WO2021118454A1

WO2021118454A1 - Spinal fixation device

Info

Publication number: WO2021118454A1
Application number: PCT/SG2019/050613
Authority: WO
Inventors: Sanjay AMARASINGHE; Srihari DEEPAK
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-12-13
Filing date: 2019-12-13
Publication date: 2021-06-17
Anticipated expiration: 2022-06-13

Abstract

The present application provides a spinal fixation device (100) which comprises a first receptacle comprising a drill system for performing an osteotomy process, a second receptacle comprising a pedicle advancer system for performing a pedicle tract preparation process, a third receptacle comprising a pedicle screw system for performing a spinal fixation process, and a central motor (104) for automatically controlling the first receptacle, the second receptacle and the third receptacle. Methods of making and using the Spinal Fixation Device are also proposed in the present application.

Description

SPINAL FIXATION DEVICE

[0001] The present application relates to a Spinal Fixation Device, as well as methods for making and/or using the spinal fixation device. The spinal fixation device is alternatively known as spinal fixation device, spinal fixer, automatic spinal fixation device, spinal drill screwdriver or automated spinal fixation device.

[0002] Known spinal fixation tools are developed with several advantageous aspects: reducing surgical operation time, minimising morbidity of patients, reducing complication rates, minimising scarring, reducing severity and length of postoperative pain. As a result, analgesic requirements are reduced, expedited patient recovery and shorten length of hospital stay are achieved with assistance of the known spinal fixation tools. In recent years, robots are introduced and integrated with some of the known spinal fixation tools. However, introduction or integration of the robots generally requires radiating imaging technologies such as Computed Tomography (CT) scanning for placing fixation screws into spines accurately. Radiating imaging technologies typically cause radiation, which can be harmful to the patients. In addition, known robots or medical robots are usually cumbersome to operate due to numerous components for manual operation, especially during spine surgery. Therefore, the present patent application aims to provide a spinal fixation device and its relevant methods in order ease, simplify and optimise the accuracy and safety of spinal fixation operations.

[0003] As a first aspect, the present application discloses a Spinal Fixation Device for being held by a surgical arm (e.g. robotic arm). The Spinal Fixation Device comprises a pedicle screw preparation system and a pedicle screw insertion system. The pedicle screw preparation system and the pedicle screw insertion system are integrated as a unitary tool. The pedicle screw preparation system comprises a driller for making (e.g. boring, cutting) a recess or cavity in a facet joint articular process and a pedicle advancer for creating a tract for a pedicle screw. The pedicle screw insertion system comprises a drive mechanism connected to the driller and the pedicle advancer for propelling driller and the pedicle advancer independently. The drive mechanism may be manipulated either manually or automatically whenever necessary. The driller and pedicle advancer are also known as a pedicle screw preparation system, whilst the pedicle screwdriver is also known as a pedicle screw insertion device. The Spinal Fixation Device effectively integrates the pedicle screw preparation system and the pedicle screw insertion device together as a unitary tool or a single instrument.

[0004] The Spinal Fixation Device may be held by a surgical arm (e.g. robotic arm). A first receptacle (such as a first drum) is configured in a driller (also known as drill system) for performing an osteotomy process (such as a facet joint osteotomy process or a facetectomy process), a second receptacle (such as a second drum) is configured in a pedicle advancer (also known as pedicle advancer system) for performing a pedicle tract preparation process, a third receptacle (such as a third drum) is configured in a drive mechanism (also called pedicle screw system) for performing a pedicle screw insertion/placement process, and a central motor for automatically controlling the first receptacle, the second receptacle and the third receptacle. As a result, the drill system, the pedicle advancer system, and the pedicle screw system are all integrated into the Spinal Fixation Device. Driven by the central motor, the drill system, the pedicle advancer system, and the pedicle screw system are switched by rotating the first receptacle, the second receptacle and the third receptacle, in sequence. In addition, the Spinal Fixation Device may comprise an enclosure for encapsulating the first receptacle, the second receptacle, the third receptacle, the central motor and other additional components. The enclosure may have any shape (such as a cylindrical shape) suitable for a spinal fixation operation. Accordingly, the first receptacle, the second receptacle and the third receptacle may also have a cylindrical shape as the first drum, the second drum and the third drum for being fitted into the cylindrical enclosure.

[0005] The Spinal Fixation Device optionally comprises a housing (e.g. main body) that encloses, supports and holds the first receptacle, the second receptacle, the third receptacle and the central motor in order to rotate all components simultaneously along one axis and preventing any interference from an external environment. The housing or main body can have exterior features (e.g. slots, screw holes) or fixtures (e.g. jig, anchor) for holding a position or an orientation of the Spinal Fixation Device by the surgical arm, whether idling or in operation. Particularly, the Spinal Fixation Device can be supported by a robotic arm or holder at the exterior features or fixtures so that the drill system, the pedicle advancer system and/or the pedicle screw system are able to be operated in accuracy, consistency and reliability. The surgical arm comprises a robotic arm, which is a subsystem or component of a robotic guidance platform, a robotic guidance system or surgical assurance platform for spine surgery. The robotic guidance platform combines advanced software, robotic technology, navigation, and instrumentation to help surgeons to deliver high-quality care and supports a commitment to accurate and precise trajectory guidance for their spine surgical procedures. Embodiments of the application provides that the Spinal Fixation Device is held rigidly by the robotic arm and other accessory adjuncts are rigidly affixed to a patient’s skeletal anatomy during spine surgery, ensuring precision and consistency through a secure, robust and solid connection.

[0006] The Spinal Fixation Device may comprise a central disc for attaching the first receptacle, the second receptacle and the third receptacle respectively. The central disc is required to have a suitable size and shape for being better fitted into the enclosure. For example, the central disc has a cylindrical shape when a cylindrical enclosure is adopted; and the central disc has a slightly smaller diameter than that of the cylindrical enclosure. The central disc is also attached to the central motor for transferring motion of the central motor to the first receptacle, the second receptacle and the third receptacle. In addition, the Spinal Fixation Device optionally comprises a central axis, one end of which is connected to the central motor and the other end is connected to the central disc. The central motor and the central disc are placed far away from each other inside the enclosure. Therefore, the first receptacle, the second receptacle and the third receptacle are automatically switched by rotating the central motor via the central disc and the central axis during the spinal fixation operation.

[0007] The first receptacle optionally comprises a first motor for automatically driving the drill system to move (such as advance or retract) along a first axis along a first port. Similarly, the second receptacle optionally comprises a second motor for automatically driving the pedicle advancer system to move (such as advance or retract) along a second axis along a second port; while the third receptacle optionally comprises a third motor for automatically driving the pedicle screw system along a third axis along a third port. The first motor, the second motor and the third motor are configured to be attached to a first disc (such as a first cylindrical disc) of the first receptacle, a second disc (such as a second cylindrical disc) of the second receptacle and a third disc (such as a third cylindrical disc) of the third receptacle, respectively. In particular, the first motor, the second motor and the third motor may work independently for manipulating the drill system, the pedicle advancer system and the pedicle screw system with minimum interference to each other.

[0008] In the Spinal Fixation Device, the first receptacle comprises a first motion transmission mechanism for transmitting a first motion of the first motor to the drill system; the second receptacle comprises a second motion transmission mechanism for transmitting a second motion of the second motor to the pedicle advancer system; and the third receptacle comprises a third motion transmission mechanism for transmitting a third motion of the third motor to the pedicle screw system. Since the first motor, the second motor and the third motor work independently, the first motion transmission mechanism, the second motion transmission mechanism and the third motion transmission mechanism also work independently for minimum interference to each other.

[0009] The first motion transmission mechanism optionally comprises a first gear arrangement for precisely controlling the drill system. The first gear arrangement may further comprise a first driving gear configured to be connected to and driven by the first motor, a first driven gear configured to mesh the first driving gear, and a first worm (also known as worm gear) configured to be driven by the first driven gear.

[0010] In some implementations, the first driving gear comprises a plurality of first driving cogs; and the first driven gear comprises a plurality of first driven cogs meshing the first driving cogs and the first worm. In other words, the first driven gear and the first worm consist of a first worm drive; and the first driven gear is also called a first worm gear or a first worm wheel. The first worm optionally comprises a plurality of worm teeth linearly arranged on the worm for meshing the first driven cogs of the first worm gear. According to the first driving cogs of the driving gear, the first worm gear optionally comprises a non-throated worm gear, a single-throated worm gear or a double-throated worm gear. Therefore, the drilling system has a drilling speed controlled by the first motor which drives the first worm to move linearly via the first driving gear and the first driven gear.

[0011] The first worm may be detachable coupled to the first axis approximate to the first port of the first receptacle. Thus, the first worm moves along the first axis in and out of the first receptacle along the first port. In the design, the first axis should be long enough for the osteotomy process. Alternatively, when the first axle is made shorter than a required length, the first worm may be either detachably or permanently attached to a first worm shaft. The first worm shaft is detachably attached to the first receptacle for fulfilling the osteotomy process to the required length. For example, the first worm shaft is further detachable coupled to the first axis and thus the first drilling system is extended by the first worm draft. The first worm shaft optionally has various designs for meeting different osteotomy processes.

[0012] The drill system comprises at least one drill bit approximate to the first worm. The drill bit is used as a cutting tool for removing a portion of the facet joint to create a recess or cavity in the facet joint (i.e. shaved facet joint) at the starting point of the trajectory. The drill bit has a flexible geometry comprising a range of characteristics such as a spiral (or a rate of twist) for controlling a drilling rate, a point angle (or an angle formed at a tip of the drill bit) determined by the facet joint, a lip angle for determining an amount of support provided to a cutting edge of the drill bit, and a length for determining a depth of the hole. The drill bit may be made of any material suitable for drilling the facet joint, such as steel, tungsten carbide, or polycrystalline diamond (PCD). The drill bit may further comprise a coating for encapsulating the material. The coating is biologically compatible with the joint facet and thus would not induce any rejection between the Spinal Fixation Device and the patient. In addition, the drill bit may also be detachably attached to the worm approximate to the first port such that the drill bit is changeable for meeting various requirements of different osteotomy processes.

