Method and device for perineal prostate needle biopsy

Abstract

The invention relates to a method and a device for perineal prostate needle biopsy. In one embodiment, the device for perineal prostate needle biopsy comprises: (a) a first parallel mechanism for translating or rotating an ultrasonic probe; (b) a series-parallel hybrid mechanism as an end effector of the first parallel mechanism for accommodating the ultrasonic probe and a puncture needle introducer; (c) a driving module of the series-parallel hybrid mechanism for driving the ultrasonic probe to rotate and translate along the axis of the ultrasonic probe; (d) a second parallel mechanism of the series-parallel hybrid mechanism for controlling the configuration of the puncture needle guider relative to the ultrasonic probe and limiting the motion trail of the puncture needle within the axial imaging plane of the ultrasonic probe; and a controller for executing a kinematic modeling method.

Description

Technical Field

[0001] This invention relates generally to transperineal prostate biopsy, and more particularly to a novel device that can be used to assist surgeons in performing transperineal prostate biopsy, to position the puncture needle based on the device of this invention, and to the surgical procedure of transperineal prostate biopsy performed using the device of this invention. Background Technology

[0002] Prostate cancer is the second most common cancer after breast cancer and a leading cause of death in men. Early and reliable detection of prostate cancer is crucial for successful treatment of high-risk patients and for avoiding overtreatment of low-risk patients. Typically, the most reliable technique for detecting prostate cancer and assessing its aggressiveness is a prostate biopsy.

[0003] In clinical practice, there are three main types of prostate biopsy. A key difference lies in the site through which the needle passes. Since the puncture site may include the urethra, perineum, and rectum, prostate biopsies are generally classified as transrectal, transperineal, and transurethral. As a common method for diagnosing prostate cancer, transrectal ultrasound-guided prostate biopsy requires inserting an ultrasound probe into the rectum to visualize suspicious areas. The needle then passes through the anterior rectal wall to enter the prostate. However, transrectal biopsy is prone to complications such as rectal bleeding and infection. Furthermore, the needle cannot easily cover the entire prostate. This method has been described in several systems, such as US Patent No. 9877788B2, entitled "MRI-Safe Robot for Transrectal Prostate Biopsy," filed January 30, 2018, and US Patent No. 10368850B2, entitled "System and Method for Real-Time Ultrasound-Guided Prostate Biopsy Using a Flexible Robotic Arm," filed August 6, 2019. For transurethral prostate biopsy, to ensure safety, the puncture needle usually needs to be displayed in real-time on the ultrasound imaging plane. Therefore, this method is difficult to use with real-time ultrasound imaging, and its safety is also difficult to guarantee. In addition, the puncture site needs to penetrate too many parts of the urethral wall, leading to a higher risk of complications. Transperineal prostate biopsy involves inserting a puncture needle through the perineal skin under the guidance of an ultrasound probe. This method is relatively safer and reduces the risk of infection. This method does not require general anesthesia; the patient only needs local anesthesia. Therefore, in this case, the biopsy site does not require a demanding medical environment, thus helping to improve the overall biopsy efficiency.

[0004] A typical transperineal prostate biopsy is performed with the aid of transrectal ultrasound guidance. Guided by the acquired ultrasound images, the surgeon inserts a needle into the prostate through a guide template. This template is equipped with a series of through-holes parallel to the probe. The needle is inserted through these through-holes to reach the target area. The surgeon needs one hand to hold the probe in place while inserting the needle with the other. The outcome of this procedure largely depends on the surgeon's experience, making it difficult to standardize and replicate the prostate biopsy procedure. To improve the accuracy and quality of interventional puncture treatment, developing a flexible robotic device system capable of performing positioning and aiming tasks during a prostate biopsy is of great significance. In this method, the surgeon only needs to perform the manual needle insertion operation with the assistance of the designed device.

[0005] It is worth noting that the clinical robot-assisted prostate biopsy procedure includes two stages: preoperative preparation and intraoperative operation. Because prostate cancer is a heterogeneous and multifocal disease, targeted localization guided by cancer imaging to identify suspicious cancer areas is crucial. Magnetic resonance imaging (MRI) provides the highest contrast and spatial resolution regarding prostate anatomy. Therefore, in the preoperative preparation stage, the patient undergoes an MRI scan, and the obtained prostate MRI images are segmented and reconstructed in three dimensions. However, the real-time performance of MRI images is poor. Furthermore, MRI has high requirements for the working environment and strict requirements for resistance to magnetic interference from other equipment. This makes it inconvenient for surgeons to perform biopsies in an MRI environment. In contrast, transrectal ultrasound (TRUS) scanning provides real-time images and is easier to use. One of the simplest biopsy targeting methods is MRI-TRUS image fusion. Therefore, an ultrasound probe is inserted into the rectum and scanned to obtain a series of two-dimensional ultrasound images, and the prostate region is segmented and reconstructed in three dimensions. Subsequently, the MRI and ultrasound three-dimensional models are registered and fused. Furthermore, during the surgical procedure, the ultrasound probe needs to be fixed in a suitable position while the surgeon selects the target lesion. This auxiliary device plans the biopsy path and aligns the puncture needle guide. The surgeon then inserts the puncture needle and performs the biopsy.

[0006] Based on the above methods, some commercial devices (such as Monalisa and Artemis) have designed robotic systems for prostate biopsy. For example, Monalisa uses a transperineal biopsy approach, combined with MRI-TRUS-guided imaging. However, this system lacks real-time collinear ultrasound monitoring of the puncture path because its probe cannot remain collinear with the puncture needle. Therefore, the precise position of the puncture needle cannot be clearly displayed in the ultrasound image window, leading to decreased system quality control and operational safety. The probe has only two degrees of freedom, resulting in insufficient flexibility. During the biopsy, the probe must have yaw or pitch capabilities to avoid interference from pubic bone obstruction. In the case of Artemis, there are differences between puncture points. Therefore, it lacks an RCM (remote center of motion) constraint mechanism. It is worth noting that reducing the number of puncture sites helps reduce patient trauma. In robotic arm-based operations, transperineal puncture needle guides have limitations in reaching different areas of the prostate, such as the extremely anterior region that is difficult to reach due to pubic bone obstruction. The system appears to be highly dependent on the operator for target positioning, and its robotic arm appears to provide only the main positional freedom other than rotational degrees of freedom.

