Device and method for automated bone drilling in orthopedic surgery

Abstract

The invention relates to a device and method for automated bone drilling in orthopedic surgery, equipped with a main body with a body (1) configured with a handle (13) and an inner space in which a linear bearing (2) is mounted, in which a hollow cylindrical linear guide (3), in which the first rotary electric motor (4) and second electric motor (6) are mounted, to which the working mechanism equipped with a working tool (5) is fixedly attached, where the second rotary motor (6) is fixedly mounted in the bottom of the housing (1) with an axis parallel to the axis of the linear bearing (2) with a screw (7) and a bracket nut (8) fixedly connected to the hollow cylindrical linear guide (3) or the second rotary motor (6) is fixedly mounted in the upper part inside the handle (13) of the main body (1), in which its axis is crossed with the axis of the linear bearing (2), and a helical gear (14) is mounted on the rotor of the second motor (6) connected to a second helical gear (15) with the screw (7) and a cantilever nut ( 8), fixedly connected to the hollow cylindrical linear guide (3), and the axis of the screw (7), bearing at both ends in the housing (1), is parallel to the axis of the linear bearing (2), where between the cantilever nut ( 8) and the hollow cylindrical linear guide (3) is positioned force sensor (9) located in a housing (10) in which the force sensor (9), piston (11) and adjusting screw (12) are located on one axis, provided with a screw and a lock nut (24), the housing (10) being fixedly connected to the cylindrical linear guide (3) and the piston (11) being fixedly connected to the cantilever nut (8) by means of lock nuts (23), and to the outside at one end of the main body (1) by means of a supporting arm, a non-contact temperature sensor (16) is immovably mounted, and the device is connected through a control system with controllers and power supplies of an interface device (21) to a control, processing and information storage module (22) with the possibility of connecting to a specialized robot. The described device precisely and automatically controls the drilling process with force feedback, hence the significant improvement in the quality of the bone drilling process, guaranteeing no damage to the bone and the area around it.

Description

[0001] DEVICE AND METHOD FOR AUTOMATED BONE DRILLING IN ORTHOPEDIC

[0002] SURGERY

[0003] FIELD OF THE INVENTION

[0004] The invention relates to medical devices and in particular orthopedic ones for automated bone drilling, applied as automated tools by an orthopedist or by an executive unit of a specialized medical robot in orthopedic surgery, as well as a method for automated bone drilling.

[0005] BACKGROUND OF INVENTION

[0006] Many medical devices for piercing human bones, incl. and drills in use today are manually operated, with the position and orientation of the device being used performed by a surgeon. An Integra kit manufactured by Integra Life Sciences is known where drilling using such hand-held devices requires significant energy from the surgeon's hands, both to provide normal force to the drill and to crank the drill to penetrate the bone. In addition to being a relatively slow process, such hand-driven drilling can lead to inaccurate hole direction due to difficult control and surgeon fatigue. In order to avoid damage to the subject's bone tissue or other internal tissues, it is necessary for the surgeon to apply normal and torsional forces at the moment the drill penetrates the bone very precisely.

[0007] It is known from BG66136B1 an orthopedic device consisting of a cylindrical housing, on the bottom of which an electric motor is attached, to the axis of which a screw with a nut is mounted, where the shaft of the motor being connected to the screw and to the nut from the inside of the housing, two parallel guide with bearing bushings to which is clamped a linearly moving second electric motor coaxial with the first and carrying a cutting tool on its axis, wherein the tool being provided with a temperature sensor located at its tip.

[0008] The described orthopedic device does not provide force feedback (force sensor), which significantly complicates the process of drilling bones for the needs of orthopedics, and the configurated two sequentially and coaxially located motors provide a large length of the orthopedic device and make it difficult to operate it during work. The lack of a non-contact temperature sensor to measure the temperature of the drill shaft outside the bone also makes the operation of the orthopedic device difficult in terms of not allowing the bone to overheat and risk osteonecrosis. Also known from US987734 B2 is a medical drilling device with control of drilling depth, which consists of a housing having a proximal end and a distal end, provided with a handle and a working part; a motor located in the housing; a gearbox connecting the motor to a working tool, alternatively interchangeably connected by a clutch, wherein the motor rotates the gearbox, the clutch and the working tool; a torque sensor configured to measure the punching torque at the gearbox output and convert the measured punching torque into a torque measurement signal.