[0013] The second motion transmission mechanism optionally comprises a second gear arrangement further comprising a second driving gear configured to be connected to and driven by the second motor; and a second linear actuator configured to be driven by the second driving gear. The second linear actuator translates a rotational motion of the second driving gear into a linear motion of the pedicle feeler.

[0014] In some implementations, the second linear actuator comprises a spoke wheel such as a circular gear (or a pinion) configured to mesh the second driving gear; and a gear rack for meshing the spoke wheel. For example, the second driving gear comprises a plurality of second driving cogs; while a circular gear as the spoke wheel comprises a plurality of pinion cavities for conjugating the second driving cogs and a plurality of pinion cogs. Meanwhile, the gear rack also comprises a plurality of rack teeth linearly arranged for meshing the pinion cogs of the circular gear. Therefore, the pedicle advancer system has an advancing speed controlled by the second motor which drives the gear rack to move linearly via the second driving gear and the second linear actuator.

[0015] The pedicle advancer system of the second receptacle may comprise a pedicle feeler for forming a pedicle tract along a planned trajectory. The pedicle feeler may be configured to be integrated with a non-radiating imaging mechanism for creating an image of an internal body structure. In this way, the non-radiating imaging mechanism may provide a real-time position of the pedicle feeler when the non-radiating mechanism is small enough in size to be inserted into the pedicle tract. Particularly, the non-radiating mechanism comprises ultrasonography imaging technologies such as an ultrasonic probe for providing an ultrasonographic guidance of the pedicle feeler. Pulses of ultrasound are firstly sent from the ultrasonic probe and propagate through the cancellous tissue to the pedicle cortex; and reflected back to the ultrasonic probe. In addition, other non-radiating imaging mechanisms such as optical imaging technologies or photo-thermal imaging technologies may be also adopted individually or combined collectively with the ultrasonography imaging technologies. It is noted that the modelling of the real-time trajectory with the planned trajectory and revision of any skewed path can be performed by complex computational algorithms.

[0016] The pedicle feeler may have a linear structure comprising a shaft and a tip attached on one end of the shaft. In some implementations, the ultrasonic probe has a larger dimension for accommodating a transducer of 3.5 millimetres (mm) in diameter. For example, the ultrasonic probe has a diameter of 3.5 millimetre (mm). Therefore, the ultrasonic probe may be integrated into the shaft and optionally located proximal to the tip of the pedicle feeler. Aa a result, the ultrasonic probe also enters into the trajectory for providing a real-time and precise position of the pedicle feeler, when the pedicle feeler is inserted into the trajectory.

[0017] The ultrasonic probe optionally comprises one or more ultrasonic transducers. The ultrasonic transducer converts an electrical signal to and from an ultrasonic signal through a transduction process. The transducer may comprise one or more transmitters (or emitters) for transmitting the ultrasonic signal; and one or more receivers for receiving a reflected ultrasonic signal. The reflected ultrasonic signal is generated by a reflection of the ultrasonic signal on a pedicle cortex in the propagating direction. Alternatively, the transducer may comprise one or more transceivers for fulfilling the functions of both the transmitter and the receiver. The transducer may also comprise a combination of the transmitter/receiver and the transducer. In addition, the ultrasonic probe may be operated in several modes for the ultrasonography imaging technologies, such as an amplitude mode (A-mode) for detecting a depth of the trajectory, or a brightness mode (B-mode) for constructing two-dimensional (2D) images.

[0018] In some implementations, the ultrasonic probe comprises a first ultrasonic transducer and a second ultrasonic transducer. The first ultrasonic transducer and the second ultrasonic transducer are optionally arranged in a back-to-back configuration for producing a 360-degree visualization of pedicle cortex surrounding the pedicle feeler.

[0019] The ultrasonic transducer of the ultrasonic probe optionally comprises a plurality of piezo-electric elements for converting an electrical energy into a sound energy and vice versa. A spatial resolution of the image is thus determined by the piezo-electric elements to distinguish between two points at a particular depth in the internal body structure. The spatial resolution consists of an axial resolution (also known as a longitudinal resolution) measuring a minimum distance differentiated between two reflectors parallel in the propagating direction of the ultrasound; while a lateral resolution measuring a minimum distance differentiated between two reflectors perpendicular in the propagating direction of the ultrasound. The axial resolution is determined by a number of cycles in a single pulse of ultrasound and a wavelength (i.e. frequency) of the ultrasound. Thus, the axial resolution is enhanced when the number of cycles is reduced by a damping effect of the piezo-electric elements and/or when the ultrasound has a higher frequency. However, with increasing depth, the pulses of high-frequent ultrasound tend to be attenuated or absorbed more by a soft tissue. Therefore, the ultrasound has a limited range for a frequency or a wavelength in order to improve the axial resolution of the image of the internal body structure. In particular, the range of frequency for the pedicle cortex adopted depends on the patient’s individual characteristics of cancellous tissue density and distance to the cortex. From research evidence, this can range from 2-2.5MHz for a 3.5mm transducer. [0020] In some implementations, the ultrasonic probe optionally comprises a backing material located opposite and lateral to the ultrasonic transducer for dampening vibrations of the ultrasonic transducer. Hence, the damping effect of the backing material improves the axial resolution.

[0021] The ultrasonic probe may have a flexible design in relation to a number, a shape and a position of the ultrasonic transmitter. In some implantations, the ultrasonic probe comprises a first concave ultrasonic transmitter for transmitting a first ultrasonic signal in a cranial direction; and a second concave ultrasonic transmitter for transmitting a second ultrasonic signal in a caudal direction. The second concave ultrasonic transmitter is positioned distal to (such as substantially opposite to) the first concave ultrasonic transmitter.

[0022] In some implementations, the ultrasonic probe comprises a third concave ultrasonic transmitter for transmitting a third ultrasonic signal in a medial direction; and a fourth concave ultrasonic transmitter for transmitting a fourth ultrasonic signal in a lateral direction. The fourth concave ultrasonic transmitter is positioned distal to (such as substantially opposite to) the third concave ultrasonic transmitter.

[0023] In some implementations, the ultrasonic probe comprises a first concave ultrasonic transmitter for transmitting a first ultrasonic signal in a cranial direction; a second concave ultrasonic transmitter for transmitting a second ultrasonic signal in a caudal direction; a third concave ultrasonic transmitter for transmitting a third ultrasonic signal in a medial direction; and a fourth concave ultrasonic transmitter for transmitting a fourth ultrasonic signal in a lateral direction. The second concave ultrasonic transmitter is positioned distal to (such as substantially opposite to) the first concave ultrasonic transmitter; while the fourth concave ultrasonic transmitter is positioned distal to (such as substantially opposite to) the third concave ultrasonic transmitter.

[0024] The pedicle feeler comprises a safety mechanism for preventing a cortical breach during the pedicle tract preparation process. The rate of linear advancement of the pedicle feeler along a planned trajectory is determined by the magnitude of force-torque required to drive the feeler. When a pedicle cortex is approached or reached, the resistance at the tip of the pedicle feeler increases. In order to overcome this resistance and maintain the same rate of advancement, the force torque required must increase. Hence, when a pedicle cortex is about to be breached, the increased force torque required will provide indication of an inherent cortical breach, thereby prompting the operator to revise the current trajectory. The revision (i.e. revising) process can hinder detection of these changes as it may brush the facet joint entry point. In order to avoid this a smooth linear pedicle feeler advancement avoids this. In order to compensate for the revision process, a self-tapping screw or pedicle feeler with a short segment along its shaft for revision can be used. Overall, this indirect pressure-sensing safety mechanism facilitates and optimises the accuracy of pedicle screw placement in the spinal fixation process.

[0025] In some implementations, the safety mechanism comprises a pressure sensing mechanism such as a pressure sensor located at the tip of the pedicle feeler.

[0026] In some implementations, the pressure sensor is small enough in size such that the pressure sensor may also be integrated into the pedicle probe. Therefore, the pressure sensor and the ultrasonic probe are both inserted into the pedicle with the pedicle feeler such that the ultrasonographic technology and the pressure-sensing technology are combined for the spinal fixation process.

[0027] The third motion transmission mechanism comprises a third gear arrangement further comprising a third driving gear configured to be connected to and driven by the third motor; a third driven gear configured to mesh the third driving gear; and a third worm configured to be driven by the third driven gear.

[0028] In some implementations, the third driven gear further comprises a first cogwheel configured to mesh the third driving gear; a second cogwheel configured to mesh the third worm; and a third gear handler configured to connect the first cogwheel and the second cogwheel such that the first cogwheel, the second cogwheel and the third gear handler move (such as rotate) as a whole. As a result, the second cogwheel is driven by the third gear handler which is further driven by the first cogwheel of the third driven gear.

[0029] The pedicle screw system further comprises at least one pedicle screw detachably attached to the third worm. The pedicle screw may be detachably attached directly to an end of the third axis of the third receptacle. Alternatively, the pedicle screw may be detachably attached to the third worm of the third motion transmission mechanism. The pedicle screw is optionally advanced out of the third receptacle and initially docked onto the facet joint before being driven into the pedicle tract and the vertebral body. The pedicle screw is then fully purchased when reaching a pre determined position accurately. The pedicle screw is finally disengaged from the pedicle screw system of the third receptacle. The pedicle screw should be firmly and steadily fixed such that the pedicle screw cannot be forcibly removed after fixation. In some implementations, the pedicle screw comprises a self-tapping screws that may tap the pedicle tract as it is driven into the pedicle.