[0007] Since the prostate gland has a volume of approximately 75 mL, the corresponding workspace of the robotic device should cover this volume. Considering the requirements of the workspace and working environment, the device should be relatively compact. The system should provide sufficient support when the surgeon inserts the puncture needle. The position of the puncture needle should be visible in real-time on the probe's imaging plane during the procedure to ensure safety. All of these factors together constitute a complete transperineal prostate biopsy system.

[0008] To date, there are very few flexible interventional devices designed for transperineal prostate biopsy. Introducing robotic devices into such systems and achieving precise aiming through RCM constraint mechanisms would offer significant advantages. Such devices could have a compact size, sufficient rigidity, and a certain degree of freedom. Therefore, there is a need in the art for a flexible assisted biopsy device to improve the efficiency and accuracy of prostate biopsy. Summary of the Invention

[0009] This invention achieves the aforementioned objectives by providing a transperineal prostate biopsy device with probe configuration control and puncture needle configuration control functions, and a surgical procedure that combines MRI-TRUS-guided imaging to target and locate suspicious cancerous areas. The flexible device includes a lower parallel mechanism and an upper series-parallel hybrid mechanism: the upper part of the device includes a drive module for driving the probe to rotate and translate along its axis, and a parallel mechanism for controlling the configuration of the puncture needle relative to the probe. The lower part of the device includes two universal joints and four drive actuators for generating the rotational and translational motion of the upper part.

[0010] In one aspect of the invention, the device can simultaneously implement two RCM restraint mechanisms, including an RCM-probe restraint mechanism and an RCM-needle restraint mechanism. The device has a total of eight degrees of freedom. The probe mounted on the device has six degrees of freedom, including rotational motion in three directions and translational motion in three directions, through the coordinated action of the upper and lower parts of the device. The RCM-probe restraint mechanism is located at the patient's anus, with no relative movement between the probe and the anus. The configuration of the needle guide relative to the probe is determined by a parallel mechanism with two degrees of freedom. Under different operating conditions, the position of the RCM-needle restraint mechanism can be moved relative to the probe.

[0011] More specifically, based on the characteristics of the transperineal prostate biopsy device, a kinematic analysis model is established to handle the RCM-probe constraint mechanism and the RCM-puncture needle constraint mechanism, and to describe the relationship between the displacement of each actuator or motor and the target position.

[0012] In another aspect of the invention, the device can maintain an ultrasound probe in an appropriate configuration and move along a predetermined trajectory under an RCM-probe constraint mechanism to acquire the desired ultrasound image. Based on previously obtained MRI images, the target point can be determined by three-dimensional fusion and registration of the MRI images and the acquired ultrasound images.

[0013] The surgical procedure using the device of the present invention can be described as follows: First, the device fixes the ultrasound probe, establishing a specific probe configuration under the RCM-probe constraint mechanism to acquire a series of ultrasound images. Then, based on the fusion and registration of the MRI and ultrasound images, areas suspected of being cancerous are identified. On this basis, the device performs aiming under two RCM constraint mechanisms, simultaneously confining the motion plane of the puncture needle within the imaging plane of the ultrasound probe. Finally, the surgeon manually inserts the puncture needle into the patient's prostate via the perineum.

[0014] The invention and its features can be understood in more detail through the following description and illustrative drawings. Attached Figure Description

[0015] Figure 1 An orthographic view of the prostate biopsy device described in this invention is shown.

[0016] Figure 2A The upper part of the prostate biopsy device is shown. According to the features of the invention, the upper part can realize the rotational and translational movement of the probe along its axis, as well as the movement of the puncture needle relative to the ultrasound probe in the imaging plane.

[0017] Figure 2B This is a partial cross-sectional view of the upper part of the prostate biopsy device described in this invention.

[0018] Figure 3A An orthogonal view showing the passive motion module at the lower part of the prostate biopsy device. The passive motion module mainly includes two universal joints.

[0019] Figure 3B This is a partial cross-sectional view of a passive motion module at the lower part of the device described in this invention.

[0020] Figure 4 A schematic diagram of the local kinematics of the prostate biopsy device described in this invention is shown.

[0021] Figure 5 The present invention demonstrates the RCM constraint mechanisms involved in the biopsy process of the device described in this invention, including the RCM-puncture needle constraint mechanism and the RCM-probe constraint mechanism.

[0022] Figure 6 A kinematic schematic diagram of the lower structure of the device described in this invention is shown.

[0023] Figure 7A A schematic diagram of the overall kinematics of the device described in this invention is shown.

[0024] Figure 7B A schematic diagram illustrating the overall motion of the device described in this invention under two RCM constraint mechanisms is shown.

[0025] Figure 8 An orthogonal view of the upper part of the prostate biopsy device of the present invention is shown when the probe performs rotational and translational movements along its axis.

[0026] Figure 9A and Figure 9B An orthogonal view of the upper puncture needle movement module of the prostate biopsy device of the present invention is shown, illustrating the situation when the puncture needle performs an inclined movement relative to the probe of the device.

[0027] Figure 10A and Figure 10BAn orthogonal view of the upper puncture needle movement module of the prostate biopsy device of the present invention is shown, illustrating the situation when the puncture needle performs translational movement relative to the probe of the device.

[0028] Figures 11(a) and 11(b) show orthogonal views of the prostate biopsy device of the present invention when performing yaw motion.

[0029] Figure 12A and Figure 12B An orthogonal view showing the prostate biopsy device of the present invention performing pitching motion.

[0030] Figure 13 A flowchart of a transperineal prostate biopsy procedure performed using the apparatus described in this invention is shown.

[0031] Figures 14A to 14C The present invention demonstrates the structure of another puncture needle motion module, which enables the puncture needle to tilt and translate relative to the probe of the device within the imaging plane.

