Patent ID: 12220293

DETAILED DESCRIPTION OF EMBODIMENTS

The disclosure will be described in detail below with reference to the embodiments and accompanying drawings to make the objectives, technical solutions, and advantages clearer. It should be understood that these embodiments are only illustrative of the application, and are not intended to limit the application. For those skilled in the art, the present application can be implemented without some of these specific details. The following description of the embodiments is only to promote the understanding of the present application.

It should be noted that as used herein, relational terms such as “first” and “second” are merely intended to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply such an actual relationship or order between these entities or operations. Furthermore, the term “comprise”, “include”, “contain” or any other variations are intended to encompass a non-exclusive inclusion, such that a process, method, article, or instrument not only includes those listed elements, but also includes those that are not clearly listed, or those elements that are inherent to such a process, method, article, or instrument. If there are no more restrictions, the elements defined by the sentence “comprising . . . ” do not exclude the existence of other identical elements in the process, method, article, or instrument comprising the elements.

The disclosure provides a robot system for the root canal treatment, whereFIG.1illustrates an overall structural of the robot system according to an embodiment of the present application; andFIG.2ashows the robot system according to an embodiment of the present application in use. As shown inFIGS.1and2a, the robot system includes a robot1for the root canal treatment. In some embodiments, the robot system further includes a tooth retainer2used in conjunction with the robot1.FIG.2bschematically shows the operation status of the tooth retainer2according to an embodiment of the present application.

InFIG.2a, A is the three-dimensional data of the dentition. In the practical application, the tooth retainer2is fixed to the patient's dentition by a retaining material (such as silicone rubber), and the target tooth (requiring the root canal treatment) is exposed to the surgical field2-1, then the robot1for the root canal treatment controls the working laser to treat root canals of the target tooth according to a pre-designed procedure and path.

The robot1is mainly used to control the four degrees of freedom of the optical fiber for the root canal treatment (referred to as working optical fiber below), including three translational degrees of freedom, namely translations along x, y, and z directions perpendicular to each other, and one rotational degree of freedom, namely the rotation around the z-axis (a-axis rotation), as shown inFIG.3. The overall structure of the robot1is shown inFIG.4, including an x-axis driving motor4, a y-axis driving motor7, a z-axis driving motor13, an a-axis driving motor16and other components to enable the four-degree-of-freedom movement of the working optical fiber. In practice, in addition to the motor, the four-degree-of-freedom movement of the working optical fiber can also be enabled based on hydraulic pressure, air pressure, artificial muscle and dielectric, thermal or magnetic elastomer materials.

FIGS.5aand5bshow an x-y movement unit of the robot, including the x-axis driving motor4, an x-axis screw rod3, an x-axis movable sliding rail6, an x-axis movable sliding rod10, the y-axis driving motor7, a y-axis screw rod8, a y-axis movable sliding rail5, a y-axis movable sliding rod11and a pan tilt9. The x-axis driving motor4, the y-axis driving motor7, the x-axis movable sliding rail6and the y-axis movable sliding rail5can be fixed to the main body17by screw fastening, welding, riveting or adhesive bonding. The x-axis movable sliding rod10fits with the x-axis screw rod3through a first surface10-A, and the y-axis movable sliding rod11fits with the y-axis screw rod8through a second surface11-A. The x-axis movable sliding rod10fits with a chute6-A of the x-axis movable sliding rail6through a third surface10-C, and the y-axis movable sliding rod11fits with a chute5-A of the y-axis movable sliding rail5through a fourth surface11-C. The pan tilt9fits with a chute10-B of the x-axis movable sliding rod10through a fifth surface9-A, and fits with a chute11-B of the y-axis movable sliding rod11through a sixth surface9-B. Through the above design, the x-axis driving motor4drives the x-axis screw rod3to rotate, and the x-axis screw rod3further drives the x-axis movable sliding rod10to slide along the x-axis relative to the x-axis movable sliding rail6, thereby driving the pan tilt9to move along the x-axis. Similarly, the y-axis driving motor7drives the y-axis screw rod8to rotate, and the y-axis screw rod8further drives the y-axis movable sliding rod11to slide along the y-axis relative to the y-axis movable sliding rail5, thereby driving the pan tilt9to move along the y-axis. In practice, in addition to the screw transmission, the wire rope transmission, belt transmission, chain transmission or gear transmission is also feasible.