[0009] The motor is a first drive which is axial motor and a second drive which is rotary motor with a second shaft. The working mechanism is equipped with a guide mechanism, including: a tool guide around the working tool; front surface guide; and a programmable electronic module configured to control torque in the at least second drive member.

[0010] The first drive shaft and the second drive shaft are in parallel arrangement with respect to each other. The device is functionally connected to a robotic arm. It also equipped with a torque and axial force sensor, along with providing the user with information on the status of the actuator during its use. The described device does not have the ability to set and adjust the readings of the force sensor, which does not allow to precisely determine the starting position at the start of drilling, as well as to perform the autonomous force control of the drilling process with feedback from the force sensor and the automated stop of the process without affecting the surrounding tissues. The lack of a non-contact temperature sensor to measure the temperature of the drill shaft outside the bone makes the operation of the orthopedic device difficult in terms of not allowing the bone to overheat and risk osteonecrosis. The control methods described use two buttons to control the motors and do not allow the implementation of temperature feedback control. In addition to adjusting the linear and angular speed of the drill, ensuring drilling accuracy, it is also essential to establish the upper limit of the drilling temperature at which overheating of the bone may occur during drilling.

[0011] THE SUMMARY OF INVENTION

[0012] The purpose of the invention is to create a device and a method for automated bone drilling in orthopedic surgery, which works with high accuracy and precision with minimal overall dimensions, as well as providing the optimal management of the "bone drilling" process with minimal trauma as in the bone tissue in the drilling area, as well as adjacent tissues outside the bone and full control of the temperature and speed of the drill when passing through sections of the bone of different density. This purpose is solved by means of a device for automated bone drilling in orthopedic surgery, equipped with in one embodiment of a main body with a housing configured with a handle forming an internal space housing first and second rotary motors, one of which is connected to working (cutting) tool, where a linear bearing is installed in the inner space of the main body, in which a hollow cylindrical linear guide is mounted, in which the first rotary electric motor is installed coaxially, with the working tool fixedly clamped to the rotor of the motor, wherein with the second rotary motor fixedly mounted at the bottom of the main body, whose axis is parallel to the axis of the linear bearing, with a screw with a cantilever nut mounted to the rotor of the second motor, and between the cantilever nut and the hollow cylindrical linear guide is mounted a force sensor located in a housing in which on one axis are located in addition to the force sensor and a piston with an adjusting screw equipped with a lock nut, where the housing is fixedly connected to the cylindrical linear guide and the piston is fixed connected to the cantilever nut by means of a screw and lock nut. A non-contact temperature sensor is fixed to the main body and is directed to the working tool.

[0013] In a further version, the device has the same construction as the above, it equipped with a main body with an housing configured with a handle, inside which a linear bearing is mounted, in which a hollow cylindrical linear guide is mounted, a rotary electric motor is coaxially mounted in it, to which rotor is a fixedly clamped working tool, with the difference that the second rotary motor is fixedly mounted to the handle of the main body. The axis (axis 1) of the second motor is crossed with the axis (axis 2) of the linear bearing or their axes intersect at an angle greater than 90 degrees, and a helicoid gear is mounted on the rotor of the second motor, connected to a second helicoid wheel, by means of a screw equipped with a cantilever nut, which is fixedly connected to the hollow cylindrical linear guide, the axis (axis 2) of the screw being parallel to the axis of the linear bearing, where the screw bears at both ends in the main body, as between the cantilever the nut and the hollow cylindrical linear guide, a force sensor is mounted in a housing, inside which a piston, the force sensor and an adjusting screw are connected coaxially, connected with a lock nut. The housing is immovably connected to the cylindrical linear guide, and the piston is provided with a fixing nut and is fixedly connected to the cantilever nut. A non-contact temperature sensor is fixed to the main body and is directed to the working tool. In another further embodiment, the device provides for the maintenance of a permanent rigid connection between the bone and the body of the main body during drilling, the device in both its variants of a second motor can be additionally implemented at the end of its body from the working tool with detachable, replaceable cannulas, and can also be provided with sharp adjustable cylindrical tips, which are parallel to the working instrument and clamped to one end of the main body by means of set screws, so that their length can be adjusted in relation to the length of the working instrument.

