal end of the main rod,
• a second frictional gripper provided at the distal end of the main rod and a second lock screw mounted on the second frictional gripper, the second frictional gripper configured to minimize movements of the main rod in response to the second lock screw being tightened on the second frictional gripper;
• and
• a second rotational mechanism configured to provide both a second rotational degree of freedom about the pitch axis and a third rotational degree of freedom about the roll axis to the surgical device, the second rotational mechanism including:
• a circular frame disposed coaxially and movably inside the c-type connector in a configuration rotatable about a pitch axis,
• a slotted rod disposed movably inside the circular frame in a configuration rotatable about the roll axis,
• an end-effector mounted securely on the slotted rod in a configuration synchronously rotatable with the slotted rod about the roll axis,
• a first worm gear attached to the circular frame and a first worm screw attached to the c-type member, the first worm gear meshing with the first worm screw in a configuration that is responsive to the first worm screw being turned in either a clockwise direction or a counterclockwise direction, the circular frame thereby rotating about the pitch axis, and
• a third lock screw, mounted on the c-type member in a configuration wherein tightening the third lock screw promotes friction between the third lock screw and the circular frame, thereby minimizing movements of the circular frame.