Patent ID: 12207976

Where considered appropriate, reference numerals may be repeated among the drawings to indicate corresponding or analogous elements. Moreover, some of the blocks depicted in the drawings may be combined into a single function.

DETAILED DESCRIPTION

In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of embodiments of the invention. However, it will be understood by those of ordinary skill in the art that the embodiments of the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, components, and circuits have not been described in detail so as not to obscure the present invention.

For example, various functional neurosurgery operations or procedures involve implantation of electrodes or other components. These operations, deep brain stimulation, stereoelectroencephalography, and hemorrhagic stroke treatment, are described here for reference. Deep brain stimulation (DBS) is a neurosurgical procedure in which an electrode (neurostimulator) is implanted in the brain to supply electrical impulses to a specific target area. DBS may be used to treat Parkinson's disease and other medical conditions involving tremors. Placement of neurostimulators requires a high degree of accuracy. The electrodes may be placed deep inside the patient's brain. The trajectory of the insertion needle must be very accurate in order to avoid damage to other parts of the brain structure, otherwise severe medical complications may result. DBS is performed using intra-operative imaging, such as magnetic resonance imaging (MRI). Pre-operative imaging of patient is usually performed before the operation. The software used in the surgery can perform fusion between the pre-operative imaging and the intra-operative imaging. A non-limiting example of such fusion can be between an MRI scan and a computed tomography (CT) scan. Implantation can be performed under local anesthesia or under general anesthesia (depending on the medical condition of the patient). The patient's head is fixed on a patient bed using a frame-based or frameless headset, and the probe electrode is inserted using a stereotactic assembly. The patient lays on the bed in a supine position. A hole (about 14 mm in diameter) is drilled into the patient's skull using a cranial drill. The drilling position in the skin and skull can be marked with a surgical pen/pencil using a stereotactic headframe.

Stereoelectroencephalography (SEEG) is a surgical procedure involving the placement of electrodes in a targeted area of the brain. SEEG can reach areas deep in the brain. This procedure is commonly used and is a minimally invasive approach to identify the origin of epileptic seizures. SEEG can be considered an evolution of conventional electroencephalography (EEG). To implant the electrodes, the surgeon makes ten to twenty (depending on the patient) small incisions in the scalp and skull, with minimal blood loss. SEEG surgery lasts about four hours and requires general anesthesia, but removal of the electrodes is a simple procedure that takes only ten to fifteen minutes under local anesthesia.

A hemorrhagic stroke is bleeding (hemorrhage) that suddenly occurs and interferes with the brain's function. The hemorrhage could be located in different sites in the brain. This condition can be treated with stereotactic aspiration assisted by intra-operative computed tomography (CT), which helps locate the hemorrhage site, and a specially developed suction tool to drain it. The patient is immobilized in a stereotactic head frame that allows a greater degree of precision and accuracy than otherwise possible. Since hemorrhagic stroke is considered a medical emergency (high fatality rate and immediate treatment required), it is usually treated in the Intensive Care Unit (ICU).

These neurosurgery procedures require a high degree of accuracy in both locating the target of the procedure, e.g., an electrode or a stroke site, and guiding an instrument's trajectory to place the electrode or drain the site. These procedures often involve intra-operative imaging, such as, but not limited to CT, digital radiography, fluoroscopy, or MRI. They are also often performed with the assistance of a robot. For example, while treating hemorrhagic stroke, it may be useful to have a CT-mounted robot performing a fast detection of the site of the hemorrhage, to allow for quick and precise positioning and draining.

These neurosurgery procedures use stereotactic devices to assist in the surgery. Four different kinds of stereotactic devices are described below: (1) an orthogonal system; (2) a burr-hole mounted system; (3) an arc-quadrant system; and (4) an arc-phantom system.

In a simple orthogonal system, a probe is directed perpendicular to a square base unit fixed to the skull. This provides three degrees of freedom by means of a carriage that moves orthogonally along the base plate or along a bar attached parallel to the base plate of the instrument. Attached to the carriage is a second track that extends perpendicularly across a head frame.

