Abstract:
A system and method for image guided assisted medical procedures using modular units, such that a controller, under the direction of a computer and imaging device, can be utilized to drive and track low cost, purpose specific manipulators. The system utilizes modular actuators, self tracking, and linkages. The system can be optimized at a low cost for most effectively performing surgical procedures, while reusing the more costly components of the system, e.g. the control, driving, and tracking systems. The system and method may utilize MRI real time guidance during the above procedures.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to a U.S. provisional application Ser. No. 61/238,405 entitled SYSTEM AND METHOD FOR ROBOTIC SURGICAL INTERVENTION, filed on Aug. 31, 2009 which is incorporated in its entirety herein by reference. 
    
    
     FIELD OF INVENTION 
     The present teachings relate generally to the field of guidance equipment and, more particularly, to equipment that is used to aid in the accurate guidance of surgical tools and/or sensors to locations in the human body. 
     BACKGROUND 
     While the field of image guided surgical robotic assistance is still in its infancy, it is expanding rapidly. The benefit of image guided robotically assisted surgery is fairly clear: the combination of computer controlled precision movement and high resolution soft tissue imaging allows the surgeon to accomplish the procedural goals with minimized damage to surrounding tissue. There are many organizations across the globe developing imaging compatible systems of, though currently few are on the market. Most research facilities are either attempting to re-build general purpose serial manipulators for imaging compatibility, or developing single purpose units to perform a multitude of tasks on a single area of the body. 
     Stereotactic neural intervention is a commonly practiced surgical procedure today. There are many treatments and operations that require the accurate targeting of, and intervention with, a specific area of the brain which utilize stereotactic neural intervention. One common use of this procedure is Deep Brain Stimulation (DBS), which is often used for the treatment of Parkinson&#39;s Disease. 
     Magnetic resonance imaging (MRI) compatible systems have been developed, though they typically manually driven, bulky and/or inconvenient to use. There are systems for specific procedures such as DBS therapy, though those systems are inconvenient to use and/or lack accuracy due to the lack of real time image guidance. 
     DBS is a technique for influencing brain function through the use of implanted electrodes. Direct magnetic resonance (MR) image guidance during DBS insertion would provide many benefits; most significantly, interventional MRI can be used for planning, real-time monitoring of tissue deformation, insertion, and placement confirmation. The accuracy of standard stereotactic insertion is limited by registration errors and brain movement during surgery. With real-time acquisition of high-resolution MR images during insertion, probe placement can be confirmed intraoperatively. Direct MR guidance has not taken hold because it is often confounded by a number of issues including: MR compatibility of existing stereotactic surgery equipment and patient access in the scanner bore. The high resolution images required for neurosurgical planning and guidance require high-field MR (1.5-3T); thus, any system must be capable of working within the constraints of a closed, long-bore diagnostic magnet. Currently, no technological solution exists to assist MRI guided neurosurgical interventions in an accurate, simple, and economical manner. 
     Currently, a typical DBS placement procedure is comprised of the following events: 
     1. Patient arrives at hospital for pre-procedure MRI scan. 
     2. Surgeons analyze the patient&#39;s images, and produces a surgical plan. 
     3. Patient returns to the hospital where a stereotactic surgical frame is attached to the skull in the operating room. 
     4. A computed tomography (CT) scan is taken of the patient with the frame to register the surgical plan to the frame. 
     5. The surgical frame is manually aligned and used to guide a drill for drilling the burr holes to gain access to the cranial cavity. 
     6. The surgical frame is used to guide the placement of electrodes through the burr hole. 
     7. Some form of placement confirmation is utilized (often micro electrode recordings, fluoroscopy, or computed tomography.) 
     8. Often the procedure is repeated for bilateral insertion of a second electrode. 
     8. Patient is sent to recovery. 
     This process has been used for several decades, though tissue deformation can cause registration errors between the preoperative images used to create the surgical plan, and the state of the patients anatomy during the procedure. These errors can lead to a host of negative side effects including: reduced effectiveness of the DBS equipment, unwanted neurological changes (mood shift, chronic gambling), brain injury, brain hemorrhage, etc. 
     This procedure has several other drawbacks, such as the following:
         during the time between when the surgical plan is generated and the procedure occurs, there is a possibility of soft tissue shift within the patient, causing inaccurate placement of electrodes;   when the cerebrospinal fluid drains after the first burr hole is drilled, there is another possibility of soft tissues shift;   for some applications of DBS, micro electrode recordings cannot be used for placement confirmation due to a high possibility of causing brain damage;   shifts in soft tissue increase the risk of a blood vessel being moved into the surgical path, which could cause brain hemorrhage; and   electrode insertion itself will cause tissue deformation as it is being inserted into the operative area.       

     Therefore, it would be beneficial to have a superior system and method for performing a plurality of robotic surgical interventions utilizing real-time MRI imaging. 
