Surgical needle holder three-dimensional positioning device with nested robot

Abstract

A positioning device comprising a pair of nested robots is suitable for magnetic resonance guided real-time imaging and head-mounted bilateral stereotactic neurosurgery. In particular, the positioning device is suitable for positioning a needle holder of a tubular / needle-shaped instrument in a neurosurgical procedure. The positioning device keeps enough working space (+ / -35 degrees), also has the characteristics of light weight (203g) and compactness (the diameter is 81mm * the height is 97mm), and can be mounted on the skull and used in most standard imaging head coils. The five-connecting-rod structure can reserve an exposed space around a notch part (a drill hole in the skull), so that operation and observation are facilitated. The robotic system operates in two phases: i) manually coarse tuning interactively by a surgeon within a large workspace; ii) subsequently performing automatic fine tuning by the fluid-driven flexible actuator within the local range of motion.

Description

Field of the Invention

[0001] The invention relates to the field of robotic positioning devices for tubular surgical tool holders in stereotactic surgery, which positioning devices can be mounted on the body of a patient. Background Art

[0002] In stereotactic surgery, typical robotic positioners used to control cannula devices or biopsy needles rely on a large stereotactic frame that is rigidly mounted to the skull to orient the instrument relative to a three-dimensional coordinate system. Recent advances in MRI hardware, imaging protocols, and coils have made it an effective option for real-time image-guided interventions. However, automating equipment in the MRI environment presents challenges because typical robots are often made of metal or magnetic components that can interfere with MRI images. Furthermore, most robots are not designed with the limited space inside the MRI machine, where the patient must be positioned.

[0003] Some locators, such as Clearpoint TM The brand's positioner requires the surgeon to manually adjust the positioner using a long-reach manual handle. The surgeon must repeatedly try to position the needle holder to the target location with the help of repeated magnetic resonance imaging until it is accurately positioned.

[0004] The same inventor proposed a device in WO2019144904A1 in which two slender deep brain stimulation needles (300 mm in length and 1.3 mm in diameter) are guided separately by dual stereotactic frames. Each frame includes an upper actuator and a lower actuator mounted on a common platform, which is mounted on the patient's skull by screws. This pair of frames cannot be mounted on the skull at different angles, and the movement of the actuators relative to each other exceeds the original footprint of the device, making the space required for the full range of motion of the frame larger than it appears.

[0005] Therefore, there is a need for a surgical positioner for stereotactic positioning of a rod-shaped end effector that has a robust structure and occupies a relatively small space, leaving room for the installation of dual devices in applications such as deep brain stimulation surgery. Summary of the Invention

[0006] In a first aspect, the present invention provides a positioning device for a surgical needle holder, comprising a second robot installed within a first robot; the second robot can be used to clamp the surgical needle holder and move the surgical needle holder within a workspace so that the surgical needle holder always maintains stereotactic alignment with a center of motion; the first robot can be used to clamp and move the second robot within the workspace so that the surgical needle holder always maintains stereotactic alignment with the center of motion.

[0007] Optionally, the first robot has a spherical five-bar series structure. Other first robots, even those in the prior art, can also be used, and the second robot can be an upgrade of the robots in these prior art.

[0008] Therefore, it is preferred that the second robot is replaceable.

[0009] Typically, the second robot is capable of adjusting the position of the surgical needle holder around the center of motion independently of the spherical five-bar series structure mechanism.

[0010] One embodiment includes a pair of nested robots for gripping and moving a surgical needle holder. These robots are capable of moving the needle holder with varying motion resolutions. For example, a spherical five-bar tandem structure can move the needle holder in response to manual control, while a second robot can more finely adjust the needle holder's position through software automation.

[0011] Preferably, the positioning device further comprises a light emitting device of a predetermined color for indicating that the position of the surgical needle holder is within a predetermined error range of the target position; wherein the spatial range defined by the error range is equal to or smaller than the working space in which the second robot can move the surgical needle holder.

[0012] This feature eliminates the need for the surgeon to rely on multiple MRIs to determine whether the needle holder has been moved to a position within the desired needle holder position.

[0013] Preferably, the positioning device further comprises a curved base rod; the curved arc angle of the base rod enables the entire curved portion of the base rod to contact a certain position on the head of an average person.

[0014] While not strictly true in all cases, this characteristic generally prompts manufacturers to produce positioning devices that are sized to fit on the patient's head and provide sufficient space for mounting a dual positioning device or any other appropriately sized device elsewhere on the head, while allowing the patient's head, with the dual positioning device mounted, to fit within a typical MRI head coil.

[0015] Preferably, the spherical five-bar series structure includes: a curved base rod; the curved base rod has two ends; one end of the curved base rod is rotatably connected to the proximal end of the first double-bar series link arm; the other end of the curved base rod is rotatably connected to the proximal end of the second double-bar series link arm; the distal end of the first arm and the distal end of the second arm act as the distal link of the spherical five-bar series structure through mutual tension cooperation; wherein the spherical five-bar series structure clamps the second robot and aligns it with the distal link and moves it.

[0016] The distal link does not necessarily have to be a physical link. The functional distal link has the same effect as a physical distal link. In addition, it has the advantage of being able to detach the distal link when needed.

[0017] Typically, the distal end of the first arm clamps the surgical needle holder; the distal end of the second arm clamps the second robot; the mutual tension is a force that pushes the surgical needle holder and the second robot in opposite directions, and its target is the device that prevents the surgical needle holder from separating from the second robot.

[0018] This ensures that the second robot can move in coordination with the first robot when the needle holder is manually pushed, and avoids the situation where the needle holder moves the second robot relative to the first robot when the first robot is stationary.