FIG.6shows a z-axis movement unit of the robot1, including an upper platform12, a z-axis driving motor13, a first rolling wheel axle14, a second rolling wheel axle15, and their individual components.FIGS.7aand7bare exploded views of the z-axis movement unit of the robot1for the root canal treatment.

The upper platform12is fixedly connected to the pan tilt9by a screw12-3. The z-axis driving motor13is fixedly connected to the upper platform12by a flange and a screw, and a motor shaft13-4of the z-axis driving motor13is in rotating fit with a seventh surface12-B and an eighth surface12-E of the upper platform12. A driving transmission friction wheel13-1, a permanent magnet13-2, and a driving optical fiber friction wheel13-3are fixedly connected to the motor shaft13-4of the z-axis driving motor13, so that they can be driven by the z-axis driving motor13to rotate together. A ninth surface14-A of the first rolling wheel axle14is in rotation fit with a tenth surface12-F of the upper platform12, and is capable of sliding on an eleventh surface12-C of the upper platform12. A first driven transmission friction wheel14-1, a first electromagnetic coil14-2, a first driven optical fiber friction wheel14-3are fixedly connected to a first wheel axle tube14-4. The first wheel axle tube14-4is in rotating fit with the first rolling wheel axle14, both of which can rotate relative to each other. Meanwhile, the first wheel axle tube14-4is limited by a snap spring or an axle sleeve to move along an axial direction of the first rolling wheel axle14. A twelfth surface14-B of the first rolling wheel axle14is provided with a torsion spring to separate the first rolling wheel axle14from a z-axis driving shaft in the initial state (the first electromagnetic coil14-2is not energized). A thirteenth surface15-A of the second rolling wheel axle15is in rotating fit with a fourteenth surface12-D of the upper platform12, and is capable of sliding on a fifteenth surface12-A of the upper platform12. A second driven transmission friction wheel15-1, a second electromagnetic coil15-2and a second driven optical fiber friction wheel15-3are fixedly connected to the second wheel axle tube15-4, and the second wheel axle tube15-4is in rotating fit with the second rolling wheel axle15, both of which can rotate relative to each other. The second wheel axle tube15-4is limited by a snap spring or an axle sleeve to move along an axial direction of the second rolling wheel axle15. A sixteenth surface15-B of the second rolling wheel axle15is provided with a torsion spring to separate the second rolling wheel axle15from the z-axis driving shaft in the initial state (the second electromagnetic coil15-2is not energized).

The implementation process that the robot drives the illuminating and imaging optical fiber12-1and the working optical fiber12-2to move along the z-axis is described as follows. As mentioned above, in the initial working state, the first rolling wheel axle14and the second rolling wheel axel15are separated from the motor shaft of the z-axis driving motor under the action of the torsion spring, and if it is required to drive the working optical fiber to move along the z-axis, the first electromagnetic coil14-2is needed to be energized to generate a magnetic field that attracts the permanent magnet13-2. As a consequence, the permanent magnet13-2attracts the first rolling wheel axle14to rotate relative to the tenth surface12-F, so that the first driven transmission friction wheel14-1contacts the driving transmission friction wheel13-1, and simultaneously, the working optical fiber12-2is clamped by the driving optical fiber friction wheel13-3and the first driven optical fiber friction wheel14-3. At this time, the z-axis driving motor13rotates to drive the first rolling wheel axle14to rotate by friction wheel transmission and drive the working optical fiber12-2to move along the z-axis. If it is required to drive the illuminating and imaging optical fiber12-1to move along the z-axis, the second electromagnetic coil15-2is energized to generate a magnetic field that attracts the permanent magnet13-2. As a consequence, the permanent magnet13-2attracts the second rolling wheel axle15to rotate relative to the fourteenth surface12-D, so that the second driven transmission friction wheel15-1is in contact with the driving transmission friction wheel13-1, and simultaneously, the illuminating and imaging optical fiber12-1is clamped by the driving optical fiber friction wheel13-3and the second driven optical fiber friction wheel15-3. In this case, the z-axis driving motor rotates to drive the second rolling wheel axle15to rotate by the friction wheel transmission and drive the illuminating and imaging optical fiber12-1to move along the z-axis direction. The first electromagnetic coil14-2and the second electromagnetic coil15-2cannot be energized at the same time, namely, only one of the working optical fiber12-2and the illuminating and imaging optical fiber12-1can be driven to move along the z-axis at the same time.

