Reconfigurable hall-effect sensor array unit and system thereof

Abstract

A reconfigurable Hall-effect sensor array unit, comprises: (a) a mounting rack; (b) a plurality of elastic backbones (3-8) connected to the mounting rack, comprising a bending mechanism; (c) flexible Hall-effect sensors (3-10) distributed on the plurality of elastic backbones (3-8); wherein the bending mechanism controls curvature of the plurality of elastic backbones (3-8) to provide a configuration suitable for magnetic localization in a measurement space. A system for magnetic localization of a magnetic object is also disclosed.

Description

RECONFIGURABLE HALL-EFFECT SENSOR ARRAY UNIT AND SYSTEM THEREOFFIELD OF THE INVENTION

[0001] The present invention relates to wirelessly magnetic location-aware system, particularly, for the pose estimation of magnetic devices in surgery.BACKGROUND OF THE INVENTION

[0002] Magnetically actuated robots have attracted promising attention in the past few years due to their high potential in medical and bioengineering. Among different kinds of magnetically actuated robots, such as magnetic robotic capsule endoscope or colonoscope, magnetic anchored endoscopic robots, magnetic micro-swarm robots and so on, one of the common advantages of these devices is that there is no need for an onboard locomotion system but embedded magnets, and utilizing the externally controlled and safe actuation system to generate the magnetic force and torque. Such a non-contacting actuation enhances the broad applicability in infra-body scenarios, including medical image screening, targeted elimination, and drug delivery.

[0003] Meanwhile, these complex and diversified infra-body scenarios pose more demands on magnetic localization from the technique viewpoint. Especially in certain surgery interventions, the accurate localization under sufficient measured space for the magnetic robots is required, which is a pivotal technical underpinning for the increment of successful operations and the fulfilment of close-loop control and further autonomous performance.

[0004] In In response to such requirement, researchers have been working on the localization of magnetic robots and many practical approaches are proposed, including X-ray imaging localization, radio-frequency localization, magnetic tracking and so on. Noted that compared to the other approaches, the magnetic tracking method is broadly implemented peculiarly in medical applications on account of its preferential advantagesof utilizing the immanent magnetic field generated by the magnetic robots so that less electromagnetic radiation through the human body and harmless to living cells.

[0005] One on the applicable magnetic tracking method is generally to utilize the magnetic sensor array to measure the magnetic field produced by the magnetic robots. In fact, many efforts have been made for the development of using magnetic sensor array technique for localization. Son et al. used a 2-D Hall-effect sensors array with 8 x 8 mono-axial Hall-effect sensors to achieve a 5-D localization of a dipole-modelled magnet (“A 5-D localization method for a magnetically manipulated untethered robot using a 2-D array of halleffect sensors,” IEEE / ASME Trans. Mechatron., vol. 21, no. 2, pp. 708-716, 2016.). Likewise, Xu et al. analysed the selection of an optimal sensor subarray form a wide range of planar sensor array, and achieved simultaneous magnetic actuation and localization (“Adaptive simultaneous magnetic actuation and localization for WCE in a tubular environment,” IEEE Trans. Robot., vol. 38, no. 5, pp. 2812-2826, 2022.).

[0006] Notwithstanding there are many works utilizing the planar Hall-effect sensor array and developing diverse magnetic tracking strategy to estimate the pose of diverse magnetic devices, how to achieve sufficient measured space, especially for body dimension, still pose a challenge. This is because even though the extension of the Halleffect sensor array could enlarge the measured dimensions in x / y direction, the available measured dimension in z direction remains to be limited in such a planar configuration.