A burr-hole mounted system provides a limited range of possible intracranial target points with a fixed entry point. It provides two angular degrees of freedom and a depth adjustment. A surgeon can place the burr hole over non-essential brain tissue and can use an instrument to direct a probe to the target point from the fixed entry point at the burr hole.

In an arc-quadrant system, a probe is directed perpendicular to the tangent of an arc (which rotates about the vertical axis) and a quadrant (which rotates about the horizontal axis). The probe, directed to a depth equal to the radius of the sphere defined by the arc-quadrant, always arrives at the center or a focal point of that sphere.

In an arc-phantom system, an aiming bow attached to a head ring and fixed to a patient's skull can be transferred to a similar ring that contains a simulated target. In this system, a phantom target is moved on the simulator to 3D coordinates. After adjusting a probe holder on the aiming bow so that the probe touches the desired target on the phantom, the transferable aiming bow is moved from the phantom base ring to the base ring on the patient. The probe is then lowered to the determined depth in order to reach the target point deep in the patient's brain.

Examples of stereotactic devices are the Leksell® head frame, inomed RM stereotactic system, and the N-localizer.

The Leksell® head frame (manufactured by Elekta AB) is a device that can be used to perform a DBS procedure. (Other similar devices may also be used for this type of procedure.) The Leksell Stereotactic System includes the Leksell® coordinate frame and the Leksell® multipurpose stereotactic arc. The Leksell® head frame includes a support that holds an end effector (e.g., a needle). The support slides along the multipurpose stereotactic arc, which is pivotally coupled to revolute joints disposed coaxially to allow the arc to rotate around the R axis. The Leksell Stereotactic System provides globally five degrees of freedom. The system may include an optional Elekta MicroDrive™ that includes a passive slider, manually actuated by a leadscrew, which can be mounted on the support to provide a sixth degree of freedom allowing radial motion of the end effector. This permits a fine adjustment of the insertion depth.

The inomed RM stereotactic system is a high-precision system with a high level of stability and precision. It includes three fixation points. This system can be used for DBS, pallidotomy, thalamotomy, brachytherapy, stereotactic biopsy, and SEEG depth electrodes.

The N-localizer (also called “N-bar”) is a device that enables guidance of a stereotactic surgery or radiosurgery based on imaging. The N-localizer includes a diagonal rod that allows calculating the point where a tomographic image plane intersects the diagonal rod. This system is disclosed in U.S. Pat. No. 4,608,977; Russell Brown, “The Mathematics of the N-Localizer for Stereotactic Neurosurgery,” Cureus vol. 5, no. 10 (2013); and Russell Brown, “The Mathematics of Three N-Localizers Used Together for Stereotactic Neurosurgery,” Cureus vol. 7, no. 10 (2015).

Besides needing to accurately locate the target and the trajectory for accessing the target, there are other issues to consider when using robot-assisted neurosurgery to perform functional neurosurgery procedures in conjunction with an imaging system. These issues include the hindrance of the imaging system, the patient's body, the patient's bed, the presence of surgical instruments (e.g., depressors, needle guides, draining surgical instruments, etc.) that are manually operated by a surgeon or inserted into a patient's tissues during the operation, and that the workspace for the robot should keep enough free space around a patient's head. Furthermore, a surgeon performing a manual operation during such a procedure should be able to freely access the upper part of a patient's skull. To do so, a removable section or a “parking position” may be provided on the robot. Moreover, the system should be quickly movable and easily repositionable to reduce procedure time, minimize the risk of medical complications, and reduce a surgeon's stress. In addition, an automated system could considerably reduce the effort expended by the medical staff. Easy sterilization and cleaning of the system play an important role to prevent medical complication caused by infection and to reduce set-up time. Further, a surgeon needs enough degrees of freedom to carry out a surgical operation to locate a surgical instrument at a given position and orientation and to adjust an insertion depth. At the same time, the spanning area should be wide enough to perform the surgical operation (also considering patients' anatomical differences). Also, a dynamic control issue (i.e., a singularity) can occur due to the kinematic design. Such issues are addressed by the present invention.

