Skull clamping device for fixing and aligning a head of a patient for a medical intervention

A skull clamping device for fixing and aligning a head of a patient for a medical intervention includes a first ring element and a second ring element arranged concentrically. The second ring element is arranged within the first ring element and is connected hereto by a second axis, about which the second ring element is mounted rotatably within the first ring element. The first ring element is mounted rotatably about a first axis that is orthogonal to the second axis. The skull clamping device also includes a motor-driven drive that drives rotation of the first ring element and/or the second ring element about the respective axis, at least two pins arranged in an innermost ring element, two telescope bars that hold the first ring element and the second ring element, and a control unit for the motor-driven drive.

This application claims the benefit of DE 10 2019 200 591.8, filed on Jan. 17, 2019, which is hereby incorporated by reference in its entirety.

BACKGROUND

The present embodiments relate to a skull clamping device for fixing and aligning a head of a patient for a medical intervention and a medical imaging system.

Injuries to the cervical spine (e.g., C-spine) are particularly common after car or motorcycle accidents. In this regard, vertebrae may be damaged and fully or partially displaced and exert pressure on the spinal cord as a result. Aside from pain and malposition, in the long term, this may also cause nerve degenerations and lameness and even full paralysis. In order to prevent such aftereffects, the pressure on the spinal cord is to be relieved neurosurgically. In this regard, the affected vertebrae are realigned, and spinal fusion surgery is carried out in order to fix the vertebrae once again.

In order to relieve pressure on the spinal cord neurosurgical and to align the vertebrae, the patient is positioned face down on the operating table. The head is fixed in a Mayfield skull clamp, by which a fixed and secure fixing takes place between two sharp pins. The surgeon then pulls, rotates, and extends the head of the patient, while monitoring under fluoroscopy, until the cervical spine is in the correct position for spinal fusion surgery. In this position, the head is then fixed by the screws of the skull clamp being closed. The surgical intervention is then carried out in this fixed position.

SUMMARY AND DESCRIPTION

The present embodiments may obviate one or more of the drawbacks or limitations in the related art. For example, a skull clamping device for fixing and aligning a head of a patient, which eliminates the disadvantages of known devices, is provided.

The present embodiments describe a skull clamping device for fixing and aligning a head of a patient for a medical intervention. The skull clamping device includes at least two ring elements that may be aligned concentrically. A second ring element of the at least two ring elements is mounted rotatably about a second axis within a first ring element of the at least two ring elements. The first, outer ring element is mounted rotatably about a first axis that is orthogonal to the second axis. The skull clamping device also includes at least one motor-driven drive that drives the rotation of at least one of the at least two ring elements about a respective axis, and at least two pins that are arranged in an innermost ring element of the at least two concentric ring elements and are embodied to fix a head of a patient. The skull clamping device includes two telescope bars that hold the ring elements, and a control unit for the motor-driven actuation of the at least one motor-driven drive. A skull clamping device of this type may be used to quickly, easily, and flexibly align the head of a patient for a corresponding intervention in at least two degrees of freedom (e.g., directions of rotation) without the physician having to carry out a time-consuming and laborious manual alignment while illuminating under fluoroscopy. Pressure is therefore taken off the physician and both the physician, and the patient is protected from long and unnecessary x-ray irradiation. The alignment may be carried out in a motor-driven or even automatic manner and minimizes health risks to the patient and physician.

According to one embodiment, the second ring element is the innermost ring element.

According to a further embodiment, the two telescope bars are held on both sides of the first ring element by two brackets so that the first ring element is arranged rotatably about the first axis. An additional degree of freedom or an additional adjustability for the skull clamping device is available on account of the ability of the telescope bars to retract and extend.

According to a further embodiment, the skull clamping device has a third ring element that is alignably arranged concentrically herewith within the second ring element and is connected rotatably with this by a planetary gear. The third direction of rotation is also covered in this way, and the head of the patient may be adjusted in at least three degrees of freedom (e.g., angles of rotation). A planetary gear represents a simple but effective possibility of realizing a third degree of freedom in addition to the two existing degrees of freedom. Four degrees of freedom are possible overall in combination with the adjustable telescope bars.

Alternatively, in a further embodiment, the skull clamping device has a third ring element that is alignably arranged concentrically herewith within the second ring element and is mounted rotatably about a third axis. The third axis is orthogonal to the second axis. This corresponds to a universal mounting and is a further option of easily realizing a third degree of freedom.

For an adjustability in at least three degrees of freedom, the third ring element may be the innermost ring element.

