DE20311610U1 - Robot-based device for inserting implants and for avoiding relative movements - Google Patents

Description

ReneBaltus, Auf den Steinen 7, 53125 Bonn, 2^.(57.2003 : .' .: &iacgr;^# . Page 1 of

Robot-assisted device for inserting implants and avoiding relative movements.

Robot-assisted devices for inserting implants, e.g. half-shells for hip joints, are well known. It is important that the handling machine or an actuator guides the device. This measure enables the surgeon to insert the half-shell precisely. One device consists of an impact device, the shaft of which is stabilized by a linear guide and held in the exact, predetermined position, whereby a linear movement in the direction of impact can take place unhindered. The half-shell or the implant is screwed onto the free end of the impact tool.

The operator can concentrate fully on driving in the half-shell, unhindered by possible angular deviations. Once the implant is firmly in place and in the correct position, the surgeon will unscrew the impact tool from the shell and pull it back. The tool must therefore be able to perform a linear movement (for driving in) and a rotating movement (for unscrewing).

However, for reasons of principle and in order to proceed cautiously, it is advisable, especially since the view of the hip joint and the insertion site may be blocked, to enable the tracking of the tool and the half-shell by means of sensors and to display them on a display (interactive registration).

However, such registration is not possible with the tools currently in use. The reason for this is that the impact tool can rotate freely and therefore attaching optical sensors for interactive registration is pointless - they would display completely incorrect values when the tool rotates.

Another disadvantage is that there is no mechanical connection or locking mechanism between the tool carrier (e.g. a robot arm) and the patient or the operation site. This means that uncontrollable movements by the patient that disrupt the operation cannot be ruled out.

The invention has the task of designing an impact tool in such a way that rotation is prevented during the execution of a linear movement and then allows the tool to be unscrewed from the half-shell or the implant by means of a rotational movement. Furthermore, the "switching" between impact and rotational movement should be quick and uncomplicated.

Furthermore, the task must be solved to enable the surgical field to be locked and to at least limit relative movement between patient and robot.

For this purpose, the shaft of the impact tool is provided with at least one lateral flattening or two flattenings opposite one another over a certain minimum length, so that the other sides retain their radius. At least two openings, preferably holes, are made in the guide, into which at least one straight or U-shaped shaped piece can be inserted, which guides the flattenings of the tool laterally. The clearance between the legs of the U corresponds to the size of the flattenings of the impact tool. If a linear movement is to be carried out to drive in the implant, the shaped piece is retracted, making a rotary movement impossible, and the sensors remain stable and non-rotatable in their position. If a rotary movement is to be carried out, the

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The molded piece is simply pulled out. Three sensors or reflectors are arranged at the upper end of the impact tool, which use a stereo camera to determine the position of the tool.

In order to exclude or at least limit relative movement between the patient and the handling machine, it is planned to arrange at least one, preferably two or three linearly movable and lockable steel pins, each with at least one tip, next to the tools. These steel pins are extended so far that they are inserted directly next to the surgical field, e.g. in the bone. This at least limits the relative movements, which can also be used for other work with tools, e.g. with drills, and makes working on the patient safer.

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List of reference symbols

1. Reflector/Sensor

2. Handle

3. Shaft

4. Lateral flattening

5. Drilling

6. Leadership

7. Thread for half shells/implants

8. Removable guide piece

9. Steel pin

10. Leadership

11. Locking screw

Claims (3)

1. Robot-assisted device for inserting implants, e.g. half-shells for artificial hip joints, and for preventing relative movements, characterized in that the striking tool is provided with a lateral flattening or several lateral flattenings which prevent a rotary movement as desired by means of at least one movably arranged guide piece and thus only a linear movement can be carried out at times, wherein a rotary movement can be carried out after the guide piece or guide pieces have been pulled out. 2. Robot-assisted device for inserting implants, e.g. half-shells for artificial hip joints, and for avoiding relative movements according to claim 1, characterized in that displaceable and lockable steel pins are arranged on the side of the tools, the tool carriers or the robot arm, which can be inserted into the bone and make a relative movement between the patient and the handling machine at least limitable. 3. Robot-assisted device for inserting implants, e.g. half-shells for artificial hip joints, and for avoiding relative movements according to claims 1 and 2, characterized in that the impact tool and the steel pins can be provided with optical sensors or reflectors.