[0019] Preferably, the second robot includes a motion guide device, which is fixed to the distal end of the second arm; the distal end of the first arm can cooperate with the motion guide device to enable the needle holder to achieve two degrees of freedom of movement in the curved plane around the same center of the spherical five-bar series structure without being affected by the corresponding movement of the second arm.

[0020] As explained in the embodiments, the motion guide can be in the form of a dome and a slider, whose curvature can guide the needle holder to move around the center within the working space. Any other method that can guide the needle holder to move around the center in a curved plane with two degrees of freedom can also be used.

[0021] Optionally, this movement of the needle holder, independent of corresponding movement of the second arm, is accomplished by automated means.

[0022] Preferably, the automation is achieved by hydraulic actuation of a polymer bellows; the base joint and elbow joint are ceramic and polymer based rotary joints; and the device includes a particle blocking pack for fixing the position of the needle holder relative to the second arm.

[0023] The above features make the positioning device suitable for deployment in a magnetic resonance environment without interfering with magnetic resonance imaging.

[0024] In a second aspect, the present invention provides a nested motion guide device for installation in a nested motion guide device, wherein the nested motion guide device is configured to clamp a surgical needle holder and maintain stereotactic alignment with a center of motion; and the nested motion guide device is configured to clamp and move the nested motion guide device and the surgical needle holder so that the surgical needle holder always maintains stereotactic alignment with the center of motion.

[0025] Preferably, the movement of the nested motion guides can be controlled by software automation.

[0026] In another aspect, the present invention provides a method for positioning a surgical needle holder to align with a surgical target within a patient's body, the method comprising the following steps: moving a nested motion guide, which holds a nested motion guide, which in turn holds the surgical needle holder, away from an opening on the patient's body and moving the nested motion guide around the opening, the opening coinciding with a center of motion of the nested motion guide; aligning the surgical needle holder with the opening and the surgical target within an error range; moving the nested motion guide around the opening as the center of motion of the nested motion guide without being affected by a corresponding movement of the nested motion guide; and aligning the surgical needle holder with the opening and the surgical target within a smaller error range.

[0027] Preferably, moving the nested motion guide device includes an automated manner using software control.

[0028] Optionally, the method includes a preliminary step of installing the nested motion guide device into the nested motion guide device. Typically, this includes adjusting the distance between the centers of motion of the nested motion guide device and the nested motion guide device so that the centers of motion of the nested motion guide device are the same as the centers of motion of the nested motion guide device. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] It will be more convenient to further describe the present invention in conjunction with the accompanying drawings, which illustrate possible configurations of the present invention, wherein like integers refer to like parts. The present invention may also have other configurations, and therefore, the specific details of the accompanying drawings should not be construed as superseding the generality of the invention described above.

[0030] Figure 1 A prior art is shown;

[0031] Figure 2 An embodiment of the present invention is shown;

[0032] Figure 3 To explain the effects of applying this embodiment;

[0033] Figure 4 The principle of the structure used in this embodiment is shown;

[0034] Figure 5 The principle of the structure used in this embodiment is also shown;

[0035] Figure 6 One component of this embodiment is shown;

[0036] Figure 7 The mechanism used in this embodiment is shown;

[0037] Figure 8 One component of this embodiment is shown;

[0038] Figure 9 is an exploded view of this embodiment;

[0039] Figure 10 is another exploded view of this embodiment;

[0040] Figure 11 It shows a function of this embodiment;

[0041] Figure 12 is another exploded view of this embodiment;

[0042] Figure 13 is another exploded view of this embodiment;

[0043] Figure 14 Another feature of this embodiment is shown;

[0044] Figure 15 The effect of applying this embodiment is also shown;

[0045] Figure 16 An application of this embodiment is shown;

[0046] Figure 17 Another embodiment of the present invention is shown;

[0047] Figure 18 Another embodiment of the present invention is shown;

[0048] Figure 19 Shown in more detail Figure 18 Embodiments of

[0049] Figure 20 Shown separately Figure 18 Embodiments and needle holders thereof;

[0050] Figure 21 Shown Figure 18 The embodiment of the present invention is nested in the prior art device;

[0051] Figure 22 Shown Figure 18 The embodiment of the present invention is nested in the prior art device;

[0052] Figure 23 Shown Figure 18 The embodiment of FIG. 1 is nested within a possible prior art device. DETAILED DESCRIPTION

[0053] Examples of stereotactic neurosurgery include biopsy, deep brain stimulation (DBS, which may involve applying electrical pulses to specific locations in the brain or implanting therapeutic objects deep in the brain), and ablation. Examples of tubular instruments include surgical needles, cannula devices, biopsy needles, or ablation rods. In the remainder of this specification, these instruments will be collectively referred to as "surgical needles." Those skilled in the art will understand that this includes all slender or tubular devices, whether rigid or flexible, that are inserted through an incision anywhere in the body.

[0054] In order to allow the surgical needle to enter the interior of the patient's head, a drill hole 301 is opened in the skull 300 to provide an entrance. Figure 2 A positioning device is shown that is configured to be mounted on a patient's skull 300 and includes a nested robot for holding a needle guide (also referred to as a needle holder 201) in stereotactic alignment with a burr hole 301 as a remote center of motion (RCM 501). A remote center of motion is a remote fixed point at which there is no physical rotational joint, but about which a mechanism or a portion thereof can rotate.