According to a further embodiment, the rotational movements of all ring elements may be motor-driven. In this way, a time-consuming and laborious manual alignment while illuminating under fluoroscopy by the physician is no longer necessary, and the operative intervention may be carried out more quickly and with less risk to the patient and physician. In this way, for an independent adjustment in each of the degrees of freedom, at least one motor-driven drive may be provided for each rotational movement. In one embodiment, a motor-driven drive is also provided to operate the telescope bars.

According to a further embodiment, the control unit is configured to control all available motor-driven drives. In this way, the overall movement of the skull clamping device may be actuated by a single control unit. The control unit may be connected to the device by cable or wirelessly, for example.

According to a further embodiment, the skull clamping device has three or four pins. The three or four pins are arranged in the innermost ring element of the at least two ring elements and are embodied to fix a head of a patient. A significantly more stable fixing of the head of the patient is possible by the one or two additional pins. As a result of this, the risk of injury to the patient by slipping out of the skull clamping device is minimized.

For a particularly stable and anti-slip fixing of the head of the patient, the skull clamping device has a chin guard for additionally holding the head of the patient.

According to a further embodiment, the skull clamping device is configured to be connectable with a patient couch using the telescope bars. In this way, the device is stationary relative to the patient couch. In this way, the risk of injury to the patient is minimized, and a high-quality fluoroscopic imaging by ruling out motion artifacts is provided.

According to a further embodiment, the control unit has a checking unit (e.g., a user interface) for users to input control commands for the motor-driven rotation of the ring elements about corresponding axes. The input rotations are then implemented by the respective drives. The speed of the rotational movement may, for example, be preset or likewise adjusted. The checking unit provides simple operation of the rotations of the ring elements. The checking unit is configured for a particularly simple, rapid, and intuitive operation in that the checking unit has at least three degrees of freedom for operation purposes. A rotational movement about an axis is assigned to each degree of freedom. This may be provided, for example, so that the operating element may be adjusted mechanically even in three degrees of freedom (e.g., in the manner of a joystick).

The present embodiments also include a medical imaging system for recording a three-dimensional (3D) volume image of a patient mounted on a patient couch with a control system, to which a skull clamping device of the present embodiments is assigned.

According to one embodiment, the control system is embodied to determine a proposal for adjusting and/or aligning the ring elements of the skull clamping device from a volume image of a spinal column of a patient with his/her head fixed by the skull clamping device. This may be implemented automatically or semi automatically, for example, after inspection by the physician by the control unit actuating the adjustments of the ring elements and/or the telescope bars, and carrying the adjustments out accordingly.

DETAILED DESCRIPTION

FIG.1shows one embodiment of a skull clamping device1with two ring elements, a first ring element2and a second ring element3. Two pins6for fixing a head of a patient are arranged in an innermost ring element of the two ring elements, the second ring element3. The first ring element2is arranged rotatably about a first axis A1, where for this purpose, the first ring element2is fastened by two bearings21to brackets9, respectively. The two brackets9, which are arranged in symmetry on both sides of the first ring element2, are connected to extendible telescope bars7. The second ring element3is arranged within the first ring element2and is connected hereto via two bearings21, so that the second ring element may be rotated about a second axis A2.

A motor-driven drive5is assigned to each bearing21. The motor-driven drive5effects a motor-driven rotation of the respective ring element. The first ring element2may therefore be rotated about the first axis A1by two motor-driven drives5, and the second ring element3may be rotated about the second axis A2likewise by two motor-driven drives5. The two motor-driven drives5, which are assigned to an axis, may be actuated in synchrony, for example. Only one motor-driven drive may also be present per axis. Motor-driven drives5may also be present for operating the telescope bars7, as also shown inFIG.1. A control unit8(e.g., a controller) that is embodied to actuate the motor-driven drives5is assigned to the skull clamping device1. The control unit8is either connected to the skull clamping device or the motor-driven drives5by a connecting line or wirelessly, so that simple and rapid actuation is provided. Provision may also be made for the control unit to be integrated in the skull clamping device1(e.g., in the region of the telescope bars7). The control unit8may be operated by a checking unit16, for example. Details relating to an embodiment of a checking unit16are shown inFIGS.5and6.

