Methods and devices for transperineal prostate biopsy

Abstract

The present invention relates to a method and apparatus for transperineal prostate biopsy. In one embodiment, the apparatus for transperineal prostate biopsy includes: (a) a first parallel mechanism for generating translational or rotational motion of an ultrasound probe; (b) a series-parallel hybrid mechanism as an end effector of the first parallel mechanism for accommodating the ultrasound probe and a biopsy needle guide; (c) a drive module of the series-parallel hybrid mechanism for generating rotational and translational motion of the ultrasound probe along an axis of the ultrasound probe; (d) a second parallel mechanism of the series-parallel hybrid mechanism for controlling the configuration of the biopsy needle guide relative to the ultrasound probe and constraining the trajectory of the biopsy needle to an axial imaging plane of the ultrasound probe; and a controller for performing kinematic modeling.

Description

[Technical Field]

[0001] The present invention relates generally to transperineal prostate biopsy, and more particularly to novel mechanisms that can be used to assist a surgeon in performing a transperineal prostate biopsy, biopsy needle positioning based on the device, and the surgical workflow for transperineal prostate biopsy using the device of the present invention. [Background technology]

[0002] Prostate cancer is the second most common cancer after breast cancer and one of the leading causes of death in men. Early and reliable detection of prostate cancer has a significant impact on the successful treatment of high-risk patients and the avoidance of overtreatment in low-risk patients. In general, the most reliable technique for detecting prostate cancer and estimating its malignancy is prostate biopsy.

[0003] There are three types of prostate biopsies in clinical practice. The key difference is where the needle passes. Because puncture sites include the urethra, perineum, and rectum, prostate biopsies are generally divided into transrectal biopsy, transperineal biopsy, and transurethral biopsy. Transrectal ultrasound-guided prostate biopsy, a common method for diagnosing prostate cancer, requires an ultrasound probe to be inserted into the rectum to identify a suspicious area. The biopsy needle then penetrates the anterior rectal wall into the prostate. However, transrectal prostate biopsy is prone to several complications, such as rectal bleeding and infection. Furthermore, it is difficult for the biopsy needle to cover the entire prostate. This method has been previously described in several systems, such as U.S. Patent No. 9,877,788 B2, filed January 30, 2018, entitled "MRI-safe robot for transrectal prostate biopsy," and U.S. Patent No. 10,368,850 B2, filed August 6, 2019, entitled "System and method for real-time ultrasound-guided prostate needle biopsies using a compliant robotic arm." For transurethral prostate biopsy, the needle is typically displayed on the ultrasound imaging surface in real time to ensure safety. Therefore, this biopsy method is difficult to use with real-time ultrasound imaging, making it difficult to ensure safety. In addition, there are too many puncture sites that penetrate the urethral wall, increasing the risk of complications. Transperineal prostate biopsy involves inserting a biopsy needle through the skin of the perineum under the guidance of an ultrasound probe. Transperineal biopsy may be safer and poses a lower risk of infection. Instead of undergoing general anesthesia, the patient only needs local anesthesia. Therefore, in this situation, no harsh medical environment is required at the biopsy site, which may improve overall biopsy efficiency.

[0004] A typical transperineal prostate biopsy is guided by transrectal ultrasound-guided images. The surgeon inserts a biopsy needle into the prostate through a guide template guided by the acquired ultrasound images. The guide template has a series of through-holes parallel to the probe. The transperineal biopsy needle is inserted through these holes to enter the target. The surgeon needs to hold the probe with one hand and insert the biopsy needle with the other. This procedure is highly dependent on the surgeon's experience, making the prostate biopsy process difficult to define and follow. To improve the accuracy and quality of needle insertion, it is important to develop a flexible robotic device system that handles positioning and aiming tasks during the prostate biopsy process, so that the surgeon only needs to perform manual needle insertion with the assistance of the designed device.

[0005] It is worth mentioning that the workflow of clinical robotic prostate biopsy includes preoperative and intraoperative procedures. Because prostate cancer is a heterogeneous and multifocal disease, it is important to identify suspicious areas of cancer with the help of cancer image-guided targeting. Magnetic resonance imaging (MRI) can provide the best contrast and spatial resolution for the anatomical structures of the prostate. Therefore, during the preoperative process, an MRI scan is performed on the patient, and the MRI images of the prostate are segmented and reconstructed in three dimensions. However, the real-time performance of MRI images is relatively poor. In addition, MRI is very demanding in the working environment and has high magnetic resistance requirements for other equipment. It is inconvenient for surgeons to perform biopsies in an MRI working environment. Transrectal ultrasound (TRUS) scans can provide real-time images and are convenient to use. One of the simplest methods of biopsy targeting is MRI-TRUS image fusion. Therefore, an ultrasound probe is moved into the rectum and scanned to obtain a series of 2D ultrasound images, and the prostate area is segmented and reconstructed in 3D. Next, registration and fusion of the MRI model and the ultrasound 3D model are performed. Furthermore, for the intraoperative process, the physician holds the ultrasound probe in the appropriate position while selecting the target lesion. The assist device plans and aligns the biopsy needle guide. The surgeon then inserts the needle and performs the biopsy.

[0006] Based on the above-mentioned method, several commercial devices (such as Monalisa and Artemis) have designed their own robotic systems for prostate biopsy. For example, Monalisa employs transperineal biopsy under the guidance of MRI-TRUS-guided imaging. However, Monalisa lacks real-time inline ultrasound monitoring of the needle path because the probe cannot be aligned with the biopsy needle. Therefore, the exact needle position cannot be seen on the ultrasound imaging window, which reduces the quality control and safety of the system. The probe only has two degrees of freedom and is not flexible enough. To avoid the pubic bone getting in the way, the probe needs to yaw or pitch during the biopsy process. As for Artemis, its puncture points are different from each other. Therefore, there is no RCM (remote center of motion) constraint. It is worth mentioning that using a small number of puncture positions can reduce patient trauma. Based on a robotic arm, transperineal biopsy needle guidance has some limitations in reaching various regions of the prostate, such as the anteriormost region, due to the pubic bone getting in the way. It appears to be more operator dependent in targeting, and the arm arrangement only appears to provide primary position in addition to rotational degrees of freedom.