     SUMMARY 
     The needs set forth herein as well as further and other needs and advantages are addressed by the present embodiments, which illustrate solutions and advantages described below. 
     The system of the present invention is based on embodiments which use modular units, such that a controller can be utilized to drive and track low cost, purpose specific manipulators. The system utilizes modular actuators, self tracking, and linkages constructed from, for example, but not limited to, hard image compatible plastics that are not ferro magnetic, although under other circumstances such as, where magnetics are not utilized, ferro magnetic material may be used. Therefore, the system can be optimized at a low cost for most effectively performing a plurality of individual surgical procedures, while reusing the more costly components of the system, e.g. the control, driving, and tracking systems. 
     In one embodiment the system comprises a manipulator linkage which targets DBS electrode placement and allows the procedure to be performed based on interactively updated MRI images. Alternatively, the system may be used to perform the procedure based almost entirely on pre operative images in a manner similar to the typical approach in the operating room. The system is a safe and reliable electrode placement assistant that overcomes the difficulties of working in a closed high-field MRI. The objective of the system, but is not limited to, enables registering and placing electrodes within the brain under image guidance with half millimeter accuracy. The system reduces procedure time, cost, and complications while improving effectiveness and availability. 
     The method of the present embodiment includes, but is not limited to, MRI-compatible self-positioning stereotactic surgical guidance that bridges the gap between high resolution imaging modalities and interventional procedures that utilize them for planning purposes. 
     Further embodiments are used to facilitate MRI guided insertion of electrodes for deep brain stimulation under live imaging. The embodiments comprise a central controller or controller, and actuated manipulator or armature, and a user workstation. The controller of the system contains a computing unit that can process sensor information from the actuated armature as well as generate driving signals to operate the armatures&#39; actuators. Additionally, the central control unit communicates with a user workstation which combines position information from the armature with scanner images in order to register the armatures position within the imaging space, and allow the user to generate position commands for the robotic manipulator. 
     The method for the design of all of these components has generated a system which produces minimal degradation (that is, almost no visually identifiably interference) on MRI image quality. The modular system is designed to be able to use a wide variety of procedure specific mechanism, with the same controller so that the mechanism can have numerous, limited degrees of freedom and more of the system is precision mechanically constrained. The workstation may register the position of the robotic manipulator relative to the scanner and the patient, at which point the operator may develop or import a surgical plan to interact with the desired intervention points. Once the plan is developed, the operator may perform the procedure under live or real-time imaging guidance. 
     Thus, the embodiments provide for a modular system for image guided robotic assisted medical procedures. The embodiments of the system comprises a manipulator for a specific medical procedure, a controller, an imaging device and a computer. The controller of the system is connected to the manipulator. The controller directs at least one motion of the manipulator. The controller is also capable of directing at least one other manipulator. The imaging device of the system enables visualization of a tissue at the specific medical procedure. The computer of the system is connected to the imaging device and the controller. The computer collects and processes images from the imaging device and instructs the controller to direct the manipulator. The system of the present invention can also be used when the medical procedure is a surgical procedure. The surgical procedure can be, but is not limited to, a deep brain stimulation procedure. 
     The embodiments also provide for a method for image guided robotic assisted medical procedures. The method comprises identifying an area of a body for a medical procedure. The method also comprises defining at least one motion of an instrument, this, at least one motion, is required for performing the medical procedure. The method further comprises assembling a manipulator which can be used for the medical procedure. Assembling of the manipulator comprises identifying linkages for performing the above at least one motion, and selecting actuators and sensors for connecting to the linkages. The actuators and sensors are used for controlling movements of the linkages. The method even further comprises connecting the manipulator to a controller which is capable of directing the manipulator. The controller is also capable of directing at least one other manipulator. 
     Other embodiments of the system and method are described in detail below and are also part of the present teachings and can include work with various other body parts such as, but not limited to, prostates, lungs, breasts, hearts, limbs such as knees, hips and the like. 