[0032] Figure 15 This invention demonstrates the advantages of the device described in this invention compared to traditional methods in transperineal prostate biopsy. Detailed Implementation

[0033] This invention presents a novel transperineal prostate biopsy device that improves treatment efficiency, accuracy, and quality. Guided by MRI-ultrasound image fusion, the device performs positioning and aiming during prostate biopsy, reducing reliance on manual needle insertion by the surgeon. Based on this robotic system, the needle is inserted through the patient's perineum and continuously observed in real-time ultrasound images, enhancing safety and reducing infection risk. This method eliminates the need for general anesthesia; the patient receives only local anesthesia. The biopsy can be performed in a less demanding medical environment, further improving overall biopsy efficiency. Furthermore, the device holds the ultrasound probe in the appropriate position and moves it along a pre-defined trajectory to acquire the desired ultrasound images. Based on previously acquired MRI images, the target point is determined through three-dimensional fusion and registration of the MRI and acquired ultrasound images. Once the target point is determined, the device performs the corresponding movements to complete the aiming task.

[0034] The device has a total of eight degrees of freedom. The probe, fixed to the device, has six degrees of freedom, including rotational motion in three directions and translational motion in three directions. The position of the puncture needle guide relative to the probe can be determined by a parallel mechanism with two degrees of freedom. Furthermore, based on this flexible structure, the entire system includes two RCM (remote center of motion) constraint mechanisms: an RCM-puncture needle constraint mechanism and an RCM-probe constraint mechanism. Under different operating conditions, the position of the RCM-puncture needle constraint mechanism can move relative to the probe.

[0035] The main advantages of the device include: its rigidity is higher than that of a serial robot, and it employs a hybrid series-parallel configuration; the imaging plane of the probe is always on the same plane as the puncture needle to ensure safety; the device is a flexible structure that achieves eight degrees of freedom within a compact housing, enabling it to cope with confined workspaces; the entire system can cleverly implement two RCM constraint mechanisms simultaneously; the probe of the device has multiple degrees of freedom and can implement an RCM-probe constraint mechanism; the positions of the RCM-probe constraint mechanism and the RCM-puncture needle constraint mechanism can be moved relative to the patient.

[0036] This invention provides a device for transperineal prostate biopsy. In one embodiment, the transperineal prostate biopsy apparatus includes: a) a parallel mechanism comprising two universal joints for realizing translational movement of the ultrasound probe under an RCM-probe constraint mechanism, including horizontal and vertical movement, and rotational movement, including pitch and yaw movement; b) a series-parallel hybrid mechanism as the end effector of the parallel mechanism for accommodating the ultrasound probe and the puncture needle guide; c) a drive module of the series-parallel hybrid mechanism for driving the ultrasound probe to rotate and translate along its axis; and a parallel mechanism of the series-parallel hybrid mechanism for controlling the configuration of the puncture needle guide relative to the ultrasound probe and restricting the movement trajectory of the puncture needle within the axial imaging plane of the probe; d) a kinematic modeling method capable of realizing the RCM-probe constraint mechanism based on the parallel mechanism and the drive module; and simultaneously realizing the RCM-probe constraint mechanism and the RCM-puncture needle constraint mechanism based on the parallel mechanism and the series-parallel hybrid mechanism.

[0037] In one embodiment, the parallel mechanism includes two universal joints and two linear motion modules providing four degrees of freedom; the series-parallel hybrid mechanism is connected to the four-degree-of-freedom parallel mechanism and further includes the ultrasound probe, the drive module, and a two-degree-of-freedom parallel mechanism connected to the drive module; the two-degree-of-freedom parallel mechanism includes two lifting modules and the puncture needle guide. The series-parallel hybrid mechanism, as the upper part of the device of the present invention, is the end effector of the four-degree-of-freedom parallel mechanism, which is the lower part of the device of the present invention.

[0038] In one embodiment, the linear motion module of the four-degree-of-freedom parallel mechanism further includes a two-degree-of-freedom front motion module and a two-degree-of-freedom rear motion module.

[0039] In one embodiment, the two-degree-of-freedom front motion module further includes a horizontal motion module and a vertical motion module, the horizontal motion module being connected to the vertical motion module, and a universal joint being connected to the horizontal motion module.

[0040] In one embodiment, the two-degree-of-freedom rear motion module further includes a horizontal motion module and a vertical motion module, the horizontal motion module being connected to the vertical motion module, and another universal joint being connected to the horizontal motion module.

[0041] In one embodiment, the drive module further includes a cavity for fixing the ultrasonic probe.

[0042] In one embodiment, the two-degree-of-freedom parallel mechanism controls the configuration of the puncture needle guide relative to the probe, and the puncture needle guide can perform translational and tilting movements relative to the probe.

[0043] In one embodiment, the two-degree-of-freedom parallel mechanism is connected to the cavity.

[0044] In one embodiment, the two-degree-of-freedom parallel mechanism further includes an additional mechanism that enables the puncture needle to perform tilting and translational movements relative to the probe in the imaging plane. The additional mechanism includes: a parallelogram mechanism connected to the cavity; a puncture needle guide for guiding the puncture needle, the puncture needle guide being connected to the parallelogram mechanism; and two motors, respectively connected to two joints of the parallelogram mechanism.

[0045] In one embodiment, the two-degree-of-freedom parallel mechanism with the puncture needle guide makes the motion plane of the puncture needle coincide with the imaging plane of the probe.

[0046] In one embodiment, the universal joint of the four-degree-of-freedom parallel mechanism further includes a front universal joint and a rear universal joint.

[0047] In one embodiment, the front universal joint further includes a joint bracket, a pitch rotation part, and a yaw rotation part. The joint bracket is connected to the horizontal motion module of the front motion module.

[0048] In one embodiment, the rear universal joint further includes a joint bracket, a pitch rotation portion, and a yaw rotation portion. The joint bracket is connected to the horizontal motion module of the rear motion module.

[0049] In one embodiment, each of the universal joints of the four-degree-of-freedom parallel mechanism is interconnected via a linear bearing and a linear shaft parallel to the base of the series-parallel hybrid mechanism.

[0050] In one embodiment, the four-degree-of-freedom parallel mechanism and the series-parallel hybrid mechanism can simultaneously implement two RCM constraint mechanisms.

[0051] In one embodiment, the RCM restraint mechanism further includes an RCM-probe restraint mechanism and an RCM-puncture needle restraint mechanism. The RCM-probe restraint mechanism is located at the patient's anus, and the RCM-puncture needle restraint mechanism is located on the skin of the patient's perineum.