FIGS.8aand8bshow the a-axis movement unit of the robot, including an a-axis driving motor16, a driving transmission friction wheel17, an idler wheel18, and a driven transmission friction wheel19. The driving transmission friction wheel17is fixedly connected to a motor shaft of the a-axis driving motor16. The idler wheel18is in rotating fit with a first shaft9-C arranged at a bottom of the pan tilt9, and the driven transmission friction wheel19is in rotating fit with a second shaft12-I arranged at the bottom of the pan tilt9. The driving transmission friction wheel17, the idler wheel18and the driven transmission wheel19together form the friction wheel transmission. The working optical fiber12-2passes through a pipe12-G and extends out from the outlet19-A, and the illuminating and imaging optical fiber12-1passes through the pipe12-H and extends out from the outlet19-A. The Y-shaped optical fiber channel is shown inFIG.9. It should be noted that the Y-shaped channel can be any channel that has two inlets and shares one outlet. For example, the Y-shaped channel can be a T-shaped channel or other Y-shaped channels.

The rotation of the working optical fiber12-2around the z-axis is performed as follows. The working optical fiber12-2is driven by the z-axis movement unit to extend out from the outlet19-A of the pipe12-G, where the working optical fiber12-2of the micro-robot for the root canal treatment may have a circular or non-circular cross section, preferably a non-circular cross section, such as an elliptical, dumbbell-shaped and polygonal cross section. Moreover, the cross section of the working optical fiber12-2is matched with the outlet19-A in shape, so that when the a-axis driving motor drives the driven transmission friction wheel19to rotate through the friction wheel transmission, the working optical fiber12-2will be driven to rotate around the z-axis.

In practice, in order to make the working optical fiber12-2reach the designated position precisely, it is feasible to move the illuminating and imaging optical fiber12-1to the vicinity of the target root canal orifice through the z-axis movement unit to determine the position of the root canal orifice by imaging recognition. Then the z-axis movement unit pulls out the illuminating and imaging optical fiber12-1, and moves the working optical fiber12-2to the determined position of the root canal orifice through the Y-shaped channel, and to be inserted into the target root canal for treatment.

It can be seen that the above Y-shaped channel makes the working optical fiber12-2and the illuminating and imaging optical fiber12-1be located in the same coordinate system, and further in combination with the xyza-axis motor feedback system, the position of the working optical fiber12-2can be precisely determined. In the practical application, the working optical fiber12-2and the illuminating and imaging optical fiber12-1can be changed from the horizontal (vertical) direction to the vertical (horizontal) direction by rotating the suspension disk, which facilitates the a-axis driving motor16to drive the 360-degree rotation of the optical fiber.

FIG.10shows the gas/liquid circuit unit of the root canal treatment robot system.FIG.11shows the line connection of the robot for the root canal treatment. In the root canal preparation, it is required to feed cold air for cooling and remove the dust generated in the cutting process. After the preparation, it is required to feed the relevant drugs for filling and disinfection. The gas/liquid circuit unit mainly includes a container for holding relevant drugs and a filling paste (Liquid1, Liquid2and Liquid3), a recycling container, electromagnetic valves (E1, E2, E3and E4) for controlling the communication of each branch, and power pumps (Pump1and Pump2) and a pipeline. The gas/liquid input pipe delivers the gas or the liquid into the pulp cavity or the root canal, and the gas/liquid output pipe transfers gas, dust and other substances from the pulp cavity and the root canal to the recycling container. The gas/liquid input pipe passes through the hole1-D and the hole12-J to reach the pulp cavity, and the gas/liquid output pipe passes through the hole1-A and the hole9-D to reach the pulp cavity. The working optical fiber12-2passes through the hole1-B and the hole12-G and extends out from the hole9-A to reach the pulp cavity and the root canal, and the illuminating and imaging optical fiber12-1passes through the hole1-C and the hole12-H and extends out from the hole9-A to reach the pulp cavity and the root canal orifice.