[0055] This positioning device comprises an external robot and a fine-tuning robot 202. The external robot utilizes a spherical five-bar tandem structure, with the fine-tuning robot 202 mounted within the distal link of the spherical five-bar tandem structure. A needle holder 201 extends through the fine-tuning robot 202. The surgical needle holder 201 is capable of gripping and linearly moving a surgical needle. To accurately reach the surgical target 303, the trajectory provided by the needle holder 201 must be straight and aligned with the borehole 301 and the surgical target 303. Both robots have the same remote center of motion (RCM 501) and can only move the needle holder 201 stereotactically on the curved surface of an imaginary sphere. Their positioning ensures that the remote center of motion 501 coincides with the borehole 301. The external robot can be manually operated to move the needle holder 201 around the borehole 301 until it is aligned with the surgical target 303 within an acceptable error range. Subsequently, software automatically controls the fine-tuning robot 202 to move the needle holder 201 to a position more precisely aligned with the surgical target 303.

[0056] The use of a spherical five-bar series structure helps limit the size of the positioning device, allowing most embodiments to fit onto a patient's head and fit within the head coil of an MRI machine. However, this also limits the distance between the tip of the needle holder 201 and the remote center of motion 501. The short distance between the tip of the needle holder 201 and the remote center of motion 501 (which acts as a fulcrum) may be too sensitive to manual adjustment for the relatively long distance between the remote center of motion 501 and the surgical target 303. Figure 3To illustrate this, the figure shows that the surgical target 303 is located on the other side of the remote motion center 501. The farther the surgical target 303 is from the remote motion center 501, each small movement of the tip of the needle holder 201 will cause a larger swing of the long needle behind the remote motion center 501.

[0057] To understand the mechanism of the spherical five-bar series structure, first consider Figure 4 The planar five-bar cascade structure shown here is easier to understand. The simplest planar five-bar cascade structure consists of five identical, slender, flat bars. Each bar is connected at both ends to the end of another bar by a joint. This joint allows rotation in a plane parallel to the ends of the two bars, with the axis of each joint perpendicular to the plane of the corresponding stacked end. The distal joints, marked with circles, can assume different positions within this plane. The bar facing the main joint is the base bar 207, which is fixed to a surface and provides support for the movement of the other four bars. In other words, the structure consists of a fixed base bar 207 with two ends. Extending from each end are arms consisting of two bars connected in series, known as a two-bar cascade link. The distal ends of the two arms are connected to form the distal joint of the five-bar ring. For ease of distinction, the joint in the middle of each arm is called the elbow joint 203, and the joint between the proximal end of each arm and the base bar 207 is called the base joint 205. Pulling the distal joint to any position requires corresponding adjustments to the positions of the other four bars and the angles of all the joints. The planar five-bar series structure can only move in a plane perpendicular to the axis, with two degrees of freedom along the z-axis and the x-axis. Any force that attempts to lift the distal joint out of this plane will be mechanically resisted by the two arms extending in different directions from the base rod 207.

[0058] A simple spherical five-bar tandem structure is similar to a planar five-bar tandem structure, but with one additional feature: the axes of the five joints are aligned with the center of an imaginary sphere of a predetermined radius, e.g. Figure 5 These rods are elongated blades with a wide cross section and thin edges, and the blades are curved along their length. Figure 6 As shown, the joint between each curved rod is formed by a pivot axis that passes perpendicularly through the plane in which the ends of the two associated blade stacks lie. The axes 601 of the joints at each end of the rod converge on the concave side of the rod to a common origin, which is the center of an imaginary sphere. This structure constrains the movement of the elbow joint and distal joint to the curved plane of the imaginary sphere's surface, ensuring that the axis 601 always points toward the center of the sphere.

[0059] Preferably, the bars are provided at their mid-width with at least one rib extending along the length of the bar to prevent the concave side of the bar from sagging.

[0060] The distal joints have limited motion within the bending plane, depending on the length or arc angle of the spherical five-bar series structure, which also defines the workspace of the spherical five-bar series structure. Generally speaking, the larger the arc angle of the bars, the larger the workspace, but the entire spherical five-bar series structure will also be bulkier, potentially occupying the surgical area around the drill hole 301. It is recommended to set the arc angle of the two proximal bars to 70 degrees and the arc angle of the two distal bars to 60 degrees to achieve a good balance between the overall workspace and the size of the positioning device 200, namely, suitable for installation on the skull 300 within the MRI head coil and providing a ±38-degree workspace (derived from kinematic analysis). Typically, to prevent the needle holder 201 from being positioned at the extremes of the workspace, mechanical constraints are imposed on the joints to limit the workspace to ±30 degrees. It is important to note that as long as the axis 601 of the joint is aligned with the center of the imaginary sphere, the curve along the length of the blade does not have to match the curvature of the imaginary sphere's surface. For example, the ends of the bars can be bent at a certain angle relative to the shaft.

[0061] The preferred joint type for connecting these rods is a revolute joint, which provides one degree of freedom between the two connected rods about the joint axis and restricts relative sliding between the rods. The orientation of the needle holder 201 relative to the imaginary sphere or robot frame can be calculated simply by the angles of the base joint 205 and the elbow joint 203 of one of the arms, as shown in Figure 2. Figure 7 As shown in FIG. Therefore, an optical encoder 211 is mounted on each of the base section 205 and the elbow section 203 of one arm to monitor and provide angular data between the associated rods, from which the position of the needle holder 201 can be inferred in real time. For convenience, the arm equipped with the optical encoder 211 is referred to as the encoder arm 215, and the other arm is referred to as the passive arm 217.