[0052] In one embodiment, the working environment of the two-degree-of-freedom parallel mechanism is not limited to the fixed mode of the probe, which includes handheld, passive mechanisms and automated robot systems.

[0053] This invention also provides a method for performing a transperineal prostate biopsy, which combines MRI and ultrasound images, a transrectal ultrasound probe, and three-dimensional fusion and registration of MRI and ultrasound images. In one embodiment, the method includes the following steps: a) acquiring an MRI image of the patient's prostate; b) fixing the ultrasound probe using the device described in this invention and constructing a specific configuration under the RCM-probe constraint mechanism; c) acquiring an ultrasound image of the subject's prostate and completing the fusion and registration of the MRI and ultrasound images; d) selecting a target region based on the fusion result; and controlling the device described in this invention to perform an aiming task under the RCM-puncture needle constraint mechanism and the RCM-probe constraint mechanism; e) the surgeon manually inserting the puncture needle into the target region through the puncture needle guide.

[0054] In one embodiment, the RCM-probe constraint mechanism further includes a kinematic modeling method for determining the position of the RCM-probe relative to the base of the device of the present invention.

[0055] In one embodiment, the method further includes: a method for kinematic modeling of the entire device based on the device of the present invention, so as to simultaneously realize the RCM-probe constraint mechanism and the RCM-puncture needle constraint mechanism.

[0056] In one embodiment, after selecting a target area, the device can automatically adjust the position of the RCM-puncture needle restraint mechanism.

[0057] The present invention also provides an apparatus for performing transperineal prostate biopsy on a subject. In one embodiment, the apparatus includes: a) a first parallel mechanism for realizing translational or rotational movement of an ultrasound probe, the translational or rotational movement including horizontal, vertical, pitch, or yaw movements under an RCM-probe constraint mechanism; the first parallel mechanism includes one or more universal joint motion modules, the universal joint motion modules including one or more passive joints; b) a series-parallel hybrid mechanism, as the end effector of the first parallel mechanism, for receiving the ultrasound probe and a puncture needle guide; the first parallel mechanism and the series-parallel hybrid mechanism jointly control the configuration of a puncture needle relative to the subject and complete the alignment task under the RCM-puncture needle constraint mechanism; c) d) a drive module of the series-parallel hybrid mechanism for driving the ultrasound probe to rotate and translate along its axis; e) a second parallel mechanism of the series-parallel hybrid mechanism for controlling the configuration of the puncture needle guide relative to the ultrasound probe and restricting the motion trajectory of the puncture needle within the axial imaging plane of the ultrasound probe; and e) a controller for performing a kinematic modeling method to achieve the following objectives: i) realizing an RCM-probe constraint mechanism based on the first parallel mechanism and the drive module; ii) simultaneously realizing an RCM-probe constraint mechanism and an RCM-puncture needle constraint mechanism based on the first parallel mechanism and the series-parallel hybrid mechanism.

[0058] In one embodiment, the one or more universal joint motion modules further include two linear motion modules providing four degrees of freedom; the second parallel mechanism is a two-degree-of-freedom mechanism including two lifting modules and the puncture needle guide, the second parallel mechanism being connected to the drive module; the transperineal prostate biopsy device includes an upper part and a lower part, the series-parallel hybrid mechanism constituting the upper part and serving as the end effector of the first parallel mechanism, while the first parallel mechanism constitutes the lower part.

[0059] In one embodiment, the two linear motion modules include a two-degree-of-freedom front motion module or a two-degree-of-freedom rear motion module.

[0060] In one embodiment, the two-degree-of-freedom front motion module includes a horizontal motion module and a vertical motion module, the horizontal motion module being connected to the vertical motion module, and the one or more passive joints being connected to the horizontal motion module.

[0061] In one embodiment, the two-degree-of-freedom rear motion module includes a horizontal motion module and a vertical motion module, the horizontal motion module being connected to the vertical motion module, and the one or more passive joints being connected to the horizontal motion module.

[0062] In one embodiment, the drive module includes a cavity for fixing the ultrasonic probe.

[0063] In one embodiment, the second parallel mechanism controls the configuration of the puncture needle guide relative to the ultrasound probe, and the puncture needle guide is capable of translational and tilting movements relative to the ultrasound probe.

[0064] In one embodiment, the drive module includes a cavity for fixing the ultrasound probe, and the second parallel mechanism is connected to the cavity.

[0065] In one embodiment, the second parallel mechanism further includes an additional mechanism for tilting and translating the puncture needle within the axial imaging plane of the ultrasound probe; the drive module includes a cavity for fixing the ultrasound probe, and the additional mechanism includes: a parallelogram mechanism connected to the cavity, the parallelogram mechanism including two joints; a puncture needle guide for guiding the puncture needle, the puncture needle guide being connected to the parallelogram mechanism; and two motors, respectively connected to the two joints of the parallelogram mechanism.

[0066] In one embodiment, the second parallel mechanism cooperates with the puncture needle guide to move the puncture needle in a plane that coincides with the axial imaging plane of the ultrasound probe.

[0067] In one embodiment, the one or more passive joints include a front universal joint and a rear universal joint.

[0068] In one embodiment, the one or more passive joints include a front universal joint and a rear universal joint. The front universal joint includes a joint bracket, a pitch rotation part, and a yaw rotation part. The joint bracket is connected to the horizontal motion module of the front motion module.

[0069] In one embodiment, the one or more passive joints include a front universal joint and a rear universal joint, the rear universal joint including a joint bracket, a pitch rotation part and a yaw rotation part; the joint bracket is connected to the horizontal motion module of the rear motion module.

[0070] In one embodiment, the series-parallel hybrid mechanism includes a base, and the one or more passive joints are interconnected via a linear bearing and a linear shaft parallel to the base.

[0071] In one embodiment, the first parallel mechanism and the series-parallel hybrid mechanism can simultaneously implement two RCM constraint mechanisms.

[0072] In one embodiment, the RCM restraint mechanism includes an RCM probe restraint mechanism and an RCM needle restraint mechanism, wherein the RCM probe restraint mechanism is located at the anus of the subject and the RCM needle restraint mechanism is located on the skin of the perineum of the subject.