FIG.2shows an exemplary skull clamping device1fromFIG.1in a lateral view and rotated by 90° compared withFIG.1about the axis A1. The skull clamping device1has a chin guard14and is connected to a patient couch12. The head11of a patient10is clamped into the skull clamping device1with the aid of the pins6, where the chin guard14also stabilizes the connection. As already shown inFIG.1, the first ring element2may be rotated about the first axis A1, the second ring element3may be rotated about the second axis A2, and the telescope bars7may be retracted and extended. The skull clamping device1may be used to adjust the position of the head11of the patient10for an intervention on a cervical vertebra13of the patient10in a rapid manner that is gentle on the patient and simple for the physician.

A further skull clamping device1that has three ring elements is shown inFIG.3. The first ring element2is suspended rotatably about a first axis A1, similarly to inFIGS.1and2between two telescope bars7and two brackets9. The second ring element3is arranged rotatably about the second axis A2in the inside of the first ring element2and concentrically hereto by two further bearings21. The first axis A1and the second axis A2are orthogonal to one another so that the first axis A1and the second axis A2cause the head of the patient to tilt in two different directions. A third ring element4is arranged inside the second ring element3and is connected to the second ring element3via a planetary gear so that the third ring element4may be rotated about a third axis A3that is orthogonal to both of the other axes. For greater clarity, only two motor-driven drives5are shown; however, at least one motor-driven drive may be available for each axis.

Planetary gears are generally known. The planetary gear shown may, for example, be implemented so that the second ring element3(corresponding to the hollow wheel) has teeth on an inner periphery, and the third ring element4(correspondent to the sun wheel) likewise has teeth on an outer periphery. A number of likewise toothed small planetary wheels22(e.g., three or four planetary wheels22) are arranged between the two ring elements. The third ring element4may be rotated about the third axis A3by at least one motor-driven drive (not shown here). If the head11of the patient10is clamped between the pins6, the head11may be positioned in three different rotational directions for an intervention by rotating the three ring elements. The axes may be embodied, for example, so that the rotation about the first axis A1corresponds to a raising or lowering of the chin of the head, the rotation about the second axis A2corresponds to a rotation of the head, and the rotation about the third axis A3corresponds to a manner of shaking the head to the right or left. In addition, the telescope bars7may also be retracted and extended, thereby causing a stretching or compression of the spinal column to materialize.

The positioning of the head may be carried out semi automatically or automatically by the motor-driven drives, which may be available for each of the three axes. The drives are actuated by the control unit8, which may be operated by a user interface16(not shown).

In order to avoid interfering artifacts with fluoroscopic illumination of the head, the skull clamping device is manufactured at least partially from an x-ray transparent material. At least the ring elements may be x-ray transparent and are produced from carbon fibers, for example. The motor-driven drives5may also have metallic elements. The entire skull clamping device may also be embodied from x-ray transparent material. The arrangement of the telescope bars at the height of the table top allows a largely artifact-free x-ray imaging of the cervical spine.

FIG.4shows a further alternative of a skull clamping device with three ring elements. InFIG.4, the three ring elements are universally mounted (e.g., the third ring element4is arranged alignable concentrically herewith within the second ring element3and mounted rotatably about the third axis A3). The third axis A3is orthogonal to the second axis A2.

The skull clamping devices shown inFIGS.3and4have four degrees of freedom, three angles of rotation (e.g., rotation of the ring elements about the respective axis) and a longitudinal setting (e.g., deflect telescope bars).

An exemplary checking unit16is shown inFIGS.5and6and is configured for an intuitive actuation of the skull clamping device. The checking unit16therefore includes, for example, a rotary disk20. The user is able to turn the rotary disk20in a first movement B1with thumbs and index fingers using operating holes19in order to adjust the skull clamping device. The rotary disk20may have a scale18to display the gradual adjustment, for example. A second movement B2corresponds to a tilting of the rotary disk20, and a third movement B3corresponds to a pushing/pulling of the rotary disk20. Operation of the checking unit16is then transferred by the control unit8to the skull clamping device1, and the motor-driven drives5bring about a corresponding adjustment of the ring elements and/or the telescope bars. In this way, the position of the head of the patient is adjusted quickly but gently and with minimal effort for the user. The precision and sensitivity of the possibilities for adjustment by the checking unit may be smaller than 1 mm and smaller than 1 degree.

Other types of checking units may also be provided for operation by a user in order to actuate the skull clamping device. An input menu on a touch-sensitive monitor may therefore also be easily available, via which it is possible to input angles of rotation for the rotation about the axes A1, A2, and A3and to input lengths for deflecting the telescope bars.

The user may use a monitor17to monitor the settings. The current settings of the skull clamping device may be shown on the monitor17(e.g., the three angles of rotation (rotation of the ring elements about the respective axis) and a length setting (deflect telescope bars)).

