OPTIMAL IMAGING POINT OF VIEW BASED ON INTERVENTION INSTRUMENT LOADING

Abstract

An optimal imaging POV intervention system employs an intervention instrument (30), an instrument guide (40), one or more force/torque sensors and an optimal imaging POV controller (20). In operation, the instrument guide (40) establishes a planned trajectory of the intervention instrument (30), and the force/torque sensor(s) sense a force and/or a torque exerted against the intervention instrument (30) and/or the instrument guide (40) when the intervention instrument (30) is positioned within the instrument guide (40). The optimal imaging POV controller (20) controls a determination of an optimal imaging POV of the intervention instrument (30) by deriving an imaging axis of the intervention instrument (30) from a measurement of the force and/or the torque exerted against the intervention instrument (30) and/or the instrument guide (40) as sensed by the force/torque sensor(s).

Claims

1. An optimal imaging POV intervention system, comprising: an intervention instrument; an instrument guide configured to establish a planned trajectory of the intervention instrument; at least one force/torque sensor configured to sense at least one of a force and a torque exerted against at least one of the intervention instrument and the instrument guide when the intervention instrument is positioned within the instrument guide; and an optimal imaging POV controller operable for controlling a determination of an optimal imaging POV of the intervention instrument, wherein the optimal imaging POV controller is configured to: derive an imaging axis of the intervention instrument from a measurement of at least one of the force and the torque exerted against at least one of the intervention instrument and the instrument guide as sensed by the at least one force/torque sensor.

2. The optimal imaging POV intervention system of claim 1, wherein the at least one force/torque sensor is embedded in at least one of the intervention instrument and the instrument guide.

3. The optimal imaging POV intervention system of claim 1, further comprising: a guide positioning system configured to the position the instrument guide to establish the planned trajectory of the intervention instrument, wherein the guide positioning system includes the at least one force/torque sensor.

4. The optimal imaging POV intervention system of claim 1, where the optimal imaging POV controller implements the at least one force/torque sensor.

5. The optimal imaging POV intervention system of claim 1, wherein the optimal imaging POV controller is configured to: execute at least one of a force measurement and a torque measurement as a maximum at least one of the force and the torque exerted against at least one of the intervention instrument and the instrument guide.

6. The optimal imaging POV intervention system of claim 1, wherein the optimal imaging POV controller is configured to: execute at least one of a force measurement and a torque measurement as a sensed at least one of the force and the torque exerted against at least one of the intervention instrument and the instrument guide as sensed after an event.

7. The optimal imaging POV intervention system of claim 1, wherein the optimal imaging POV controller is configured to: execute at least one of a force measurement and a torque measurement as an average of at least one of the force and the torque exerted against at least one of the intervention instrument and the instrument guide over a period of time.

8. The optimal imaging POV intervention system of claim 1, wherein the optimal imaging POV controller is configured to: execute at least one of a force measurement and a torque measurement as an average of at least one of the force and the torque exerted against at least one of the intervention instrument and the instrument guide when the intervention instrument is stationary within the instrument guide.

9. The optimal imaging POV intervention system of claim 1, wherein the optimal imaging POV controller is configured to: execute at least one of a weighted force measurement and a weighted torque measurement of at least one of the force and the torque exerted against at least one of the intervention instrument and the instrument guide based on a proximity of the intervention instrument to a target location of the planned trajectory.

10. The optimal imaging POV intervention system of claim 1, wherein the optimal imaging POV controller is configured to: execute at least one of a weighted force measurement and a weighted torque measurement of at least one of the force and the torque exerted against at least one of the intervention instrument and the instrument guide based on a kinematic model of the instrument guide.

11. The optimal imaging POV intervention system of claim 1, wherein the optimal imaging POV controller is configured to: calculate the imaging axis as function of a location of a force/torque vector exerted against at least one of the intervention instrument and the instrument guide as sensed by the at least one force/torque sensor and an imaging vector in an imaging coordinate system formed by a cross product of the planned trajectory and the force/torque vector.

