Robots in MRI-guided interventions

Abstract

This specification discloses a novel robotic system and method for MRI-guided interventions, adapted to various MRI scanners, particularly low-field scanners with small bores. The system and method disclosed herein enable precise, minimally invasive procedures.

Description

Technical Field

[0001] Cross-reference This application claims the benefit of U.S. Provisional Application No. 63 / 462,914, filed Apr. 28, 2023, the disclosure of which is hereby incorporated by reference in its entirety.

Background Art

[0002] Magnetic resonance imaging (MRI) is an imaging method that provides excellent soft tissue contrast, high spatial resolution, and multi-planar volume imaging capabilities.

Summary of the Invention

[0003] In one aspect, a robotic system is provided. In some embodiments, the robotic system includes an end effector configured to perform one or more percutaneous interventions, a base configured to be fitted inside a magnetic resonance scanner bore or mounted on a bed, and a parallel manipulator configured to connect the end effector to the base using a plurality of parallel kinematic chains.

[0004] In some embodiments, the parallel manipulator has three degrees of freedom (DOF).

[0005] In some embodiments, the one or more percutaneous interventions include biopsy or brachytherapy.

[0006] In some embodiments, the robotic system further includes a plurality of pneumatic stepper motors configured to move the end effector.

[0007] In some embodiments, the driving force of the plurality of pneumatic stepper motors is by compressed air.

[0008] In some embodiments, at least one of a plurality of parallel kinematic chains includes a proximal system connected to a distal system.

[0009] In some embodiments, the robotic system further includes at least one sensor configured to recognize the home position of the end effector.

[0010] In some embodiments, the robotic system further includes at least one optical sensor.

[0011] In some embodiments, at least one optical sensor is configured to track the rotational output of multiple pneumatic stepper motors.

[0012] In some embodiments, an additional degree of freedom is added to the robotic system to drive a device added to the end effector.

[0013] Further aspects and advantages of this disclosure will be readily apparent to those skilled in the art from the following detailed description; hereafter, only exemplary embodiments of this disclosure are shown and described. It is to be understood that this disclosure is adaptable to other and different embodiments, and some of its details can be modified in various obvious ways without departing from this disclosure. Therefore, the drawings and description should be considered illustrative and not limiting.

[0014] Embedding by reference All publications, patents, and patent applications described herein are incorporated herein by reference to the same extent as each individual publication, patent, or patent application is specifically and individually incorporated herein by reference. [Brief explanation of the drawing]

[0015] The novel features of the present disclosure are particularly defined in the appended claims. A better understanding of the features and advantages of the present disclosure will be obtained by reference to the following detailed description that defines exemplary embodiments. In the exemplary embodiments, the principles of the present disclosure are utilized, and the accompanying drawings (referred to herein as "FIG." and "FIG.") are as follows.

[0016] [Figure 1] An isometric view of an exemplary MRI system according to some embodiments.

[0017] [Figure 2] A schematic view of an MRI system according to some embodiments.

[0018] [Figure 3] A side view of an exemplary shaft that transmits movement from an actuator to a kinematic chain according to some embodiments.

[0019] [Figure 4] A front view of an exemplary pneumatic stepper motor according to some embodiments.

[0020] [Figure 5] A side view of an exemplary MRI system of an alternative configuration according to some embodiments.

[0021] [Figure 6] A perspective view of an exemplary robot inside a low-field MRI system according to some embodiments.

[0022] [Figure 7] A perspective view of an exemplary robot inside a low-field MRI system with a portion of the scanner cut away for a better field of view according to some embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] This disclosure relates to medical devices. More specifically, this disclosure relates to a robotic system made of a medical imaging-safe material that can be used to perform MRI-guided diagnostic procedures and minimally invasive interventions.

[0024] Magnetic resonance imaging (MRI) is an imaging method that provides excellent soft tissue contrast, high spatial resolution, and multi-planar volume imaging capabilities. There have also been developed body-worn robots that include fluid-driven actuators for positioning needles for biopsy or RF ablation. However, in the system, manual (hand-held) placement on the patient and gross targeting by manual induction based on an initial MRI dataset are available. Additionally, the intervention physician can manually place the needle outside the bore. Another system is an MRI-compatible surgical robot that can perform microsurgery and stereotactic surgery for brain and spinal surgeries. The robot can use the MRI imaging method to guide surgical instruments and provide real-time feedback to the surgeon. A parallel robot for prostate biopsy has been constructed to track and manipulate needles to reach targets behind obstacles.