[0062] Preferably, the joints of both arms (but at least the joints of the passive arm 217) can be locked so that the arms are immobile. Figure 8 As shown, friction-based joint brake mechanisms 213 are provided on the base joint 205 and the wrist joint 203 of the passive arm 217 to prevent the rotation of the corresponding rotary joints, which is sufficient to fix the spherical five-bar series structure and thus fix the external robot. Figure 8 The joint braking system 213 is shown, which includes a pair of friction rings 603 ( Figure 6(also shown in ), is used to squeeze the rubber layer between the outer rod and the inner rod of the rotary joint, instantly preventing the two rods of the rotary joint from rotating to ensure precise positioning. The friction ring 603 is configured as a two-layer stacked structure, surrounding the inner and outer surfaces of the joint in arcs arranged counterclockwise and clockwise, with each ring covering three-quarters of the circumference of the joint. One end of each ring is fixed and the other end is connected to the Bowden cable 605, which pulls the ring down to make contact with the joint. This creates a two-way braking effect that prevents the joint from exceeding the desired position due to imbalanced braking of the rods in the rotary joint. To enhance the braking effect, the inner surface of the ring is made of rubber material to increase the grip of the brake 213.

[0063] Preferably, optical encoder 211 incorporates fiber optic illumination to indicate to the surgeon the degree of error relative to surgical target 303. For example, if the needle holder 201's current position deviates from the target by more than 20 degrees, the fiber optic will emit red light; if the error is between 20 and 5 degrees, the fiber optic will emit purple light; and if the error is less than 5 degrees, the fiber optic will emit green light.

[0064] Preferably, the fine-tuning robot 202 is a soft robot made of deformable soft materials, which are usually organic materials and have magnetic resonance inertness. The fine-tuning robot 202 is placed below the distal end of the encoder arm 215. Figure 9 The distal rod on the encoder arm 215 is shown bent upward at its mid-length and slightly extended to accommodate the fine-tuning robot 202. The needle holder 201 is clamped to the distal end of the encoder arm 215, aligned with the remote center of motion 501, and inserted into the fine-tuning robot 202, which is held by the passive arm 217. The needle holder 201 has no independent movement other than rotation about its own axis and cannot tilt in any direction relative to the distal rod. Instead, the position of the needle holder 201 is adjusted by angular changes in the elbow joint 203 and base joint 205 of the encoder arm 215, which are detected by optical encoders 211 mounted on these joints.

[0065] Figure 9 The fine-tuning robot 202 is also shown in an exploded view. As can be seen, the fine-tuning robot 202 includes a housing that is circular when viewed from above, although different shapes may be used in other embodiments. The passive arm 217 clamps the housing through the housing base 911.

[0066] The housing has an axis pointing to the remote center of motion 501. The top of the housing is a cover 901 with an opening in the center of the cover through which the needle holder 201 is inserted into the fine-tuning robot 202. All relevant components within the housing of the fine-tuning robot 202 each have a central opening, and these openings are axially aligned to allow the needle holder 201 to pass through. The base of the housing 911 also has an axially aligned opening for the surgical needle in the needle holder 201 to pass through. The diameters of all openings together allow the needle trajectory to have a positional variation of ±5 degrees, which is the working space of the fine-tuning robot 202, as shown in FIG. Figure 10 shown.

[0067] Below the housing cover 901 is a particle blocking bag 903 for locking the needle holder 201 on the fine-tuning robot 202. That is, when the position of the needle holder 201 is fine-tuned, the positioning device 200 will be fixed for inserting the surgical needle.

[0068] The particle blocking bag 903 is firmly fixed to the top of the dome 905 by strong glue or other fixing means. The dome 905 is shaped like an inverted plate and is firmly fixed to the housing. The lower surface of the dome 905 has a curvature that matches the curvature of the imaginary sphere workspace. Below the dome 905 is a slider 907, which includes three blades extending radially from its center, and the edges of the blades are radially aligned with the axis of the housing. The top surfaces of the blades together form a curvature that completely matches the curvature of the inner surface of the dome 905, and therefore also matches the curvature of the workspace. When the positioning device 200 is assembled, the slider 907 is put on the needle holder 201 and fixed at a specific position on the slender body or rod of the needle holder 201.

[0069] Below the slider 907, the rod of the needle holder 201 is inserted between three actuators 909. These actuators are evenly distributed around the axis of the housing (and therefore the rod of the needle holder 201) and are spaced 120 degrees apart from each other. The actuators 909 are made of a polymer and elastomeric material that is magnetically inert. Each actuator has an axisymmetric bellows shape to provide a piston-like mechanism. The bellows shape is formed by the diameter difference between a series of alternating inner and outer pleats distributed along the axis. Each actuator can be individually actuated by fluid inflation / deflation. To limit undesirable radial expansion, the circumference of the top of the larger pleats is hardened with another polymer material so that deformation occurs preferentially in the direction of elongation rather than radial expansion.

[0070] The portion of the needle holder 201 that extends upward from the slider 907 is pushed out of the opening in the dome 905 toward the distal end of the encoding arm 215, but the slider 907 is too large to pass through the opening in the dome 905. The slider 907 prevents the needle holder 201 from extending too far from the dome 905.

[0071] Figure 11 and Figure 12 The figure shows how actuators 909 push against the rod of needle holder 201 inserted between them. Each actuator's force is directed upward, with a lateral force vector pointing toward the lower portion of the needle holder 201 rod and an upward force vector acting on slider 907 mounted on needle holder 201. Actuators 909 are continuously supplied with a minimum amount of hydraulic pressure, which keeps slider 907 pressing upward against dome 905. However, because this minimum hydraulic pressure is also applied to the needle holder 201 rod from three directions (120 degrees apart), the lateral forces cancel each other out. The other end of each actuator rests downward on housing base 911, which provides a platform for actuators 909 to push downward, generating a reaction force opposing the upward force acting on slider 907 and simultaneously pressing upward against dome 905, which is securely fastened to the housing.

[0072] In this manner, the needle holder 201 and the encoder arm 215 are always in tension and prevented from sagging, which helps ensure that the distance between the needle holder 201 and the remote center of motion 501 remains constant. This allows the angles of the elbow joint 203 and the base joint of the encoder arm 215 to be used to accurately infer the orientation of the needle holder 201 relative to the remote center of motion 501.