[0014] All variants of the described devices are connected through a management system with controllers and power supplies of an interface device receiving information from the sensors to a control and controlling module equipped with programs for its management, processing and storage of information, as well as with the ability to connect to specialized robot. fe-a Further object of the present invention also represents a method for automated bone drilling with the described device providing the specific operating modes in orthopedic surgery, including: a) drive the working device at a speed with an initial incremental movement of the working tool forward to drill bone and measure the axial force on the working tool with reading the contact with the bone and signaling the interface device and command and control module with automatic switching on of a first rotary motor to rotate the the working tool; b) contacting a field of bone with a distal gripping end of the working tool of the device and initiating drilling of the bone; c) accounting for contact of the working tool with the bone, reducing the speed of forward movement of the tool within the limits of 6 mm / s to 0.5 mm / s and obtaining a shallow conical recess (centering hole) preventing the tip of the working tool from sliding on the surface of the bone with subsequent drilling at a high feed rate in the range of 4 mm / s to 6 mm / s and identifying the bone density; d) control during the forward movement of the working tool in the course of drilling through the near cortex of the bone of the progressive (axial) and rotational movement of the working tool in accordance with the data received from the force and temperature sensor in real time and depending on the data received during the identification of the bone density, according to step c), as well as automatic stopping of the forward axial movement of the working tool after the entry of its tip into the medullary channel by means of the force sensor; e) automatic drilling of cortical bone until reaching the inner surface of the far cortex as obtained from step c). a shallow conical recess (centering hole) preventing the tip of the working tool from sliding on the inner surface of the bone and preventing bending of the working tool; f) automatic stop by means of the force sensor of the axial forward movement of the instrument and prevention of damage to the soft tissues behind the bone during the forward movement of the instrument (drilling) through the distal cortex of the bone according to step d) after exiting the tip of the working tool outside the bone surface; g) completing the cortical bone drilling process and automatically performing axial backward movement of the working tool to its home position by means of the control system of the interface device and the command and control module.

[0015] A significant design advantage of the device and method for automated bone drilling in orthopedic surgery is that it has a reduced length due to the parallel arrangement of the axes of the two motors or when a second motor is positioned in the handle of the device. The participating force sensor allows both to measure the pressure force during the drilling process and to control the drilling process precisely and automatically with force feedback, hence the significant improvement of the qualities of the bone drilling process, ensuring no damage to the bone and the area around it. The positioning of the force sensor inside the housing allows its regulation.

[0016] The mounted non-contact temperature sensor for measuring the temperature of the working tool during drilling provides precise control of the device in terms of the applied force and the reported temperature during drilling, which significantly improves the quality of the work process. The orthopedic device and its method based on the management and control module, equipped with a specialized software product, allow the collection of information about the "bone drilling" process for research purposes and improvement of its management modes. The motors and sensors included in it achieve the optimal management of the "bone drilling" process. The well-fixed position of the adjusting screw by means of the locking nut allows the force sensor integrated in the mechanical system of the device to accurately identify the mechanical properties of the specific bone, the object of the drilling manipulation, as well as the precise control of the pressure force during drilling on a supplied and received basis information from the sensor, motors and control and management module. The unit's motors are driven and controlled with the appropriate power supplies and microprocessor controllers based on the computer program for management and control developed for the purpose. The device and method allow for the collection of information about the "bone drilling" process for research purposes and refinement of modes for its management, as well as connection to a specialized robot.