12. The optimal imaging POV intervention system of claim 1, wherein the optimal imaging POV controller is configured to: calculate the imaging axis as an average of a force vector exerted against the at least one of the intervention instrument and the instrument guide as sensed by the at least one force/torque sensor and a torque vector exerted against the at least one of the intervention instrument and the instrument guide as sensed by the at least one force/torque sensor.

13. The optimal imaging POV intervention system of claim 1, wherein the optimal imaging POV controller is configured to at least one of: control a communication of the imaging axis to an intervention imaging system; and control a repositioning of an intervention imaging system in accordance with the imaging axis.

14. The optimal imaging POV intervention system of claim 1, wherein the optimal imaging POV controller is configured to at least one of: control a visualization of a model illustrative positions of the intervention instrument and measurements of at least one of a force and a torque associated with the positions of the intervention instrument relative to the planned trajectory; and control a visualization of a model illustrative of a plurality of imaging POVs of intervention instrument and measurements at least one of a force and a torque associated with the positions of the intervention instrument relative to the planned trajectory.

15. The optimal imaging POV intervention system of claim 1, wherein the optimal imaging POV controller is configured to at least one of: control a motion of an image guidance system to align motion of the intervention instrument a plane passing through a point at force event sensed by the at least one force/torque sensor and parallel to a POV plane; and control a motion of an image guidance system along a force vector sensed by the at least one force/torque sensor.

16. An optimal imaging POV intervention method, comprising: establishing, by an instrument guide, a planned trajectory of an intervention instrument; sensing, by at least one force/torque sensor, at least one of a force and a torque exerted against at least one of the intervention instrument and the instrument guide when the intervention instrument is positioned within the instrument guide; and controlling, by an optimal imaging POV controller, a determination of an optimal imaging POV of the intervention instrument, wherein the optimal imaging POV controller derives an imaging axis of the intervention instrument from a measurement of at least one of the force and the torque exerted against at least one of the intervention instrument and the instrument guide as sensed by the at least one force/torque sensor.

17. The optimal imaging POV intervention method of claim 16, wherein the controlling, by the optimal imaging POV controller, the determination of the optimal imaging POV of the intervention instrument includes at least one of: executing, by the optimal imaging POV controller, at least one of a force measurement and a torque measurement as a maximum at least one of the force and the torque exerted against at least one of the intervention instrument and the instrument guide; executing, by the optimal imaging POV controller, at least one of a force measurement and a torque measurement as a sensed at least one of the force and the torque exerted against at least one of the intervention instrument and the instrument guide after an event; executing, by the optimal imaging POV controller, at least one of a force measurement and the torque measurement as an average of at least one of the force and the torque exerted against at least one of the intervention instrument and the instrument guide over a period of time; executing, by the optimal imaging POV controller, at least one of a force measurement and a torque measurement as an average of at least one of the force and the torque exerted against at least one of the intervention instrument and the instrument guide when the intervention instrument is stationary within the instrument guide; and executing, by the optimal imaging POV controller, at least one of a weighted force measurement and a weighted torque measurement of at least one of the force and the torque exerted against at least one of the intervention instrument and the instrument guide based on a proximity of the intervention instrument to a target location of the planned trajectory.

18. The optimal imaging POV intervention method of claim 16, wherein the controlling, by the optimal imaging POV controller, the determination of the optimal imaging POV of the intervention instrument includes at least one of: calculating, by the optimal imaging POV controller, imaging axis as function of a location of a force/torque vector exerted against at least one of the intervention instrument and the instrument guide as sensed by the at least one force/torque sensor and an imaging vector in an imaging coordinate system formed by a cross product of the planned trajectory and the force/torque vector; and calculating, by the optimal imaging POV controller, the imaging axis as an average of a force vector exerted against the at least one of the intervention instrument and the instrument guide as sensed by the at least one force/torque sensor and a torque vector exerted against the at least one of the intervention instrument and the instrument guide as sensed by the at least one force/torque sensor.

19. The optimal imaging POV intervention method of claim 16, wherein the controlling, by the optimal imaging POV controller, the determination of the optimal imaging POV of the intervention instrument includes at least one of: controlling, by the optimal imaging POV controller, a communication of the imaging axis to an intervention imaging system; and controlling, by the optimal imaging POV controller, a repositioning of an intervention imaging system in accordance with the imaging axis.