[0007] The volume of the prostate gland is approximately 75 ml, so the corresponding workspace of the robotic device must encompass the volume of the prostate gland. Considering the workspace and working environment, the device volume must be relatively compact. The system must provide sufficient support when the surgeon inserts the biopsy needle. The biopsy needle must be observed in the real-time image plane of the probe to ensure safety. All factors contribute to a complete transperineal biopsy system.

[0008] To date, few flexible interventional devices have been designed for transperineal prostate biopsy. The introduction of a robotic device into such a system would be a significant advantage, allowing for accurate targeting under RCM constraints. The device could be compact in volume and have sufficient rigidity and flexibility. Therefore, there is a need in the art for a flexible assisted biopsy device to improve the efficiency and accuracy of prostate biopsies. Summary of the Invention

[0009] The present invention achieves the above-mentioned objectives by providing a transperineal prostate biopsy device with probe configuration control and needle configuration control functions, and a surgical workflow using MRI-TRUS-guided images to target cancer-suspected areas. The flexible device includes a lower-half parallel mechanism and an upper-half series-parallel hybrid mechanism, and the upper portion of the device includes a drive module for generating rotational and translational motion of the probe along an axis and a parallel mechanism for controlling the needle configuration relative to the probe. The lower portion of the device includes two designed universal joints with four driver actuators for generating rotational and translational motion of the upper portion.

[0010] In one embodiment of the present invention, the device can ensure two RCM constraints involving the RCM probe and the RCM needle synchronously. The device has a total of eight degrees of freedom. The probe fixed on the device will have six degrees of freedom, including three rotational movements and three translational movements, based on the integration of the upper and lower parts of the device. The RCM probe is positioned at the patient's anus, and the probe does not move relative to the patient's anus. The configuration of the needle guide associated with the probe is determined by a two-degree-of-freedom parallel mechanism. The position of the RCM needle can be movable relative to the probe under various operating conditions.

[0011] More specifically, based on the features of the device of the present invention for transperineal prostate biopsy, a kinematic analysis is established to address the constraints of the RCM probe and RCM needle, as well as to describe the relationship between the displacement of all actuators or motors and the target position.

[0012] In another embodiment of the present invention, the device can hold the ultrasound probe in a suitable configuration with the constraints of the RCM probe, and then achieve a specific trajectory to obtain the desired ultrasound image. Based on the previous MRI image, the target point will be obtained by the result of 3D fusion and registration of the MRI image and the acquired ultrasound image.

[0013] According to the device of the present invention, the surgical workflow can be described as follows: First, the ultrasound probe is held by the device in a specific configuration with the RCM probe constraints, after which a series of ultrasound images are acquired. Next, the suspected cancer area is targeted based on the fusion and registration of the MRI and ultrasound images. As a result, the device performs the aiming operation with the two RCM constraints, and at the same time, the needle's movement plane will always be limited to the probe's imaging plane. Finally, the surgeon manually inserts the needle into the patient's prostate through the perineum.

[0014] The invention and its features can be best understood in detail from the following description and illustrative drawings. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is an orthogonal view of a prostate biopsy device in accordance with a proposed aspect of the present invention; [Figure 2(a)] 1 illustrates the upper portion of a prostate biopsy device capable of rotating and translating the probe relative to an axis and moving the biopsy needle in the image plane relative to the ultrasound probe, in accordance with aspects of the present invention. [Figure 2(b)] 1 is a partial cross-sectional view of an upper portion of a prostate biopsy device in accordance with aspects of the present invention. [Figure 3(a)]1 is an orthogonal view of the passive motion module of the lower part of the prostate biopsy device, which mainly includes two designed universal joints. [Figure 3(b)] 1 is a partial cross-sectional view of a passive motion module of a lower portion of a prostate biopsy device in accordance with aspects of the present invention. [Figure 4] 1A and 1B show a motion diagram of a prostate biopsy device in partial view according to a proposed feature of the present invention. [Figure 5] FIG. 10 illustrates RCM constraints during a biopsy process of a device, including needle RCM constraints and probe RCM constraints, in accordance with aspects of the present invention. [Figure 6] 10A and 10B show kinematic diagrams of the lower portion of a device according to aspects of the present invention. [Figure 7(a)] 1 is a kinematic diagram of an overall device according to aspects of the present invention; [Figure 7(b)] 1 is a diagram of the overall system operating under two RCM constraints according to aspects of the present invention. [Figure 8] 1 is an orthogonal view of the upper portion of a prostate biopsy device as the probe rotates and translates about its axis, in accordance with aspects of the present invention. [Figure 9(a)] 1 is an orthogonal view of a needle motion module in the upper portion of a prostate biopsy device as the needle undergoes a tilting motion relative to the device's probe, in accordance with aspects of the present invention. [Figure 9(b)] 1 is an orthogonal view of a needle motion module in the upper portion of a prostate biopsy device as the needle undergoes a tilting motion relative to the device's probe, in accordance with aspects of the present invention. [Figure 10(a)] 1 is an orthogonal view of a needle motion module in the upper portion of a prostate biopsy device as the needle translates relative to a probe of the device, in accordance with aspects of the present invention. [Figure 10(b)] 1 is an orthogonal view of a needle motion module in the upper portion of a prostate biopsy device as the needle translates relative to a probe of the device, in accordance with aspects of the present invention. [Figure 11(a)] 1 is an orthogonal view of a prostate biopsy device as it undergoes a yaw motion, in accordance with aspects of the present invention. [Figure 11(b)]1 is an orthogonal view of a prostate biopsy device as it undergoes a yaw motion, in accordance with aspects of the present invention. [Figure 12(a)] 1 is an orthogonal view of a prostate biopsy device as it undergoes a pitch motion, in accordance with aspects of the present invention. [Figure 12(b)] 1 is an orthogonal view of a prostate biopsy device as it undergoes a pitch motion, in accordance with aspects of the present invention. [Figure 13] 1 illustrates a workflow with an apparatus of the present invention for transperineal prostate biopsy in accordance with aspects of the present invention. [Figure 14(a)] 10A-10C illustrate another mechanism for the needle motion module that allows tilt and translation of the needle in the image plane relative to the probe of the apparatus according to aspects of the present invention. [Figure 14(b)] 10A-10C illustrate another mechanism for the needle motion module that allows tilt and translation of the needle in the image plane relative to the probe of the apparatus according to aspects of the present invention. [Figure 14(c)] 10A-10C illustrate another mechanism for the needle motion module that allows tilt and translation of the needle in the image plane relative to the probe of the apparatus according to aspects of the present invention. [Figure 15] 1A-1D illustrate the advantages of the device of the present invention compared to conventional methods during a transperineal prostate biopsy procedure. DETAILED DESCRIPTION OF THE INVENTION