During the operation, the surgeon can have a free access to a patient's head. A rest area for the device can be provided in order to reduce the encumbrance. Furthermore, the system can be removed from the area of interest to avoid artifact in the imaging acquisition. In order to obtain high degree of precision, a surgical robot can be mechanically linked to an imaging device. In certain embodiments, the imaging device may be a CT scanner, and the surgical robot may be mechanically linked to a CT gantry, in accordance with PCT Pub. No. WO 2017/134546 and U.S. Pat. No. 10,772,577, each of which is incorporated by reference in its entirety. The number of degrees of freedom suitable for the surgical operation can also be considered. High precision and repeatability are important. A headset should be normally connected (not rigidly) on the bed, connectible in a rigid way to the CT scanner. For safety during the surgical operation, the patient's bed should be able to be quickly moved away from the CT scanner.

Reference is now made toFIG.1, which shows robot-assisted surgery system10. System10includes articulated arm11attached to the top of CT scanner12. A patient's head is fixed on frameless headset13, which is rigidly connected to the patient bed. A robot can be mounted on the top of the gantry (in accordance with, e.g., U.S. application Ser. No. 16/402,002 (U.S. Pat. Pub. No. 2019/0336093), which is incorporated by reference in its entirety). The headset is connected (not rigidly) to the patient bed. The headset may be connected to the CT gantry using two pins21a,21bas shown inFIG.2, allowing a fast disconnection in case of emergency. This configuration is not suitable for the DBS procedure because all the instruments must be located toward the lower part of the patient's head (see the red line inFIG.3).

The inventors have developed a novel stereotactic device that allows the instruments to be located toward the lower part of the patient's head during robot-assisted neurosurgery.FIG.4shows the kinematics chain for a planar five-bar mechanism made up of links0to4as the basis for the novel stereotactic device. Such a closed-loop kinematics chain is composed of five links0to4joined by five hinges or joints, providing two degrees of freedom. If link0is fixed, it can be omitted in the illustration.

FIG.5illustrates the kinematics ofFIG.4projected on a spherical surface. The axes of joints A-E, which are parallel in the planar mechanism, are now incident to the center of the sphere.FIG.5also shows an angle θ between joints A and E. All the points of the links move around the spherical surface. When link0is fixed, it can converge to a point. In such a case, the number of degrees of freedom does not change.FIG.6illustrates the spherical projection for the special (and optional) case where angle θ=0 and joints B and D are located in the diametral plane of the sphere. This results in joints/hinges A and E being located at the same point (so hinge E can be suppressed).

FIG.7Aillustrates what happens when links1and4are suppressed.FIG.7Billustrates when the end of link2is optionally extended past point C to C′. The connection between2and3, provided by a hinge, is located at the same point C, the end of link2is now C′.

FIG.8illustrates the result of replacing hinged joints B and D with sliders s1and s2in the stereotactic device. The sliders allow independent motion of joints B and D around the diameter of the sphere. Sliders s1and s2may be provided with actuators if hinges B, C, and D are passive.

FIGS.9A-9Cillustrate an equivalent way of describing the mechanism ofFIG.8. The concept of this mechanism is based on the projection of a common planar kinematics chain on a three-dimensional surface, for example, a hemisphere. This method can be used to design a two-degree-of-freedom device moving an end effector along a spherical surface.FIG.9Aillustrates the planar kinematics for a two-degree-of-freedom mechanism. These kinematics comprise two links1and2. Link2is coupled to link1by a hinge located at point C. Each link is coupled to a slider in the lower extremities at points A and B. The sliders are connected to the same horizontal axis r allowing translation. The linkage is a two degree-of-freedom chain.FIG.9Billustrates displacement of the sliders along the r-axis by an equal distance d, moving points A, B, and C to A′, B′, and C′, respectively. This displaces end effector E-E along an axis p (parallel to r).FIG.9Cillustrates link rotation—what happens when the sliders are displaced by different distances. When slider s2is moved relative to slider s1, link1rotates around point A. As before inFIG.8, sliders s1and s2may be provided with actuators if hinges A, B, and C are passive. These figures show how end effector E-E can be moved along a plane using sliders s1and s2. By projecting these kinematics on a spherical surface, the end effector can be moved along a sphere. This model demonstrates how two-degree-of-freedom links (e.g., a five-bar mechanism as described above) can be projected on a spherical surface.