20. The optimal imaging POV intervention method of claim 16, wherein the controlling, by the optimal imaging POV controller, the determination of the optimal imaging POV of the intervention instrument includes at least one of: controlling, by the optimal imaging POV controller, a visualization of a model illustrative positions of the intervention instrument and measurements of at least one of a force and a torque associated with the positions of the intervention instrument relative to the planned trajectory; and controlling, by the optimal imaging POV controller, a visualization of the model illustrative of a plurality of imaging POVs of intervention instrument and measurements at least one of a force and a torque associated with the positions of the intervention instrument relative to the planned trajectory.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG. 1 illustrates an exemplary embodiment of optimal imaging POV intervention system in accordance with the inventive principles of the present disclosure.

[0028] FIGS. 2A-2F illustrate an exemplary optimal imaging POV suggestion in accordance with the inventive principles of the present disclosure.

[0029] FIG. 3 illustrates an exemplary embodiment of the optimal imaging POV intervention system of FIG. 1 in accordance with the inventive principles of the present disclosure.

[0030] FIG. 4 illustrates an exemplary embodiment of an optimal imaging POV controller in accordance with the inventive principles of the present disclosure.

[0031] FIG. 5 illustrates a flowchart representative of an exemplary embodiment of optimal imaging POV intervention method in accordance with the inventive principles of the present disclosure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] To facilitate an understanding of the various inventions of the present disclosure, the following description of FIGS. 1 and 2 teaches basic inventive principles associated with optimal imaging POV intervention systems and methods of the present disclosure. From this description, those having ordinary skill in the art will appreciate how to apply the inventive principles of the present disclosure for making and using additional embodiments of optimal imaging POV intervention systems and methods of the present disclosure.

[0033] Referring to FIG. 1, an optimal imaging POV intervention system of the present disclosure employs an intervention instrument 30, an instrument guide 40, an intervention imaging system 60 and a position tracking system 70.

[0034] Examples of intervention instrument 30 include, but are not limited to, vascular interventional tools (e.g., guidewires, catheters, stents sheaths, balloons, atherectomy catheters, IVUS imaging probes, deployment systems, etc.), endoluminal interventional tools (e.g., endoscopes, bronchoscopes, etc.) and orthopedic interventional tools (e.g., k-wires and screwdrivers).

[0035] In practice, instrument guide 40 may be a stand-alone guide such as, for example, handheld guide devices and templates. Also in practice, instrument guide 40 may be an end-effector of a guide positioning system, such as, for example, an end-effector of a passive robot platform or an end-effector of an active navigation robot. Examples of active navigation robots include, but are not limited to, the da Vinci® Robotic System, the Medrobotics Flex® Robotic System, the Magellan™ Robotic System, and the CorePath® Robotic System.

[0036] Examples of intervention imaging system 60 include, but are not limited to, a stand-alone x-ray imaging system, a mobile x-ray imaging system, an ultrasound volumetric imaging system (e.g., TEE, TTE, IVUS, ICE), a computed tomography (“CT”) imaging system (e.g., a cone beam CT), a positron emission tomography (“PET”) imaging system and a magnetic resonance imaging (“MRI”) system.

[0037] Examples of position tracking system 70 include, but are not limited to, an electromagnetic (“EM”) measurement system (e.g., the Auora® electromagnetic measurement system), an optical-fiber based measurement system (e.g., Fiber-Optic RealShape™ (“FORS”) measurement system), an ultrasound measurement system (e.g., an InSitu or image-based US measurement system), an optical measurement system (e.g., a Polaris optical measurement system), a radio frequency identification measurement system, a magnetic measurement system and an encoder system of active intervention robots.

[0038] Generally as known in the art of present disclosure, during an interventional procedure, instrument guide 40, intervention imaging system 60 and position tracking system 70 support an image-guided navigation of intervention instrument 30 relative to an anatomical object 10 in accordance with an intervention treatment plan delineating one or more trajectories for intervention instrument 30 to target location(s) of anatomical object 10.