[0030] The ultrasonic probe optionally comprises one or more internal wiring cables configured to communicate with a computing device for transmitting the reflected ultrasonic signal to the computing device. The internal wiring cables optionally comprises one or more networking cables, such as twisted pair cable (e.g. unshielded twisted pair (UTP) cable, and shielded twisted pari (STP) cable), coaxial cable, fiber optic cable, universal series bus (USB) cable, serial and parallel cable, crossover cable, patch cable or power line. The computing device may accordingly comprise a local computing device, such as a personal computer, a mainframe computer, a laptop computer, a tablet computer, a desktop computer; or a remote computing device such as a rackmount server, a router computer, a server computer, a mainframe computer. Alternatively, the reflected ultrasonic signal may be wirelessly communicated to the local computing device or the remote computing device, such as radio frequency identification, cellular communication, Wi-Fi, or Bluetooth.

[0031] The Spinal Fixation Device may comprise a warning apparatus or alarm apparatus configured to communicate with the computing device for sending a warning signal when the reflected ultrasonic signal changes beyond a reference range. The warning apparatus optionally sends out an audible, visual or other forms of the warning signal to an operator of the Spinal Fixation Device. Meanwhile, the warning apparatus may also suspend any operation of the Spinal Fixation Device until an error causing the warning signal has been cleared or solved.

[0032] The Spinal Fixation Device optionally comprise one or more sensors connected to the driller, the pedicle advancer or both for detecting operation parameters (e.g. speed, distance or force) of the Spinal Fixation Device. The operation parameters are either manually or automatically adjusted for the Spinal Fixation Device.

[0033] The Spinal Fixation Device optionally comprises one or more control terminals for connecting to an external control device through cables/wires or wirelessly. The control terminal may comprise a communication terminal (e.g. terminal block, USB port, Ethernet port, wired/wireless terminal, Bluetooth) for communicating sensor data of the Spinal Fixation Device to the external control device. The control terminal further optionally comprises a power terminal configured to be affixed on the housing for receiving external power supply in order to drive the central and receptacle motors.

[0034] The auto mated fixation device may comprise an ultrasound-guided probe, a pressure sensing mechanism (e.g. pressure or force sensor) or both for guiding movement of the automated fixation device. In some implementations, the ultrasound- guided probe is integrated with the pedicle feeler.

[0035] As a second aspect, the present application discloses a robotic guidance platform for spine surgery or spinal fixation surgery. The robotic guidance platform optionally comprises an imaging system for visualizing spine anatomy of a patient; a display screen configured to be connected to the imaging system for showing images of the spine anatomy of the patient; a control unit configured to be connected to the imaging system and the display screen for controlling; a robotic arm (also known as surgical arm) further configured to be connected to the control unit for operating the robotic arm; and the Spinal Fixation Device. The Spinal Fixation Device is optionally detachable from the robotic arm.

[0036] In some implementations, the control unit having a computer memory is configured to track (e.g. record) positions of its components or instruments (e.g. Spinal Fixation Device) during a spinal surgery in relation to the surgical anatomy and identifies this position on diagnostic or intraoperative images of a patient.

[0037] The robotic guidance platform may also comprise a communication unit that is connected to the control unit for transmitting data between the robotic guidance platform and an external or remote computer. [0038] As a third aspect, the present application discloses a method of making the Spinal Fixation Device. The method of making the Spinal Fixation Device comprises a first step of providing a pedicle screw preparation system comprising a driller configured in a first receptacle and a pedicle advancer in a second receptacle; a second step of providing a pedicle screw insertion system comprising a drive mechanism in a third receptacle; and a third step of integrating the pedicle screw preparation system and the pedicle screw insertion system into a unitary tool. The method of making may further comprise a step of providing a central motor for automatically controlling the first receptacle, the second receptacle and the third receptacle; and a step of integrating the first receptacle, the second receptacle and the third receptacle with the central motor together.

[0039] The method of making optionally comprises a step of providing a central disc (such as a cylindrical central disc); and a step of attaching the first receptacle, the second receptacle and the third receptacle to the central disc.

[0040] The method of making optionally comprises a step of firstly installing a pedicle feeler to the pedicle advancer system; and then installing a non-radiating mechanism (such as an ultrasonic probe) inside the pedicle feeler.

[0041] The method of making optionally comprises a step of installing a safety mechanism (such as a pressure sensing mechanism) to the pedicle feeler. The pressure sensing mechanism may be either embedded inside the pedicle feeler or attached outside the pedicle feeler.

[0042] The method of making optionally comprises a step of providing a first motor to the first receptacle for automatically managing (such as advancing or retracting) the drill system by a first axis along a first central port; a step of providing a second motor for automatically managing (such as advancing or retracting) the pedicle advancer system by a second axis along a second central port; a step of providing a third motor for automatically managing (such as advancing or retracting) the pedicle screw system by a third axis along a third central port; and a step of attaching the first motor, the second motor and the third motor to the central disc;. The first motor, the second motor and/or the third motor is configured to operate independently from each other; and thus the drill system, the pedicle advancer system and the pedicle screw system also work independently from each other.

[0043] The method of making optionally comprises a step of providing at least one internal wiring cable; and a step of installing the at least one internal wiring cable inside the non-radiating mechanism (such as the ultrasonic probe). The at least one internal wiring cable is configured to communicate with a computing device for transmitting a reflected ultrasonic signal to the computing device.

[0044] The method of making optionally comprises a step of providing a first driving gear configured to be driven by the first motor; a step of providing a first driven gear configured to mesh the first driving gear; a step of providing a first worm configured to be driven by the first driven gear; and a step of installing the first driving gear, the first driven gear and the first worm for forming a first motion transmission mechanism.

[0045] The method of making optionally comprises a step of providing a second driving gear configured to be driven by the second motor; a step of providing a second linear actuator configured to be driven by the second driving gear; and a step of installing the second driving gear and the second linear actuator for forming a second motion transmission mechanism. The second linear actuator is configured to translate a rotational motion of the second driving gear into a linear motion of the pedicle feeler.

[0046] The method of making optionally comprises a step of providing a third driving gear configured to be driven by the third motor; a step of providing a third driven gear configured to mesh the third driving gear; a step of providing a third worm configured to be driven by the third driven gear; and installing the third driving gear, the third driven gear and the third worm for forming a third motion transmission mechanism.

[0047] The method of making optionally comprises a step of providing one or more pedicle screws; and a step of detachably attaching the one or more pedicle screws to the third worm or axis of the pedicle screw system.

[0048] As a fourth aspect, the present application discloses a method of using the Spinal Fixation Device. The method of using may comprise a first step of mounting the Spinal Fixation Device on a facet joint and aligning it with a planned trajectory; a second step of performing an osteotomy process (such as a facet joint osteotomy process) on the facet joint by projecting a drill system out of a first receptacle; a third step of performing a pedicle tract preparation process on the facet joint by projecting a pedicle advancer system out of a second receptacle; and a fourth step of performing a spinal fixation process by projecting a pedicle screw system out of a third receptacle. The Spinal Fixation Device may manage the drilling system, the pedicle advancer system and the pedicle screw system by adopting a central motor for automatically switching or rotating the first receptacle, the second receptacle and the third receptacle. In the first mounting step, the planned trajectory may be determined by the existing technologies such as Computer Tomography (CT) scanning routinely performed before the operation. The planned trajectory is optionally revised while the Spinal Fixation Device is in use.

[0049] The method of using optionally comprises a step of removing (such as shaving) a portion of the facet joint with a drill bit for forming an entry point for the trajectory; and retracting the drill bit out of the vertebral body and the trajectory. The shaving and the retracting are automatically controlled by a first motor of the first receptacle. Therefore, the drill system may work independently driven by the first motor. The trajectory is optionally revised while the Spinal Fixation Device is in use. The method may further comprise a step of withdrawing the pedicle feeler from the trajectory; a step of adjusting the trajectory using a computational algorithm for forming a revised trajectory; and a step of re-inserting the pedicle feeler into the revised trajectory.

[0050] The pedicle tract preparation process optionally comprises a first step of inserting a pedicle feeler into the trajectory; a second step of advancing the pedicle feeler for forming a transpedicular tract; a third step of extending the pedicle feeler to a desired position of the vertebral body; and a fourth step of removing the pedicle feeler out of, the prepared transpedicular tract. The inserting and the removing are automatically controlled by a second motor of the second receptacle. Therefore, the pedicle advancer system may work independently driven by the second motor. In some implementations, hydrogen peroxide is injected into the trajectory before inserting the pedicle feeler in order to minimise potential infection.

[0051] The pedicle tract preparation process optionally comprises a step of revising the transpedicular tract and the vertebral body in order to promote better pedicle screw integration. This can be achieved using a self-tapping screw or introducing a short revision segment on the pedicle feeler.

[0052] The revision step optionally comprises a step of retracting the pedicle feeler out of a skewed trajectory; and a step of revising the skewed trajectory to align with the planned trajectory. After the retracting step and the revising step, the transpedicular tract may be revised for better placing and fixing the pedicle screw in the spinal fixation process.

[0053] The pedicle tract preparation process optionally comprises a step of constructing a real-time image by the pedicle feeler in order to monitor the live progress of pedicle advancement along the planned trajectory. The image has an axial resolution which is determined by the parameters that the imaging technologies of the pedicle feeler adopts.

[0054] The pedicle tract preparation process optionally comprises a step of constructing a real-time image by a non-radiating mechanism such as ultrasonography imaging technologies, optical imaging technologies or photo-thermal imaging technologies. For example, the ultrasonography imaging technologies utilizes an ultrasonic probe installed inside the pedicle feeler.