[0017] DESCRIPTION OF THE FIGURES

[0018] Fig.1 General view and partial section of the device retracted into the main body, without the cannula (drill guide) and the second motor located in the device body;

[0019] Fig.2 General view and partial section of the device with a second motor in the main body of the device, after performing the linear stroke of the cutting tool, together with the peripheral control devices;

[0020] Fig.3 Enlarged detail A of Figures 1 and 2 of the force sensor mechanical adjustment module;

[0021] Fig.4 General view and partial section of the device with a second motor located in the handle;

[0022] Fig.5 Axonometric view of the implementation of the device with a second motor located in the handle;

[0023] Fig.6 Axonometric view of the main components of the device with a second motor located in the handle;

[0024] Fig.7 An axonometric view of the main components of the second motor device in its housing together with the cannula;

[0025] Fig.8 Side view of device with cannula attached;

[0026] Fig.9 Axonometric view of the device with mounted cannula and non-contact temperature sensor;

[0027] Fig.10 Sharp adjustable cylindrical tips clamped to the body of the device;

[0028] Fig.11 Axonometric view of the device with mounted sharp adjustable cylindrical tips and non-contact temperature sensor.

[0029] EXEMPLES OF THE INVENTION

[0030] The device for automated bone drilling is presented in fig. 1-11. According to variant 1 presented in fig. 1, 2, 3 and 7, the device for automated bone drilling in orthopedic surgery consists of a main body 1 with a housing and a handle 13, and a linear bearing 2 is installed in the cavity of the main body 1 , in which a hollow cylindrical linear guide is mounted 3, a rotary electric motor 4 is coaxially mounted in it, to the rotor of which a working tool, in particular a drill 5, is immovably clamped, and a second rotary motor 6 is immovably mounted to the main body 1, the axis of which is parallel to the axis of the linear bearing 2 . A screw 7 with a cantilever nut 8 is attached to the rotor of the second motor 6. A force sensor 9 is mounted between the cantilever nut 8 and the hollow cylindrical linear guide 3. The force sensor 9 is located in a housing 10, where a piston 11, the force sensor 9 and an adjusting screw 12 are located on one axis in the housing 10, which is fixedly connected to the cylindrical linear guide 3, and the piston 11 is equipped with nuts 23 and is fixedly connected to the cantilever nut 8.

[0031] Between the cantilever nut 8 and the hollow cylindrical linear guide 3, the force sensor 9 is mounted and connected to a regulating screw 12, the position of which is fixed by means of a lock nut 24, and the housing 10 is immovably connected to the cylindrical linear guide 3 and the piston 11 is immovably connected to the cantilever nut 8. A non-contact temperature sensor 16 is fixed to the main body 1 and is directed to the drill 5. The orthopedic device is connected through a control system with controllers and power supplies to an interface device 21 receiving information from the sensors to a control and monitoring module 22 equipped with programs for its management, processing and storage of information. In fig.l (U) and (v) indicate the possibilities for realizing the angular velocity and the incremental movement by the tool, respectively.

[0032] In a further variant of embodiment (see Figs. 3, 4, 5 and 6), the device for automated bone drilling in orthopedic surgery, consists of a main body 1 with a housing and a handle 13, inside which housing a linear bearing is mounted 2, in which a hollow cylindrical linear guide 3 is mounted, a rotary electric motor 4 is coaxially mounted in it, to the rotor of which a working tool, in particular a drill 5, is immovably clamped, and a second rotary motor 6 is immovably mounted to the handle of the main body, (axis 1) of the second motor 6 is crossed with the axis (axis 2) of the linear bearing 2 or their axes intersect at an angle greater than 90 degrees, in particular from 120°- 135°, as to the rotor of the second motor 6 a first helical gear 14 is mounted, which meshes with a second, larger diameter than the first helical gear 15, which transmits rotary motion to a screw 7 driving a cantilever nut 8, which is fixedly connected to the hollow cylindrical linear guide 3, as the axis (axis 2) of the screw 7 is parallel (axis 3) to the linear bearing 2, and the screw 7 bears at both ends in the main body 1. Between the cantilever nut 8 and the hollow cylindrical linear guide 3, a force sensor 9 is mounted, and in the housing 10, a piston 11, the force sensor 9 and an adjusting screw 12 are located coaxially, the position of which is fixed by means of a locking nut 24, and the housing 10 is immovably connected to the cylindrical linear guide 3, and the piston 11 is equipped with nuts 23 and is fixedly connected to the console nut 8. A non-contact temperature sensor 16 is fixedly mounted to the main body 1, which is directed to the drill bit 5.