[0073] In one embodiment, the ultrasonic probe is selected from a handheld probe, a passive mechanism probe, or an automated robot system probe.

[0074] The present invention also provides a method for performing transperineal prostate biopsy using the device described herein. In one embodiment, the method includes the following steps: a) acquiring an MRI image of the prostate of the subject; b) fixing the ultrasound probe using the transperineal prostate biopsy device and constructing a specific configuration under the RCM-probe constraint mechanism; c) acquiring an ultrasound image of the prostate of the subject; d) fusing and registering the MRI image and the ultrasound image to form a fusion result; e) selecting a target region based on the fusion result; and controlling the device to aim the RCM-puncture needle position under the RCM-puncture needle constraint mechanism and the RCM-probe constraint mechanism; and f) manually inserting the puncture needle into the target region through the puncture needle guide.

[0075] In one embodiment, the device includes a base and the RCM-probe constraint mechanism, and further includes a kinematic modeling method for determining the position of the RCM-probe constraint mechanism relative to the base.

[0076] In one embodiment, the method further includes a kinematic modeling method based on the device for simultaneously implementing the RCM-probe constraint mechanism and the RCM-puncture needle constraint mechanism.

[0077] In one embodiment, after selecting a target area, the device can automatically adjust the position of the RCM-puncture needle restraint mechanism.

[0078] Figure 1 A preferred embodiment of the prostate biopsy device of the present invention is shown. The device comprises two sub-assemblies: an upper part and a lower part of the prostate biopsy device. The upper and lower parts of the device are connected by a connector 7. The main components of the upper part include a drive mechanism for rotating and translating the probe along its own axis, and parallel mechanisms 2-4 for controlling the movement of the puncture needle 1 relative to the probe 6. The lower part is a parallel mechanism, mainly comprising two universal joints driven by four linear actuators numbered 33, 40, 62, and 63. The entire device can be mounted on other mechanisms via its base connector 41.

[0079] Figure 2A The detailed structure of the upper part of the prostate biopsy device is shown. The upper part is connected to the lower part of the device via a connector 7, which can be considered the base of the upper part. The probe support 8 is connected to the connector 7 via a linear guide rail 24. The support 8 is capable of translational movement relative to the connector 7, driven by a motor 18 via gears 21 and 22 and a lead screw 23. A nut is fixed to the support 8. The probe 6 is capable of rotational movement relative to the component 8 along its axis, driven by a motor 17 via a set of three gears 27, 20, and 5, which can reduce speed and increase torque generated by the motor 17. The probe 6 is fixed by a cavity 12, which is connected to the support 8 via a bearing 11. The parallel mechanism consists of components 2-4 for controlling the movement of the puncture needle 1 relative to the probe 6. The movement includes translational and tilting movements relative to the probe, driven by motors 10 and 19. Racks 13 and 16, along with linear guides 15 and 14, convert the rotational motion of the motors into translational motion. Furthermore, the two sets of racks and linear guides are fixed to the cavity 12 via components 26 and 25, and the two sets of motors are fixed to the cavity 12 via component 30. The puncture needle guide 2 is connected to the lifting modules 3 and 4 of the parallel mechanism. Through the relative movement of motors 10 and 19, the tilting and translational motion of the puncture needle guide within the imaging plane is achieved.

[0080] Figure 2B This is a partial sectional view of the upper part of the device, which more clearly shows the connection relationship between the support 8, the cavity 12, the component 30, and the probe 6. The parallel mechanism at the top of the device is driven by two motors, and its rotational motion is converted into translational motion through gears 9, 28, and a rack. Linear guides 29 and 24 allow the support 8 to move forward and backward linearly along the probe axis.

[0081] Figure 3AAn orthogonal view of the lower passive motion module of the prostate biopsy device is shown. This parallel mechanism mainly includes two universal joints 47 and 34. Universal joint 47 mainly consists of a support 53, a pitch rotation part 54, a yaw rotation part 61, and two linear bearings 60 and 56. The linear bearing 60 is fixed below the support 53, and the linear bearing 56 is fixed inside the yaw rotation part 61. The pitch rotation part 54 can perform pitch rotation relative to the support 53, and the yaw rotation part 61 can perform yaw rotation relative to the pitch rotation part 54. Furthermore, universal joint 34 has a slightly different structure from universal joint 47. Similarly, the main components of universal joint 34 include a support 51, a pitch rotation part 50, a yaw rotation part 49, and a linear bearing 64. The linear bearing 64 is fixed below the support 51. Furthermore, the pitch rotation unit 50 can perform pitch rotation relative to the support 51, and the yaw rotation unit 49 can perform yaw rotation relative to the pitch rotation unit 50. Unlike the universal joint 47, the yaw rotation unit 49 of the universal joint 34 has a slider of a linear guide rail 48 installed inside.

[0082] One end of the linear shaft 55 passes through the interior of component 49 and is fixed therein, while the other end passes through the linear bearing 56 inside component 53 of the universal joint 47. The linear shaft 55 can slide along the axial direction of the linear bearing 56. The base 7 at the top of the device is fixed to component 61. Furthermore, one end of the linear guide rail 48 is fixed below the base 7, and the other end can slide along a slider inside component 49. Therefore, the linear guide rail 48 and the linear shaft 55 always remain parallel.

[0083] Two horizontally placed linear shafts 52 and 32 pass through two linear bearings 64 and 60, respectively, fixed below universal joints 47 and 34. Furthermore, the two linear shafts 52 and 32 are fixed to connecting plates 31 and 37, respectively. Therefore, the two universal joints 47 and 34 can perform linear extension and retraction movements in the direction of the linear shafts, driven by linear actuators 33 and 63, respectively. The ends of the linear actuators 33 and 63 are connected to brackets 51 and 53, respectively, and the bases of the linear actuators are fixed to connecting plates 31 and 37, respectively. When the extension and retraction amounts of the two linear actuators 33 and 63 are equal, the two universal joints 47 and 34 simultaneously perform horizontal translational movements; when the extension and retraction amounts of the two linear actuators 33 and 63 are unequal, the relative positions of the two universal joints 47 and 34 in the horizontal direction change, thereby causing the yaw rotation parts 49 and 61 to rotate, resulting in yaw movement of the base 7.