     For a better understanding of the present embodiments, together with other and further aspects thereof, reference is made to the accompanying drawings and detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1A and 1B  block diagrams illustrating a design of the system architecture; 
         FIG. 2  is a flowchart illustrating a method of the system; 
         FIG. 3  is a flowchart illustrating a method of using the system; 
         FIG. 4  is a schematic diagram illustrating functional units comprising the controller of the system and their interconnects; 
         FIG. 5  is a schematic diagram of an embodiment of the system of this invention; 
         FIG. 6  is a schematic diagram of the components and connections of the controller; 
         FIGS. 7A and 7B  illustrate the modular equipment rack design of the Gausian cage for the controller without the feet shown; 
         FIG. 8  illustrates schematically the power converter of the controller; 
         FIG. 9  is a schematic diagram of the actuator drivers of the controller; 
         FIG. 10  is a schematic diagram of the power converter; 
         FIG. 11  is a schematic illustration depicting the kinetic equivalency of the eight-degree of freedom embodiment of the manipulator of the system; 
         FIG. 12A  illustrates the three degrees of freedom  6 ,  7  and  8  of  FIG. 11  provided by the yolk of the manipulator; 
         FIG. 12B  illustrates the three degrees of freedom provided by a prismatic X-Y-Z-stage as the manipulator is used with a skull; 
         FIG. 13  is a schematic depiction of an embodiment of the manipulator with six degrees of freedom; and 
         FIG. 14  illustrates the basic system configuration of an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     The present teachings are described more fully hereinafter with reference to the accompanying drawings, in which the present embodiments are shown. The following description is presented for illustrative purposes only and the present teachings should not be limited to these embodiments. In addition, the publication entitled, “MRI Compatibility Evaluation of a Piezoelectric Actuator System for a Neural Interventional Robot,” authored by Yi Wang&#39; Gregory A. Cole, Hao Su, Julie G. Pilitsis and Gregory Fischer, presented at the 31 st  Annual International Conference of the IEEE EMBS, Minneapolis, Minn., USA, Sep. 2-6, 2009 is incorporated in its entirety by reference. 
     Referring now to  FIG. 1 , shown is a block diagram depicting an embodiment of the system architecture. The system  100  comprises a workstation  102 , a controller  104 , a robotic device or manipulator  106 . Also shown is the clinical equipment or hospital equipment  108  that may cooperate with the system. The user workstation  102  serves as a planning and navigation workstation for the user. Workstation  102  may be, but is not limited to, a laptop computer located in an MRI scanner&#39;s console room. Alternatively, it may be a separate computer, integrated into the medical imaging equipment, or a part of a standalone system (not shown). Workstation  102  is communicative coupled via data connections or couplings  110  and  112  to the robot controller  104  which, in one embodiment, is located inside the MRI scanner room and coupled via fiber optic communications. Alternatively, coupling  110  and  112  may be a shielded cable or wireless link. The workstation  102  sends commands and registration to the robotic device or manipulator  106  via  110  and receives robot status and location via connection  112 . In one embodiment, the controller  104  receives alternating current (AC) power from the scanner room via a grounded cable  118 . Alternatively, direct current (DC) power may be directly supplied or a battery may be used to provide power. The physical manipulator  106  can be the robotic device that interacts with the patient. It typically is MRI compatible and sits inside an MRI scanner bore while performing an intervention. Manipulator  106  is coupled to controller  104  via information connectors or signals  114  and  116 . Connector  114  provides the robot controller  104  with information from the robot&#39;s sensors, including the position of the controller or manipulator  104 . Connector  114  may be an electrical connection containing one or more channels from, for example, an optical encoder utilizing a differential signal output. Alternatively, it may provide a digital or analog digital from other encoder or potentiometer. Position sensing may alternatively be performed using fiber optics that communicate along connection  114 . Connection  114  may also include pressure, force, torque, or other sensory information. Connection  116  provides control signals to the manipulator&#39;s actuators. In one embodiment, connection  116  is a shielded electrical cable that provides a drive signal to piezoelectric motors. Alternatively, connection  116  may transmit pneumatic or hydraulic power to the manipulator  106 . Manipulator  106  performs the surgical intervention. In one embodiment, manipulator  106  is an actuated frame for assisting deep brain stimulation lead placement inside an MRI scanner. In one embodiment, the manipulator  106  is composed of two separable components, a motor module and an application-specific or patient-specific mechanism. 
     Hospital equipment  108  can include the medical imaging equipment. In one embodiment, equipment  108  includes an MRI scanner. The MRI scanner transmits images via communication coupling  120  to the workstation  102 . The workstation  102  can operate software which tracks a patient anatomy and generates the user interface overlaying the position of the manipulator  106 . This workstation  102  is designed to contain all of the software utilized to interface with the user and manages a large portion of the high power processing such as three dimensional image creation and analysis. The software facilitates interactions with the MRI scanner located in the equipment  108  and the controller  104  of the system  100 . The workstation  102  may communicate with an image server located in hospital equipment  108  associated with the MRI so that images generated by the scanner may be utilized by the navigation software. The images may be transferred via a Digital Imaging and Communications in Medicine (DICOM) server, direct connection, real-time streaming, or other means. In one embodiment, the workstation  102  can also send commands to the MRI scanner to control scan parameters including, but not limited to, scan plane location, scan plane orientation, field of view, image update rate and resolution. The workstation  102  may first register the position of the robotic device or manipulator  106  relative to the patient or imaging system, at which point the operator may develop a surgical plan to interact with the desired intervention points. Once the plan is developed, the operator may perform the procedure under live imaging or real-time guidance so that during the procedure the operator will be able to confirm that the intervention axis is oriented optimally for insertion. Additionally, the operator will be able to confirm the placement of surgical instruments at desired locations. 