[0073] Needle holder 201 and fine-tuning robot 202, without requiring a physical connection, form a spherical five-bar tandem kinematic mechanism to guide the movement of needle holder 201. The minimal pressure exerted by the actuator on slider 907, pressing against dome 905, is sufficient to maintain a tensioned relationship between needle holder 201 and fine-tuning robot 202, enabling coordinated motion, much like a distal joint physically connected between the distal ends of encoder arm 215 and passive arm 217. Within the fine-tuning robot 202 housing, the position of slider 907 and needle holder 201 relative to dome 905 is unimportant, as the remote center of motion 501 of dome 905 and slider 907 is identical to the remote center of motion 501 of the external robot.

[0074] In the simplest embodiment, the base rod 207 is supported on the blade edge by a mounting base 209. The mounting base can be simple, such as two L-shaped plates at each end of the base rod 207. The mounting base 209 has holes through which titanium screws pass and engage with screw holes in the skull 300 (or other flat bones when performing surgery elsewhere in the body). The mounting base 209 also allows the base rod 207 to be lifted and slightly rotated downward so that the axis 601 of the coxa profunda is pointed toward the drill hole 301 for proper alignment.

[0075] Guided by dome 905 and a slider 907 attached to the stem of needle holder 201, needle holder 201 can move within a relatively small working space within the perimeter of the hole in dome 905. Slider 907 and dome 905 form a physical motion guide that maintains the stereotactic orientation of needle holder 201 relative to remote center of motion 501. The number of blades on slider 907 is an optional design feature; for example, it could be replaced with a single curved surface extending in all directions around the stem of needle holder 201 like an umbrella. Slider 907 simply moves, guided by the inner surface of dome 905, to maintain needle holder 201 within the stereotactic working space. Preferably, the contact interface between slider 907 and dome 905 is pre-treated to reduce friction, such as by applying a suitable lubricant or laser treatment to both surfaces.

[0076] Figure 13 This is another exploded view, again showing the fine-tuning robot 202, but only including the components relevant to securing the needle holder 201. These components include a particle blocking pack 903, which surrounds the portion of the needle holder 201 protruding from the dome 905. As previously described, the particle blocking pack 903 is securely secured to the upper surface of the dome 905 by glue or other means. Before the particle blocking pack 903 is activated by the withdrawal of air, the particles 1401 within the pack are able to flow like a fluid. When the particle blocking pack 903 contracts due to the withdrawal of air, the particles 1401 gather and attach to each other, forming a hard, solid state that tightly grips the portion of the needle holder 201 protruding from the pack 903. This locks the needle holder 201 in place within the housing of the fine-tuning robot 202. Figure 14 The diagrams, moving from left to right, illustrate this process. When air reenters the bag 903, the hardened state can be reversed back to a fluid state, releasing the grip on the needle holder 201. Optionally, the toggle 203 and base 205 of the encoder arm 215 can be locked using the same type of friction lock as the passive arm 217 joints, though particle blocking and locking the toggle 203 and base 205 of the passive arm 217 may be sufficient to secure the positioning device 200. However, the particle blocking bag is not activated to lock the needle holder 201 to the fine-tuning robot 202, as the needle holder 201 needs to be able to rotate relative to the fine-tuning robot 202 to accommodate the changing angles of the encoder arm 215 and passive arm 217 when they are in different positions.

[0077] During deployment, positioning device 200 is mounted on skull 300 at a location such that the center of an imaginary sphere coincides with borehole 301, serving as the distal center of motion 501. A spherical five-bar series structure extends upward from base bar 207, its curve following the contour of the imaginary sphere. Needle holder 201 is clamped coaxially with distal joint 501 and can be moved to other positions within the workspace without losing alignment with borehole 301. The surgeon moves needle holder 201 by pushing or pulling on its tip, which is typically covered with a nut.

[0078] Therefore, the positioning device 200 has three operating modes with respect to the positioning of the needle holder 201: a coarse adjustment mode, a fine adjustment mode, and a fixed or frozen mode.

[0079] Before surgery, the patient is imaged using MRI or other imaging techniques, such as computed tomography (CT), and the coordinates of the surgical target 303 are determined using markers placed on the patient's body to precalculate the desired orientation. The images determine the location of the drill hole 301, the intended installation position of the positioning device on the skull 300, and the linear alignment of the needle holder 201 with the drill hole 301 and the surgical target 303. The positioning device 200 is then installed on the patient's skull 300 at a suitable location that overlaps the target location. The positioning device 200 is then registered or coordinated with the patient's head in the MRI imaging environment using the magnetic resonance markers on the positioning device 200.

[0080] Next, the positioning device enters the coarse adjustment mode. All wrist joints 203 and base joints 205 are in a loose state. In response to the change in the position of the needle holder 201, the actuator 909 is supplied with a minimum amount of hydraulic pressure to ensure that the needle holder 201 is extended to the maximum extent from the top of the fine adjustment robot 202 housing, thereby coaxially aligning the needle holder 201 on the encoder arm 215 and providing distal articulation generated by tension.

[0081] The surgeon pushes the needle holder 201 within the workspace defined by the spherical five-bar series structure until it reaches a position where the optical fiber emits a green light, indicating that the error from the surgical target 303 is within ±5 degrees, without the need to review an MRI (which, with prior art equipment, would require multiple MRIs to accurately determine the position of the needle holder 201). Before entering fine-tuning mode, the surgeon activates the brake mechanisms on the elbow and base of the passive arm 217 by pressing pedal 1601, thereby securing the spherical five-bar series structure. Subsequently, in fine-tuning mode, the computer takes over and finely adjusts the position of the needle holder 201.