Provision may be made to regulate the speed of the adjustments or to define threshold values for the angle of rotation, the speed, or the deflection that may not be exceeded. These may either be defined by the user or may already be available as a basic setting. As a result, this may prevent an excessively fast or broad adjustment, so as not to injure the patient. Haptic feedback (e.g., in the form of a vibration) may be available in order to indicate to the user when a threshold value (e.g., an angle of rotation) is reached. Alternatively, optical or acoustic warning signals (e.g., yellow/red light) or displays may also be available in order to point the user to the exceeding of threshold values or signal other warnings. Safety requests or safety cut-outs may also be provided when threshold values are exceeded.

FIG.7shows one embodiment of a medical imaging system30for recording x-ray images of a patient10supported on a patient couch. A skull clamping device1is assigned to the imaging system30. The imaging system30may be, for example, a C-arm x-ray system with an adjustable C-arm31and an x-ray source32and an x-ray detector33held on the adjustable C-arm31. The imaging system30may be embodied, for example, for a fluoroscopic imaging (e.g., 2D fluoroscopy) and/or for a 3D imaging. The imaging system is actuated by a control system34. The patient10is supported on a patient couch12, and the head11of the patient10is fixed by the skull clamping device1. The patient and the imaging system are located in a hybrid operating room (hybrid OP), for example. The user interface16for the user to input control commands may be arranged inside or outside of the operating theater. Provision may be made to arrange the user interface16close to the patient couch and in addition behind a lead screen.

A display unit35assigned to the imaging system35shows, for example, a current x-ray recording of the spinal column and/or of the head of the patient (e.g., in the lateral view (side view)). Various views may be indicated with a biplanar imaging system. The imaging system may alternatively also be formed by a computed tomography system or a magnetic resonance tomography system.

An alignment of a head of a patient for a medical intervention generally takes place such that the cervical spine is extended, and the inclinations are then adjusted so that the bodies of vertebrae move into a suitable position that is required for strengthening the spinal column. This may likewise be carried out with the skull clamping device shown by a lengthening of the telescope bars firstly being actuated and the rotations then being carried out about the axes.

The imaging system shown inFIG.7may be used to record a 3D volume image of the cervical spine and/or the head of the patient10(e.g., by the C-arm31being adjusted in a number of angulations, a plurality of x-ray projections being recorded, and these then being reconstructed to form the volume image). The control system34is embodied to determine a proposal for adjusting and/or aligning the ring elements and/or telescope bars of the skull clamping device from the volume image. A calculation unit or software may also be provided herefor. In order to determine such a proposal, further information may also be used (e.g., information about the planned intervention on the cervical spine, which cervical vertebra the planned intervention should involve, further information about the patient, databases relating to similar interventions, etc.).

If a proposal exists, this may be confirmed or rejected by a physician, for example. If the proposal is confirmed or implemented without confirmation, the proposal may then therefore be transferred to the control unit8and implemented there automatically or semi automatically by the control unit8of the skull clamping device actuating the adjustments of the ring elements and/or the telescope bars and carrying them out accordingly.

The present embodiments have a series of advantages. With skull clamping devices from the prior art, which have no motor-driven drives, the physician is to position the head of the patient manually; this expends effort and time. This usually takes place under fluoroscopy and may last 20 to 30 minutes. In doing so, the physician is to be prudent not to injure the patient. Using the motorized, actuatable and remotely-operable skull clamping device of one or more of the present embodiments, the positioning is significantly simplified, may be carried out more quickly and gently, requires less effort, and is associated with fewer risks to the patient. A dose saving is also to be expected for both the patient and also the physician, since persons are no longer radiated with direct x-ray radiation. Health risks are therefore reduced.

One or more of the present embodiments may be summarized as follows. A skull clamping device is provided for a particularly simple and rapid positioning of a head of a patient for interventions on the cervical spine. The skull clamping device includes at least two ring elements that may be aligned concentrically. The second ring element is mounted rotatably about a second axis within the first ring element, and the first, outer ring element is mounted rotatably about a first axis that is orthogonal to the second axis. At least one motor-driven drive drives the rotation of at least one of the at least two ring elements about a respective axis. At least two pins are arranged in the innermost ring element of the at least two concentric ring elements and are embodied to fix a head of a patient. Two telescope bars hold the ring elements, and a control unit is configured for the motor-driven actuation of the at least one motor-driven drive.