[0055] The pedicle tract preparation process optionally comprises a step of constructing a real-time image by transmitting digital information from an ultrasonic probe to a computer processor. The ultrasonic probe is optionally installed inside the pedicle feeler.

[0056] The pedicle tract preparation process optionally comprises a step of constructing a real-time image by a combining an ultrasonic probe and a pressure sensing mechanism. The ultrasonic probe is optionally installed inside the pedicle feeler.

[0057] The pedicle tract preparation process optionally comprises a step of combining an amplitude mode (A-mode) and a brightness mode (B-mode) of the ultrasonic probe for enhancing an accuracy of placing the pedicle screw. The A-mode and the B-mode may detect a depth of the trajectory and construct two-dimensional (2D) images, respectively.

[0058] The pedicle tract preparation process optionally comprises a step of performing an intraoperative test for determining a velocity of the ultrasonic wave in the vertebral body (such as a cancellous tissue medium). The intraoperative test is used for readjusting the trajectory in both a horizontal direction and a vertical direction to realign the pedicle advancer system with the trajectory. In addition, the computing device may comprise a computer algorithm for registering and adjusting the trajectory during the intraoperative test.

[0059] The spinal fixation process further comprises a first step of carrying a pedicle screw along the trajectory, the transpedicular tract and the vertebral body until the desired position; a second step of fixing the pedicle screw at the desired positon of the vertebral body; and a third step of disengaging the pedicle screw system from the pedicle screw. The carrying, the fixing and the disengaging steps are automatically controlled by a third motor of the third receptacle. Therefore, the pedicle screw system may work independently.

[0060] The spinal fixation process optionally comprises a step of purchasing one or more self-tapping screws. The self-tapping screw may tap the pedicle tract as it is driven into the pedicle. This may avoid the process of revision.

[0061] The method of making optionally comprises a step of aligning the Spinal Fixation Device with a neuronavigational system or a clamping system. For example, the Spinal Fixation Device may be mounted onto and aligned with an extension arm of a Mazor X or Excelsius GPS system as the neuronavigational system.

[0062] The spinal fixation process optionally comprises a step of docking the pedicle screw onto the facet joint. Therefore, the pedicle screw insertion system is firmly mounted onto the facet joint without relocation during the spinal fixation process.

[0063] The Spinal Fixation Device and methods of making and using the Spinal Fixation Device have the following advantages. Firstly, all the three processes (i.e. the osteotomy process, the pedicle tract preparation process and the spinal fixation process) are performed with the Spinal Fixation Device by rotating the first receptacle, the second receptacle and the third receptacle along the central axle automatically by the central motor. Hence, the Spinal Fixation Device does not need to manually switch between individual instruments. Secondly, the Spinal Fixation Device is configured to use ultrasonic guidance or combine the ultrasonic guidance and the existing neuro- navigational technologies for enhancing the accuracy of pedicle screw placement. Thirdly, the Spinal Fixation Device is easy to operate since the three processes are independently driven by the first motor, the second motor and the third motor respectively. Fourthly, the Spinal Fixation Device adopts the non-radiating mechanism and thus avoids intraoperative radiation exposure when using existing CT scanning modalities. Fifthly, the Spinal Fixation Device constructs a real-time image for placing the pedicle screw more accurately. Sixthly, the Spinal Fixation Device utilizes a pressure sensing mechanism as an additional safety mechanism for ensuring that the pedicle feeler does not breach the cortex. Seventhly, the Spinal Fixation Device significantly reduces an operation time since all the three systems (i.e. the drill system, the pedicle advancer system and the pedicle screw system) are integrated together. Eighthly, the spatial resolution (i.e. the axial resolution of the real-time image can be optimised by modulating the frequency of the ultrasound. Ninthly, the Spinal Fixation Device can rapidly and efficiently revise the planned trajectory. Tenthly, the Spinal Fixation Device can be applied to cervical, thoracic and lumbar of the spine. Last but not the least, the Spinal Fixation Device can be used in collaboration with the existing technologies such as the Mazor X or the Excelsius GPS navigational robotic system by merging it with a surgical/robotic arm.

[0064] The accompanying figures (i.e. Figs., drawings, pictures or diagrams) illustrate embodiments and serve to explain principles of the disclosed embodiments. It is to be understood, however, that these figures are presented for purposes of illustration only, and not for defining limits of relevant applications.

Fig. 1 illustrates a first perspective view of a Spinal Fixation Device;

Fig. 2 illustrates a second perspective view of the Spinal Fixation Device;

Fig. 3 illustrates a third perspective view of the Spinal Fixation Device;

Fig. 4 illustrates a fourth perspective view of the Spinal Fixation Device;

Fig. 5 illustrates a side view and a cross-sectional view of the Spinal Fixation

Device;

Fig. 6 illustrates a side view and a cross-sectional view of a first drum; Fig. 7 illustrates a perspective view and a cross-sectional view of a second drum;

Fig. 8 illustrates a second motion transmission mechanism of the second drum;

Fig. 9 illustrates a perspective view and a cross-sectional view of a third drum;

Fig. 10 illustrates a cross-sectional view of a facetectomy process;

Fig. 11 illustrates a first cross-sectional view of a pedicle tract preparation process;

Fig. 12 illustrates a second cross-sectional view of the pedicle tract preparation process;

Fig. 13 illustrates a graph of a density of the pedicle measured along its cross section with a Computed Tomography (CT) scanning;

Fig. 14 illustrates a current-distance graph of a pressure sensing mechanism;

Fig. 15 illustrates a first cross-sectional view of a spinal fixation process;

Fig. 16 illustrates a second cross-sectional view of a spinal fixation process;

Fig. 17 illustrates a third cross-sectional view of a spinal fixation process;

Fig. 18 illustrates a side view of a pedicle feeler integrated with an ultrasonic probe;

Fig. 19 illustrates an ultrasonic probing system;

Fig. 20 illustrates an enlarged side view and a cross-sectional view of the ultrasonic probing system;

Fig. 21 illustrates a cross-sectional view of a first arrangement of the ultrasonic probe;

Fig. 22 illustrates a cross-sectional view of a second arrangement of the ultrasonic probe;

Fig. 23 illustrates a cross-sectional view of a third arrangement of the ultrasonic probe;

Fig. 24 illustrates an axial view of a planned projector of the pedicle feeler in the vertebral body;

Fig. 25 illustrates a hemiwidth-distance graph of the planned transpedicular trajectory;

Fig. 26 illustrates a cross-sectional view of a transmitted ultrasound wave and a reflected ultrasound wave;

Fig. 27 illustrates an oscilloscope display of the reflected ultrasound wave and back- scattered ultrasound waves;

Fig. 28 illustrates a diagram of calculating a time interval of the reflected ultrasound wave and the back-scattered ultrasound waves;

Fig. 29 illustrates a diagram of a time interval ratio of the reflected ultrasound wave and the back-scattered ultrasound waves; Fig. 30 illustrates a diagram of the time interval ratio and a depth ratio of a pedicle cortex;

Fig. 31 illustrates a diagram of quantitatively defining a maximal time interval ratio;

Fig. 32 illustrates a three-dimensional (3D) model showing a skewed derivation of the pedicle advancer system from the planned trajectory.

[0065] Exemplary, non-limiting embodiments of relevant inventions will now be described with references to the above-mentioned figures.

[0066] Fig. 1 to Fig. 5 describes a spinal fixation device 100. Fig. 1 illustrates a first perspective view of the Spinal Fixation Device 100. The Spinal Fixation Device 100 comprises a first drum 110 as a first receptacle comprising a drill system for performing a facetectomy process 700, a second drum 112 as a second receptacle comprising a pedicle advancer system for performing a pedicle tract preparation process 800, a third drum 114 as a third receptacle comprising a pedicle screw insertion system for performing a spinal fixation process 900, and a central motor 104 for automatically controlling the first drum 110, the second drum 112 and the third drum 114. In addition, the Spinal Fixation Device 100 comprises a main body 102 for enclosing all components inside. The main body 102 further comprises a first end 130 where the central motor 104 is located and a second end 132 distal to the first end 130. In addition, the main body 102 further comprises exterior fixtures 103 for holding a position or an orientation of the spinal fixation device 100 by the surgical arm, whether idling or in operation. Particularly, the Spinal Fixation Device 100 is supported by a robotic arm or holder (not shown in Fig. 1) at the exterior features 103 so that the drill system, the pedicle advancer system and/or the pedicle screw system are able to be operated in accuracy, consistency and reliability.

[0067] The central motor 104 is configured to rotate a central axis 106. The Spinal Fixation Device 100 also comprises a central cylindrical disc 108 for attaching the first drum 110, the second drum 112 and the third drum 114. The central cylindrical disc 108 is connected with the central axle 106 such that the central cylindrical disc 108 drives the first drum 110, the second drum 112 and the third drum 114 to rotate or to turn. An arrow in Fig. 1 shows a rotating direction 122 of the central axis 106. In other words, the central motor 104 drives the drums 110, 112, 114 to rotate to turn via the central axle 106 and the central cylindrical disc 108. [0068] The first drum 110 further comprises a first motor 204 configured to rotate around a first axis 116, a second motor 304 configured to rotate around a second axis 118 and a third motor 404 around a third axis 120. The motors 204, 304 and 404 work independently and thus the drums 110, 112, 114 also rotate independently around the axes 116, 118, 120 respectively.

[0069] Fig. 2 illustrates a second perspective view of the Spinal Fixation Device 100, showing only the main body 102, the central motor 104, the central axis 106 and the central cylindrical disc 108.