[0039] While position tracking system 70 has proven to very beneficial during the interventional procedures, the inventions of the present disclosure address potential positional errors that may arise due to forces/torques exerted on intervention instrument 30 and/or instrument guide 40 that are undetectable from a current imaging POV of intervention imaging system 60 of intervention instrument 30 relative to anatomical object 10. To this end, the optimal imaging POV intervention system of the present disclosure employs an optimal POV imaging controller 20 and one or more force/torque sensor(s) 50 to implement an optimal imaging POV intervention method of the present disclosure.

[0040] In practice, force/torque sensor(s) 50 may be embedded in intervention instrument 30 or instrument guide 40, incorporated within a guide positioning system employing instrument guide 40 and/or embodied within a force/torque control module 21 of optimal POV imaging controller 20 (not shown) to measure one or more forces and torques applied, directly and/or indirectly, to intervention instrument 30 and/or instrument guide 40.

[0041] In practice, force/torque sensor(s) 50 may have one or more degrees of freedom.

[0042] In one embodiment, a force/torque sensor 50 is a six (6) degree of freedom (DOF) (3 axis force/3 axis torque) sensor positioned between the instrument guide 40 and associated guide positioning system. The measured force/torque is gravity compensated for the weight of intervention instrument 30, resolved at the estimated tip position of intervention instrument 30 and transformed into the imaging coordinate system of intervention imaging system 60.

[0043] In another embodiment, as known in the art of the present disclosure, a force/torque control module 21 may infer forces/torques exerted on intervention instrument 30 and/or instrument guide 40 from deflections of intervention instrument 30 and/or instrument guide 40, a motor current in a guide positioning system associated with instrument guide 40 or pressure sensing of intervention instrument 30 and/or instrument guide 40.

[0044] The optimal imaging POV intervention method involves an inputting of an intervention treatment plan 11 by force/torque control module 21, and a monitoring and storing by force/torque control module 21 of force/torque data 51, intervention imaging data 61 and intervention position data 71.

[0045] Force/torque control module 21 initiates a force/torque analysis when a target position and orientation are within the acceptable threshold (e.g., 1 Degree, 1 mm), i.e., intervention instrument 30 is aligned with the target trajectory and moving down the instrument guide 40, or when intervention instrument 30 penetrates skin of the patient (derived from position data, or a force sensor event). Thereafter, force/torque control module 21 signal a surgeon with a beep or graphical warning whenever the force/torque analysis exceeds an empirically predefined threshold.

[0046] In practice, the empirically predefined threshold is established a demarcation between positional errors undetected by position tracking system 70 whereby a current navigation trajectory of intervention instrument 30 is within an acceptable tolerance of the target location and between positional errors undetected by position tracking system 70 whereby a current navigation trajectory of intervention instrument 30 is not within an acceptable tolerance of the target location.

[0047] In response to the alert, optimal POV control 22 calculates a new imaging axis in the imaging coordinate system of intervention imaging system 60 that is defined by the location of the resolved force/torque, and a vector in the image coordinate system of intervention imaging system 60 formed by a cross product of the target trajectory and the force/torque vector. Thereafter, optimal POV control 22 communicates a new imaging axis (position and the angles) to the surgeon and suggest repositioning intervention imaging system 60 at the new POV to acquire a more optimal view of intervention instrument 30. Alternatively, optical POV control 22 may autonomously control a repositioning of intervention imaging system 60 at the new POV.

[0048] For example, FIG. 2A illustrates a planned trajectory 11a in an XY plane imaging POV of anatomical object 10 having a target location symbolized by the black dot in anatomical object 10. As an intervention instrument 30a is navigated toward the target location along a navigation trajectory, force/torque control 21 performs the force/torque analysis in view of the empirically predefined threshold.