[0016] A novel transperineal prostate biopsy device is designed to improve efficiency, accuracy, and treatment quality. This device can perform positioning and aiming during the prostate biopsy process under the guidance of MRI-ultrasound fusion images, allowing the surgeon to perform only manual needle insertion, making the process less operator-dependent. Based on this robotic system, the biopsy needle is inserted through the patient's perineum and is constantly monitored based on real-time ultrasound images, which is safer and can certainly reduce the risk of infection. Instead of general anesthesia, the patient only needs local anesthesia. No harsh medical environment is required at the biopsy site, which can improve overall biopsy efficiency. Furthermore, this device can hold the ultrasound probe at an appropriate position and then achieve a specific trajectory to acquire the desired ultrasound image. Based on the previous MRI image, a target point can be obtained through 3D fusion and registration of the MRI image and the acquired ultrasound image. After the target point is given, the device performs its motion to achieve the aiming task.

[0017] This device has a total of eight degrees of freedom. The probe fixed on the device will have six degrees of freedom, including three rotational movements and three translational movements. The position of the needle guide relative to the probe can be determined by a two-degree-of-freedom parallel mechanism. Furthermore, based on a flexible structure, the entire system includes two RCM (remote center of motion) constraints: the RCM needle and the RCM probe. The position of the RCM needle can be movable relative to the probe under various working conditions.

[0018] The main advantages of this device include: It is more rigid than a serial robot and uses a series-parallel hybrid method. To ensure safety, the imaging surface of the probe is always on the same plane as the needle. The device is flexible and guarantees eight degrees of freedom in a compact case, allowing it to accommodate a constrained workspace. The entire system can skillfully guarantee two RCM constraints. The probe of this device has multiple degrees of freedom, and the RCM probe constraints are also guaranteed. The RCM probe position and RCM needle position can be moved relative to the patient.

[0019] The present invention provides a transperineal prostate biopsy device. In one embodiment, the transperineal prostate biopsy device comprises: a) a parallel mechanism with two designed universal joints, for generating translation of an ultrasonic probe, including horizontal and vertical movement, and rotational movement, including pitch or yaw movement, with the constraint of an RCM probe; b) a series-parallel hybrid mechanism as the end effector of the parallel mechanism, for accommodating the ultrasonic probe and a biopsy needle guide; c) a drive module of the series-parallel hybrid mechanism, for generating rotational and translational movement of the ultrasonic probe along the axis of the ultrasonic probe; a parallel mechanism of the series-parallel hybrid mechanism, for controlling the configuration of a needle guide relative to the ultrasonic probe and limiting the trajectory of the biopsy needle to the axial imaging plane of the probe; and d) a kinematic modeling method for ensuring the constraint of the RCM probe based on the parallel mechanism and the drive module, and for simultaneously ensuring the constraint of the RCM probe and the constraint of the RCM needle based on the parallel mechanism and the series-parallel hybrid mechanism.

[0020] In one embodiment, the parallel mechanism includes two of the designed universal joints and two designed linear motion modules with 4 DoF, and the series-parallel hybrid mechanism is connected to the 4-DoF parallel mechanism, which further includes the ultrasound probe, the drive module, the parallel mechanism with 2 DoF connected to the drive module, the 2-DoF parallel mechanism including two lift modules and the needle guide. The series-parallel hybrid mechanism as the upper part of the device of the present invention is used as an end effector of the 4-DoF parallel mechanism, which is considered as the lower part of the device of the present invention.

[0021] In one embodiment, the linear motion module of the 4-DoF parallel mechanism further includes a 2-DoF forward motion module and a 2-DoF rearward motion module.

[0022] In one embodiment, the 2-DoF forward motion module further includes a horizontal motion module and a vertical motion module, the horizontal motion module connected to the vertical motion module, and the universal joint connected to the horizontal motion module.

[0023] In one embodiment, the 2-DoF rearward motion module further includes a horizontal motion module and a vertical motion module, the horizontal motion module connected to the vertical motion module, and the other universal joint connected to the horizontal motion module.

[0024] In one embodiment, the drive module further comprises a chamber for securing the ultrasonic probe.

[0025] In one embodiment, the 2-DoF parallel mechanism controls the configuration of the needle guide relative to the probe, and the needle guide can perform translation and tilt motion relative to the probe.

[0026] In one embodiment, the 2-DoF parallel mechanism is connected to the chamber.

[0027] In one embodiment, the 2-DoF parallel mechanism further includes another mechanism for tilting and translating the needle within the image plane relative to the probe, the other mechanism including a parallelogram mechanism connected to the chamber, a needle guide for guiding the biopsy needle connected to the parallelogram, and two motors connected to two joints of the parallelogram mechanism.