[0070] Fig. 3 illustrates a third perspective view of the Spinal Fixation Device 100, showing only the main body 102, the first drum 110, the second druml 12 and the third drum 114.

[0071] Fig. 4 illustrates a fourth perspective view of the Spinal Fixation Device 100, showing only the main body 102, the drums 110, 112, 114, the first axle 116, the second axle 118 and the third axle 120.

[0072] Fig. 5 illustrates a side view and a cross-sectional view of the Spinal Fixation Device 100. Fig. 5 shows that the first drum 110, the second drum 112 and the third drum 114 comprise a first port 124, a second port 126 and a third port 128 respectively for accommodating the first axle 116, the second axle 118 and the third axle 120. In particular, the port 124, 126, 128 are exposed from the second end 132 of the main body 102 such that the axles 116, 118, 120 are extendable from the second end 132.

[0073] Fig. 6 illustrates a side view and a cross-sectional view of a first drum 110. The first drum 110 comprises a first motor 204 and a first motion transmission mechanism 203 for transmitting a first motion of the first motor 204 to the drill system. The first motion transmission mechanism 204 comprises a first gear arrangement comprising a first driving gear 206 driven by the first motor 204, a first driven gear 210 meshing the first driving gear 206 and a first worm 214 meshing the first driven gear 210. Accordingly, the first driving gear 206, the first driven gear 210 and the first worm 214 have a first driving rotation 208, a first driven rotation 212 and a first worm rotation 216, respectively. In Fig. 6, the first driving rotation 208 and the first worm rotation 216 are counterclockwise in a plane perpendicular to the cross-sectional view; while the first driven rotation 212 is clockwise in the same plane. Since the first worm 214 is connected to the first axle 116, the first worm 214 translates the first worm rotation 216 into a first rotatory advancing motion 220 of the first axle 116. Therefore, the first motion of the first motor 204 is transferred to the first axle 116 via the first driving gear 206, the first driven gear 210 and the first worm 214.

[0074] The first drum 110 also comprises a first cylindrical disc 205 for attaching the first axle 116 and the first motor 204, a drill bit 218 detachably coupled to one end of the first axle 116 approximate to the first worm 214, and a first body 202 for enclosing all the components inside the first drum 110. In particular, the drill bit 218 moves out of the first drum 110 and the second end 132 of the main body 102 from the first port 124 and along with the first axel 116 for drilling a facet joint 224.

[0075] Fig. 7 illustrates a perspective view and a cross-sectional view of a second drum 112. The first drum 112 comprises a second motor 304 and a second motion transmission mechanism 303 for transmitting a second motion of the second motor 304 to the pedicle advancer system. The second motion transmission mechanism 304 comprises a second gear arrangement comprising a second driving gear 306 configured to be connected to and driven by the second motor 304; and a second linear actuator configured to be driven by the second driving gear 306. The second linear actuator further comprises a spoke wheel 310 meshing the second driving gear 306 and a gear rack 314 meshing the spoke wheel 310.

[0076] Fig. 8 illustrates a second motion transmission mechanism 303 of the second drum 112. The second driving gear 306 and the spoke wheel 310 have a second driving rotation 308 and a spoke wheel rotation 312 respectively; while the gear rack 314 has an actuator linear advancing motion 316. In Fig. 7, the second driving rotation 308 is clockwise in a plane perpendicular to the cross-sectional view; while the spoke wheel rotation 312 is also clockwise in the cross-sectional view. In particular, the gear rack 314 has a plurality of straight teeth 315 at an outside surface of the gear rack 314 for translating the spoke wheel rotation 312 into the actuator linear advancing motion 316 in the cross-sectional view. Since the gear rack 314 is connected to the second axle 118, the second motion of the second motor 304 is transferred to the second axle 118 via the second driving gear 306, the spoke wheel 310 and the gear rack 314. [0077] The second drum 112 also comprises a second cylindrical disc 305 for attaching the second axle 118 and the second motor 304, a pedicle feeler 318 detachably coupled to one end of the second axle 118 approximate to the gear rack 314, and a second body 302 for enclosing all the components inside the second drum 112. In particular, the pedicle feeler 318 has a second linear advancing motion 320 moving out of the second drum 112 and the second end 132 of the main body 102 from the second port 126 and along with the second axel 118 for performing a pedicle tract preparation process 800.

[0078] Fig. 9 illustrates a perspective view and a cross-sectional view of a third drum 114. The third drum 114 comprises a third motor 404 and a third motion transmission mechanism 403 for transmitting a third motion of the third motor 404 to the pedicle screw system. The third motion transmission mechanism 404 comprises a third gear arrangement comprising a third driving gear 406 configured to be connected to and driven by the third motor 404; and a third driven gear 410 configured to mesh the third driving gear 406; and a third worm 422 configured to be driven by the third driven gear 406. In particular, the third driven gear 410 comprises a first cogwheel 412 meshing the third driving gear 406, a second cogwheel 416 meshed by the third worm 422, and a gear handle 420 for connecting the first cogwheel 412 at one end and the second cogwheel 416 at the other end. Accordingly, the third driving gear 406, the first cogwheel 412, the second cogwheel 416 and the third worm respectively have a third driving rotation 408, a rotation of the first cogwheel 414, a rotation of the second cogwheel 418 and a third worm rotation 423 that are in a same plane perpendicular to the cross-sectional view. Since the third worm 422 is connected to the third axle 120, the third worm 422 translates the third worm rotation 423 into a third rotatory advancing motion 426 of the third axle 120. Therefore, the third motion of the third motor 404 is transferred to the third axle 120 via the third driving gear 406, the first cogwheel 412, the gear handle 420, the second cogwheel 416 and the third worm 422.

[0079] The third drum 114 also comprises a third cylindrical disc 405 for attaching the third axle 120 and the third motor 404, a pedicle screw 424 detachably coupled to one end of the third axle 120 approximate to the third worm 422, and a third body 402 for enclosing all the components inside the third drum 114. In particular, the pedicle screw 424 moves out of the third drum 114 and the second end 132 of the main body 102 from the third port 128 and along with the third axle 120 for performing a pedicle screw fixation process 900.

[0080] Fig. 10 to Fig. 32 describe a method of using the Spinal Fixation Device 100. The method of using comprises the facetectomy process 700, the pedicle tract preparation process 800 and the pedicle screw fixation process 900 in sequence. Fig. 10 illustrates a cross-sectional view of the facetectomy process 700. The Spinal Fixation Device 100 is initially mounted on the facet joint 224; then the drill bit 218 is driven by the first motor 204 and projected from the first drum 110 for preparing the facetectomy process 700; and finally the facetectomy is performed by translationally rotating the drill bit 218 and shaving the facet joint 224 in line with the intended trajectory 234 required to create a pedicle tract 242 formed later in a pedicle 226 and a vertebral body 236. A first arrow 240 shows a movement direction of the drill bit 218. In particular, the drill bit 218 is aligned with a planned trajectory towards the facet joint 224, the pedicle 226 and the vertebral body 236. The planned trajectory may be revised or adjusted during the facetectomy process 700 for forming the trajectory 234. The facetectomy process 700 should not damage any surrounding internal body structures such as a lamina 228, a transverse process 230, a spinous process 232 and a spinal canal 238. After the facetectomy process 700, the drill bit 218 is retracted from the trajectory 234 by reversing the first motor 204.

[0081] Fig. 11 illustrates a first cross-sectional view of a pedicle tract preparation process 800 where the pedicle feeler 318 is inserted into the trajectory and extended into the pedicle 226. After the drill bit 218 is fully retracted and withdrawn into the first drum 110, the first drum 110 is turned away from the facet joint 224 by rotating the central motor 104 in a clockwise direction. Meanwhile, the second drum 112 is turned towards the facet joint 224 with the pedicle feeler 318 aligned towards the trajectory 234. The pedicle feeler 318 driven by the second motor 304 and projected from the second drum 112 for performing the pedicle tract preparation process 800. The pedicle feeler 318 is then inserted along the trajectory 234 through the facet joint 224.

[0082] Fig. 12 illustrates a second cross-sectional view of the pedicle tract preparation process 800 where the pedicle feeler 318 is fashioned into the pedicle 226 and the vertebral body 236 for forming the pedicle tract 242. After the pedicle tract preparation process 800, the pedicle feeler 318 is also retracted from the pedicle tract 242 by reversing the second motor 304 and finally withdrawn in to the second drum 112.

[0083] In particular, the pedicle feeler 318 is integrated with an ultrasonic probe 326 and a pressure sensing mechanism. During the pedicle tract preparation process 800, the ultrasonic probe 326 provides continuous feedback about the real-time trajectory in comparison to the planned trajectory. The pressure sensing mechanism is used as a safety mechanism for anticipating a cortical breach. Once a cortical breach is suspected, the pressure sensing mechanism promptly deactivates the pedicle advancer system. The trajectory 234 is then revised before the pedicle tract preparation process 800 is resumed.

[0084] The ultrasonic probe 326 is utilized following a series of steps for effectively guiding the pedicle feeler 318 in the pedicle tract preparation process 800. A Computed Tomography (CT) scanning as a neuronavigational guidance is used for determining an initial point and orientation in relation to a horizontal plane and a vertical plane for the pedicle feeler 318. A breadth of the pedicle 226 is defined by marking a start and an end of the pedicle 226 in the horizontal plane. The CT scanning of a high resolution is used for reconstructing and magnifying in a coronal plane (i.e. along axis of pedicle) and in an axial plane. Therefore, the start and the end of the pedicle 226 and a transpedicular trajectory is planned before using the ultrasonic probe 326.