[0049] When the force/torque analysis is less than the threshold, the navigation of intervention instrument 30a along a navigation trajectory 11b as viewed in the XY plane is uninterrupted by force/torque control 21 to thereby proceed to the target location. FIG. 2B illustrates a force F.sub.Z1 exerted on intervention instrument 30a that is less than the empirically predefined threshold whereby the navigation of intervention instrument 30a along navigation trajectory 11b as viewed in the XY plane is uninterrupted by force/torque control 21 to thereby proceed to the target location as shown in FIG. 2C. In this case, force F.sub.Z1 has not caused any significant differential between planned trajectory 11a and navigation trajectory 11b.

[0050] When the force/torque analysis exceeds the threshold, the navigation of intervention instrument 30a along navigation trajectory 11b as viewed in the XY plane is interrupted by force/torque control 21 to thereby determine a more optimal imaging POV. FIG. 2D illustrates a force F.sub.Z2 exerted on intervention instrument 30a that exceeds the empirically predefined threshold whereby the navigation of intervention instrument 30a along navigation trajectory 11b as viewed in the XY plane is interrupted by force/torque control 21 to thereby determine a more optimal imaging POV. For this example, based on the Z-direction of force F.sub.Z2, optimal POV control 22 determines a more optimal imaging POV is the ZY plane as shown in FIG. 2E whereby a surgeon or optimal POV control may reposition intervention imaging system 60 accordingly. As a result, the differential between planned trajectory 11a and navigation trajectory 11b enables a surgeon or an autonomous imaging-guided guide positioning system to adjust the navigation of intervention instrument 30 to match planned trajectory 11b to thereby reach the target location as shown in FIG. 2F. In this case, the determination of the optimal imaging POV addressed a significant differential caused by force F.sub.Z2 between planned trajectory 11a and navigation trajectory 11b that was undetected by position tracking system 70 and not visibly ascertainable in the XY plane imaging POV.

[0051] To facilitate a further understanding of the various inventions of the present disclosure, the following description of FIGS. 3-5 teaches exemplary embodiments of optimal imaging POV intervention systems and methods of the present disclosure. From this description, those having ordinary skill in the art will appreciate how to apply the inventive principles of the present disclosure for making and using additional embodiments of optimal imaging POV intervention systems and methods of the present disclosure.

[0052] Referring to FIG. 3, an optimal imaging POV system employs a X-ray imaging system 63 (e.g., a mobile c-arm as shown), a robot platform 41 (passive or active), a tracking generator 72 (e.g., an EM generator, an optical generator), an intervention workstation 80 and a control network 90 including a monitor controller 91, an intervention controller 92 and optimal POV imaging controller 20 (FIG. 1) for deploying an interventional instrument 31 held by robot platform 41 within an anatomical region of a patient P lying prone on an operating table OT during an interventional procedure of any type.

[0053] As known in the art of the present disclosure, X-ray imaging system 63 generally includes an X-ray generator 64, an image intensifier 65 and a collar 68 for rotating X-ray imaging system 63. In operation as known in the art, an X-ray controller 67 controls a generation by X-ray imaging system 63 of X-ray imaging data 61 informative of a X-ray imaging of the anatomical region of patient P (e.g., a heart of patient P during a minimally invasive aortic valve replacement or vertebrae during a minimally invasive screw placement).

[0054] In practice, X-ray controller 67 may be installed within an X-ray imaging workstation (not shown), or alternatively installed within intervention workstation 80.

[0055] Still referring to FIG. 4, robot platform 41 provides for a manual or controlled lateral translation and angular movements of end-effector 42. Robot platform 41 may further include an one or more encoders (not shown) and one or more force/torque sensors (not shown).

[0056] The encoders are any type of encoder as known in the art of the present disclosure for generating robot pose data 43 informative of a location and/or orientation of each arm/link of robot platform 41 relative to a reference to thereby facilitate a determination by an interventional controller 92 of a pose of intervention instrument 31 as held by robot platform 41 within the anatomical region of patient P.

[0057] The force/torque sensors are any type of sensor as known in the art of the present disclosure for generating force torque sensor data 35 informative of a degree of any force applied by robot platform 41 via interventional instrument 31 or robot platform 41 itself to tissue within the anatomical region of patient P. Alternatively, the force/torque sensors may be embedded within intervention instrument 31 or implemented as force/torque algorithms of force/torque control 21 as known in the art of the present disclosure.