FIG.10illustrates an embodiment of the novel stereotactic device based on the previously described kinematics. The sliders can be replaced with two coaxial and coplanar rings. A vertical rigid column, e.g., c1or c2, may be mounted on each of the two rings. The rings may rotate independently around the common axis z. Pivot1is located at the top of column c1, replacing hinge D inFIG.8. Pivot2is located at the top of column c2, replacing hinge B inFIG.8. Pivot3replaces hinge C inFIG.8and allows relative rotation of links2and1connected to pivot1and pivot2, respectively. The rotatable joints may be passive, and two actuators may be located on the base to move the rings. The two columns may be driven by actuating the rings. Rotating a single ring, the two columns get closer together (raising the end effector) or get farther from each other (lowering the end effector). If the two rings are moved together, the end-effector rotates around the head (motion along a meridian of the sphere).

FIG.11Aillustrates a simulation of neurosurgery using the novel stereotactic device. The figure shows five different configurations of the device and the location of the end effector.FIG.11Billustrates a simulation of an embodiment of the novel stereotactic device operating on a patient's head. Distal section111of the longer link may be removable and/or disposable. This allows quick replacement of the end effector or surgical instrument holder. Furthermore, this distal section may be easily disconnected for cleaning and sterilization.

FIG.12illustrates translation of the novel stereotactic device in the direction marked by lines121a,121b. In addition, the novel stereotactic device may be mounted on two parallel rails122disposed on a frame linked to a CT scanner. This feature allows the assembly to be moved away from an operating position to a rest position. The novel stereotactic device allows positioning of an end effector along a spherical (or hemispherical) surface. The end effector may be a surgical instrument holder. Generally, the surgical instrument holder holds a surgical instrument (e.g., a needle) having an axis incident to the center of the sphere (radial position). However, it is not possible to adjust the surgical instrument orientation with the two-degree-of-freedom kinematics.

FIGS.13A-13Dillustrate positioning and orientation of a surgical instrument during deep brain stimulation (DBS). Arc130is the intersection between the spherical workspace and the section plane. A surgeon can move surgical instrument holder131along arc130. If surgical instrument holder131is mounted radially, surgical instrument axis132points to sphere center133(located within the brain).FIGS.13A and13Bshow the surgical instrument positioned with no orientation adjustment. During DBS, the surgeon may need to avoid a certain area of the brain due to a possible medical complication caused by brain structure damage. In that case, depending on the point of interest, the orientation of the surgical instrument may need to be adjusted. Line134represents a suitable trajectory for the needle insertion. In order to follow this trajectory, surgical instrument holder131may be oriented along lines135as shown inFIGS.13C and13D.

FIGS.14-16Cillustrate three systems that may be used to allow this surgical instrument orientation adjustment.FIG.14illustrates a four-degree-of-freedom mechanism. This mechanism couples two two-degree-of-freedom stereotactic devices having concentric rings141(internal ring142and external ring143). The two end effectors are moved along two concentric spheres. Globally, each end effector can be positioned along a two-dimensional surface, so this system provides four degrees of freedom altogether. The extremities of the two links are connected to surgical instrument holder131. Surgical instrument holder131may support spherical joints144that allow for the orientation of surgical instrument axis132. These spherical joints can be moved along the two hemispheres corresponding to the stereotactic device kinematics. Surgical instrument axis132is incident to points of the two hemispheres. This embodiment, compared to the others described below, allows for quick repositioning and reorientation of the surgical instrument during the procedure. This can be useful to reduce a surgeon's effort and set-up time.

