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EP-4734869-A1 - STEREOTACTIC DEVICE FOR CUTTING HARD TISSUE ON THE CRANIAL BONE USING ENERGETIC RADIATION

EP4734869A1EP 4734869 A1EP4734869 A1EP 4734869A1EP-4734869-A1

Abstract

A stereotactic device for cutting hard tissue on the cranial bone using energetic radiation has a stereotactic frame (22) and a stereotactic bow (25) fastened to the stereotactic frame (22) by at least one rotary joint. A laser applicator (17) is attached to the stereotactic bow (25) and can be moved along the stereotactic bow (25) via a motorised drive (28´´), said bow also being able to be tilted on the stereotactic frame (22) via a motorised drive (28, 28´). The laser applicator (17) has a dynamic 2D beam deflection apparatus (11) for a processing laser beam (2), focusing optics (12) with an adjustable focal position and a measuring apparatus (6) or is connected thereto, by means of which the cutting depth and the remaining thickness of the cranial bone (15) in the kerf can be measured. The device permits a safe opening of the cranium which is vibration-free and silent for the patient.

Inventors

  • LENENBACH, ACHIM
  • REINACHER, Peter Christoph
  • BOCHVAROV, Lazar
  • GIESEN, Christina
  • Müller, Leo

Assignees

  • Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V.

Dates

Publication Date
20260506
Application Date
20240624

Claims (11)

  1. Patent claims 1. Stereotactic device for cutting hard tissue on the skull bone, with - a stereotactic frame (22) which is designed to be attached to the head of a patient, and - a stereotactic arch (25) which is attached to the stereotactic frame (22) via at least one rotary joint and which can be tilted over the head by the rotary joint when the stereotactic frame (22) is attached to the head of a patient, characterized in that a laser applicator (17) is attached to the stereotactic arch (25) and can be moved along the stereotactic arch (25) via a motor drive (28''), and the stereotactic arch (25) can be tilted on the stereotactic frame (22) via a further motor drive (28, 28'), wherein the laser applicator (17) has a dynamic 2D beam deflection device (11), via which a processing laser beam (2) coupled into the laser applicator (17) can be directed over an area of the hard tissue, and has a focusing optics (12) with a focus position for the coupled processing laser beam (2) that can be adjusted by the focusing optics (12) or other optical elements, and wherein a measuring device (6) is arranged in the laser applicator (17) or connected to the laser applicator (17), with which a cutting depth of a cutting gap produced with the processing laser beam (2) and a residual thickness of the skull bone (15) in the cutting gap can be measured.
  2. 2. Stereotactic device according to claim 1, characterized in that the measuring device (6) is an OCT measuring device which directs a measuring beam (7) for measuring the cutting depth and the residual thickness of the skull bone (15) coaxially to the processing laser beam (2) onto the hard tissue to be cut.
  3. 3. Stereotactic device according to claim 1 or 2, characterized in that the laser applicator (17) has a spray device with which a liquid film moistening and cooling the bone surface can be applied to the skull bone (15) during cutting.
  4. 4. Stereotactic device according to one of claims 1 to 3, characterized in that the laser applicator (17) is connected to a flexible or articulated beam guiding device (3) via which the processing laser beam (2) is coupled into the laser applicator (17).
  5. 5. Stereotactic device according to claim 4, characterized in that the beam guiding device (3) is formed by an articulated mirror arm or a fiber optic with an optical fiber.
  6. 6. Stereotactic device according to one of claims 1 to 5, characterized in that the stereotactic arch (25) has a carriage (26) which can be moved along the stereotactic arch by the motor drive (28''), on which the Laser applicator (17) is attached.
  7. 7. Stereotactic device according to claim 6, characterized in that the laser applicator (17) is attached to the carriage (26) via a detachable connection.
  8. 8. Stereotactic device according to one of claims 1 to 7, characterized in that the stereotactic frame (22) has an inner annular frame part (22') and an outer frame part (22'') which is rotatable about the inner annular frame part (22') and to which the stereotactic arch (25) is attached via the at least one rotary joint.
  9. 9. Stereotactic device according to one of claims 1 to 8, characterized in that the laser applicator (17) is attached to the stereotactic arch (25) via a motorized linear adjustment unit (27), via which the laser applicator (17) can be moved in a direction radial to the arch (25).
  10. 10. Stereotactic device according to one of claims 1 to 9, characterized in that the dynamic 2D beam deflection device (11) has a 2D scanner mirror or two 1D scanner mirrors which are designed for beam deflection in two mutually orthogonal axes of rotation.
  11. 11. Stereotactic device according to one of claims 1 to 10, characterized in that the motor drives (28, 28', 28'') which The measuring device (6) and the laser applicator (17) are connected to a control unit which controls them for cutting guidance when cutting the hard tissue on the skull bone.