[0058] Still referring to FIG. 3, intervention workstation 80 is assembled in a known arrangement of a standalone computing system employing a monitor 81, a keyboard 82 and a computer 83.

[0059] Control network 90 is installed on computer 83. As installed on computer 83, an embodiment 120 of POV imaging controller 20 includes processor(s) 121, memory 122, a user interface 123, a network interface 124, and a storage 125 interconnected via one or more system buses 126 as shown in FIG. 4.

[0060] Referring to FIG. 4, each processor 121 may be any hardware device, as known in the art of the present disclosure or hereinafter conceived, capable of executing instructions stored in memory or storage or otherwise processing data. In a non-limiting example, each processor 121 may include a microprocessor, field programmable gate array (FPGA), application-specific integrated circuit (ASIC), or other similar devices.

[0061] The memory 122 may include various memories, as known in the art of the present disclosure or hereinafter conceived, including, but not limited to, L1, L2, or L3 cache or system memory. In a non-limiting example, the memory 122 may include static random access memory (SRAM), dynamic RAM (DRAM), flash memory, read only memory (ROM), or other similar memory devices.

[0062] The user interface 123 may include one or more devices, as known in the art of the present disclosure or hereinafter conceived, for enabling communication with a user such as an administrator. In a non-limiting example, the user interface 123 may include a command line interface or graphical user interface that may be presented to a remote terminal via the network interface.

[0063] The network interface 124 may include one or more devices, as known in the art of the present disclosure or hereinafter conceived, for enabling communication with other hardware devices. In an non-limiting example, the network interface 124 may include a network interface card (NIC) configured to communicate according to the Ethernet protocol. Additionally, the network interface may implement a TCP/IP stack for communication according to the TCP/IP protocols. Various alternative or additional hardware or configurations for the network interface will be apparent\

[0064] The storage 125 may include one or more machine-readable storage media, as known in the art of the present disclosure or hereinafter conceived, including, but not limited to, read-only memory (ROM), random-access memory (RAM), magnetic disk storage media, optical storage media, flash-memory devices, or similar storage media. In various non-limiting embodiments, the storage 125 may store instructions for execution by the processor or data upon with the processor may operate. For example, the storage 125 may store a base operating system for controlling various basic operations of the hardware. For purposes of the inventions of the present disclosure, storage 125 stores control modules 127 in the form of executable software/firmware for implementing the various functions of force/torque control 128 and optical POV control 129 as further described in the present disclosure.

[0065] Referring back to FIG. 3, monitor controller 91 and interventional controller 92 may be segregated, or partially or entirely integrated within optimal PV imaging controller 20. Alternatively, monitor controller 91 and interventional controller 92 may be distributed in any manner between two (2) workstations 80.

[0066] In operation, monitor controller 91 processes X-ray image data 61 to generate an X-ray image 66 and controls a display of X-ray image 66 on monitor 81 as known in the art of the present disclosure. Monitor controller 91 further controls a display on monitor 81 of an overlay of planned trajectories and navigated trajectories of intervention instrument 31 as known in the art of the present disclosure.

[0067] Intervention controller 92 processes robot position data 35 and intervention position data 71 to control a posing of robot platform 41 to facilitate a navigation of intervention instrument 31 within the anatomical region of patient P.

[0068] Force/torque control 21 and optical POV control 22 execute a flowchart 200 representative an optimal imaging POV intervention method of the present disclosure.

[0069] Referring to FIG. 5, a stage S202 of flowchart 200 encompasses force/torque control 21 monitoring and storing force/torque vector(s) as indicated by force/torque data 51 (FIG. 3), an intervention instrument position and target trajectory position as indicated by robot position data 35 (FIG. 3) and intervention tracking data 71 (FIG. 3) and a target location indicated by the planned treatment.