FIG.15illustrates a four-degree-of-freedom mechanism obtained by mounting a stereotactic device on a cartesian robot. Thus, this mechanism provides two more degrees of freedom than the stereotactic device. The cartesian robot can move along two planar axes x and z. Another degree of freedom (vertical translation) may also be provided. Such a configuration makes it easier to select a position at the center of the spherical workspace of the stereotactic device.

FIGS.16A-16Cillustrate the use of a stereotactic device having a passive arm. The device inFIG.16Ainitially includes spherical joint144and locking element166on the end effector. Spherical joint144may be used to adjust the orientation of surgical instrument axis132(in the unlocked position). The spherical joint can be locked to maintain the selected orientation. The surgical instrument may be oriented as follows: (i) switch spherical joint144to the unlocked position; (ii) insert a pin (using an external robot) in spherical joint144to rotate it into the desired position; (iii) switch spherical joint144to the locked position; (iv) adjust spherical joint144to the proper orientation and insert surgical instrument holder131along the spherical joint axis; and (v) the stereotactic device locates the surgical instrument in the proper position moving in its spherical workspace.FIGS.16B and16Cadd a passive arm to the system inFIG.16A. This passive arm can perform the task of the external robot described in the previous paragraph, resulting in a simpler system. Passive arm161is mounted on fixed passive arm support162. Passive arm161is provided with second spherical joint163on its end. The stereotactic device can be moved relative to passive arm161. The surgical instrument may be oriented as follows: (i) move the stereotactic device to locate the end effector closer to passive arm161(a proper relative position can be obtained using control software depending on the desired surgical instrument orientation); (ii) unlock surgical instrument spherical joint144; (iii) insert pin164in the two spherical joints to properly orient surgical instrument spherical joint144(FIG.16C); (iv) lock surgical instrument spherical joint144; and (v) remove pin164. Moreover, to make the passive arm embodiment less intrusive when not in use, passive arm161may include foldable end165(FIG.16B), which provides a “parking position” for passive arm161.

EXAMPLES

FIG.17Ashows a two degree-of-freedom stereotactic device including rotating ring171, fixed rings172, magnetic track173, absolute position sensor174, and columns175, which include motors, gearboxes, and brakes. Rotation of the rings can be carried out by cable power transmission176. An electric actuator can be embedded in the column (e.g., to reduce the total encumbrance and provide a wider workspace), and the driving pulley is located in the lower part of column175(seeFIG.17B). Removable section177at the end of the longer link can be disposable or removable for cleaning and sterilization.FIG.17Bshows the transmission including two pulleys (e.g., fixed pulley178and motor pulley179) and cable180(e.g., a steel cable) having a configuration resembling an “8” to increase the contact length with the smaller pulley (e.g., motor pulley179) and to reduce the force on the motor pulley axis. The cable terminals can be fixed on fixed pulley178, and the power is transmitted by means of friction between cable180and motor pulley179. Correct tension of the cable is required. Motor pulley179is fixed on the output shaft of the motor gear. In order to avoid interference, the cable can follow a spiral path on both pulleys, and these two paths can be congruent.FIG.17Cshows a pinion and annular gear, andFIG.17Dshows a transmission belt in a system based on a belt for driving the ring. Actuators can be mounted on the fixed section instead of being located within the column. One of the advantages is that motors are fixed in a stable position. This configuration reduces the global workspace of the end effector.FIG.17Eshows actuators mounted on a fixed part. Each of the four motors can move a large disk through an O-shaped belt, allowing each of four disks to rotate independently between them driven by the related motor.