     In one embodiment, the manipulator  106  is mechanically coupled to a platform placed upon the bed of the MRI scanner, wherein the platform also includes imaging coils and head fixation. In a further embodiment, the controller  104  also controls the orientation of the MRI imaging coil to align an opening with the planned robot trajectory. The imaging coil may be controlled by the robot controller or controller  104  or by other means such that it may be reconfigured to optimize patient access while maintaining image quality. Further, the manipulator  106  and the platform may also incorporate active or passive tracking fiducials or coils to localize the robot in the MRI scanner. In alternate embodiment, the manipulator  106  is coupled to a head frame and/or operating room table and the controller  104  is also located in the operating room. 
     This system  100  of the present invention is, essentially, a high precision, closed loop system that can be used to compile MRI image slices into three dimensional images, overlay a three dimensional image of a manipulator that can be operated within the scanner bore, select a course of motion for an intervention, and execute the intervention under live image guidance. While this has benefits in the medical world, there are also benefits to other industries where the precision internal images of the MRI can be utilized. Some of the industries used with the system can be instrumental and are, for example, art restoration, plant splicing, and veterinary work. Additionally, while this system is MRI compatible, it is also compatible with most other imaging modalities currently utilized. As such, under other imaging modalities that do not require magnetic compatibility, this system could be utilized, for example, by law enforcement, or manipulation of internal structures of devices. 
     The system  100  described herein has modular architecture. The system  100  can be integrated into an MRI surgical suite. Individual surgeons or hospitals can use a variety of manipulators  106  or end effectors for the manipulator  106  for the specific procedures that they perform. Alternatively, custom patient-specific modules for the manipulators  106  may be used with the system. A single controller  104  is capable of operating the variety of manipulators  106 . This distributes the cost of both equipment and maintenance of the devices in a manner where “everyone just pays for what they use.” By distributing the payment structure, different institutions and individuals may be responsible for their own segments of equipment. 
     In another embodiment, although not limited thereto, the system comprises an MRI-compatible self-positioning surgical guide utilizing a similar procedure planning to stereotactic intervention. This system bridges the gap between high resolution imaging modalities and interventional procedures that utilize them for planning purposes. The system may utilize live MRI guidance during these procedures. Alternate embodiments of the system may be used for applications other than deep brain stimulation such as with other body parts such as prostrates, lungs, hearts, knees and the like. Other neurosurgical procedures may be performed with the present invention including lead placement, thermal and cryogenic ablation, injections, evacuation, and surgical interventions. The invention is not restricted to only the specifically mentioned clinical applications. Further embodiments may be used to access other organ systems including for MRI image-guided prostate brachytherapy, biopsy and ablation. 
     The system  100  allows the use of in situ MRI guidance during a neural intervention procedure with the added benefit of computer controlled motion for the positioning of a tool guide. In one embodiment, although not limited thereto, the system  100  operates within the scanner bore of a closed-bore, high-field, diagnostic MRI scanner. This device may actively drive the position of the tool guide while leaving an acceptable volume of workspace for performance of the operation by the surgeon. In order to accomplish this, the system  100  may utilize similar planning methods to a manual stereotactic surgical procedure. For instance, although not limited thereto, system  100  may utilize a mechanically constrained remote center of motion (RCM) style linkage, where the RCM point is placed within the cranial volume at the target location. In such a way, the primary insertion axis of the device targets the RCM point no matter where the insertion guide is moved. This allows the operator to set a desired intervention point and insert tools from an arbitrary burr hole location on the skull to reach the same target point. Alternatively, the RCM point may be placed in the more traditional manner at the skull entry point and allow access to a range of target locations through the same burr hole. 
     The system  100  may also incorporate power transmission, although not limited thereto, that permits the use of modular end effecters to expand the functionality of the system  100  with two additional degrees of freedom (DOF) See  FIG. 11 . In one embodiment, the system uses an armature that mounts to either side of the patient&#39;s skull and is contained within a small volume in order to leave as much room as possible within the scanner bore for the surgeon to move. The system may also be integrated with the tray that the patient rests on during the procedure, although not limited thereto. The system may also be integrated with the MR imaging coil, although not limited thereto. 
     The method of configuring the system  100  of the present invention is illustrated in  FIG. 2 . The configuration is defined by the medical procedure described in block  202  to be performed by the system  100 . The specific procedure and/or patient configuration are used to determine the requirements as described in  204 . The requirements are used to select or develop manipulator  106  or end effector as described in  206 . The manipulator  106  or end effector  106  is coupled to the robotic system and controller  104 . 
     A method used in system  100  can be as follows:
         1) identify the area of the body to be manipulated   2) identify motions required to perform procedure   3) analyze motions and forces   4) design manipulator to meet requirements   5) select and apply actuators   6) select and apply sensors and fiducial markers   7) analyze and insert kinematics of manipulator in software system   8) once the manipulator is constructed and the kinematics are inserted to the control software, the new manipulator can be utilized.       