[0028] In one embodiment, the 2-DoF parallel mechanism with the needle guide causes the plane of movement of the needle to coincide with the imaging plane of the probe.

[0029] In one embodiment, the universal joints of the 4-DoF parallel mechanism further include a front universal joint and a rear universal joint.

[0030] In one embodiment, the forward universal joint further includes a joint support, a pitch rotator, and a yaw rotator, The joint support is connected to the horizontal motion module of the forward motion module.

[0031] In one embodiment, the aft universal joint further includes a joint support, a pitch rotator, and a yaw rotator, The joint support is connected to the horizontal motion module of the aft motion module.

[0032] In one embodiment, the universal joints of the 4-DoF parallel mechanism are integrally connected by linear bearings and linear shafts parallel to the base of the series-parallel hybrid mechanism.

[0033] In one embodiment, the 4-DoF parallel mechanism and the series-parallel hybrid mechanism can simultaneously guarantee two RCM constraints.

[0034] In one embodiment, the RCM constraint further includes an RCM probe and an RCM needle, the RCM probe being positioned at the patient's anus and the RCM needle being positioned on the skin of the patient's perineum.

[0035] In one embodiment, the 2-DoF parallel mechanism is such that the working environment is not limited by the fixed mode of the probe, which includes handheld terminals, passive mechanisms, and automated robotic systems.

[0036] The present invention also provides a method for a surgical workflow in transperineal prostate biopsy using MRI and ultrasound images, a transrectal ultrasound probe, and 3D fusion and registration of the MRI and ultrasound images. In one embodiment, the method includes: a) acquiring an MRI image of a patient's prostate; b) holding the ultrasound probe with the device of the present invention to perform a specific configuration with the constraints of the RCM probe; c) acquiring an ultrasound image of the patient's prostate and obtaining fusion and registration of the MRI and ultrasound images; d) selecting a target region of interest based on the fusion results and instructing the device of the present invention to perform a targeting operation according to the constraints of the RCM needle and the RCM probe; and e) manually inserting the biopsy needle into the target region by a surgeon through the needle guide.

[0037] In one embodiment, the constraints on the RCM probe further include kinematic modelling to determine the position of the RCM probe relative to the base of the device of the invention.

[0038] In one embodiment, the method further comprises a method for kinematic modelling of the entire device to simultaneously realise the constraints of the RCM probe and the constraints of the RCM needle based on the device of the present invention.

[0039] In one embodiment, the position of the RCM needle is automatically adjusted by the device after selecting the target area.

[0040] The present invention also provides an apparatus for transperineal prostate biopsy on a subject, which in one embodiment includes: a) a first parallel mechanism for generating translational or rotational motion of an ultrasound probe, the translational or rotational motion including horizontal, vertical, pitch, or yaw motion with RCM probe constraints, the first parallel mechanism including one or more universal joint-motion modules including one or more passive joints; b) a series-parallel hybrid mechanism as an end effector of the first parallel mechanism for accommodating the ultrasound probe and a biopsy needle guide, the first parallel mechanism and the series-parallel hybrid mechanism controlling the configuration of the biopsy needle relative to the subject and aligning it with the RCM needle constraints; and c) the series-parallel hybrid mechanism. a drive module of the series-parallel hybrid mechanism for generating rotational and translational movement of the ultrasonic probe along the axis of the ultrasonic probe; d) a second parallel mechanism of the series-parallel hybrid mechanism for controlling the configuration of the biopsy needle guide relative to the ultrasonic probe and restricting the trajectory of the biopsy needle to the axial imaging plane of the ultrasonic probe; and e) a controller for: i) ensuring constraints of the RCM probe based on the first parallel mechanism and the drive module; and ii) executing a kinematic modeling method for simultaneously ensuring constraints of the RCM probe and constraints of the RCM needle based on the first parallel mechanism and the series-parallel hybrid mechanism.

[0041] In one embodiment, the one or more universal joint-motion modules further include two designed linear motion modules providing 4DoF, the second parallel mechanism is a 2DoF mechanism including two lifting modules and the biopsy needle guide, the second parallel mechanism is connected to the drive module, and the device for transperineal prostate biopsy comprises an upper portion and a lower portion, and the series-parallel hybrid mechanism forms the upper portion for use as an end effector of the first parallel mechanism forming the lower portion.

[0042] In one embodiment, the two designed linear motion modules include a 2-DoF forward motion module or a 2-DoF rearward motion module.

[0043] In one embodiment, the 2-DoF forward motion module includes a horizontal motion module and a vertical motion module, the horizontal motion module connected to the vertical motion module, and the one or more passive joints connected to the horizontal motion module.

[0044] In one embodiment, the 2-DoF rearward motion module includes a horizontal motion module and a vertical motion module, the horizontal motion module connected to the vertical motion module, and the one or more passive joints connected to the horizontal motion module.

[0045] In one embodiment, the drive module includes a chamber that secures the ultrasonic probe.

[0046] In one embodiment, the second parallel mechanism controls the configuration of the biopsy needle guide relative to the ultrasound probe, and the biopsy needle guide may undergo translation and tilt motion relative to the ultrasound probe.

[0047] In one embodiment, the drive module includes a chamber for fixing the ultrasonic probe, and the second parallel mechanism is connected to the chamber.

[0048] In one embodiment, the second parallel mechanism further includes an additional mechanism for tilting and translating the biopsy needle in the axial imaging plane of the ultrasound probe, the drive module including a chamber for fixing the ultrasound probe, and the additional mechanism including a parallelogram mechanism connected to the chamber, the parallelogram mechanism including two joints, a needle guide for guiding the biopsy needle connected to the parallelogram mechanism, and two motors connected to the two joints of the parallelogram mechanism.

[0049] In one embodiment, the second parallel mechanism with the biopsy needle guide moves the biopsy needle in a plane coincident with the axial imaging plane of the ultrasound probe.