[0025] These systems can use MRI to guide surgical instruments, provide feedback to the surgeon, and enable precise minimally invasive procedures. This approach can reduce the risk of complications, shorten the recovery time, and improve patient outcomes. Additionally, these systems can reduce the time required for the procedure and minimize the need to add diagnostic imaging such as CT or ultrasound.

[0026] Image-guided robot assistance can improve clinical outcomes by facilitating more precise, less invasive, and more effective interventions, reducing procedural infections, and leveraging medical imaging-based feedback. Another advantage of MRI-guided robot-assisted intervention may be its potential to reduce procedure time. In standard intraoperative procedures, the patient may be moved out of the bore for the intervention and then returned to the bore for imaging. However, with a robot designed to perform the intervention inside the MRI bore, the intervention and imaging can be performed simultaneously, improving outcomes and reducing time. Furthermore, MRI-guided robot-assisted intervention can significantly improve ergonomics. Manual interventions with closed-bore scanners can often be challenging.

[0027] While MRI imaging provides high-quality visual information during interventions, it can have limitations for both conventional and robot-assisted interventions. In some cases, spatial limitations within the MRI bore restrict access to the patient during imaging, making it difficult to use robotic systems that need to be integrated into the remaining space between the patient and the MRI. Furthermore, the magnetic field can hinder the use of metal-based materials in robotic systems.

[0028] From another perspective, low-field MRI, which is gaining increasing attention due to healthcare disparities between developed and developing countries, can provide useful diagnostic information even without producing high-quality images. However, while MRI-guided interventions can be studied within a dual-donut magnet, performing them with a low-field MRI scanner can be challenging.

[0029] This specification discloses a novel robotic system and method for MRI-guided interventions, adapted to various MRI scanners, particularly low-field scanners with small bores. The system and method disclosed herein can enable precise, minimally invasive procedures.

[0030] A robotic system that can be adapted to several interventional medical devices is disclosed herein. Such medical devices may, but are not limited to, include various end-effectors for various percutaneous interventions such as biopsy or brachytherapy. The robot may be configured for use with MRI equipment, including low-field-intensity MRI scanners. Challenges with robot-assisted MRI-guided interventions may arise from electromagnetic compatibility issues due to the MRI environment and spatial limitations due to the common closed-bore geometry. Ensuring bidirectional MRI compatibility can ensure that neither the equipment nor the scanner affects other functions.

[0031] The disclosed robot may be of a size that is accessible within a closed bore tunnel-shaped scanner. The robot may be constructed of materials suitable for the operating environment associated with MRI, including, but not limited to, non-magnetic and dielectric materials such as plastics (e.g., polymers, ceramics, porcelain, metal oxides, rubber, and other similar materials), or any combination thereof.

[0032] The robot can use high-torque, high-resolution pneumatic stepper motors to drive the end effector. These motors can be driven by compressed air. Optical sensors may be used to track the motor rotation output. The robot can be configured and positioned to move within the bore of the MRI scanner.

[0033] According to several embodiments, as shown in Figure 1, the developed robot may have a parallel manipulator with three degrees of freedom (DOF), and the robot's base platform is connected to a common plate / end effector by three parallel identical kinematic chains. The manipulator 100 may comprise a base 102, three identical kinematic chains 104, and an end effector 106. The robot may be considered to be in its home position when the end effector 106 is parallel to the base 102. The base 102 can be fitted inside a scanner bore and designed to match the shape of the bore. Also shown in Figure 1 are a sensor 108 for the home position of the end effector 106, the geometric center 110 of the manipulator 100, and a round hex wrench mechanism 112.

[0034] As shown in Figure 2, according to some embodiments, each kinematic chain may comprise a proximal system 122 connected to a distal system 124 by a free-rotating joint 126. The top cover of the robot manipulator 100 has been removed to allow a view of the system's interior. One key feature of the robot is that the base 102 comprises four collinear actuators. On each kinematic chain, one fixed-acting rotary joint 120 and two free-rotating joints 126 can connect the proximal system 122 and the distal system 124 to the end effector 106. Three free-rotating joints 126 can connect the distal system 124 to the end effector 106. Three rotary motors can actuate the proximal system 122 on the base 102. This manipulator 100 can achieve three rotational DOFs: roll, pitch, and yaw. Figure 2 further shows the air intake port 114, the optical sensor 116, and the high-torque and high-resolution pneumatic stepper motor 118.