[0085] A pedicle height in a craniocaudal plane and a pedicle width in the axial plane are obtained automatically or manually at pre-specified fixed distances along the planned trajectory. Accurate automated measurements of the pedicle height and the pedicle width are obtained by measuring from a cortical-cancellous interface (i.e. a steepest gradient in a density 804 of the pedicle 226) to a midline 812 of the planned trajectory. The density 804 of the pedicle 226 is measured in Hounsfield units. Fig. 13 illustrates a graph 802 of the density 804 of the pedicle 226 measured along its cross section with the Computed Tomography (CT) scanning. The graph 802 shows a relationship between the density 804 and cross-sectional position 806 along the pedicle from medial wall to lateral wall. The relationship is limited by a medial cancellous-cortical interface 808 on the left side and a lateral cancellous-cortical interface 810 on the right side. A hemiwidth 814 is measured either from the medial cancellous-cortical interface 808 to the midline 812 or from the midline 812 to the lateral cancellous-cortical interface 810 along the pedicle position 806. The graph 802 forms a basis for CT-measured ratios of the hemiwidth 814 and also is used for comparing with ultrasound-guided time interval ratios by using linear graphs of ratios of both imaging modalities versus a transpedicular distance.

[0086] Fig. 14 illustrates a current-distance graph 820 of the pressure sensing mechanism, showing a relationship between a current 822 and a transpedicular distance 824. The relationship shows a pedicle cortex transgression 826 characterized by a rising trend and a pedicle cortex breach characterized by a falling trend.

[0087] Fig. 15 a first cross-sectional view of a spinal fixation process 900, where the pedicle screw 424 is inserted into the pedicle tract 242. After the pedicle feeler 318 is fully retracted and withdrawn into the second drum 112, the second drum 112 is turned away from the facet joint 224 by rotating the central motor 104. Meanwhile, the third drum 114 is turned towards the facet joint 224 with the pedicle screw 424 aligned towards the pedicle tract 242. The pedicle screw 424 is driven by the third motor 404 and projected from the third drum 114 for performing the spinal fixation process 900. The pedicle screw 424 is then inserted along the pedicle tract 242 through the facet joint 224.

[0088] Fig. 16 illustrates a second cross-sectional view of a spinal fixation process 900 where the pedicle screw 424 is inserted into the vertebral body 236. The third motor 114 is finally stopped when the pedicle screw 424 reaches a pre-determined position 428. In particular, the pedicle screw 424 comprises a self-tapping pedicle screw to eliminate the need for tapping/revision (i.e. revising) and provide better purchase within the pedicle tract 242.

[0089] Fig. 17 illustrates a third cross-sectional view of a spinal fixation process 900 where the pedicle screw 424 is fully purchased at the pre-determined position 428. The pedicle screw 424 is then detached from the pedicle screw system of the third drum 114. The pedicle screw system is retracted from the pedicle tract 242 and withdrawn into the third drum 114. The Spinal Fixation Device 100 is finally dismounted and removed from the facet 224. [0090] Fig. 18 illustrates a side view of a pedicle feeler 318 integrated with an ultrasonic probe 326. Specifically, the ultrasonic probe 326 is integrated into a shaft 324 of the pedicle feeler 318, proximal to the tip 322 of the pedicle feeler 318. The ultrasound probe 326 comprises two ultrasonic transducers, i.e. the first ultrasonic transducer 328 and the second ultrasonic transducer 330. Each of the ultrasonic transducers 328, 330 further comprises a transmitter plate and a receiver plate that are assembled in a side-to-side configuration. The transmitter transmits ultrasound waves and the receiver picks up reflected ultrasonic signals from the pedicle cortex 346 and cancellous tissues 528 of the pedicle 226.

[0091] The ultrasonic probe 326 also comprises a first backing material 332 and a second backing material 334 positioned at backsides of the first ultrasonic transducer 328 and the second ultrasonic transducer 330 respectively. The backing materials 332, 334 are adopted as vibration dampeners for reducing a pulse length of the ultrasonic waves and improving the axial resolution. Meanwhile, the backing materials 332, 334 also minimize lateral and posterior ultrasonic wave transmissions. The ultrasonic probe 326 adopts a 2MHz ultrasound and has a diameter of 3.5 millimeter (mm).

[0092] Fig. 19 illustrates an ultrasonic probing system 336, comprising the ultrasonic probe 326 and two internal wiring cables 338, 339 integrated within the shaft 324 of the pedicle feeler 318. Fig. 20 illustrates an enlarged side view and a cross-sectional view of the ultrasonic probing system 336. A first internal wiring cable 338 and a second internal wiring cable 339 are communicatively connected to the first ultrasonic transducer 328 and the second ultrasonic transducer 330 respectively. The internal wiring cables 338, 339 are further communicatively connected to a computing device 340. Propagating ultrasound waves 342 are transmitted from the ultrasonic transducers 328, 330 and then reflected back as reflected ultrasound waves 344 by the pedicle cortex 346. The reflected ultrasound waves 344 are received by the ultrasonic transducers 328, 330 and then converted to reflected signals that are further transferred to the computing device 340 via the internal wiring cables 338, 339. If the reflected signals are either extremely strong or substantially diminished/absent, the pedicle feeler 318 is indicated to be traversing in very close proximity or has breached the pedicle cortex 346. The computing device 340 finally digitally constructs images of the pedicle cortex 346 that are displayed on the screen 341 . [0093] The ultrasonic probe 326 may have a flexible design according to various requirements. Fig. 21 illustrates a cross-sectional view of a first arrangement 352 of the ultrasonic probe 326. The first arrangement 352 comprises a first concave ultrasonic transmitter 356 in a cranial part 358, a second concave ultrasonic transmitter 360 in a caudal part 362, a third concave ultrasonic transmitter 364 in a medial part 366 and a fourth concave ultrasonic transmitter 368 in a lateral part 370. The four concave ultrasonic transmitters 356, 360, 364, 368 transmit the propagating ultrasound waves 342 in an upward direction, a downward direction, a medial direction and a lateral direction, respectively. In other words, the four concave ultrasonic transmitters 356, 360, 364, 368 placed at 90 degrees to each other for determining depths in both craniocaudal (or vertical) plane and a cross-sectional (or horizontal) plane simultaneously. The four concave ultrasonic transmitters 356, 360, 364, 368 have concave surfaces for focusing the propagating ultrasound waves 342 on the pedicle cortex 346 and reflected back to the adjacent receivers. The four concave ultrasonic transmitters 356, 360, 364, 368 surround the backing materials 332, 334 and are enclosed by a circumference 354 of the pedicle feeler 318.

[0094] Fig. 22 illustrates a cross-sectional view of a second arrangement 372 of the ultrasonic probe 326, similar to the first arrangement 352. Flowever, the second arrangement 372 comprises two concave ultrasonic transmitters, i.e. the first concave ultrasonic transmitter 356 in the cranial part 358 and the second concave ultrasonic transmitter 360 in the caudal part 362. In other words, the concave ultrasonic transmitters 356, 360 are placed at 180-degree to each other in the craniocaudal (or vertical) plane.

[0095] Fig. 23 illustrates a cross-sectional view of a third arrangement 374 of the ultrasonic probe326, similar to the first arrangement 352. Flowever, the third arrangement 374 comprises two concave ultrasonic transmitters, i.e. the third concave ultrasonic transmitter 364 in the medial part 366 and the fourth concave ultrasonic transmitter 368 in the lateral part 370. In other words, the concave ultrasonic transmitters 364, 368 are placed at 180-degree to each other in the axial (or horizontal) plane.

[0096] The ultrasonic probe 326 may have an alternative design to the second arrangement 372 and the third arrangement 374. The ultrasonic probe 326 of the alternative design comprises a single transducer that are used by rotating the pedicle feeler 318 90-degree and by taking measurements at fixed distances or locations along a transpedicular route, such as a start point, a midpoint and an end point of pedicle 226. The measurements are used for construct images along the transpedicular route and also in comparison with the planned transpedicular trajectory

501.

[0097] Fig. 24 illustrates an axial view of the planned transpedicular trajectory 501 (i.e. a midline) of the pedicle feeler 318 in the vertebral body 236. The planned transpedicular trajectory 501 passes from the shaved facet joint 506 through a center of the pedicle 226 into a main part of the vertebral body 236. A series of perpendicular lines are projected, running from the planned transpedicular trajectory 501 (the midline) to a medial line 502 (i.e. a left line) tangent to a medial pedicle cortex 508 and a lateral line 503 (i.e. a right line) tangent to a lateral pedicle cortex 510. The lines 501 , 502, 503 span a full length of the pedicle 226 and are separated by small, fixed increments(/mm).

[0098] Measurements of distance or time perpendicular to the trajectory 234 to the medial pedicle cortex 508 or the lateral pedicle cortex 510 are made using the transmitted ultrasound waves and the reflected ultrasound signals. The measurements are then used to calculate distance or time ratios between the medial pedicle cortex 508 and the lateral pedicle cortex 510. The distance or time ratios are used for comparing with the CT-measured ratios determined along the same trajectory 234. If the distance or time ratios match both the CT measurements and the ultrasound measurements along a specific trajectory length, the pedicle feeler 318 is indicated to pass along a correct trajectory in real time. The distances comprise a first distance 514 and a second distance 516 both measured from the medial pedicle cortex 508 to the planned transpedicular trajectory 501 ; and a first length 518 and a second length 520 measured from the lateral pedicle cortex 510 to the planned transpedicular trajectory 501.