[0050] In one embodiment, the one or more passive joints include a forward universal joint and a rearward universal joint.

[0051] In one embodiment, the one or more passive joints include a forward universal joint and an aft universal joint, the forward universal joint including a joint support, a pitch rotator, and a yaw rotator, the joint support connected to the horizontal motion module of the forward motion module.

[0052] In one embodiment, the one or more passive joints include a forward universal joint and an aft universal joint, the aft universal joint including a joint support, a pitch rotator, and a yaw rotator, the joint support connected to the horizontal motion module of the aft motion module.

[0053] In one embodiment, the series-parallel hybrid mechanism comprises a base, and the one or more passive joints are integrally connected by a linear bearing and a linear shaft parallel to the base.

[0054] In one embodiment, the first parallel mechanism and the series-parallel hybrid mechanism can simultaneously guarantee two RCM constraints.

[0055] In one embodiment, the RCM constraint comprises an RCM probe and an RCM needle, the RCM probe being positioned at the subject's anus and the RCM needle being positioned on the skin of the subject's perineum.

[0056] In one embodiment, the ultrasound probe is a probe selected from the group consisting of a handheld device, a passive mechanism, and an automated robotic system.

[0057] The present invention provides a method for transperineal prostate biopsy using the device of the present invention. In one embodiment, the method includes the steps of: a) acquiring an MRI image of the subject's prostate gland; b) holding the ultrasound probe with the transperineal prostate biopsy device to perform a specific configuration with the constraints of the RCM probe; c) acquiring an ultrasound image of the subject's prostate gland; d) fusing and registering the MRI image and the ultrasound image to form a fusion result; e) selecting a target region of interest based on the fusion result and instructing the device to aim an RCM needle position according to the constraints of the RCM needle and the constraints of the RCM probe; and f) manually inserting the biopsy needle through the biopsy needle guide into the target region of interest.

[0058] In one embodiment, the apparatus includes a base and constraints for the RCM probe, and the method further includes kinematic modeling to determine a position of the RCM probe relative to the base.

[0059] In one embodiment, the method further comprises kinematic modeling of the device to simultaneously implement the constraints of the RCM probe and the constraints of the RCM needle based on the device.

[0060] In one embodiment, the RCM needle position is automatically adjusted by the device after selecting the target area of ​​interest.

[0061] Referring to FIG. 1, a preferred embodiment of the prostate biopsy device according to the present invention is illustrated. Two subassemblies are shown within the device: an upper portion of the prostate biopsy device and a lower portion of the prostate biopsy device. The upper and lower portions of the device are connected by a connector 7. The main components of the upper portion are a drive mechanism that rotates and translates the probe about its axis, and parallel mechanisms 2-4 that control the motion of the biopsy needle 1 relative to the probe 6. The lower portion of the device, as a parallel mechanism, primarily includes two designed universal joints driven by four linear actuators, designated 33, 40, 62, and 63, respectively. The entire device can be attached to other mechanisms via its base connector 41.

[0062] The upper part of the prostate biopsy device is shown in detail in Figure 2(a). The upper part is connected to the lower part of the device by connector 7, which can be considered the base of the upper part. Probe support 8 is connected to 7 via linear slide 24. Support 8 is translationally movable relative to 7, which is driven by motor 18 via gears 21 and 22 and lead screw 23. The screw is fixed on support 8. Probe 6 is rotationally movable along its axis relative to part 8 and is driven by motor 17 and a triad of gears 27, 20, and 5, which reduce the speed and increase the torque generated by motor 17. Probe 6 is fixed by chamber 12, which is connected to support 8 by bearing 11. The parallel mechanism consists of 2-4, which control the movement of biopsy needle 1 relative to probe 6. This movement includes translation and tilt relative to the probe, which are driven by motors 10 and 19. Racks 13 and 16 and linear guides 15 and 14 convert the rotational motion of the motor into translational motion, and the two sets of racks and linear guides are fixed on chamber 12 via parts 26 and 25, while the two sets of motors are fixed on chamber 12 via part 30. Needle guide 2 is connected to lifting modules 3 and 4 of the parallel mechanism. The relative movement of motors 10 and 19 realizes the movement of the needle guide in tilt and translation within the image plane.

[0063] 2(b) is a partial cross-sectional view of the upper part of the apparatus, which can better reflect the above-mentioned connection relationship between the support 8, chamber 12, part 30 and probe 6. The parallel mechanism in the upper part of the apparatus is driven by two motors, and the rotational motion is converted into translational motion by two gears 9, 28 and a rack. Linear guides 29 and 24 allow the support 8 to advance and retract linearly along the axis of the probe.

[0064] FIG. 3(a) is an orthogonal view of the passive motion module of the lower part of the prostate biopsy device. This parallel mechanism mainly includes two designed universal joints 47 and 34. The universal joint 47 mainly consists of a support 53, a pitch rotation section 54 and a yaw rotation section 61, and two linear bearings 60 and 53. The linear bearing 60 is fixed below the support 53, and the linear bearing 56 is fixed within the yaw rotation section 61. Among these, the pitch rotation section 54 can perform pitch rotation relative to the support 53, and the yaw rotation section 61 can perform yaw rotation relative to the pitch rotation section 54. In addition, the configuration of the universal joint 34 is slightly different from that of the universal joint 47. Similarly, the main components of the universal joint 34 are the support 51, the pitch rotation section 50 and the yaw rotation section 49, and the linear bearing 64. The linear bearing 64 is fixed below the support 51. Additionally, pitch rotating part 50 can pitch rotate relative to support 51, and yaw rotating part 49 can yaw rotate relative to part pitch rotating part 50. Unlike U-joint 47, yaw rotating part 49 of U-joint 34 has a slider on a linear guide 48 mounted therein.