     The method of utilizing the system  100  of the present invention is illustrated  FIG. 3 . in a flow diagram re-procedural imaging  302  is acquired prior to the intervention. Imaging  302  may include, but is not limited to, anatomical MRI, functional MRI, spectroscopic imaging and computed tomography or the like. These images may be acquired days or weeks before the procedure, or may be performed the day or immediately prior to the intervention. Pre-procedural images  302  are used in medical procedure planning  304 . The target or targets are identified  306 . This step may be manual, semi-automated, or fully automated. In one embodiment, statistical atlases may be used to assist in locating the target location. A planned trajectory is also identified in  306 . This trajectory may be manually generated or it may be generated in an automated or semi-automated fashion. In one embodiment, blood vessels and other critical structures are automatically located and a safe trajectory is planned. Once the procedure is defined, a patient is placed within the bore of a diagnostic scanner. In an embodiment, the patient is placed inside air MRI scanner along with the robotic device or manipulator  106 . A series of images are taken of the patient anatomy that the procedure needs to be performed on and used to register the patient with eth pre-procedural plan. This step may also be repeated iteratively or continuously during the procedure. The images are assembled in the workstation  102  of  FIG. 1  into a three-dimensional display where the physician can view and modify the medical plan. 
     The robotic manipulator  106  is localized within the scanner and registered to the patient in  308 . Localization may be performed by imaging fiducials, active tracking coils, an external tracking system or other means. The motion plan for the robot is generated based on the relative pose of the robot to the patient and the planned trajectory or target  306 . The manipulator  106  is commanded to move and align the surgical tool as described in  312 . The surgical tool may be a needle, electrode, marker, drill, drill guide, cannula, ablation probe, laser, or other similar device. Real time or interactive medical images of the manipulator  106  and the patient may be performed during motion  312  to guide alignment. Position sensing on board the manipulator  106  or external to it may be used to guide for alignment. Upon completion of motion or at a stopping point in an iterative insertion, confirmation images are acquired  314 . If the tool is not yet at the target location, the plan is updated in  310  and the process is repeated or iterated. In one embodiment, continuous MRI images are used for closed loop control of an electrode, cannula or other instrument. Once placed, the interventional procedure, or a current step within, is performed in  318 . Placement is confirmed in  320  and the process may be iterated to ensure appropriate position as defined in  324 . In one embodiment, confirmation  320  is performed via micro electrode recordings. In an alternate embodiment, high resolution MRI imaging is utilized. In another embodiment, fluoroscopy or computed tomography imaging confirms appropriate placement. In procedures with multiple stages, the process may be repeated as shown in  322 . This may be the result of multiple stages. In one embodiment, the manipulator guide alignment of a surgical drill to generate a burr hole in the skull and then later aligns a guide cannula and an electrode. The robot manipulator  106  may move in and out of position between stages to allow improved patient access. Further, the procedure may be repeated for multiple targets. When complete, the manipulator  106  retracts or is removed  326 . Additional validation may be performed to ensure a successful procedure  328  and the procedure is completed  330 . For procedural planning, guidance and validation, the MRI imaging may include one or more of: traditional diagnostic imaging, rapid imaging, 3D imaging of arbitrary pose, volumetric imaging, functional imaging, spectroscopic imaging, blood flow sensing, diffusion imaging or other approach. Further, multi-modality imaging may be incorporated to couple MRI imaging with ultrasound or other medical imaging means. 
     The configuration of one embodiment of system  100  of the present invention is illustrated in the block diagram of  FIG. 4 . Navigation software  402  is located on workstation  102 . The navigation software  402  is used to guide the intervention and may also be used for preoperative and intraoperative planning as described previously. In one embodiment, the navigation software  402  is based on the modular, open source 3D Slicer software. Alternatively, navigation software  402  may be a commercially developed platform. Navigation software  402  is communicative coupled to an MRI medical imaging system or interface computer or interface  404 . The communication interface may be an established protocol such as DICOM or OpenIGTLink. Alternate protocols or connections may be utilized. The navigation software  402  may send control signals to the imaging system interface  404  to control scan plane location, orientation or other parameters. In one embodiment, the imaging continuously streams images to the navigation software  402  that visualizes them on workstation  102  of  FIG. 1 . Imaging system interface  404  controls the MRI scanner or other imaging system  408  and retrieves planar and volumetric image data from the scanner. The robot controller  406  represents the controller  104  of  FIG. 1 . The controller  104  is communicatively coupled to the navigation software  402 . In one embodiment, the coupling is a fiber optic network connection. In an embodiment the navigation software  402  sends commands including, but not limited to, positions, orientations, velocities, and/or forces to the controller  104 . In an embodiment, the robot controller  104  incorporates a control computer that receive the data from the navigation software  402  and performs the necessary computations. The computations may include one or more of forward kinematics, inverse kinematics, trajectory generation and registration. The robot controller  104  sends data to navigation software  402  including, but not limited, to the manipulator  106  position, orientation, workspace, and interaction forces. 