[0035] One of the key features of this parallel manipulator is that the rotation axes of all joints may intersect at a common point called the geometric center 110 of the manipulator 100. The geometric center 110 may be the point around which any end-effector element rotates.

[0036] Another feature of the robot is that the base may include four collinear actuators (Figure 2). According to some embodiments, the shaft 128 that transmits motion from the actuators to the kinematic chain can be designed to be hollow in order to realize a collinear actuator configuration (Figure 3). Referring to Figure 3, in some cases the shaft 128 that transmits motion from the actuators to the kinematic chain is designed to be hollow in order to realize a collinear actuator configuration. The actuator shaft 130 for driving any devices added to the end effector 106 may also be designed to be hollow. It should be noted that according to some embodiments, the central axis of the actuator of a high-torque and high-resolution pneumatic stepper motor 118 may be designed to be hollow and / or may have a bore 132 (Figure 4).

[0037] The robot base may have three fiber optic optical sensors for returning the proximal systems to their home position. When the three proximal systems rotate and each moves in front of one optical sensor 116, the end effector 106 may be parallel to the base. This position may be the robot's home position.

[0038] An additional 1DOF may be added to the system to drive any additional devices attached to the end effector. The output of the fourth actuator may extend to the geometric center on the end effector. This rotational motion on the end effector can be converted into any required motion. Since the end effector can rotate around the roll, pitch, and yaw axes, the round-head hex wrench mechanism 112 can be configured to transmit rotation to the device (Figure 1). This mechanism may comprise a cylindrical tool with one end hexagonal and which can fit into the socket of the driven part. A fiber optic sensor 116 may be positioned on the end effector to return the added device to its home position.

[0039] The robot base can be designed in various shapes and sizes so as to fit inside the scanner bore or be mounted on the patient bed. By adjusting the robot's position inside the bore, additional depth of field (DOF) can be added to the system. Furthermore, the shape of the end effector may be modified to hold any required equipment.

[0040] A bundle of tubes, optical fibers, pneumatic distributors, electrical circuits, a robot controller, or any combination thereof may be used to drive the robot. This device may be located far from the magnetic field. This device can operate reliably in an MRI system environment.

[0041] Figure 5 shows a side view of an exemplary random configuration of a robotic manipulator system 100, not in a home position, according to several embodiments. In some embodiments described herein, all elements of the end effector rotate around the robot's geometric center 110. The end effector 106 may be parallel to its base when the three proximal systems rotate, each moving in front of one home positioning sensor 108 for the home positioning of the end effector 106. This position can be referred to as the robot's home position.

[0042] Figure 6 shows perspective views of a robotic manipulator 100 located inside a low-field MRI scanner system 200 according to several embodiments. Since the shape of the robotic system is the same as the bore, the robotic system can easily move within the bore. The robotic system may also be fixed inside the bore.

[0043] Figure 7 shows perspective views of a robotic manipulator 100 inside a low-field MRI scanner system 200, with a portion of the scanner cropped for clarity, according to several embodiments.

[0044] definition Unless otherwise defined, all technical terms, expressions, and other technical and scientific terms or terminology used herein are intended to have the same meaning as commonly understood by those skilled in the art to which the claimed subject matter pertains. In some cases, terms having a commonly understood meaning are defined herein for clarity and / or for easy reference, and the inclusion of such definitions herein should not necessarily be interpreted as representing a substantial difference beyond what is commonly understood in the art.

[0045] Throughout this application, various embodiments may be presented in range form. It should be understood that range form descriptions are merely for convenience and conciseness and should not be interpreted as inflexible limitations on the scope of this disclosure. Therefore, a range description should be considered to encompass not only the individual numerical values ​​within that range but also all specifically disclosed feasible subranges. For example, a range description such as 1 to 6 should be considered to encompass not only the individual numerical values ​​within that range, such as 1, 2, 3, 4, 5, and 6, but also the specifically disclosed subranges such as 1 to 3, 1 to 4, 1 to 5, 2 to 4, 2 to 6, and 3 to 6. This applies regardless of the breadth of the range.