[0065] One end of the linear shaft 55 passes through and is fixed inside the yaw rotation section 49, and the other end passes through a linear bearing 56 inside the portion 53 of the U-joint 47. The linear shaft 55 is slidable along the axis of the linear bearing 56. The base 7 of the upper part of the apparatus is fixed on the yaw rotation section 61. Furthermore, one end of the linear guide 48 is fixed below the base 7, and the other end is slidable along a sliding slider inside the yaw rotation section 49. Therefore, the linear guide 48 and the linear shaft 55 are always parallel to each other.

[0066] Two horizontally arranged linear shafts 52 and 32 pass through two linear bearings 64 and 60 fixed under U-joints 47 and 34, respectively. In addition, these two linear shafts 52 and 32 are fixed to connecting plates 31 and 37, respectively. Therefore, the two U-joints 47 and 34 can linearly extend and retract along 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 supports 51 and 53, and the bases of the linear actuators are fixed on connecting plates 31 and 37. When the extension amounts of the two linear actuators 33 and 63 are equal, the two U-joints 47 and 34 simultaneously perform horizontal translation. When the extension amounts of the two linear actuators 33 and 63 are unequal, the relative positions of the two U-joints 47 and 34 in the horizontal direction change, which causes the yaw rotors 49 and 61 to rotate, and therefore the base 7 also exhibits yaw movement.

[0067] Two vertically arranged linear bearings 57 and 59 are fixed to both ends of connecting plate 31, and similarly, linear bearings 58 and 36 are fixed to both ends of connecting plate 37. Linear shafts 44 and 46 pass through linear bearings 57 and 59, respectively, and these two linear shafts are also fixed on base 39. Similarly, linear shafts 65 and 35 pass through linear bearings 58 and 36, respectively, and are also fixed on base 39. Therefore, the two U-joints 47 and 34 and the two connecting plates 31 and 37 constitute two modules that move vertically, and these modules are driven by linear actuators 40 and 62. When the two linear actuators 40 and 62 expand and contract by equal amounts, the two U-joints 47 and 34 simultaneously translate in the vertical direction. When the two linear actuators 40 and 62 expand and contract by unequal amounts, the relative positions of the two U-joints 47 and 34 in the vertical direction change, thereby rotating pitch rotation units 47 and 50. Therefore, the base 7 also exhibits pitch movement. Thus, through this designed parallel structure, the upper part of the device can be made to achieve vertical and horizontal translational movements, as well as pitch and yaw rotations.

[0068] 3(b) is a partial cross-sectional view of the passive motion module of the lower portion of the prostate biopsy device, which can better reflect the above-mentioned connection relationship between the components of the two universal joints 47 and 34 (yaw rotators 61 and 49, pitch rotators 54 and 50, linear shaft 55, linear guide 48, and base 7). Because the yaw rotators 61 and 49 rotate relative to the components 54 and 50, they need to be connected to each other via bearings 66 and 62, respectively. The linear guide 48 increases the rigidity and stability of the base 7.

[0069] A partial view of the motion of the prostate biopsy device according to the present invention is shown in FIG. 4. In its zero configuration, the axial direction of the probe 6 is horizontal 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 needle 1 has translational motion (T5) relative to the needle guide 2, which is driven by the surgeon when the prostate biopsy device completes its aiming operation. Translation (T1 and T2), yaw (R1), and pitch (R2) are controlled by four linear actuators. The probe 6 can perform rotational motion (R3) and translational motion (T3) about its own axis, which are driven by motors 17 and 18 in conjunction with a set of gears. In summary, a probe fixed on the device will have six degrees of freedom, including three rotational movements and three translational movements. Additionally, the needle guide 2 is always positioned in the axial ultrasonic imaging plane of the probe 6, ensuring that the needle can be displayed to the physician on the ultrasound image in real time. Furthermore, the position of the needle guide 2 relative to the probe 6 can be determined by a two-degree-of-freedom parallel mechanism. The relative movement of motors 10 and 19 enables translation (T4) and tilt (R4) of the needle guide relative to the probe. When the system is functioning, the front end of the probe 6 is inserted into the patient's rectum, and the rear end is fixed on the device. After the physician selects the target point and the system completes the positioning operation, the physician performs the final insertion operation (T5). The biopsy needle is inserted into the prostate through the patient's perineum, completing the biopsy sampling. Therefore, in this embodiment, the device assists the physician in performing a transperineal prostate biopsy to the maximum extent possible while ensuring safety.

[0070] Figure 5 shows the RCM constraint of the device during the biopsy process. Based on a flexible structure, the entire system includes two RCM (remote center of motion) constraints: the RCM needle and the RCM probe. The position of the RCM needle can be moved relative to the probe 6 under various operating conditions. The RCM probe is located at the patient's anus, and there is no relative displacement between the probe and the anus, which can reduce patient discomfort. The RCM needle is located on the skin of the patient's perineum. It is worth noting that the RCM needle is located in the axial imaging plane of the probe 6. As shown in the figure, the RCM needle is usually located on both sides to avoid central vital nerves. A biopsy usually requires more than 20 needle sticks. Therefore, restraining the RCM needle can reduce superficial trauma to the patient's skin, thereby reducing the risk of infection. In addition, this can reduce the use of anesthesia and the patient's anesthetic range.

[0071] Figure 6 shows the kinematic diagram of the lower part of the device. Since the RCM probe is expected to be at the patient's anus, a forward and backward kinematic model of the parallel mechanism can be constructed based on geometric constraints. It is worth mentioning that the geometric constraints include the distance between the linear actuator 40 and the linear actuator 62, represented by M, and the initial distance between the position of the RCM probe and the linear actuator 62, represented by L. The distance (e(x e ,y e ,z e The position of the anus (represented by φ and θ) is determined according to the actual working conditions. Considering the position of the anus, the pitch angle and yaw angle (represented by φ and θ) can be determined by the expansion values ​​of linear actuator 40 and linear actuator 33 (represented by q1 and q2), so that (θ,φ)=f(q1,q2). And based on the geometric constraints, the expansion values ​​of linear actuator 62 and linear actuator 63 (represented by q4 and q3) can be determined, so that (q1,q2)=f(q3,q4).