[0082] Depending on the type of surgery, the ±5 degree accuracy of this embodiment may be sufficient to reach the surgical target 303, such as when inserting a needle to inject a drug to spread over a large target area. However, for surgeries requiring extremely high positioning accuracy, such as deep brain stimulation surgery (which requires the needle position to be within 2 mm of the surgical target 303 deep in the head), a fine-tuning robot 202 is required.

[0083] When the surgeon determines that needle holder positioning device 200 is in the desired position, positioning device 200 is fixed to provide a stable platform and prevent needle holder 201 from shifting. Thus, a surgical needle can be inserted into the patient's body via needle holder 201. Needle insertion can be performed manually or with the assistance of other robots, which is beyond the scope of this description.

[0084] Accordingly, the fine-tuning robot 202 does not use a spherical five-bar cascade to move the same needle holder 201; the spherical five-bar structure's tension-inducing distal joints are not used during fine-tuning. Instead, when moving the needle holder 201 via position-responsive automation, the fine-tuning robot 202 uses prefabricated motion guides to maintain the stereotactic orientation of the needle holder 201. Software control allows for increased hydraulic pressure to be supplied to one or both actuators, enabling movement of the needle holder 201 and encoder arm 215 relative to the fixed passive arm 217, independent of the spherical five-bar cascade or external robotic mechanisms.

[0085] Fine-tuning the position of the needle holder 201 can be accomplished under real-time MRI imaging by software-coordinating the actuator 909, causing it to move toward the pre-calculated position of the surgical target 303. If the surgical target 303 moves during surgery, the needle inserted into the brain can be withdrawn, the needle holder 201 unlocked, and the brakes 213 on the elbow joint 203 and base joint 205 of the arm released. The needle holder 201 can then be repositioned using the fine-tuning robot 202 based on the position of the surgical target 303 observed after the movement through real-time MRI imaging. The likelihood of the surgical target 303 moving outside the ±5-degree range of motion of the fine-tuning robot 202 is extremely low.

[0086] Figure 15 It was demonstrated that by adding the fine-tuning workspace, the total workspace was extended by an additional 5 degrees, bringing the total achievable workspace to ±35 degrees.

[0087] MRI applications

[0088] An embodiment suitable for surgery under real-time MRI imaging is small enough to be mounted on a patient and placed within an MRI coil, and its components are MRI-neutral. This embodiment can assist surgeons in performing intraoperative MRI-guided stereotactic neurosurgery, such as interventions involving needle / probe targeting for biopsy, injection, ablation, catheter placement, stereoelectroencephalography (sEEG), and deep brain stimulation (DBS). Intraoperative MRI-guided DBS procedures can target anatomical targets deep within the brain (on average, 90.4 mm below the skull 300°), with a target error tolerance of less than 3 mm.

[0089] For brain surgeries requiring real-time imaging in an MRI machine, the positioning device 200, when mounted on the patient's skull 300, is able to fit and operate within the confined space of the imaging head coil, for example, with dimensions of 81 mm in diameter x 97 mm in height, and weighing only 203 grams when made of a suitable rigid polymer material. This allows for a dual positioning device 200 to be placed alongside during bilateral surgery while still providing ample working space (±35 degrees).

[0090] Figure 16 The figure shows how two independent, functionally independently controllable positioning devices 200 are mounted on the patient's skull 300 and located within an MRI head coil 1603. The figure also shows a pedal 1601 for activating the Bowden cable 605 to apply the brake 213.

[0091] As previously mentioned, the recommended arc angle of the rod between the base joint 205 and the elbow joint 203 is 70 degrees, and the recommended arc angle of the rod between the elbow joint 203 and the main joint is 60 degrees. This allows coarse adjustment to cover a ±38-degree workspace. To avoid operating at the boundaries of the workspace, mechanical constraints are imposed on the revolute joints, limiting the actual workspace covered by coarse adjustment to ±30 degrees.

[0092] To meet the stringent safety requirements of nuclear magnetic resonance (NMR), the automated soft robot used for fine-tuning is made of polymer or elastomeric materials. For example, the metal piston used in non-NMR embodiments is replaced with a fluid-driven soft polymer actuator 909 in this embodiment. The rotary joint is supported on both sides by high-precision ceramic bearings and fixed by screws made of high-performance thermoplastic plastic (i.e., polyetheretherketone). The particles 1401 in the particle blocking bag 903 are polyvinyl chloride spheres with a diameter of 2 mm.

[0093] Possibility of external robot size restrictions

[0094] Without going into detail, it can be summarized that the external robot's use of a spherical five-bar tandem structure helps keep the positioning device's dimensions within the confines of the human head and within the MRI head coil. Any segment of a perfect circle can fit any portion of a larger curved surface (such as skull 300), which is why the finite-radius base rod 207 can fit anywhere on skull 300 above the ears and eyebrows. Assuming these rods have the same arc angle, the rod lengths cannot approximate a quarter circle of the same radius; otherwise, the two-bar tandem linkage arm would stretch into a semicircle, tangential to the remote center of motion 501. However, the arc angle must be greater than 1 / 8 of the circumference; otherwise, the arm would only extend to the quarter circle, just above the remote center of motion 501, and could not extend further. Furthermore, the radius of the imaginary sphere determines the distance from the borehole 301 to the base rod 207 and the distance perpendicular to the highest point of the borehole 301. Therefore, to ensure that the remote center of motion 501 coincides with the borehole 301, the radius of the rod is limited by the curvature of the skull 300, which makes it likely that the external robot will be small enough to fit on the head and into the head coil.