[0084] Two vertically placed linear bearings 57 and 59 are fixed to both ends of the connecting plate 31. Similarly, linear bearings 58 and 36 are fixed to both ends of the connecting plate 37. Linear shafts 44 and 46 pass through linear bearings 57 and 59 respectively and are fixed to the base 39. Likewise, linear shafts 65 and 35 pass through linear bearings 58 and 36 respectively and are fixed to the base 39. Therefore, the two universal joints 47 and 34, and the connecting plates 31 and 37 constitute two modules that can move in the vertical direction, and the movement is driven by linear actuators 40 and 62. When the extension and retraction of linear actuators 40 and 62 are equal, the two universal joints 47 and 34 simultaneously perform vertical translational movements; when the extension and retraction of linear actuators 40 and 62 are unequal, the relative positions of the two universal joints 47 and 34 in the vertical direction change, thereby causing the pitch rotation part 47 and pitch rotation part 50 to rotate, causing the base 7 to pitch. Therefore, through the parallel mechanism, the upper part of the device can achieve translational movements in the vertical and horizontal directions, as well as rotational movements in the pitch and yaw directions.

[0085] Figure 3B This is a partial cross-sectional view of the lower passive motion module of the prostate biopsy device, which more clearly shows the connection relationships between the components of the two universal joints 47 and 34 (including yaw rotation parts 61 and 49, pitch rotation parts 54 and 50, linear shaft 55, linear guide rail 48, and base 7). Since yaw rotation parts 61 and 49 need to rotate relative to components 54 and 50, they must be connected to each other via bearings 66 and 62 respectively. Linear guide rail 48 improves the rigidity and stability of base 7.

[0086] Figure 4A partial kinematic diagram of the prostate biopsy device of the present invention is shown. In its zero-configuration state, the probe 6 is oriented horizontally and perpendicular to the extension and retraction directions of the linear actuators 33 and 63. The device has a total of eight degrees of freedom. Furthermore, the puncture needle 1 performs translational motion (T5) relative to the puncture needle guide 2, which is manually driven by the physician after the prostate biopsy device has completed its aiming task. Translational motion (T1 and T2), yaw motion (R1), and pitch motion (R2) are jointly controlled by four linear actuators. The probe 6 can perform rotational motion (R3) and translational motion (T3) relative to its own axis, which are driven by motors 17 and 18 in conjunction with a set of gears. In summary, the probe fixed to the device has a total of six degrees of freedom, including rotational motion in three directions and translational motion in three directions. Furthermore, the puncture needle guide 2 is always located within the axial ultrasound imaging plane of the probe 6, ensuring that the puncture needle can be displayed in the ultrasound image in real time for the physician to observe. Furthermore, the position of the puncture needle guide 2 relative to the probe 6 is determined by a parallel mechanism with two degrees of freedom. The guide's translational (T4) and tilting (R4) movements relative to the probe are achieved through the relative motion of motors 10 and 19. When the system is running, the front end of the probe 6 is inserted into the patient's rectum, while the rear end is fixed to the device. After the doctor selects the target point, the system completes the positioning operation, and then the doctor performs the final puncture insertion operation (T5). The puncture needle is inserted into the prostate through the patient's perineum to complete the perineal prostate biopsy. Therefore, in this mode, the device maximizes the assistance to the doctor in performing a transperineal prostate biopsy while ensuring operational safety.

[0087] Figure 5 This diagram illustrates the RCM restraint mechanism involved in the device during a biopsy. Based on its flexible structure, the entire system comprises two RCM (remote center of motion) restraint mechanisms: an RCM-needle restraint mechanism and an RCM-probe restraint mechanism. Under different operating conditions, the position of the RCM-needle restraint mechanism can move relative to probe 6. The RCM-probe restraint mechanism is located at the patient's anus, with no relative displacement between the probe and the anus, thus reducing patient discomfort. The RCM-needle restraint mechanism is located on the patient's perineal skin. Notably, the RCM-needle restraint mechanism is positioned within the axial imaging plane of probe 6. As shown, the RCM-needle restraint mechanism is typically positioned laterally to avoid important nerves in the central region. A single biopsy usually requires more than 20 needle punctures. Therefore, implementing the RCM-needle restraint mechanism reduces damage to the patient's skin surface, thereby lowering the risk of infection. Furthermore, this approach reduces the amount of anesthetic drugs used and decreases the area requiring anesthesia.

[0088] Figure 6 A kinematic diagram of the lower part of the device is shown. Since the RCM-probe constraint mechanism is expected to be located at the patient's anus, the forward and inverse kinematic models of the parallel mechanism can be established based on geometric constraints. It is worth noting that the geometric constraints include the distance M between linear actuators 40 and 62, and the initial distance L between the location of the RCM-probe constraint mechanism and the linear actuator 62. The position of the patient's anus relative to the device base (denoted as e(x)) e ,y e ,z e The pitch and yaw angles (denoted as q1 and q2 respectively) are determined based on actual working conditions. Given the anal position, the pitch and yaw angles can be determined by the extension and retraction of linear actuators 40 and 33 (denoted as q1 and q2 respectively). and θ), that is Based on the geometric constraints, the scaling of linear actuators 62 and 63 (denoted as q4 and q3 respectively) can be determined, i.e. (q1,q2) = f(q3,q4).