In the robot system provided herein, in addition to the traditional motor control, the movement can also be controlled by a thermodynamic, magnetic or pneumatic method, or a magnetic or dielectric elastomer artificial muscle.

The embodiment further provides a root canal treatment method, which is preferably implemented by the above-mentioned microrobot. It should be understood that this method can also be implemented with other root canal treatment apparatuses with xyza four-degrees-of-freedom motion and a controllable-bending working optical fiber.

The root canal treatment method provided herein will be described in detail below to clearly describe the differences and advantages with respect to the conventional treatment.

(S1) Determination of the Approach, Opening Position and Endodontic Access Cavity

Traditionally, the opening position and endodontic access cavity are outlined in mind through the combination of visual observation and X-ray film.

In this embodiment:

(1) the three-dimensional data of the target tooth, the pulp cavity and root canal is obtained by cone beam computerized tomography (CBCT); and

(2) the pulp hole design software is operated by the dentist to extract the pulp hole area from the three-dimensional data to obtain the 3D morphological data of the tooth hard tissue to be removed.

(S2) Penetration of the Pulp Cavity, Removal of the Roof of the Pulp Cavity, and Trimming of the Side Wall of the Pulp Cavity

Regarding the traditional method, a high-speed turbine dental handpiece and a bur are held by a dentist to remove the hard tissue on the target tooth according to the position and shape of the cavity hole in mind, so as to form the endodontic access cavity. Then the dentin protruded on the wall of the pulp cavity is removed by visual observation or the reflection of the mouth mirror, so as to make each root canal orifice completely exposed.

In this embodiment:

(1) the tooth retainer is fixed on the target tooth and its adjacent teeth and tissues, and an intraoral part of the root canal treating microrobot is rigidly connected with the tooth retainer, so that the robot's coordinate system and the target tooth's coordinate system are kept in the same coordinate system;

(2) the motion path of the femtosecond laser spot is obtained with the help of the path planning software according to the three-dimensional data of the tooth hard tissue obtained in step (1);

(3) the intelligent recognition system automatically inputs the path planning data into the controlling software of the robot, and controls the x-axis and y-axis micro-motors to drive the hollow optical fiber to reach the initial position of the pulp opening, and the ends of the air supply and suction pipes also reach the corresponding position; the rolling wheel is controlled by the automatic controlling software to drive the hollow optical fiber to move up and down to complete the focusing; and according to the predetermined motion path, the tooth hard tissue above the pulp cavity is removed by the laser spot layer by layer to complete the pulp opening process; and

(4) during the laser cutting of the tooth hard tissue, the air pump controlling software is operated to automatically control the delivery of cold air for cooling and suck out the dust generated by the cutting at the same time.

(S3) Positioning of the Root Canal Orifice

Traditionally, the root canal is explored and located using the DG-16 endodontic probe or other instruments.

In this embodiment:

(1) when the intelligent recognition system detects that the endodontic access cavity is consistent with the designed endodontic access cavity, the motion path of the outlet end of the Y-shaped channel will be planned by automatically operating the path planning software according to the three-dimensional data of the root canal orifice reconstructed in step (1); and

(2) the planned data is automatically transferred to the robot controlling software to control the movement of the Y-shaped channel, such that the end of the Y-shaped channel reaches the vicinity of each root canal in turn.

(S4) the Root Canal is Explored and Negotiated to Establish a Root Canal Access, Measure the Length of the Root Canal and Complete the Root Canal Preparation, Forming a Negotiated Root Canal with a Continuous Tapered Inner Wall.

Traditionally, a small K-file is employed to negotiate the root canal, and then the length of the root canal is measured by a root canal measurement apparatus; and then different modes of root canal files are used to gradually expand the access.