[0072] Figure 7(a) shows the kinematics of the entire device. The kinematic model shown is constructed to simultaneously accommodate the RCM probe and RCM needle. Once the position of the anus relative to the device base is determined, it is assumed to be the origin of the 6-DOF manipulator, represented by coordinate 0. It is noteworthy 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 lower parallel mechanism and its kinematic analysis described above, the yaw and pitch rotations, represented by θ1 and θ2, can be expressed as θ1 = f(q1, q2, q5) and θ2 = f(q3, q4, q5), respectively. The rotation along the probe axis, represented by q5, can provide roll motion, represented by θ3, so that θ3 = f(q6). The translational and tilt motions of the needle relative to the probe described above are represented by d4 and θ5, which are determined by the relative displacements of the motors of the parallel mechanism of the upper part of the device, represented by q7 and q8. Therefore, d4 = f(q7,q8) and θ5 = f(q7,q8). The needle insertion is considered as a passive joint of the manipulator represented by d6. Therefore, a forward kinematic model can be constructed based on the diagram, which can explain the relationship between the position of the patient's anus and the position of the target in the cancer area. Then, the RCM needle can be realized by adding constraints to the kinematic equations.

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[0077] Figure 7(b) shows the operating diagram of the entire device under two RCM constraints in two different configurations during the process of targeting various regions. As shown, the entire device can simultaneously guarantee the RCM probe and the RCM needle.

[0078] 8 shows an orthogonal view of the upper portion of the prostate biopsy device in a configuration in which the probe 6 rotates (R3) and translates (T3) about its axis. It can be seen from the perspective view of this configuration that as the probe rotates, the needle also rotates via mechanical constraints, and the needle 1 is always in the imaging plane of the probe axis. This feature ensures safety; the needle is always observed once inserted into the patient's body.

[0079] 9(a) and 9(b) are orthogonal views of the needle movement module of the upper part of the prostate biopsy device in two different configurations when the needle 1 performs a tilt movement (R4) relative to the probe 6 of the device. The needle guide 2, the parallel structure modules 3 and 4, and the chamber 12 form a closed kinematic chain. The rotation angle of the needle guide 2 is determined by the relative positions of the parallel structure modules 3 and 4 and is always in the imaging plane of the probe axis. The rotation range is ±20 degrees. With this design, the drive motors 9 and 19 of modules 3 and 4 can be located far away from the needle guide.

[0080] 10(a) and 10(b) are orthogonal views of the needle movement module of the upper portion of the prostate biopsy device in two different configurations when the needle 1 undergoes translational movement (T4) relative to the device's probe 6. The translational range of the needle guide 2 is determined by the relative positions of modules 3 and 4 in a side-by-side configuration. When the telescoping distances of modules 3 and 4 are equal, the needle guide 2 can be raised or lowered relative to the probe 6.

[0081] 11(a) and 11(b) are orthogonal views of the prostate biopsy device in two different configurations as it undergoes a yaw motion (R1). The upper portion of the device can be considered as the end effector of the lower parallel portion of the device. Furthermore, the base of the upper portion of the device can be considered as the end effector of the lower parallel mechanism. Based on the device's function and actual working conditions described above, the RCM probe is expected to be at the patient's anus, and there is no relative displacement between the probe and the patient's anus. Therefore, as the device undergoes a yaw rotation, the relative expansion displacement relationship between linear actuator 62 and linear actuator 40 can be determined.

[0082] 12(a) and 12(b) are orthogonal views of the prostate biopsy device in two different configurations when the device performs a pitch motion (R2). The yaw and pitch motions are decoupled, and the device can perform pitch rotation while also performing yaw rotation. As shown in FIG. 9, the RCM probe is expected to be at the patient's anus. Therefore, the relative expansion displacement relationship between linear actuator 63 and linear actuator 33 can be determined to meet the requirements of the RCM probe.

[0083] Figure 13 shows the workflow of the device of the present invention for transperineal prostate biopsy. First, the ultrasound probe is held by the device in a specific configuration with the RCM probe constraints, after which a series of ultrasound images are acquired. However, MRI images are always acquired before the biopsy process. Next, the suspicious cancer area is targeted based on the fusion and registration of the MRI and ultrasound images. As a result, the device performs the aiming operation with two RCM constraints, while the needle movement plane is always limited to the probe's imaging plane. Finally, for each target, the surgeon manually inserts the needle through the perineum into the patient's prostate.

[0084] Figures 14(a)-(c) show another mechanism of the needle motion module that can tilt and translate the needle in the image plane relative to the device's probe in various configurations. The parallel mechanism has two degrees of freedom, so it is driven by two actuators, just like the parallel mechanism described above. The parallelogram mechanism is connected to the chamber that fixes the probe, and the needle guide that guides the biopsy needle is connected to the parallelogram mechanism. In addition, motors are connected to the two joints of the parallelogram mechanism.

[0085] Figure 15 illustrates the advantageous features of the device of the present invention compared to conventional methods during a transperineal prostate biopsy procedure. In some methods, due to the presence of bone, the probe can only rotate around its own axis. As a result, when the cancerous area is located in the upper region of the prostate, the biopsy needle cannot reach the cancerous area through a mini-grid parallel to the probe. In addition, for some devices, such as the Monalisa, the needle has multiple degrees of freedom, but the needle cannot be limited to the image plane of the probe. The present device can comprehensively solve the above problems through the flexible structure and kinematic modeling method described above.

[0086] Although the present invention has been described in detail above, it should be noted that the present invention is not limited thereto but can be embodied in various ways as exemplified in the following claims.