     In an embodiment, the manipulator  106  is actuated by piezoelectric motors  412  and joint positions are sensed by optical encoders  414 . The piezoelectric motors  412  are controlled by piezoelectric motor drivers  410 . In a further embodiment, the piezoelectric motor drivers  410  are configured to minimize interference with the MRI scanner  408  and may include filtering. The motors  412  may be controlled to provide position control, speed control, or force control. Force control of the piezoelectric actuators may be accomplished by varying the drive waveform&#39;s amplitude, frequency, phase or other parameters to modify the friction between the driven element and the motion generating elements of motors  412 . In an additional embodiment of the present invention the robotic manipulator  106  is teleoperated. In a further embodiment, haptic feedback may be available. The robot controller  106  may communicate directly with the motor drivers  410 , or there may be an intermediate interface such as backplane with signal aggregator. In an embodiment, the piezoelectric motor drivers  410  and robot controller  406  are contained in controller  104  which is enclosed in an EMI shielded enclosure located in the MRI scanner room. In an alternate embodiment, the functionality of the robot controller  406  is integrated with the navigation software  402 , and the workstation  102  (see  FIG. 1 ) communicates directly with the motor divers  410  or corresponding interface. A modular system architecture allows the location of the breaks between software and hardware components to be adapted to a specific application. 
     A specific embodiment of system  100  of the present invention is shown in  FIG. 5 . In  FIG. 5 , the user workstation  502  represents workstation  102  and includes a computer and a communication interface. In one embodiment, the communication interface is, but not limited to, a fiber optic Ethernet media converter. A set of coordinates for the end effector of the manipulator  506  (also  106 ) are selected, and sent to the controller  504  (also  104 ). In one embodiment, the controller  504  is enclosed in a Faraday cage forming an electro-magnetic interference (EMI) shielded enclosure and contains an AC-DC power rectifier, one or more low-noise, linear or low frequency switching DC-DC power converters, a control computer, actuator drivers with output filtering, sensor interfaces and a communication interface. The in-room controller  504  represents controller  104  and uses the kinematic information about the manipulator  506  (also  106 ) and the coordinate information to generate a planned pose for the manipulator  506 . The physical manipulator  506  represents the manipulator  106 , wherein it incorporates a task-specific end effector. The end effector may be in the form of a linkage mechanism. Further, the linkage mechanism itself may be unactuated and coupled to an actuator module to complete the manipulator  506  or  106 . The manipulator  506  or  106  may also include sensors and fiducial markers. The pose is then achieved through manipulation of the individual actuators through drive signals  512  in a closed loop fashion utilizing sensor information  514  from the manipulator  506  itself. Once the controller  504  interprets that the manipulator  506  has reached the intended planned position, the workstation  502  utilizes a medical imaging system to verify the position of the manipulator&#39;s end effector. The medical imaging system may incorporate one or more of an MRI scanner, patient table, imaging coils, DICOM or other imaging server, power source and air supply as described in  508 , which represent the hospital equipment  108 . The power source and air supply  518  may be connected to the in-room robot controller  504 . In one embodiment, the power source is, but may not limited to, approximately 110 volt AC power and a ground cable that is connected to the rectifier and DC-DC converted within controller  504 . 
     Now referring to  FIG. 6 , the inner workings of one embodiment of the robot controller  504 / 104  is described. The continuous Faraday cage enclosure  602  houses the entirety of the controller equipment. The patch panel  604  acts to allow the passage of electrical and other forms of information and energy to be passed in and out of the enclosure  602  without allowing the escape of EMI. These connections include the optical data transfer connection  624  which the control computer uses to communicate with the workstation  502  (or  102 ), as well as the controller supply lines  616  and the actuator and sensor signals  626 . The next piece of equipment is the controller computer  606  which is generally a common, off the shelf computer capable of running the software required to perform the operation described in  FIG. 3 . This is generally implemented as a common, off the shelf computer with the power supply removed so its electrical power can be supplied by the custom power converter  612 . This device is connected via digital data connection to the signal aggregator  608 , which can include, but is not limited to Transmission Control Protocol/Internet Protocol (TCP/IP), Universal Serial Bus (USB), Open Image Guided Therapy Link (OpenIGTLink), or others. The signal aggregator  608  is a device that manages the passage of information from the control computer  606  to the actuator drivers  610 , and back through physical or data connections  620  and  628 . Additionally, the signal aggregator  608  combines the driving signal and sensor information lines from the actuator drivers  610  to the multiconductor connector in the patch panel  604  via the multiconductor electrical data connection  626 . Additionally, the media converter  614  communicates with the control computer via electrical data connection  618 , and converts the media to an optical data stream that is passed out of the patch panel  604  through optical connection  624 . Finally, all electrical devices within the enclosure get their power from the power converter  612 , which is built later to supply all the required DC voltages, and connected to all supported equipment via the DC voltage rail connections  622 . 