FIG.18Ashows a two-degree-of-freedom stereotactic device operating on a patient's head. The grey area189overlapping the patient's head model and the spherical workspace represents an estimation of the available working space (spanning area).FIG.18Bshows different positions of the two-degree-of-freedom stereotactic device operating on a patient's head. The first figure on the upper row shows the rest (parking) position that provides wide, free access to the patient's head. The workspace depends on the link configuration, in particular, the length of each link, column height, and hinge position. For example, the two links can have the same length as shown inFIG.18C. Such a configuration provides a more symmetric workspace.FIG.18Dshows a simulation of the two-degree-of-freedom stereotactic device with a headset with or without a frame.FIG.18Eshows a system including a two-degree-of-freedom stereotactic device integrated in an imaging device. For example, stereotactic device181can be integrated in CT scanner185, where patient182, patient bed183, and headframe184are positioned as shown.

FIG.19Ashows a double stereotactic device that provides four degrees of freedom. The double stereotactic device can include two concentric two-degree-of-freedom stereotactic devices including internal frame191and external frame192. Internal frame191can be mounted on L-shaped support193to reduce the global dimension and to avoid the risk of impact.FIG.19Bshows a simulation of the double stereotactic device with four different surgical instrument positions and orientations of the double stereotactic device including a patient's head.

FIG.20shows a two degree-of-freedom stereotactic device mounted on a cartesian robot integrated with the CT scanner, as described above with respect toFIG.15. The cartesian robot should be integrated in a manner to avoid the risk of impact to the CT gantry.

FIGS.21A-21Bshow simulations of a stereotactic device provided with a passive arm for surgical instrument orientation adjustment. Foldable end165of passive arm161can be folded when the stereotactic device is in a rest position as shown inFIG.21B.

Various accessories can be included in the system. One accessory is a locking system for the spherical joint.FIG.22Ashows stereotactic device221provided with locking system222for spherical joint223.FIG.22Bshows spherical joint locking system222coupled to passive arm161. Locking system222includes two screws224acting on the joint. Screws224can be manually manipulatable and screws224can be disposed in different configurations. Locking system222can be integrated in an embodiment of the stereotactic device provided with passive arm161for the surgical instrument orientation adjustment system (seeFIG.22Cfor more detail).

Another accessory is a surgical instrument holder integrated with the stereotactic device and locking system.FIG.23Ashows surgical instrument holder231mounted on the stereotactic device using locking system222. Surgical instrument holder231is designed to support various commercially available surgical instruments (e.g., a microdriver) as well as customized devices.FIG.23Bshows surgical instrument holder231holding customized microdriver232.

Depending on the operation to be performed, an auxiliary radial degree of freedom may be used, which permits the adjustment of the depth of the surgical instrument end in patient's head240.FIG.24Ashows slidable surgical instrument holder241adding an auxiliary radial degree of freedom. Slidable surgical instrument holder241can be actuated and precisely adjusted by microdriver232along the r-axis. Such an accessory can be added to either the two-degree-of-freedom stereotactic device or the four-degree-of-freedom (double) stereotactic device.FIG.24Bshows cranial miller242mounted on slidable surgical instrument holder241(actuated by microdriver232). Alternatively, the motor axis can be different from the surgical instrument holder axis providing a differently shaped bracket. Using a spherical mill, it is possible to perform the cranial hole drilling without making a surgical instrument orientation adjustment (within certain limits). Therefore, this system can be integrated with the two-degree-of-freedom stereotactic device having slidable surgical instrument holder241.

Stereotactic devices so far illustrated have the rings parallel to the ground. This design works well for deep brain stimulation, but is not ideal for stereoelectroencephalography (SEEG) or hemorrhagic stroke treatment because the workspace is too small. In addition, the robot dimensions may not be compatible with a commercially available head positioning system, such as the Mayfield® positioner. For such applications, the stereotactic device may include rings perpendicular to the ground.