[0046] The scope disclosed herein further includes any and all of the overlapping portions, sub-ranges, and combinations thereof. Phrases such as “up to,” “at least,” “greater than,” “less than,” and “between” include the stated figures. Figures preceded by terms such as “approximately,” “about,” and “nearly” as used herein include the stated figures and further represent a quantity close to the mentioned quantity that performs the desired function or achieves the desired result. The terms “about” or “approximately” may mean that a particular value is within an acceptable margin of error, and the acceptable margin of error will depend in part on how that value is measured or determined, for example, the limits of the measuring system. For example, the terms “approximately,” “about,” and “nearly” may refer to quantities that are less than 10%, less than 5%, less than 1%, less than 0.1%, and less than 0.01% of the mentioned quantity. For example, “about” may mean within or greater than one standard deviation according to practice in the art. Alternatively, “approximately” may mean a range of up to 20%, 10%, 5%, or 1% of a given value. Where used herein, the term “approximately” a number refers to that number plus or minus 10% of it. The term “approximately” a range refers to that range minus 10% of its lowest value and that range plus 10% of its highest value. Where a particular value is described in this application and claims, unless otherwise stated, the term “approximately” can be assumed to mean that it is within an acceptable margin of error for that particular number.

[0047] As used herein and in the claims, the singular forms “a,” “an,” and “the” include plural references unless the context clearly indicates otherwise. For example, the term “a sample” includes multiple samples, and also includes mixtures thereof.

[0048] The terms “determining,” “measuring,” “evaluating,” “assessing,” “analyzing,” and “analyzing” are often used interchangeably herein to refer to forms of measurement. These terms include determining whether an element exists or not (e.g., detection). These terms may include quantitative, qualitative, or both quantitative and qualitative determinations. Assessment may be relative or absolute. “Detecting the presence” may, depending on the context, include determining the quantity of something that exists, in addition to determining whether something exists or not.

[0049] The terms “subject,” “individual,” or “patient” are often used interchangeably herein. “Subject” may be a biological entity containing expressed genetic material. A biological entity may be a plant, an animal, or a microorganism, such as bacteria, viruses, fungi, and protozoa. A subject may be a tissue, cell, or offspring of a biological entity obtained in vivo or cultured in vitro. A subject may be a mammal. A mammal may be a human. A subject may be diagnosed or suspected of being at high risk for a disease. In some cases, a subject may not necessarily be diagnosed or suspected of being at high risk for a disease.

[0050] The section headings used in this specification are for organizational purposes only and should not be construed as limiting the subjects described.

[0051] While preferred embodiments of the present disclosure are shown and described herein, it will be apparent to those skilled in the art that such embodiments are provided only as examples. Many variations, alterations, and substitutions will now be conceivable to those skilled in the art without departing from the present disclosure. It will be understood that various alternative forms to the embodiments of the present disclosure described herein may be adopted in practice. The following claims define the scope of the invention, and methods and structures within the scope of these claims and their equivalents are intended to be covered thereby.

Claims

1. An end effector configured to perform one or more transcutaneous interventions, A base configured to be fitted inside the magnetic resonance scanner bore or mounted on the bed, A robotic system comprising a parallel manipulator configured to connect the end effector to the base using multiple parallel kinematic chains.

2. The robot system according to claim 1, wherein the parallel manipulator has three degrees of freedom (DOF).

3. The robotic system according to claim 1 or 2, wherein the one or more percutaneous interventions include biopsy or brachytherapy.

4. The robot system according to any one of claims 1 to 3, further comprising a plurality of pneumatic stepper motors configured to move the end effector.

5. The robot system according to claim 4, wherein the driving force of the plurality of pneumatic stepper motors is provided by compressed air.

6. The robotic system according to any one of claims 1 to 5, wherein at least one of the plurality of parallel kinematic chains includes a proximal system connected to a distal system.

7. The robotic system according to any one of claims 1 to 6, further comprising at least one sensor configured to recognize the home position of the end effector.

8. The robotic system according to any one of claims 1 to 7, further comprising at least one optical sensor.

9. The robot system according to claim 8, wherein the at least one optical sensor is configured to track the rotational output of a plurality of pneumatic stepper motors.

10. The robot system according to any one of claims 1 to 9, wherein an additional degree of freedom is added to the robot system in order to drive a device added to the end effector.

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