     Continuing to  FIGS. 7A and 7B , which is a diagram of the continuous Faraday cage enclosure, surrounding the controller equipment, the basic structure of this device is provided by the conductive paneling  710  which can be made of many materials such as, for example, but is not limited to, sheet aluminum, steel, or a non conductive material with a conductive coating. Cut into this sheeting is vent ports  704  which allow the exchange of air for the purposes of cooling, which have EMI shielding vents mounted to them. Additionally cut into the structural sheeting  710  is the port for the supply connection patch panel  708  (also  604 ) where the different electrical and non-electrical supplies are passed into the controller in a manner that shields EMI from escaping. These supplies can include, but are not limited to, AC wall current, compressed air, and DC voltage supplies. Additionally, cut into the structural sheeting  710  is the port for the manipulator connector patch panel  706  where the multi-element cables used to transfer driving signals and sensor information back and forth between the manipulator and the controller box. These elements can include, but are not limited to hydraulic, pneumatic, and electrical transfer lines. Finally, the cage  FIG. 7A  is completed with a lid  702  designed to be opened and closed more frequently than the patch panels and thus contains an EMI shielding gasket. 
     Referring now to  FIG. 8 , a general view of the internal operation of an actuator driver is shown, beginning with the command input  802  from the piezoelectric actuators which is fed into the signal processor  804 . The command input can be comprised of a variety of forms of analog and digital data which may include, but is not limited to velocity, position, and force commands. The input  802  may be passed to the signal processor  804  via synchronous or asynchronous serial communication, Ethernet, USB, fiber optics, or other means. Driving signals are then produced and amplified in the signal generation segment  808 , which can be comprised of but is not limited to, a series of operational amplifiers connected to the output of a digital to analog converter that receives the digital information from the signal processing unit or signal processor  804 . The output of the signal generation segment  808  is then passed into the filtering stage  810  which is used to block bandwidths of electrical signals which may be in frequency ranges that cause unfavorable image distortion. The output of the filtering stage  810  is then sent to the piezoelectric actuators  802  via the multi-element shielded cable coming from the faraday cage  602  patch panel  604 . The cables may terminate in a shielded breakout board on or near the manipulator  106  or connect directly to the actuators. 
     Now referring to  FIG. 9 , the detailed internal function of one embodiment of the piezoelectric actuator driver  610 . Initially command information  802  is passed from the signal aggregator  912  via the serial data connection  926  to the microcontroller  902 . The microcontroller  902  in this embodiment has the function of handling communications with the aggregator  912 , and control of the signal generator and sensing information. The microcontroller  902  communicates with the FPGA  904  via position data connection  914 , as well as the volatile memory  906  via data connection (wavetables)  922 . Data connection  922  where the data is in the form of waveform tables that are produced in analog form to drive piezoelectric actuators  804 . The field programmable gate array (FPGA)  904 , where the FPGA  904  is used to pull waveform information from the volatile memory  906  and use it to execute commands received over position data connection  914 . Where FPGA  904  is also used to receive sensor information over position sensor signals  928  to be used for purposes including, but not limited to, execution of said commands received from microcontroller  902 . Where the parallel data stream  916  produced by the FPGA  904  is then interpreted into analog actuator drawing signals  920 , by first converting them into a low voltage analog waveform Connector  918  by the digital to analog converter (DAC) and preamplifier  908 . The preamplifier  908 , which can be comprised of, but is not limited to, high speed parallel digital to analog converters which can convert the digital waveform information stored in volatile memory  906 . Once the low voltage analog driver signal  918  is produced, it is then amplified and filtered by the output stage  910  which is capable of multiplying the voltage and supplying a high amount of current. Components in this stage are over-specced in order to prevent noise. 
