Device and method for working material

1. An apparatus for working a bone having a surface, the apparatus comprising:

a tool head;

a cutting or drilling tool carried on the tool head and adapted to work the surface of the bone along a trajectory on the surface;

two supports mounted on and shiftable relative to the tool head and each having an end engageable with the surface of the bone being worked and adapted to support the tool head on the surface of the bone being worked at a spacing and at an angle determined by relative positions of the two supports and the tool head;

respective actuators for shifting each of the two supports relative to the tool head and to the tool for varying the angle and spacing of the tool relative to the surface of the bone being worked;

a sensor for, while working the bone, collecting data relating to properties of the bone being worked at or around a location where the tool is working the surface of the bone being worked, or data concerning acceleration, angle or position of the tool head relative to the location where the bone is being worked; and

control means connected to the sensor and to the two actuators, configured for determining, based on data collected by the sensor, at least one property of the bone being worked at or around a location where the tool is working the surface and for computing in real time an adjusted position of each of the two supports relative to the tool head depending on said at least one determined property, the control means further being connected to each actuator for operating the actuators and thereby shifting each of the two supports on the tool head according to the computed adjusted position to adjust a height or angle of the tool relative to the surface of the bone being worked.

2. The apparatus according to claim 1 , wherein the two supports flank the tool.

3. The apparatus according to claim 1 wherein the apparatus further comprises:

navigating means for determining a position of the tool head relative to the bone being worked by means of data from a database.

4. The apparatus according to claim 1 , further comprising means for capturing the data prior to working the bone depending on position by measurement techniques and storing the captured data in a database.

5. The apparatus according to claim 1 , further comprising a sensor that, while working the bone, captures data or navigation data for controlling the actuator of the support.

6. The apparatus according to claim 5 wherein the sensor is at least partially located in at least one of the two supports or in an end of one of the two supports facing the surface of a bone that is being worked.

7. The apparatus according to claim 5 wherein the sensor is at least partially located in the tool or captures performance data of the tool.

8. The apparatus according to claim 5 wherein the sensor comprises an ultrasound transmitter and an ultrasound receiver.

9. The apparatus according to claim 8 wherein ultrasound impulses transmitted by the sensor on the support are received by the same sensor or the sensor of a different support as echoes.

10. The apparatus according to claim 6 wherein the sensor is provided with means for applying a coupling fluid.

11. The apparatus according to claim 1 wherein the supports each include a slide that is moved out of and into the tool head by the respective actuator.

12. The apparatus according to claim 1 wherein the sensor is located on or in the tool head or on or in the tool such that the captured data represent information about a thickness of the bone at the location or at least in the region surrounding the location of the bone that is being worked.

13. The apparatus according to claim 1 wherein the data is correlated depending on a determined position of the tool head with data captured while the bone is being worked by the sensor on or in the tool head in order to correct an automatic path-finding of the tool head.

14. The apparatus according to claim 12 wherein the data about the thickness is captured by emission of ultrasound impulses' and capturing of ultrasound echoes by the support on tool head.

15. The apparatus according to claim 1 wherein the sensor integrated into the tool head captures navigation data.

16. The apparatus according to claim 1 wherein working of the bone takes the form of leveling, separating or joining.

17. The apparatus according to claim 1 wherein, as the result of working the bone, a cranium of a living organism is opened.

18. An apparatus for working a bone having a surface, the apparatus comprising:

a tool head;

a cutting or drilling tool carried on the tool head and adapted to work the surface of the bone along a trajectory on the surface;

a support mounted on and shiftable relative to the tool head and having an end engageable with the surface of the bone being worked and adapted to support the tool head on the surface of the bone being worked at a spacing determined by relative positions of the support and the tool head;

an actuator for shifting the support relative to the tool head and to the tool for varying the spacing of the tool relative to the surface of the bone being worked;

a sensor for, while working the bone, collecting data relating to properties of the bone being worked at or around a location where the tool is working the surface of the bone being worked, or data concerning acceleration or position of the tool head relative to the location where the bone is being worked; and

control means connected to the sensor and to the actuator and configured for determining, based on data collected by the sensor, at least one property of the bone being worked at or around a location where the tool is working the surface and for computing in real time an adjusted position of the support relative to the tool head depending on said at least one determined property, the control means further being connected to the actuator for operating the actuator and thereby shifting the support on the tool head according to the computed adjusted position to adjust a height of the tool relative to the surface of the bone being worked.

19. A method of working a bone having a surface, the method comprising:

guiding a cutting or drilling tool carried on a tool head along a trajectory on the surface of the bone with the tool extending through the surface into the bone and cutting the bone;

engaging two supports shiftable on the tool head with the surface adjacent the tool and thereby supporting the tool on the surface with the two supports at a depth in the bone and at an angle to the surface determined by positions of the two supports relative to the tool head;

detecting with a sensor a thickness of the bone in the immediate vicinity of the tool;

determining, based on data collected by the sensor, at least one property of the bone being worked at or around a location where the tool is working the surface;

computing in real time an adjusted position of each of the two supports relative to the tool head depending on said at least one determined property; and

varying the positions of the two supports relative to the tool head in accordance with data derived from the thickness detected by the sensor while the bone is being worked.