[0033] In another further variant of embodiment, according to (Figs. 7, 8 and 9) the device can be constructed with detachable, replaceable cannulas 18, by means of which it achieves the maintenance of a permanent rigid connection between the bone 17 and the main body 1 during drilling.

[0034] Also, the device can be made according to (Figs. 10 and 11) and with sharp adjustable cylindrical tips 19, which are parallel to the drill bit 5. The tips 19 are clamped to one end of the main body 1 by means of fixing screws 20 so that their length can be adjusted. Adjusting the length of the tips 19 allows the use of orthopedic drills of different lengths, ensuring the amount of axial movement of the working tool in the bone.

[0035] All variants of the orthopedic device are connected through a management system with controllers and power supplies to an interface device 21, receiving information from the sensors to a management and control module 22, equipped with programs for its management, processing and storage of information, as well as to a specialized robot.

[0036] OPERATION AND USE OF THE INVENTION

[0037] The device for automated bone drilling 17 in orthopedic surgery, (e.g. cortical (tubular) bone) is used as follows: the main body 1 of the device is moved and oriented manually by means of its handle 13 or by a specialized robot (not shown in the figures) until reaching in an appropriate position relative to the object.

[0038] The electric motor 4 rotates the working tool (drill) 5, and the second electric motor 6, by means of the screw 7 and the cantilever nut 8, moves translationally the linear guide 3 bearing in the linear bearing 2, in which the motor 4 is mounted. 6 in the handle 13, the transmission of the rotary movement of a screw 7 driving the cantilever nut 8, which is fixedly connected to a hollow cylindrical linear guide 3, is carried out by means of a first helical gear 14, which meshes with a second helical gear 15.

[0039] The control of engines 4 and 6 is carried out by the control system containing the respective controllers and power supplies of the interface device 21, by means of a control and control module 22 equipped with specialized computer programs in the corresponding program environment. The force sensor 9 and the non-contact temperature sensor 16 serve to control the "bone drilling" process and are used to collect information about the drilling process, which can be stored in the commanding and controlling module 22, which in particular can be and personal computer and sends for analysis in order to optimize the control algorithms of the engines. Adjustment and initial adjustment of the force sensor 9 is carried out by adjusting and fixing the position of the piston 11 by turning the nuts 23 so as to ensure the corresponding stroke "d" (Fig. 3), which is prescribed by the manufacturer of the force sensor 9 and provides its pressure range.

[0040] The adjustment of the initial pressure on the force sensor 9 is done by means of a screw 12, with the data being read by the control modules 21 and 22. After establishing the required voltage value, the position of the screw 12 is fixed by means of a locking nut 24.

[0041] By means of the force sensor 9, integrated in the mechanical system of the device, located in the housing 10, the mechanical properties of the specific bone subject to the drilling manipulation are identified. The data received from the force sensor on the reported force at the moment of penetration and during the drilling, using a selected algorithm, allow the control of the process to be implemented in a way that guarantees the avoidance of mechanical damage to the bone. This is achieved by controlling the pressure force during drilling. Mechanical damage to the bone in the area of drilling the holes for the implant fixation screws can significantly deteriorate the stability of the implant on the bone, which can lead to the breakdown of the bone fracture fixation.

[0042] The data obtained from the temperature sensor 16 integrated in the mechanical system of the device, when using the corresponding algorithm of the drilling method, allow the management of the process to be implemented in a way that guarantees the avoidance of thermal osteonecrosis of the bone. This is achieved by controlling the temperature by varying the motor speeds accordingly during drilling.

[0043] The inclusion of the adjustable tips 19 allows the use of orthopedic drills 5 of different length according to the bone to be drilled, which ensures the maximum amount of axial movement of the working tool. Maintaining a permanent rigid connection between the bone 17 and the main body 1 of the device during drilling is realized by means of detachable, replaceable cannulas 18.