In this embodiment:(1) when the intelligent recognition system detects that the Y-shaped channel reaches the predetermined root canal orifice, the path planning software is automatically operated to plan the extension and bending of the optical fiber according to the three-dimensional data of the root canal reconstructed by CBCT;(2) the path planning data is automatically transmitted to the controlling software of the robot, which issues instructions to control the rolling wheel in the robot to rotate, such that the illuminating and imaging optical fiber gradually extends; after reaching the designated position, the length and location of the illuminating and imaging optical fiber are recorded; then the illuminating and imaging optical fiber is retracted, and the femtosecond laser hollow optical fiber is driven to gradually extend;(3) when the intelligent recognition system detects that the hollow optical fiber reaches the predetermined position, the air pump controlling software is called to automatically control the quantitative feeding of the hot air at a fixed temperature to the optical fiber, causing the quantitative deformation and bending of the deformable materials attached to the optical fiber (including temperature-based elastic materials, and other acoustic, optical, dielectric, thermal and magnetic materials, such as polyester polymers and titanium-nickel memory wire alloys);(4) during the extension process of optical fiber, the femtosecond laser automatic control software is called to adjust the spot and power of the femtosecond laser in real time, so that it acts on the residue and inner wall of the root canal, and cuts the root canal according to the pre-planned path to prepare a continuous and unobstructed tapered root canal;to arrive at the preset taper, the self-characteristic of the laser Gaussian beam or the additional controllable micro-radius oscillating device is used to control the fiber to move from top to bottom or from bottom to top, during the extension process of the working optical fiber into the root canal, thereby obtaining a continuous unobstructed tapered root canal according to the pre-planning, see Equation 1:
F(φ)=f(ω,v)  (1);where φ is the root canal taper, ω is the laser power, and v is the moving speed of the optical fiber; and(5) during the femtosecond laser cutting of the tooth tissue, the air pump control software is called to automatically control the air flow to suck out the dust generated by the cutting in time.

(S5) Irrigation and Disinfection of the Root Canal

Traditionally, a root canal irrigator is employed to sequentially take sodium hypochlorite, EDTA, chlorhexidine and normal saline to irrigate and disinfect the root canal, so as to remove the parasitic microorganisms in the root canal completely.

In this embodiment:(1) when the intelligent recognition system detects that the tapered root canal is consistent with the predetermined design, the robot control software is automatically called to control the air inlet pipes to point to the individual root canals in sequence; and(2) the air pump controlling software is automatically called to open the valve of the medicine storage tank, quantitatively feed a irrigation and disinfection liquid, at a constant pressure, then control the suction tube to suck the liquid out, which are repeated for three to four times, and automatically control the input of hot air to dry the root canal and the pulp cavity.

(S6) Filling of the Root Canal

Warm Gutta-Percha filling is a traditional method. The prepared root canal sealer is applied to a thin layer with a paper twist on the root canal wall by the dentist, and an injection needle of a Gutta-Percha filling system is inserted into the root canal 3-5 mm distant to an apex of the root to inject the Gutta-Percha and then compact it.

In this embodiment:(1) after the intelligent pattern recognition system detects that the pulp cavity and root canal are in a dry state, the path planning program is automatically called to form the planned data, which is input to the robot controlling software to control the air inlet to point to the position of each root canal orifice in turn; and(2) the air pump controlling software is automatically called to close the air intake tube, and open the suction tube to quantitatively form a negative pressure, open the valve of the root canal sealant storage tank and close the valves of the other storage tank, and suck the root canal sealant to the wall of the root canal. Then open the valve of the hot Gutta-Percha storage tank, under the action of the negative pressure, the hot Gutta-Percha is automatically introduced into each root canal to complete the filling process.

It should be noted that the above-mentioned intelligent recognition system is an optional software for the operation of the root canal treatment microrobot. The related operations implemented by the system can also be completed manually, so that the root canal treatment micro-robot can be used to achieve the semi-automatic root canal treatment.

Described above are merely preferred embodiments of the present application, which are not intended to limit the present application. It should be understood that various modifications, replacements and changes made by those skilled in the art without departing from the spirit of the application should still fall within the scope of the present application defined by the appended claims.