Description

Stereotactic device for cutting hard tissue on the skull bone with energetic radiation Technical field of application The present invention relates to a stereotactic device for cutting hard tissue on the skull bone of a patient, which has a stereotactic frame that is designed to be attached to the patient's head and a stereotactic arch that is attached to the stereotactic frame via at least one swivel joint and that can be tilted over the head by the swivel joint when the stereotactic frame is attached to the patient's head. In neurosurgery, new therapy methods have been developed in recent years that significantly improve the quality of life and survival rate of seriously ill patients. These methods require that the patient is operated on while awake, since complex functions such as speaking must be tested during the operation. On the one hand, this concerns operations for deep brain stimulation (DBS), in which electrodes are implanted with high precision in defined target areas in the brain in order to treat complex movement disorders (e.g. Parkinson's disease, dystonia or essential tremor). Deep brain stimulation enables patients whose motor skills were so severely impaired that they became socially isolated and need care to live permanently without symptoms. Awake operations are also becoming increasingly important in the treatment of low-grade gliomas (the most common brain tumor), as it has been shown that these infiltratively growing tumors require the most extensive tumor removal possible, right up to the point of loss of brain function, in order to achieve the longest possible survival with a good quality of life. Despite the successes, the majority of patients do not have the option. Patients with severe movement disorders or a brain tumor are reluctant to undergo surgery while awake. The reason for this is the traumatic experience of drilling or milling the skull bone. This process, accompanied by immense noise and strong vibrations, is perceived as frightening and extremely stressful. State of the art The skull is currently opened during deep brain stimulation using a mechanical drill (diameter 12 mm), the rotation of which stops automatically at the point of penetration. Unfortunately, in around 10% of cases, this results in injuries to the meninges beneath the bone. In rare cases, the brain is also injured. During awake surgery for brain tumors, the skull is milled open over a large area using a hand-held milling machine (craniotomy) after a hole has been drilled. An angled metal shoe is also attached to the milling machine to protect the meninges (dura) and the brain from injury from the milling machine. Nevertheless, injuries to the meninges or even the blood vessels beneath the bone (sinus) often occur during craniotomy. Laser-assisted cutting methods are also known in the field of medical operations. For example, a system for robot-assisted osteotomy has been developed. A robot arm moves a laser head with a scanner over the bone tissue to be cut or positions it in front of the operation site in order to cut bone tissue by distributing the laser energy via the scanner. However, the robot arm and the processing head move considerable masses, so that there is a very high safety risk during operations on the head. The required precise incision on the patient's head also presents a challenge. The object of the present invention is to provide a stereotactic device for cutting hard tissue on the skull bone of a patient with energetic radiation, which device entails a lower risk of injury for the patient, ensures high cutting accuracy and enables the skull to be opened with little stress on the patient. Description of the invention The object is achieved with the device according to claim 1. Advantageous embodiments of the device are the subject of the dependent claims or can be found in the following description and the exemplary embodiment. The proposed device has a stereotactic frame which is designed to be attached to the head of a patient. A stereotactic arch in the form of an arched rail, also referred to as an aiming bar, is attached to the stereotactic frame via at least one swivel joint, which can be tilted over the head by means of the swivel joint when the stereotactic frame is attached to the patient's head, for example along the head, i.e. in the sagittal direction. The proposed device is characterized by the fact that a laser applicator is attached to the stereotactic arch and can be moved along the stereotactic arch via a motor drive. The stereotactic arch itself can also be tilted via another motor drive on the stereotactic frame. The laser applicator has a dynamic 2D beam deflection device and a focusing optics. The focus position can be adjusted via the focusing optics or other optical elements in the laser applicator. A processing laser beam coupled into the laser applicator can be guided over an area of the hard tissue to be cut with the laser beam via the 2D beam deflection