[0099] The Fig. 24 also shows an ellipse 511 demonstrates a cross-sectional view of the pedicle 226. Diametrically opposite distances or times are used for calculating the distance or time ratios. Flence, the ellipse 511 comprises the horizontal ratios ‘a’ and ‘b’ and vertical ratios ‘c’ and ‘d’. [0100] Fig. 25 illustrates a hemiwidth-distance graph 524 of the planned transpedicular trajectory 501. The hemiwidth-distance graph 524 shows hemiwidth ratios 526 from the medial pedicle cortex 508 and the lateral pedicle cortex 510 to the planned transpedicular trajectory 501 (i.e. midline) at a specified transpedicular distance 522. The hemiwidth ratios 526 are plotted against the transpedicular distances 522 corresponding to the hemiwidth ratios 526 respectively. The transpedicular distances 522 are at small, fixed-interval millimeter (mm) increments from the start point to the end point of the pedicle 226. In addition, the distance and time ratios are measured using a pre-operative or an intraoperative CT against the transpedicular distance 522 (i.e. a distance along a length of the trajectory from the start point of the shaved facet joint 506).

[0101] Fig. 26 illustrates a cross-sectional view of a transmitted ultrasound wave (i.e. the propagating ultrasound wave 342) and a reflected ultrasound wave 344. Time or distance is measured by using the propagating ultrasound wave 342 and reflected ultrasound wave 344 received by the ultrasound transducer. The time taken by the propagating ultrasound wave 342 for passing from the transducer 330 to the pedicle cortex 226 and the reflected ultrasound wave 344 back to the receiver is determined by using the computing device 340. As a speed of the ultrasound in the cancellous tissue medium of the pedicle is constant, the distance ratio is equivalent to the time ratio. As the time taken to travel to and back from the pedicle cortex 226 is equal to a double of the depth, the time interval needs to be halved to determine a true depth between the midline 501 and the pedicle cortex 226.

[0102] Fig. 27 illustrates an oscilloscope display 534 of the reflected ultrasound wave 344 and back-scattered ultrasound waves 536. The back-scattered ultrasound waves 536 further comprises a first scattered ultrasound wave 538 and a second scattered ultrasound wave 540. Therefore, the received ultrasonic signal comprises a multitude of the reflected ultrasonic signals of variable amplitudes, indicating an interface of inhomogeneous densities within the cancellous tissue 528 of the pedicle 226. In principle, the greater the difference in density between 2 interfaces, the larger the amplitude of the received signal becomes. Flence, the reflected ultrasonic signal of the largest amplitude is generated at the pedicle cortex 346 (i.e. cortical cancellous interface) that is used to calculate the time interval from the reflected ultrasound waves as the received ultrasonic signals.

[0103] Fig. 28 illustrates a diagram 542 of calculating a time interval of the reflected ultrasound wave 344 and the back-scattered ultrasound waves 536. The time interval is calculated by using crests of the transmitted ultrasound wave and the received ultrasound wave from the ultrasonic signal of the highest amplitude. In other words, the time taken from the transmitted signal to the highest amplitude signal received from the multitude of reflected signals is the time for the transmitted signal to reach the pedicle cortex 346 and then to travel back. Hence, a true time taken from the planned transpedicular trajectory 501 (midline) to the pedicle cortex 346 is equal to a half the time.

[0104] Fig. 29 illustrates a diagram of a time interval ratio 556 of the reflected ultrasound wave 344 and the back-scattered ultrasound waves 346 from the medial pedicle cortex 508 and the lateral pedicle cortex 510. A velocity of sound is constant as long as the cancellous tissue 528 has uniform density and modulus of elasticity. Similar to the CT measurements, a time ratio-distance graph is constructed by using ultrasound measurements in real time, i.e. while a spinal operation is being performed.

[0105] Fig. 30 illustrates a diagram 560 of the time interval ratio and a depth ratio of a pedicle cortex 346, showing an overlap of the time ratio-distance graphs for both CT and ultrasound measurements. The graphs 560 should match if the trajectory in real time matches the planned trajectory using CT scanning. If the ultrasound graph deviates from the CT graph, it indicates the trajectory is skewed and need to be revised. To explain in detail, as the time interval ratio correlates with the depth ratio of the pedicle cortices to the midpoint at a given transpedicular distance, the linear graphs generated should therefore be identical. Hence, any discrepancy between the projected graph of the pedicle hemiwidths and the time interval ratios mapped out by ultrasound during transpedicular advancement in real time would indicate deviation of pedicle feeler from its intended trajectory. This would therefore prompt revision of the current trajectory, in order to realign it with the planned trajectory.

[0106] Fig. 31 illustrates diagram 566 of quantitatively defining a maximal time interval ratio at the midway point and end of transpedicular path. A ratio greater than the figure calculated at each of these points signifies a deviated trajectory which is likely to lead to pedicle cortical breach. It is noted that the mapping of the planned trajectory and the synchronicity with the real-time ultrasound derived trajectory is based on computer algorithms.

[0107] Fig. 32 illustrates a three-dimensional (3D) model 600 showing a skewed derivation of the pedicle advancer system from the planned trajectory and means of correcting this deviation in both horizontal and vertical planes using computer algorithms. The 3D model 600 shows that a pedicle demonstrating the planned trajectory running through the centre of the pedicle and the deviated trajectory. The angle of deviation in both horizontal and vertical planes can be calculated. This information can be processed and using computer algorithms, the real time trajectory is re-planned to match planned trajectory when the pedicle feeler is withdrawn and then re-inserted along the revised trajectory. All the measurements can be obtained using A mode ultrasonic imaging techniques.

[0108] Alternatively, rather than using the measurements above, B mode of the ultrasonic technologies is used to provide real time visual information that the pedicle feeler is passing within the confines of the pedicle cortex, along the defined trajectory established using preoperative or intraoperative CT scanning methods.

[0109] In the application, unless specified otherwise, the terms "comprising", "comprise", and grammatical variants thereof, intended to represent "open" or "inclusive" language such that they include recited elements but also permit inclusion of additional, non-explicitly recited elements.

[0110] As used herein, the term "about", in the context of concentrations of components of the formulations, typically means +/- 5% of the stated value, more typically +/- 4% of the stated value, more typically +/- 3% of the stated value, more typically, +/- 2% of the stated value, even more typically +/- 1% of the stated value, and even more typically +/- 0.5% of the stated value.

[0111] Throughout this disclosure, certain embodiments may be disclosed in a range format. The description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the disclosed ranges. Accordingly, the description of a range should be considered to have specifically disclosed all the possible sub-ranges as well as individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numbers within that range, for example, 1 , 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range.

[0112] It will be apparent that various other modifications and adaptations of the application will be apparent to the person skilled in the art after reading the foregoing disclosure without departing from the spirit and scope of the application and it is intended that all such modifications and adaptations come within the scope of the appended claims.

Reference Numerals

100 Spinal Fixation Device;

102 main body;

103 exterior fixture;

104 central motor;

106 central axis;

108 central cylindrical disc;

110 first drum;

112 second drum;

114 third drum;

116 first axis (drum 1)

118 second axis (drum 2)

120 third axis (drum 3)

122 rotational direction;

124 first port;

126 second port;

128 third port;

130 first end;

132 second end;

202 first body;

203 first motion transmission mechanism;

204 first motor;

205 first cylindrical disc;

206 first driving gear;

208 first driving rotation;

210 first driven gear;

212 f i rst d ri ve n rotati o n ;

214 first worm;

216 first worm rotation;

218 drill bit;

220 first linear advancing motion;

224 facet joint;

226 pedicle;

228 lamina;

230 transverse process; 232 spinous process;

234 trajectory;

236 vertebral body;

238 spinal canal;

240 first arrow;

242 pedicle tract;

302 second body;

303 second motion transmission mechanism;

304 second motor;

305 second cylindrical disc;

306 second driving gear;

308 second driving rotation;

310 spoke wheel;

312 spoke wheel rotation;

314 gear rack;

315 straight teeth;

316 actuator linear advancing motion;

318 pedicle feeler;

320 second linear advancing motion;

322 tip of pedicle feeler;

324 shaft of pedicle feeler;

326 ultrasonic probe;

328 first ultrasonic transducer;

330 second ultrasonic transducer;

332 first backing material;

334 second backing material;

336 ultrasonic probing system;

338 first internal wiring cable;

339 second internal wiring cable;

340 computing device;

341 screen;

342 propagating ultrasound wave;

344 reflected ultrasound wave;

346 pedicle cortex;

348 cancellous bone; 350 cross-section of pedicle feeler;

352 first arrangement;

354 circumference of pedicle feeler;

356 first concave ultrasonic transmitter;

358 cranial part;

360 second concave ultrasonic transmitter;

362 caudal part;

364 third concave ultrasonic transmitter;

366 medial part;

368 fourth concave ultrasonic transmitter;

370 lateral part;

372 second arrangement;

374 third arrangement;

402 third body;

403 third motion transmission mechanism;

404 third motor;

405 third cylindrical disc;

406 third driving gear;

408 third driving rotation;

410 third driven gear;

412 first cogwheel;

414 rotation of the first cogwheel;

416 second cogwheel;

418 rotation of the second cogwheel;

420 gear handle;

422 third worm;

423 third worm rotation;

424 pedicle screw;

426 third linear advancing motion;

428 pre-determined position;

501 planned transpedicular trajectory (midline);

502 medial line;

503 lateral line;

504 lamina

506 shaved facet joint; 508 medial pedicle cortex;

510 lateral pedicle cortex;

511 ellipse;

512 spinal canal;

514 (Xi) first distance from the medial cortex to the planned transpedicular trajectory; 516 (X2) second distance from the medial cortex to the planned transpedicular trajectory;

518 (Yi) first length from the lateral cortex to the planned transpedicular trajectory; 520 (Y2) second length from the lateral cortex to the planned transpedicular trajectory;

522 transpedicular distance;

524 hemiwidth-distance graph;

526 hemiwidth ratio;

528 cancellous tissue;