     Referring now to  FIG. 10 , the power converter  612  as shown in  FIG. 6  is supplied by the patch panel  604  via the AC input  1002 . The AC input  1002  is carried by the wall current connector  1008  which is of the form of a cable rated to handle the electrical load required to operate the rest of the electrical equipment. This AC current is passed into the bridge rectifier  1004  where the voltage is divided before rectification to approximate the highest DC voltage required by the system. There is then a large capacitive filter pre and post rectification or full phase recited voltage  1010  in the rectifier  1004  to prevent rejection of noise back through the supply line and passing of noise to the converters. Once the input line is fully rectified and filtered  1006 , it is then passed through the programmable buck converters  1006 . Programmable converters are utilized so that the switching frequency can be controlled to prevent image degradation. Finally the DC voltage rails or supplies  1012  are passed out of the custom power converter  612  of signals via connection 
     Referring now to  FIG. 11  and  FIGS. 12A and 12B , the kinematics of one embodiment of the manipulator  106  as per its design for use assisting with DBS electrode implantation. The first, second and third degree of freedom (DOF) are all contained within what is commonly called a prismatic XYZ stage labeled as the three DOF Translation Base  1102 . The next two degrees of freedom are expressed as a two DOF remote center of motion style linkage  1104 , where the RCM linkage can be described as, but is not limited to, mimicking the motion of a stereotactic neural insertion frame. The next two degrees of freedom are expressed as an optional yoke  1106  and increases 6 degrees of freedom to 8 degrees of freedom that can be used to achieve insertion angles other than those along the RCM axis. This allows the manipulator  106  to achieve greater degrees of dexterity. The final axis which is, but is not limited to, a passive insertion axis  1108 , where the surgeon may manually insert an electrode.  FIGS. 11B and 11C  show pictorially how the manipulator allows for 8 degrees of freedom and can be used with a skull in a DBS electrode implementation. The design is not restricted to six or eight DOF, alternate embodiments may encompass other numbers of degrees of freedom. Alternate specific applications will result in alternate mechanism designs. 
     Referring now to  FIGS. 12A and 12  B, the manipulator  106  described earlier in a specific embodiment of said manipulator  106  adapted for DBS electrode insertion. The manipulator  106  can be constructed of rigid plastic links  1208  pin jointed  1202  via non conductive rods with plastic sleeve bearings  1205  as shown in  FIG. 13  and may be used at all pin joint locations. The RCM point  1204  is clearly shown, and is targeted through all positions of the manipulator sweep  1207 - 1211  allowing a single target point  1204  to be reached from multiple insertion angles  1207 ,  1209 ,  1211  shown in  FIG. 13  represents three manipulator configurations overlaid to demonstrate the mechanically constrained rotation center concept generated by motions  1104 . This mimics the motion of a standard stereotactic insertion frame. The rotation center may be placed at or near the target or it may be placed at or near the skull entry point. Additional dexterity afforded by the extra degrees of freedom of yolk  1106  enables repositioning of the rotation center though software control. The 3 DOF translation base can be used to change the position of the remote center of motion point. An enlarged view of  FIG. 11B  is shown and  FIG. 13  to show the extra DOF  6  and  7 . 
     The configuration of a specific embodiment of system  100  of the present invention is shown in  FIG. 14 . Patient  1402  is placed inside MRI scanner  1404  located in MRI scanner room  1400  and rests upon scanner bed  1406 . Patient&#39;s head  1408  rests upon an integrated head rest platform  1412 . Head fixation  1414  maintains head position relative to the platform  1412 . MRI imaging coil  1418  is coupled to platform  1412 . In one embodiment imaging coil  1418  is a standard head coil, surface coils, or other readily available imaging coil. Alternatively, imaging coil  1418  may be specific for this system. In one embodiment, the imaging coil  1418  is actuated and reconfigurable. Robot base  1420  is fixed to platform  1412 . Manipulator  1422  (also  106 ) sits upon platform  1412 . In one embodiment, robot base  1420  is a prismatic motion stage for positioning and the manipulator  106  and provides 3 degrees of freedom for manipulator  106 . The manipulator  106  may be application-specific or patient-specific. In one embodiment, the manipulator  1422  may be in itself unactuated base and coupled to an actuation module  1420  as described earlier. The robotic device comprising base  1420  and line manipulator  1422 , and also representing  106 , is coupled to the controller  1430  via line  1432 . In one embodiment, line  1432  is a shielded multiconductor cable transmitting motor power from the controller to piezoelectric motors in the robotic device or manipulator  1422  or  106  (not shown) and receiving encoder signals from the robotic device to the controller. In one embodiment, one or more breakout boards are coupled to platform  1412  or robot base  1420  to distribute control and sensor signals. In an alternate embodiment, pneumatic or hydraulic power may be transmitted via line  1432 . Alternatively, line  1432  may include fiber optic communications. In one embodiment, controller  1430 , which also represents  104 , is also coupled to imaging coil  1418  via cable  1434  for control of the imaging coil configuration. Controller  1430  receives power via cable  1438  from the MRI scanner room. Power may include AC electricity and a ground connection. Connection  1438  may also include pressurized fluid such as air or nitrogen. Controller  1430  is communicatively couple to workstation  1450  or  102  via cable or other coupling  1440 . Cable  1440  may be a fiber optic communication cable that passes through waveguide  1444  in the wall  1446  of the MRI scanner room  1400 . Workstation  1450  represents user workstation  102  and may be located in the MRI console or control room  1452  as described earlier. 
     Although the invention has been decided with various embodiments, it should be realized that this invention is also capable of further and other embodiments within the spirit and scope of the appended claims.