[0089] Figure 7A A schematic diagram of the overall kinematics of the device is shown. To simultaneously handle the RCM-probe constraint mechanism and the RCM-puncture needle constraint mechanism, a kinematic model is established as shown in the figure. Once the position of the patient's anus relative to the device base is determined, it can be considered as the origin of a six-degree-of-freedom robotic arm, represented by coordinate 0. It should be noted that there is no relative displacement between the probe and the patient's anus. The translational motion of the upper part of the device is represented by q5. Therefore, based on the aforementioned lower parallel mechanism and its kinematic analysis model, the yaw angle θ1 and pitch angle θ2 can be expressed as θ1 = f(q1, q2, q5) and θ2 = f(q3, q4, q5), respectively. The rotational motion along the probe axis is represented by q5, which can provide a rolling motion θ3, i.e., θ3 = f(q6). The translational and tilting motions of the puncture needle relative to the probe are represented by d4 and θ5, respectively, determined by the relative displacements q7 and q8 of the two motors in the upper parallel mechanism of the device. Therefore, d4 = f(q7, q8) and θ5 = f(q7, q8). The insertion point of the puncture needle is considered as a passive joint of the robotic arm, denoted as d6. Thus, the forward kinematics model can be established based on this diagram to describe the relationship between the position of the patient's anus and the position of the cancerous target region. The RCM-puncture needle constraint mechanism can be implemented by adding constraints to the kinematic equations: as well as Where p rcm This indicates the location of the RCM-puncture needle restraint mechanism. and These are the origins of the coordinates attached to the front joint of the parallel mechanism and the cancerous target area, respectively. rcmLet q be the corresponding Jacobian matrix, and λ be a parameter used to adjust the position of the RCM-puncture needle constraint mechanism. The parameter q = [θ1, θ2, θ3, t4, θ5, θ6].

[0090] Figure 7B The diagram illustrates the overall motion of the device in two different configurations when implementing two RCM constraint mechanisms during targeted localization of different regions. As shown, the entire device can simultaneously implement both the RCM-probe constraint mechanism and the RCM-puncture needle constraint mechanism.

[0091] Figure 8 An orthogonal view showing one configuration of the upper part of the prostate biopsy device when the probe 6 performs rotational (R3) and translational (T3) motion relative to its axis. As can be seen from this perspective view, when the probe rotates, the puncture needle also rotates due to a mechanical constraint mechanism, and the puncture needle 1 remains within the imaging plane of the probe axis. This feature ensures operational safety, meaning that the puncture needle can always be observed while inserted into the patient.

[0092] Figure 9A and Figure 9B The diagram shows orthogonal views of the upper puncture needle motion module of the prostate biopsy device in two different configurations when the puncture needle 1 performs a tilting motion (R4) relative to the probe 6. The puncture needle guide 2, modules 3 and 4 in the parallel mechanism, and the cavity 12 constitute a closed kinematic chain. The rotation angle of the puncture needle guide 2 is determined by the relative positions of modules 3 and 4 in the parallel mechanism and is always located within the imaging plane of the probe axis. The range of the rotation angle is ±20°. Through this invention, the drive motors 10 and 19 in modules 3 and 4 can be positioned at a distance from the puncture needle guide.

[0093] Figure 10A and Figure 10B The diagram shows orthogonal views of the upper puncture needle movement module of the prostate biopsy device in two different configurations when the puncture needle 1 performs a translational movement (T4) relative to the probe 6. The translational range of the puncture needle guide 2 is determined by the relative positions of modules 3 and 4 in the parallel structure. When the extension and retraction of modules 3 and 4 are equal, the puncture needle guide 2 can rise or fall relative to the probe 6.

[0094] Figure 11A and Figure 11BOrthogonal views are shown of the prostate biopsy device in two different configurations when performing yaw motion (R1). The upper part of the device can be considered as the end effector of the lower parallel mechanism. Furthermore, the base of the upper part of the device can also be considered as the end effector of the lower parallel mechanism. Based on the aforementioned device function and actual operating conditions, the RCM-probe constraint mechanism is expected to be located at the patient's anus. There is no relative displacement between the probe and the patient's anus. Therefore, when the device performs yaw rotational motion, the relative extensional displacement relationship between the linear actuator 62 and the linear actuator 40 can be determined.

[0095] Figure 12A and Figure 12B Orthogonal views are shown of the prostate biopsy device in two different configurations during pitch (R2) motion. Yaw and pitch motions are decoupled, allowing the device to perform yaw rotation simultaneously with pitch motion. As shown in Figure 9, the RCM-probe constraint mechanism is expected to be located at the patient's anus. Therefore, the relative extensional displacement relationship between linear actuator 63 and linear actuator 33 can be determined to meet the requirements of the RCM-probe constraint mechanism.

[0096] Figure 13 This invention demonstrates the procedure for transperineal prostate biopsy using the device described herein. First, the device fixes the ultrasound probe in a specific configuration under RCM-probe constraint, and then acquires a series of ultrasound images. Note that MRI images must be acquired before the biopsy procedure begins. Subsequently, based on the fusion and registration of the MRI and ultrasound images, areas suspected of being cancerous are identified. On this basis, the device performs aiming under two RCM constraint mechanisms, while the movement plane of the puncture needle is always confined within the imaging plane of the probe. Finally, the surgeon performs manual needle insertion for each target area, inserting the needle into the patient's prostate via the perineum.

[0097] Figures 14A to 14C The diagram illustrates another structure of the puncture needle motion module of the device, enabling tilting and translational movements of the puncture needle relative to the probe within the imaging plane in different configurations. Since the parallel mechanism has two degrees of freedom, similar to the aforementioned parallel mechanism, the motion module is also driven by two actuators. A parallelogram mechanism is connected to the cavity for fixing the probe, and a puncture needle guide for guiding the puncture needle is connected to the parallelogram mechanism. Furthermore, the motor is connected to two joints of the parallelogram mechanism.

[0098] Figure 15This invention demonstrates the advantages of the device described in this invention compared to traditional methods in transperineal prostate biopsy. Due to the presence of bone, in some methods, the probe can only rotate around its own axis. Therefore, when the cancerous area is located above the prostate, the puncture needle cannot smoothly reach the target area through the small grid parallel to the probe. Furthermore, for some devices, such as Monalisa, although the puncture needle has multiple degrees of freedom, it cannot be confined within the imaging plane of the probe. The device described in this invention, through its flexible structure and the aforementioned kinematic modeling method, comprehensively solves the above problems.

[0099] Although the invention has been described in detail above, it should be understood that the invention is not limited thereto and may be implemented in various ways as shown in the appended claims.