530 ultrasonic distance;

532 ultrasonic velocity;

534 oscilloscope display;

536 back-scattered ultrasound wave;

538 first scattered ultrasound wave;

540 second scattered ultrasound wave;

542 diagram of calculating a time interval;

544 amplitude;

546 time;

548 transmitted ultrasound wave;

550 maximal amplitude of the emitted wave;

552 maximal amplitude of the reflected wave;

554 time interval;

556 diagram of a time interval ratio;

558 ultrasonic-measured timing interval ratio;

560 diagram of ratio of medial cortex to lateral cortex;

562 ratio of medial cortex to lateral cortex;

564 digression from the planned transpedicular trajectory;

566 diagram of quantitatively defining the maximal time interval;

600 3D model of skewed derivation of the pedicle advancer;

602 length of pedicle; dimensions of cross-section from midpoint; real-time intraoperative mapped trajectory; re-planned trajectory using computer algorithms; facetectomy process; pedicle tract preparation process; graph of density; density; pedicle position; medial cancellous-cortical interface; lateral cancellous-cortical interface; midline; hemiwidth; current-distance graph; current; transpedicular distance; pedicle cortex transgression; pedicle cortex breach; spinal fixation process;

Claims

1 . A Spinal Fixation Device for being held by a surgical arm (e.g. robotic arm), the Spinal Fixation Device comprising: a pedicle screw preparation system; and a pedicle screw insertion system; wherein the pedicle screw preparation system and the pedicle screw insertion system are integrated as a unitary tool.

2. The Spinal Fixation Device of claim 1 , wherein the pedicle screw preparation system comprises

> a driller for making a recess in a facet joint articular process; and a pedicle advancer for creating a tract for a pedicle screw.

3. The Spinal Fixation Device of claim 1 , wherein the pedicle screw insertion system comprises a drive mechanism connected to the driller and the pedicle advancer for propelling driller and the pedicle advancer independently.

4. The Spinal Fixation Device of claim 2 or 3, wherein

> the driller is configured in a first receptacle for performing an osteotomy process; the pedicle advancer is configured in a second receptacle for performing a pedicle tract preparation process; the drive mechanism is configured in a third receptacle for performing a spinal fixation process; and the first receptacle, the second receptacle and the third receptacle are controlled by a central motor.

5. The Spinal Fixation Device of any of the preceding claims 2 to 4, wherein the pedicle advancer comprises a pedicle feeler for forming a pedicle tract in a pedicle along a planned trajectory; and the pedicle feeler is configured to be integrated with a non-radiating imaging mechanism for creating an image of the pedicle in a cross-section direction.

6. The Spinal Fixation Device of claims 4, wherein the first receptacle comprises a first motor for automatically driving the driller to move along a first axle from a first port;

> the second receptacle comprises a second motor for automatically driving the pedicle advancer to move along a second axle from a second port; and

> the third receptacle comprises a third motor for automatically driving the drive mechanism to move along a third axle from a third port; wherein the first motor, the second motor and the third motor work independently.

7. The Spinal Fixation Device of claim 6, wherein the first receptacle comprises a first motion transmission mechanism that comprises a first gear arrangement, the first gear arrangement comprising

> a first driving gear configured to be driven by the first motor; a first driven gear configured to mesh the first driving gear; and a first worm configured to be driven by the first driven gear.

8. The Spinal Fixation Device of claim 2, wherein the driller comprises at least one drill bit approximate to the first worm.

9. The Spinal Fixation Device of claim 4, wherein the second receptacle comprises a second motion transmission mechanism that comprises a second gear arrangement, the second gear arrangement comprising a second driving gear configured to be driven by the second motor; and a second linear actuator configured to be driven by the second driving gear; wherein the second linear actuator is configured to translate a rotational motion of the second driving gear into a linear motion of the pedicle feeler.

10. The Spinal Fixation Device of claim 4, wherein the third receptacle comprises a third motion transmission mechanism that comprises a third gear arrangement, the third gear arrangement comprising > a third driving gear configured to be driven by the third motor; a third driven gear configured to mesh the third driving gear; and

> a third worm configured to be driven by the third driven gear.

11 . The Spinal Fixation Device of claim 5, wherein the non-radiating imaging mechanism comprises at least one ultrasonic probe that comprises a first ultrasonic transducer and a second ultrasonic transducer; wherein the first ultrasonic transducer and the second ultrasonic transducer are arranged in a back-to-back configuration for producing a 360-degree visualization.

12. The Spinal Fixation Device of claim 11 , wherein the first ultrasonic transducer comprises at least one transmitter for transmitting an ultrasonic signal; and

> at least one receiver for receiving a reflected ultrasonic signal; wherein the reflected ultrasonic signal is generated by a reflection of the ultrasonic signal on a pedicle cortex.

13. The Spinal Fixation Device of claim 11 or 12, wherein the first ultrasonic transducer comprises

> a first concave ultrasonic transmitter for transmitting a first ultrasonic signal in a cranial direction; and a second concave ultrasonic transmitter for transmitting a second ultrasonic signal in a caudal direction; wherein the second concave ultrasonic transmitter is positioned opposite to the first concave ultrasonic transmitter.

14. The Spinal Fixation Device of any of the preceding claims 11 to 13, wherein the first ultrasonic transducer further comprises a third concave ultrasonic transmitter for transmitting a third ultrasonic signal in a medial direction; and a fourth concave ultrasonic transmitter for transmitting a fourth ultrasonic signal in a lateral direction; wherein the fourth concave ultrasonic transmitter is positioned opposite to the third concave ultrasonic transmitter.

15. The Spinal Fixation Device of claim 11 , wherein the at least one ultrasonic probe comprises at least one internal wiring cable configured to communicate with a computing device for transmitting the reflected ultrasonic signal.

16. The Spinal Fixation Device of claim 14, further comprising: a warning apparatus configured to communicate with the computing device for sending a warning signal when the reflected ultrasonic signal changes beyond a predetermined range.

17. The Spinal Fixation Device of any of the preceding claims, further comprising at least one sensor connected to the driller, the pedicle advancer or both for detecting operation parameters of the Spinal Fixation Device.

18. A robotic guidance platform for spine surgery, the robotic guidance platform comprising:

> an imaging system for visualizing spine anatomy of a patient; a display screen configured to be connected to the imaging system for showing images of the spine anatomy of the patient;

> a control unit connected to the imaging system and the display screen for controlling the imaging system; a robotic arm further configured to be connected to the control unit for operating the robotic arm; and the Spinal Fixation Device according to any of the preceding claims; wherein the Spinal Fixation Device is detachable from the robotic arm.

19. The robotic guidance platform of claim 18, wherein the control unit is configured to track positions of its components during spinal surgery.

20. The robotic guidance platform of claim 18 or 19, further comprising a communication unit that is connected to the control unit for transmitting data between the robotic guidance platform and an external computer.

21 . A method of making a Spinal Fixation Device, comprising: providing a pedicle screw preparation system that comprises

• a driller configured in a first receptacle; and

• a pedicle advancer in a second receptacle; providing a pedicle screw insertion system that comprises a drive mechanism in a third receptacle; and integrating the pedicle screw preparation system and the pedicle screw insertion system into a unitary tool.

22. The method of claim 21 , further comprising

> providing a central motor for automatically controlling the first receptacle, the second receptacle and the third receptacle; and integrating the first receptacle, the second receptacle and the third receptacle with the central motor.

23. The method of claim 21 or 22, further comprising:

> installing a pedicle feeler to the pedicle advancer; and installing a non-radiating mechanism inside the pedicle feeler.

24. The method of any of the preceding claims 21 or 23, further comprising: providing a first driving gear configured to be driven by the first motor; providing a first driven gear configured to mesh the first driving gear;

> providing a first worm drive configured to be driven by the first driven gear; and installing the first driving gear, the first driven gear and the first worm for forming a first motion transmission mechanism.

25. A method of using a Spinal Fixation Device, comprising:

> mounting the Spinal Fixation Device aligned with a planned trajectory towards a facet joint;

> performing an osteotomy process on the facet joint by projecting a driller out of a first receptacle;

> performing a pedicle tract preparation process on the facet joint by projecting a pedicle advancer out of a second receptacle; and > performing a spinal fixation process by projecting a pedicle screw system out of a third receptacle; wherein the Spinal Fixation Device comprises a central motor for automatically switching the first receptacle, the second receptacle and the third receptacle.

26. The method of claim 25, wherein the osteotomy process comprises

> removing a portion of the facet joint with a drill bit for forming a trajectory according to the planned trajectory; and retracting the drill bit out of the vertebral body and the trajectory; wherein the osteotomy process is automatically controlled by a first motor.

27. The method of claim 25, wherein the pedicle tract preparation process comprises inserting a pedicle feeler into the trajectory;

> advancing the pedicle feeler for forming a transpedicular tract; extending the pedicle feeler to a desired position of the vertebral body; and

> removing the pedicle feeler from the transpedicular tract; wherein the inserting and the removing are automatically controlled by a second motor of the second receptacle.

28. The method of claim 27, further comprising

> withdrawing the pedicle feeler from the trajectory;

> adjusting the trajectory using a computational algorithm for forming a revised trajectory; and

> re-inserting the pedicle feeler into the revised trajectory.

29. The method of claim 25 or 27, wherein the pedicle tract preparation process further comprises constructing a real-time image by a non-radiating mechanism for guiding the pedicle tract preparation and preventing a breach of the pedicular cortex.

30. The method of any of the preceding claims 25, 27 or 29, wherein the pedicle tract preparation process further comprises constructing a real-time image by processing intraoperative data transmitted from received signals of the ultrasonic probe; wherein the ultrasonic probe is configured to be installed inside the pedicle feeler.