[0095] The five-bar structure also forms a cantilever arm, mounted on one side of the borehole 301 and holding the needle holder 201 on one side. The other side of the borehole 301 is free of any supporting structure. The needle holder 201 is lifted and away from the borehole 301, with no pivots on the borehole 301 or the remote center of motion 501. The portion of the skull 300 opposite the borehole 301 is open, facilitating visual and physical access to the borehole 301 and allowing for simultaneous placement of a second positioning device 200 near the first. Because the two positioning devices are not constrained by a shared physical base, they can be independently positioned on the skull 300 to suit the orientation of their respective surgical targets 303. This capability is particularly useful for real-time MRI-assisted deep brain stimulation procedures, which require drilling holes 301 in the skull 300 on both sides of the sagittal plane. With fewer structures, the positioning devices 200 can be made small enough to mount two on the patient's skull 300 and fit within the confined space of the head coil of an MRI machine.

[0096] The motion limitations of the distal joints of the spherical five-bar series structure are readily apparent, as they barely extend beyond the footprint of the positioning device. Furthermore, the ability to independently position the dual positioning devices and align them with another portion of the skull 300 reduces the likelihood that the distal joints will extend too far and encroach on the space of another positioning device.

[0097] Other applications

[0098] Any procedure requiring the insertion of a surgical needle through an incision in the body close to sufficiently flat bone is suitable for the positioning device 200. One potential application is ophthalmic surgery, which involves the use of needles to repair the eye, including removing cataract lenses and implanting intraocular lenses. A similarly shaped mounting base can be used to secure the eye to the eye socket or the brow bone above the eye. Specifically, the movement of the needle holder 201 does not require any pivoting on the eye. Furthermore, the surgeon can clearly observe the needle insertion process from the open side of the cantilever, which is an advantage. The ability of the mounted positioning device 200 to maintain its orientation as the patient moves is likely a highly desirable advantage. Such procedures may not require intraoperative imaging with an MRI. Therefore, one or more cameras can be positioned on the side of the needle holder 201, pointed at the remote center of motion 501 and beyond, to track the needle's field of view. Because the eye is smaller than the skull 300, the positioning device 200 used for ophthalmic surgery can be made smaller.

[0099] In addition to directly using the actual needle, the positioning device 200 can also be used to hold laser equipment and guide the laser during laser surgery, as such surgeries can benefit from the precision of such a body-mounted, robot-assisted and finely adjustable positioning device 200.

[0100] Other embodiments

[0101] Figure 17 The illustrated embodiment does not include a nested robot. Instead, a spherical five-bar tandem structure or external robot is used to grip and move the needle holder 201. Needle holder 201 is coaxially positioned within a rotatable distal joint formed by a pivot connection between the distal ends of two arms. The axis of the distal joint, as well as the axes of the other four joints, also point toward the remote center of motion. This allows the surgeon to move needle holder 201 within the workspace defined by an imaginary sphere.

[0102] Figure 18 On the left is shown a crude robot which is supported on a tripod on the skull of the patient with a needle holder 201 in stereotactic alignment with a drill hole in the skull which serves as the remote center of motion. Such a robot may be part of the prior art. In one embodiment of the present invention, the proposed fine-tuning robot 202 may be provided separately as an add-on module to such an existing prior art robot to improve upon the existing device. All that is required is a dome and a slider which can hold the needle holder 201 (which is typically a third party product) and once the existing device has brought the needle holder 201 to within the error range of the target position, adjustments can be made. The modular fine-tuning robot 202 is Figure 19The needle holder 201 is shown in isolation, containing only the housing and the components within it, including the slider, dome, and actuator used to operate the needle holder 201. A particle blocking package may or may not be required, depending on whether an external robot is holding the needle holder 201. If the needle holder 201 is fully held by the fine-tuning robot 202, then a particle blocking package may not be required.

[0103] Generally speaking, the workspace of the fine-tuning robot 202 depends on the distance between the remote center of motion (RCM) and the fine-tuning robot 202. The closer the fine-tuning robot 202 is placed to the RCM, the larger the workspace that can be provided in the opening in the dome.

[0104] Those skilled in the art will appreciate that other methods can be used to provide a motion guide device housed within the housing to enable the needle holder 201 to move about a remote center of motion. Because the motion guide device does not move beyond the footprint of the housing, the housing can be used as a robot, mounted between the needle holder 201 and an existing robot.

[0105] Thus, these embodiments include a removable, preferably housing-enclosed nested motion guide device that can be nested or mounted within a nested or mounted motion guide device (e.g., a spherical five-bar linkage) to serve as a second robot nested within a first robot. Preferably, the nested motion guide device can be replaced or reinstalled within the nested or mounted motion guide device. The alignment or orientation of the nested motion guide device with the nested or mounted motion guide device is within the knowledge of those skilled in the art and is beyond the scope of this specification, and therefore need not be further detailed.

[0106] The nested motion guide may not necessarily provide fine adjustment of the needle holder position. For example, the improvement achieved by the nested motion guide may simply be software automation, which is not available in the coarse adjustment nested motion guide.

[0107] Likewise, the size of the nested motion guide device does not necessarily have to be smaller than the nested motion guide device; all that is required is that the installation of the nested motion guide device can improve or supplement the motion of the nested motion guide device, or even expand its working space (see Figure 15 In this way, this embodiment provides a possibility to improve or upgrade an existing coarse adjustment robot or coarse adjustment needle holder, which can be used as an optional upgrade module. Figure 21 The diagram on the left shows a stereotactic track similar to the Clearpoint TM Manually adjustable track used by the robot. Figure 21 The diagram on the right shows that the fine-tuning robot can be placed in the ClearpointTM The figure shows the fine-tuning robot placed below the existing needle holder. On the one hand, the closer the fine-tuning holder is placed, the larger the workspace will be. On the other hand, the position of the fine-tuning robot should be determined by the curvature of the dome and slider inside the fine-tuning module (or any equivalent workspace motion guide). At the appropriate height, the curvature of the stereotactic motion guide is consistent with the existing Clearpoint TM The curvature of the robot workspace matches and shares a possible center of motion. All these details can be solved by those skilled in the art in actual situations and do not need to be further elaborated here. TM For a description of the robot, see https: / / www.clearpointneuro.com / array , including Clearpoint TM Smart frame arrays are described.