[0070] Also during stage S202, force/torque control 21 starts to monitor and store a history of instrument positions whereby a 3D user interface for displaying the history of instrument positions and the forces/torques associated with those positions in the 3D model may be generated during a stage S208 of flowchart 200 in conjunction with any warning of possible positional errors. If generated, then the surgeon may cycle through the history like a VCR movie playback (replay), showing position of intervention instrument 31 and a vector (length showing intensity) of the forces, at a given time in the surgical task. The surgeon may select the scene where he or she believes that the force/torque loading could have affected the procedure whereby this measurement data is then used to suggest an imaging axis.

[0071] In addition, the 3D model facilitates a generation of virtual X-ray projections with points of view generated based on the corresponding instrument position and force/torque measurement analysis. The virtual images may be compared to real verification images: side by side or overlaid. In some cases, instead of projections, virtual slices defined by tool position and force direction, and thickness may be presented. Besides the virtual 3D model replay, corresponding operating room video and audio are synchronized (via timestamps) and presented along the force/torque measurements and instrument position data.

[0072] Still referring to FIG. 5, a stage 5204 of flowchart 200 encompasses force/torque control 21 performing the force/torque analysis.

[0073] In practice, force/torque control 21 may measure the force/torque in a variety of modes including, but not limited to measuring a maximum force/torque, measuring force/torque immediately after an event, averaging force/torque for a period when instrument 30 is not moving, and averaging force/torque in a given time period.

[0074] Additionally, force/torque control 21 may execute weighted measurements force/torque based on anatomical proximity of intervention instrument 30. More particularly, a number of loading events during a particular instrument insertion into the body may occur. For example, when inserting a needle into the body, the lateral forces maybe initially low going through the skin, and increase when the needle enters the muscle layer because it has more mass to push against. It is then possible to use anatomical information to weigh the importance of the forces/torques based on the location of the instrument relative to the anatomy. For a given measurement set (or in real-time), the forces are weighted by the associated instrument distances relative to the anatomy, and then maximum of these weighted force/torque measurements and corresponding position is used to calculate the imaging axis. As different force/torque thresholds and weights may be used for different instruments, different steps in the procedure and different approach angles.

[0075] Furthermore, force/torque control 21 may execute weighted measurements force/torque based on kinematic model of the instrument guide. More particularly, a stiffness of mechanical devices varies with their given configuration and the direction of the loading. If an arm of robot platform 41 is extended, then a given force on the distal end of robot platform 41 will cause a greater torque on the base joint of robot platform 41 than if the arm is retracted. Therefore, the displacement from mechanical (or electrical in case of motors) compliance of the device will be higher at the extend configuration. Similarly, device compliance may be asymmetric. The model of the compliance is used to normalize the force/torque measurements in Cartesian space. For example, if a robot platform 41 was stiffer in Z, than in X direction, the same force magnitude force applied by the tissue in Z and X onto intervention instrument 31 would result in bigger deformation in X with smaller X direction force magnitude.

[0076] A stage S206 of flowchart 200 involves a detection of a positional error via a comparison of a force/torque measurement to the threshold. If not, then stage S204 is continually repeated until such time flowchart 200 is terminated upon completion of the procedure or a positional error is detected.

[0077] A stage S208 of flowchart 200 encompasses optimal POV control 22 determining an imaging axis and imager position to acquire an optimal POV.

[0078] In one embodiment, optimal POV control 22 calculate a new imaging axis in X-Ray imaging coordinate system that is defined by the location of the force/torque measurement, and a vector in the image coordinate system formed by a cross product of the target trajectory and the force vector.

[0079] In a second embodiment where only torque is considered, the axis of the torque and the instrument position is used as the suggested imaging axis.

[0080] In a third embodiment in cases where force and torque are measured, two or more different imaging axis may be calculated. One way to resolve this is to take an average of these vectors and present that imaging axis to the surgeon. Weighting may also be used.

[0081] In a fourth embodiment, a maximum of the magnitude between the force and torque is chosen as the imaging axis based on empirically established torque conversion factor: max_of (k*mag(T), mag (F))

[0082] Also in practice, instead of using the instrument position, an estimated target position may be utilized by optimal POV control 22 to calculate the imaging axis whereby the force/torque location is translated onto the target position.