Claims

PATENT CLAIMS1.

1. A device for automated bone drilling in orthopedic surgery, equipped with a main body with a housing configured with a handle and an inner space housing first and second motors, a working mechanism with a working tool and sensors, characterized in that in the inner space of the main body (1) a linear bearing (2) is mounted, in which a hollow cylindrical linear guide (3) is mounted, in which the first rotary electric motor (4) is coaxially mounted, to which the working mechanism, equipped with a working tool (5), where the second rotary motor (6) is fixedly mounted in the bottom of the housing (1) with an axis parallel to the axis of the linear bearing (2), and a screw (7) is mounted to the rotor of the second motor (6) with a cantilever nut (8) which is fixedly connected to the hollow cylindrical linear guide (3), wherein the second rotary motor (6) optionally is immovably mounted inside the handle (13) of the main body (1), wherein the axis of the second motor is crossed with the axis of the linear bearing (2) and their axes intersect under angle greater than 90 degrees, with a helical gear (14) mounted to the rotor of the second motor (6) connected to a second helical gear (15) transmitting rotary motion to the screw (7) with the cantilever nut (8) which is fixedly connected to the hollow cylindrical linear guide (3) and the axis of the screw (7) bearing at both ends in the main body (1) is parallel to the axis of the linear bearing (2), as between the cantilever nut (8) and the hollow cylindrical linear guide (3 ) is a positioned force sensor (9) located in a housing (10), in which the force sensor (9), a piston (11) and an adjusting screw (12) equipped with a screw and a lock nut (24) are located on one axis, where the housing (10) is fixedly connected to the cylindrical linear guide (3), and the piston (11) is fixedly connected to the bracket nut (8) by means of lock nuts (23), where to the outer side at one end of the main body (1) by means of a bearing a non-contact temperature sensor (16) is fixedly mounted on the arm, in which the working tool (5) can be implemented with detachable, replaceable cannulae (18) or with parallel to the working tool (5) and clamped to one end of the main body (1) length-adjustable cylindrical nozzles (19) by means of fixing screws (20), wherein the device being connected through a control system with controllers and power supplies of the interface device (21), to a module for control, processing and storage of information (22) with the possibility of connecting to a specialized robot.

2. Method for automated bone drilling comprising: a) drive the working device at a speed with an initial incremental movement of the working tool forward to drill bone and measure the axial force on the working tool with reading the contact with the bone and signaling the interface device andcommand and control module with automatic activation of a first rotary motor to rotate the working tool; b) contacting a field of bone with a distal gripping end of the working tool of the device and initiating drilling of the bone; c) accounting for contact of the working tool with the bone, reducing the speed of forward movement of the tool within the limits of 6 mm / s to 0.5 mm / s and obtaining a shallow conical recess (centering hole) preventing the tip of the working tool from sliding on the surface of the bone with subsequent drilling at a high feed rate in the range of 4 mm / s to 6 mm / s and identifying the bone density; d) control during the forward movement of the working tool in the course of drilling through the near cortex of the bone of the progressive (axial) and rotational movement of the working tool in accordance with the data received from the force and temperature sensor in real time and depending on the data received during the identification of the bone density, according to step c), as well as automatic stopping of the forward axial movement of the working tool after the entry of its tip into the medullary channel by means of the force sensor; e) automatic drilling of cortical bone until reaching the inner surface of the far cortex as obtained from step c). a shallow conical recess (centering hole) preventing the tip of the working tool from sliding on the inner surface of the bone and preventing bending of the working tool; f) automatic stop by means of the force sensor of the axial forward movement of the instrument and prevention of damage to the soft tissues behind the bone during the forward movement of the instrument (drilling) through the distal cortex of the bone according to step d). after exiting the tip of the working tool outside the bone surface; g) completing the cortical bone drilling process and automatically performing axial backward movement of the working tool to its home position by means of the control system of the interface device and the commanding and controlling module.

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