Claims

1. An apparatus for performing transperineal prostate biopsy on a subject, characterized in that: The device includes: a. A first parallel mechanism for realizing translational or rotational motion of an ultrasound probe, the translational or rotational motion including horizontal, vertical, pitch, or yaw motion under an RCM-probe constraint mechanism; the first parallel mechanism includes one or more universal joint motion modules, the universal joint motion module including one or more passive joints; b. A series-parallel hybrid mechanism, serving as the end effector of the first parallel mechanism, for accommodating the ultrasound probe and a puncture needle guide; the first parallel mechanism and the series-parallel hybrid mechanism jointly control the configuration of a puncture needle relative to the subject and complete the alignment task under the RCM-puncture needle constraint mechanism; c. A drive module for the series-parallel hybrid mechanism, used to drive the ultrasonic probe to rotate and translate along its axis; d. A second parallel mechanism of the aforementioned series-parallel hybrid mechanism, for controlling the configuration of the puncture needle guide relative to the ultrasound probe and restricting the movement trajectory of the puncture needle within the axial imaging plane of the ultrasound probe; and e. A controller for implementing a kinematic modeling method to achieve the following objectives: i) Based on the first parallel mechanism and the drive module, realize the RCM-probe approximation Binding mechanism; ii) Based on the first parallel mechanism and the series-parallel hybrid mechanism, simultaneously achieve RCM - probe constraint mechanism and RCM - puncture needle constraint mechanism.

2. The apparatus according to claim 1, characterized in that: The one or more universal joint motion modules further include two linear motion modules providing four degrees of freedom; the second parallel mechanism is a two-degree-of-freedom mechanism including two lifting modules and the puncture needle guide, and the second parallel mechanism is connected to the drive module; The transperineal prostate biopsy device includes an upper part and a lower part, the series-parallel hybrid mechanism constitutes the upper part and serves as the end effector of the first parallel mechanism, while the first parallel mechanism constitutes the lower part.

3. The apparatus according to claim 2, characterized in that: The two linear motion modules include either a two-degree-of-freedom front motion module or a two-degree-of-freedom rear motion module.

4. The apparatus according to claim 3, characterized in that: The two-degree-of-freedom front motion module includes a horizontal motion module and a vertical motion module. The horizontal motion module is connected to the vertical motion module, and the one or more passive joints are connected to the horizontal motion module.

5. The apparatus according to claim 3, characterized in that: The two-degree-of-freedom rear motion module includes a horizontal motion module and a vertical motion module. The horizontal motion module is connected to the vertical motion module, and the one or more passive joints are connected to the horizontal motion module.

6. The apparatus according to claim 1, characterized in that: The drive module includes a cavity for fixing the ultrasonic probe.

7. The apparatus according to claim 2, characterized in that: The second parallel mechanism controls the configuration of the puncture needle guide relative to the ultrasound probe, and the puncture needle guide can perform translational and tilting movements relative to the ultrasound probe.

8. The apparatus according to claim 7, characterized in that: The drive module includes a cavity for fixing the ultrasound probe, and the second parallel mechanism is connected to the cavity.

9. The apparatus according to claim 7, characterized in that: The second parallel mechanism further includes an additional mechanism that allows the puncture needle to perform tilting and translational movements within the axial imaging plane of the ultrasound probe; The drive module includes a cavity for fixing the ultrasonic probe, and the additional mechanism includes: A parallelogram mechanism connected to the cavity, the parallelogram mechanism comprising two joints; A puncture needle guide for guiding a puncture needle, the puncture needle guide being connected to the parallelogram mechanism; and Two motors are connected to two joints of the parallelogram mechanism, respectively.

10. The apparatus according to claim 2, characterized in that: The second parallel mechanism cooperates with the puncture needle guide to make the puncture needle move in a plane that coincides with the axial imaging plane of the ultrasound probe.

11. The apparatus according to claim 1, characterized in that: The one or more passive joints include a front universal joint and a rear universal joint.

12. The apparatus according to claim 4, characterized in that: The one or more passive joints include a front universal joint and a rear universal joint. The front universal joint includes a joint bracket, a pitch rotation part, and a yaw rotation part. The joint bracket is connected to the horizontal motion module of the front motion module.

13. The apparatus according to claim 4, characterized in that: The one or more passive joints include a front universal joint and a rear universal joint. The rear universal joint includes a joint bracket, a pitch rotation part, and a yaw rotation part. The joint bracket is connected to the horizontal motion module of the rear motion module.

14. The apparatus according to claim 2, characterized in that: The series-parallel hybrid mechanism includes a base, and the one or more passive joints are interconnected via a linear bearing and a linear shaft parallel to the base.

15. The apparatus according to claim 2, characterized in that: The first parallel mechanism and the series-parallel hybrid mechanism can simultaneously implement two RCM constraint mechanisms.

16. The apparatus according to claim 14, characterized in that: The RCM restraint mechanism includes an RCM probe restraint mechanism and an RCM needle restraint mechanism. The RCM probe restraint mechanism is located at the anus of the subject, and the RCM needle restraint mechanism is located on the skin of the perineum of the subject.

17. The apparatus according to claim 9, characterized in that: The ultrasonic probe is selected from one of the following: a handheld probe, a passive mechanism probe, or an automated robot system probe.

18. A method for performing transperineal prostate biopsy using the apparatus of claim 1, characterized in that: The method includes the following steps: a. Obtain MRI images of the subject's prostate; b. Fix the ultrasound probe using the transperineal prostate biopsy device and construct a specific configuration under the RCM-probe constraint mechanism; c. Obtain an ultrasound image of the subject's prostate; d. The MRI image and the ultrasound image are fused and registered to form a fused result; e. Select a target region based on the fusion result; and control the device to aim at the RCM-puncture needle position under the RCM-puncture needle constraint mechanism and the RCM-probe constraint mechanism; and f. Manually insert the puncture needle into the target area through the puncture needle guide.

19. The method according to claim 18, characterized in that: The device includes a base and the RCM-probe constraint mechanism, and further includes a kinematic modeling method for determining the position of the RCM-probe constraint mechanism relative to the base.

20. The method according to claim 18, characterized in that: The method further includes a kinematic modeling method based on the device, used to simultaneously realize the RCM-probe constraint mechanism and the RCM-puncture needle constraint mechanism.

21. The method according to claim 18, characterized in that: After selecting the target area, the device can automatically adjust the position of the RCM-puncture needle restraint mechanism.

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