[0083] The determined imaging axis may be communicated to the surgeon or the X-ray C-arm may be automatically rotated or translated in position after the force event is detected. The X-ray may be automatically triggered to image when it reaches the target position.

[0084] In case where the imaging angle or position has areas that are obstructed by opaque objects, an alternative view may be suggested. This view is as close as possible to the normal of the originally suggested viewing axis. This is can be solved using techniques known in the art related to motion planning. Such adjustments are communicated to the surgeon.

[0085] Further in practice, a motion constraint may be applied to a robot that aligns possible motion of the instrument to a plane passing through a point where the force event was and parallel to the POV plane. Motion may also be constraint along the force vector.

[0086] Upon the adjustment, flowchart 200 returns to stage S204.

[0087] In practice, to minimize the possible search space for maximum force/torque loading, the force/torque and positional measurements are tagged (synchronized temporally) with activation of instrumentation such as, for example, an activation/deactivation of the instrument (e.g., bone drill on/off, a detection of a force event through vibrations detected by the sensor (hit bone, hammer) and/or an acoustic sensing of instrument operation. The surgeon is presented with one of the feedback methods mentioned above, or a timeline showing forces and various events, along with a corresponding virtual 3D view of instrument position and force/torque.

[0088] Referring to FIGS. 1-5, those having ordinary skill in the art of the present disclosure will appreciate numerous benefits of the inventions of the present disclosure including, but not limited to, an ability to adjust imaging POV in view of potential positional errors of an intervention instrument due to forces/torques exerted on the intervention instrument and/or instrument guide.

[0089] Further, as one having ordinary skill in the art will appreciate in view of the teachings provided herein, structures, elements, components, etc. described in the present disclosure/specification and/or depicted in the Figures may be implemented in various combinations of hardware and software, and provide functions which may be combined in a single element or multiple elements. For example, the functions of the various structures, elements, components, etc. shown/illustrated/depicted in the Figures can be provided through the use of dedicated hardware as well as hardware capable of executing software in association with appropriate software for added functionality. When provided by a processor, the functions can be provided by a single dedicated processor, by a single shared processor, or by a plurality of individual processors, some of which can be shared and/or multiplexed. Moreover, explicit use of the term “processor” or “controller” should not be construed to refer exclusively to hardware capable of executing software, and can implicitly include, without limitation, digital signal processor (“DSP”) hardware, memory (e.g., read only memory (“ROM”) for storing software, random access memory (“RAM”), non-volatile storage, etc.) and virtually any means and/or machine (including hardware, software, firmware, combinations thereof, etc.) which is capable of (and/or configurable) to perform and/or control a process.

[0090] Moreover, all statements herein reciting principles, aspects, and embodiments of the invention, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents as well as equivalents developed in the future (e.g., any elements developed that can perform the same or substantially similar function, regardless of structure). Thus, for example, it will be appreciated by one having ordinary skill in the art in view of the teachings provided herein that any block diagrams presented herein can represent conceptual views of illustrative system components and/or circuitry embodying the principles of the invention. Similarly, one having ordinary skill in the art should appreciate in view of the teachings provided herein that any flow charts, flow diagrams and the like can represent various processes which can be substantially represented in computer readable storage media and so executed by a computer, processor or other device with processing capabilities, whether or not such computer or processor is explicitly shown.

[0091] Having described preferred and exemplary embodiments of novel and inventive image guidance of steerable introducers, and systems and methods incorporating such image guidance of steerable introducers, (which embodiments are intended to be illustrative and not limiting), it is noted that modifications and variations can be made by persons skilled in the art in light of the teachings provided herein, including the Figures. It is therefore to be understood that changes can be made in/to the preferred and exemplary embodiments of the present disclosure which are within the scope of the embodiments disclosed herein.

[0092] Moreover, it is contemplated that corresponding and/or related systems incorporating and/or implementing the device/system or such as may be used/implemented in/with a device in accordance with the present disclosure are also contemplated and considered to be within the scope of the present disclosure. Further, corresponding and/or related method for manufacturing and/or using a device and/or system in accordance with the present disclosure are also contemplated and considered to be within the scope of the present disclosure.