[0108] Figure 22 The image shows a patient undergoing back surgery in a non-MRI environment. During the procedure, a manually operated large stereotactic robot is used to manipulate the surgical target through a hole or incision in the back. The fine-tuning robot is used to upgrade the large stereotactic robot and is installed between the large stereotactic robot and the needle holder. In this way, the fine-tuning robot can be used to upgrade existing large stereotactic robots with software-driven fine-tuning capabilities.

[0109] The fine-tuning robot 201 may also be used to upgrade incision tools of other non-stereotactic robots or motion-guided devices, such as Figure 23 As shown in the schematic diagram. Figure 23 A planar sliding support for a needle holder or laser device is shown, the movement of which is not stereotactic, e.g. https: / / ieeexplore.ieee.org / document / 9197534 The fine-tuning robot 201 can improve the fine-tuning function of the needle holder or laser device through software automation.

[0110] If the fine-tuning robot is not driven by hydraulic pressure in the magnetic resonance environment, other methods can be used in this embodiment to achieve fine-tuning movement of the needle holder, such as electric, ultrasonic, piezoelectric, pneumatic and electromagnetic drive.

[0111] Although preferred embodiments of the present invention have been described above, those skilled in the art will appreciate that various changes or modifications may be made in the details of design, construction or operation without departing from the scope of the invention as claimed.

Claims

1. A positioning device for a surgical needle holder, comprising a second robot mounted within the first robot; The second robot can be used to hold a surgical needle holder and move the surgical needle holder within the workspace so that the surgical needle holder always maintains stereotactic alignment with the center of motion; The first robot can be used to clamp and move the second robot within the workspace so that the surgical needle holder always remains stereotactically aligned with the center of motion. 2 . The positioning device for a surgical needle holder according to claim 1 , wherein the first robot has a spherical five-bar series structure.

3. The positioning device for a surgical needle holder according to claim 1, wherein the second robot is replaceable.

4. The positioning device for a surgical needle holder according to claim 1, further comprising a light emitting device of a predetermined color for indicating that the position of the surgical needle holder is within a predetermined error range relative to the target position; The second robot is capable of moving the surgical needle holder within a spatial range defined by the error range.

5. The positioning device for a surgical needle holder according to claim 1, further comprising: A curved base rod; the arc angle of the curved base rod enables the base rod to contact a certain position of the head of an average person with the entire curved portion.

6. The positioning device for a surgical needle holder according to claim 5, wherein the spherical five-bar series structure comprises: the curved base rod; The curved base rod has two ends; One end of the curved base rod is rotatably connected to the proximal end of the first double-rod tandem link arm; and The other end of the curved base rod is rotatably connected to the proximal end of the second double-rod tandem link arm; The distal end of the first arm and the distal end of the second arm cooperate with each other in tension, acting as the distal connecting rod of the spherical five-bar series structure; The spherical five-bar series structure clamps the second robot and makes it move in alignment with the distal end link.

7. The positioning device for a surgical needle holder according to claim 6, wherein The distal end of the first arm holds a surgical needle holder; The distal end of the second arm grips a fine-tuning robot; The mutual tension is a force that pushes the surgical needle holder and the second robot in opposite directions, and acts on the device that prevents the surgical needle holder from separating from the second robot.

8. The positioning device for a surgical needle holder according to claim 6, wherein the second robot comprises a motion guide device secured to the distal end of the second arm; The distal end of the first arm can cooperate with the motion guide device to enable the needle holder to move with two degrees of freedom in a curved plane around the same center of the spherical five-bar series structure without being affected by the corresponding movement of the second arm.

9. The positioning device for a surgical needle holder according to claim 8, wherein This movement of the needle holder is achieved by automated means, independent of the corresponding movement of the second arm.

10. The positioning device for a surgical needle holder according to claim 9, wherein Said automation is achieved by hydraulic actuation of the polymer bellows; The base and elbow joints are ceramic and polymer based revolute joints; and include A particle blocking pack is used to secure the position of the needle holder relative to the second arm.

11. A nested motion guide for mounting within a nested motion guide, the nested motion guide configured to hold a surgical needle holder in stereotactic alignment with a center of motion; and The nested motion guide is configured to clamp and move the nested motion guide and the surgical needle holder so that the surgical needle holder always maintains stereotactic alignment with the center of motion.

12. The nested motion guide device of claim 11, wherein the movement of the nested motion guide device is responsive to software automation.

13. A method for positioning a surgical needle holder into alignment with a surgical target within a patient's body, comprising the steps of: moving a nested motion guide, which holds a nested motion guide, and the nested motion guide, which holds a surgical needle holder, away from and about an opening in the patient's body, the opening coinciding with a center of motion of the nested motion guide; aligning a surgical needle holder with the opening and a surgical target within a tolerance range; The nested motion guide device is moved around the opening as the motion center without being affected by the corresponding movement of the nested motion guide device; The surgical needle holder is aligned with the opening and the surgical target with a smaller margin of error.

14. The method of claim 13, wherein: The mobile nested motion guide includes automation using software control.

15. The method of claim 13, further comprising the step of: Install the nested motion guide into the nested motion guide.

16. The method of claim 13, further comprising the steps of: The distance between the motion centers of the nested motion guide device and the nested motion guide device is adjusted so that the motion center of the nested motion guide device is the same as the motion center of the nested motion guide device.

Images