Claims

1. 1. An apparatus for transperineal prostate biopsy on a subject, comprising: a. a first parallel mechanism for generating translational or rotational motion of an ultrasonic probe, the translational or rotational motion including horizontal, vertical, pitch, or yaw motion with constraints of an RCM probe, the first parallel mechanism including one or more universal joint-motion modules including one or more passive joints; b. a series-parallel hybrid mechanism as an end effector of the first parallel mechanism for accommodating the ultrasound probe and biopsy needle guide, wherein the first parallel mechanism and the series-parallel hybrid mechanism control the configuration of the biopsy needle relative to the subject and align with RCM needle constraints; c) a drive module of the hybrid series-parallel mechanism for generating rotational and translational motion of the ultrasonic probe along an axis of the ultrasonic probe; d. a second parallel mechanism of the series-parallel hybrid mechanism for controlling the configuration of the biopsy needle guide relative to the ultrasound probe and constraining the trajectory of the biopsy needle to an axial imaging plane of the ultrasound probe; e. A controller, i) ensuring constraints of the RCM probe based on the first parallel mechanism and the drive module; ii) a controller for executing a kinematic modeling method based on the first parallel mechanism and the series-parallel hybrid mechanism to simultaneously guarantee the constraints of the RCM probe and the constraints of the RCM needle; An apparatus comprising:

2. the one or more universal joint-motion modules further include two engineered linear motion modules providing 4 DoF; the second parallel mechanism is a 2DoF mechanism including two lifting modules and the biopsy needle guide, and the second parallel mechanism is connected to the drive module; 10. The device of claim 1, wherein the device for transperineal prostate biopsy comprises an upper portion and a lower portion, and the series-parallel hybrid mechanism forms the upper portion for use as an end effector of the first parallel mechanism that forms the lower portion.

3. The apparatus of claim 2 , wherein the two designed linear motion modules include a 2-DoF forward motion module or a 2-DoF backward motion module.

4. 4. The apparatus of claim 3, wherein the 2-DoF forward motion module includes a horizontal motion module and a vertical motion module, the horizontal motion module connected to the vertical motion module, and the one or more passive joints connected to the horizontal motion module.

5. 4. The apparatus of claim 3, wherein the 2-DoF rearward motion module includes a horizontal motion module and a vertical motion module, the horizontal motion module connected to the vertical motion module, and the one or more passive joints connected to the horizontal motion module.

6. The apparatus of claim 1 , wherein the drive module comprises a chamber for securing the ultrasonic probe.

7. The device of claim 2 , wherein the second parallel mechanism controls the configuration of the biopsy needle guide relative to the ultrasound probe, and the biopsy needle guide is capable of translation and tilt motion relative to the ultrasound probe.

8. The apparatus of claim 7 , wherein the drive module includes a chamber for securing the ultrasonic probe, and the second parallel mechanism is connected to the chamber.

9. The second parallel mechanism further includes an additional mechanism for tilting and translating the biopsy needle in the axial imaging plane of the ultrasound probe, the drive module including a chamber for fixing the ultrasound probe, and the additional mechanism includes: a parallelogram mechanism connected to the chamber, the parallelogram mechanism including two joints; a needle guide connected to the parallelogram mechanism for guiding the biopsy needle; two motors connected to the two joints of the parallelogram mechanism; The apparatus of claim 7, comprising:

10. The apparatus of claim 2 , wherein the second parallel mechanism with the biopsy needle guide moves the biopsy needle in a plane coincident with the axial imaging plane of the ultrasound probe.

11. The apparatus of claim 1 , wherein the one or more passive joints include a forward universal joint and an aft universal joint.

12. 5. The apparatus of claim 4, wherein the one or more passive joints include a forward universal joint and an aft universal joint, the forward universal joint including a joint support, a pitch rotator, and a yaw rotator, the joint support connected to the horizontal motion module of the 2-DoF forward motion module.

13. 5. The apparatus of claim 4, wherein the one or more passive joints include a forward universal joint and an aft universal joint, the aft universal joint including a joint support, a pitch rotator, and a yaw rotator, the joint support connected to the horizontal motion module of the 2-DoF rear motion module.

14. 3. The apparatus of claim 2, wherein the series-parallel hybrid mechanism comprises a base, and the one or more passive joints are integrally connected by a linear bearing and a linear shaft parallel to the base.

15. The apparatus of claim 2 , wherein the first parallel mechanism and the series-parallel hybrid mechanism can simultaneously guarantee two RCM constraints.

16. 15. The device of claim 14, wherein the RCM constraint comprises an RCM probe and an RCM needle, the RCM probe being positioned at the subject's anus and the RCM needle being positioned on the skin of the subject's perineum.

17. 10. The apparatus of claim 9, wherein the ultrasound probe is a probe selected from the group consisting of a handheld device, a passive mechanism, and an automated robotic system.

18. 10. A method for transperineal prostate biopsy using the device of claim 1, comprising: a. obtaining an MRI image of the subject's prostate; b. holding the ultrasound probe with the transperineal prostate biopsy device to perform a specific configuration with the constraints of the RCM probe; c. acquiring an ultrasound image of the subject's prostate; d. fusing and registering the MRI image and the ultrasound image to form a fusion result; e. selecting a target region of interest based on the fusion results and instructing the device to aim at an RCM needle position according to the RCM needle constraints and RCM probe constraints; f. manually inserting the biopsy needle through the biopsy needle guide into the target area of ​​interest. A method comprising:

19. The method of claim 18 , wherein the apparatus includes a base and constraints for the RCM probe, the method further including kinematic modeling to determine a position of the RCM probe relative to the base.

20. 20. The method of claim 18, further comprising: kinematic modeling of the device to simultaneously implement the RCM probe constraints and the RCM needle constraints based on the device.

21. 20. The method of claim 18, wherein the RCM needle position is automatically adjusted by the device after selecting the target area of ​​interest.

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