FIG.25Ashows a stereotactic device with vertical rings (“vertical stereotactic device”). This type of stereotactic device allows easy access to both the front and back areas of the skull. The stereotactic device can be installed in the CT bore and can be connected to the static part of the gantry, which provides an extended workspace.FIG.25Bshows the vertical stereotactic device installed in the CT bore. In this configuration, the stereotactic device has a section251that is mechanically connected to the non-rotating part of the CT. The robot is free to rotate about the CT bore with its four movable (i.e., motorized) columns, independent of the rotation of the CT gantry.

FIGS.26A-26Bshow the positions of the vertical stereotactic device and the motorized columns of the robot in relation to the X-ray cone area. The red rectangle area261is out of the X-ray cone area (the blue square262under the head is the flat panel) while the robot, depending on its position relative to the X-ray source/panel axis may be within the X-ray cone.FIGS.26C-26Dshow the approximate workspace provided by the vertical stereotactic device in area264on the patient's head.FIGS.27A-27Cshow the movement of the robot arm synchronized with the rotation of the CT. This may improve the chances that the robotic arm stays out of the x-ray cone.

Other modifications are possible.FIGS.28A-28Bshow a modification of the links holding the end effector such that the end effector can get closer to the patient's head.FIGS.29A-29Bshow an option in which the distal section of the link is removable and able to be sterilized. The robot arm can be covered to allow the sterilization of the distal section. Alternately, the full link set or robotic arm may be removable and able to be sterilized. The movable (motorized) columns can be covered to allow for such sterilization.

Other views and embodiments are shown inFIGS.30A-35.FIGS.30A-30Bshow other views of the stereotactic device in a medical imaging bore.FIGS.31A-31Bshow other views of the stereotactic device.FIG.32shows an exemplary workspace or zone of operation in which the stereotactic device operates.FIG.33Ashows an exemplary motion transmission means for the stereotactic device.FIG.33Bshows an exemplary drive unit section for stereotactic device movement.FIG.34shows how the stereotactic device may avoid interference with a frame during surgery.

FIG.35illustrates exemplary positions for and embodiments of the stereotactic device.

The stereotactic device can be used in other, non-neurosurgical applications, such as thoracic, abdominal, pelvic and extremities (for purposes of diagnostic sampling and/or biopsies), and therapeutics (energy delivery, destructive, other).

FIGS.36A-36Cshow the stereotactic device used to operate on extremities, such as the hand, foot, arm, and elbow. Surgery on a foot may include, for example, mini-invasive surgery (MIS) for bunion and hammertoe reduction. Surgery on a hand may include, for example, carpal tunnel MIS.

FIG.37shows the stereotactic device used to operate on a shoulder. This figure reiterates that the part to be treated should be in the center of the sphere identified by the stereotactic device. Thus, for a shoulder, for example, the bore in the imaging device should be able to accommodate the body part and the stereotactic device, so the size of the bore may be at least the double the distance shoulder to shoulder.FIG.37shows interventional area371and the position of the body with respect to the device.

Aspects of the present invention may be embodied in the form of a method, apparatus, or a system. Systems for performing brain surgery have been described that provide free access to a patient's head with high precision, repeatability, and reduced encumbrance. A system can include an apparatus (e.g., a stereotactic device) that includes a first link and a second link, where the first link can be linked to the second link by a hinge, providing two degrees of freedom. One or more end effectors can be positioned at the end of a link and move along a spherical surface. In certain embodiments, each link can be coupled to a slider to provide independent motions of the links. In certain other embodiments, the links can be coupled to two coaxial and coplanar rings. Two vertical columns can be mounted on the two rings. In certain other embodiments, four degrees of freedom can be provided by coupling two stereotactic devices resulting in four concentric rings. End effectors positioned on the links can be moved along two concentric spheres.

The methods and apparatuses described above can be used in conjunction with virtual reality headsets and software for surgical visualization, planning, validation, and verification. For example, virtual reality can be used before or during a surgery to plan steps and identify potential issues or obstacles that are forthcoming.

The above discussion is meant to illustrate the principles and various embodiments of the present invention. Numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to embrace all such variations and modifications.