[0007] Fortunately, there are sound works proposing the multi-layer or movable planar Hall-effect sensor array method, which could be a practical solution. For example, Hua et al. used a double-layer symmetric sensor array to position a magnetic capsule (“Positioning a "magnetically controlled capsule robot based on double-layer symmetric sensor array,” IEEE Trans. Instrum. Meas., 2023.). Besides, Hu et al. proposed a cubic magnetic sensor array comprising four planar Hall-effect sensor arrays with 4x4 sensors(“A cubic 3- axis magnetic sensor array for wirelessly tracking magnet position and orientation,” IEEE Sens. J., vol. 10, no. 5, pp. 903-913, 2010.). Furthermore, based on a similar setup system, Song et al. further discussed the multiple objects positioning and identification method for magnetic localization (“Multiple objects positioning and identification method based on magnetic localization system,” IEEE Trans. Magn., vol. 52, no. 10, pp. l^t, 2016.). Compared with the planar Hall-effect sensors array with the fixed pose, Zhang et al. developed an eye-in-hand planar sensor array, which is located on mobile electromagnetic coils so that the sensors array could move with the coils and the measurement space will be extend (“A 5-D large workspace magnetic localization and actuation system based on an eye in-hand magnetic sensor array and mobile coils,” IEEE Trans. Instrum. Meas., vol. 72, pp. 1-11, 2023.).

[0008] However, it is true that such a planar configuration is not an optimal configuration given that the human body structure is not a regular shape, which means that the planar Hall-effect sensor array could not attach to the torso as closely as possible and adapt to diverse human body structure, inevitably leading to part of the sensor array is underutilized. For this case, researchers proposed a compliant Hall-effect sensor array to deal with such a dilemma. Fischer et al. investigated a compliant, wearable 2-D Halleffect sensor array to track the target magnet (“Compliant hall-effect sensor array for passive magnetic instrument tracking,” IEEE Sens. Lett., vol. 7, no. 3, pp. 1-4, 2023.). Resembling compliant sensor system can be found in Nguyen’ work, which enables wide range localization of a permanent magnet (“Long range localization in real-time tracking of magnet position using attentive sensing channels,” in 2022 IEEE / ASME International Conference on Advanced Intelligent Mechatronics (AIM). IEEE, 2022, pp. 871-878.).

[0009] Nevertheless, this scheme comes at the price that it is tricky to obtain the pose of the compliant Hall-effect sensor array. All these concerns remain bottlenecks of utilizing the Hall-effect sensing technique and deserves insightful investigations.SUMMARY OF THE INVENTION

[0010] This invention provides a reconfigurable Hall-effect sensor array unit. In one embodiment, said reconfigurable Hall-effect sensor array unit comprises: (a) a mounting rack; (b) a plurality of elastic backbones connected to said mounting rack, comprising a bending mechanism; (c) flexible Hall-effect sensors distributed on said plurality of elastic backbones; wherein said bending mechanism controls curvature of said plurality of elastic backbones to provide a configuration suitable for magnetic localization in a measurement space.

[0011] This invention further provides a system for magnetic localization of a magnetic object. In one embodiment, said system comprises: (a) said reconfigurable Hall-effect sensor array unit; (b) a planar Hall-effect sensor array unit; and (c) a computer unit comprising: (i) a processor; (ii) memory; and (iii) program instructions, stored in the memory, that upon execution by the processor cause the computing unit to perform operations for implementing a magnetic localization algorithm based on measurements from said planar Hall-effect sensor array and said reconfigurable Hall-effect sensor array to obtain a 5-DOF pose of said magnetic object.BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a systematic flowchart showing a procedure that uses a wirelessly location-aware system to achieve the magnetic localization for magnetic robots by the utilization of a reconfigurable magnetic sensor array method.

[0013] Figure 1 is a systematic flowchart showing a procedure that uses a wirelessly location-aware system to achieve the magnetic localization for magnetic robots by the utilization of a reconfigurable magnetic sensor array method.

[0014] Figure 2 is the conceptual representation of wirelessly magnetic location-aware system. This figure illustrates two different configurations of the wirelessly magnetic location-aware system. 2-1: Patient; 2-2: magnetic robots inside the human body; 2-3:cable-driven actuation mechanism; 2-4: linear movement units; 2-5: reconfigurable Halleffect sensor array; 2-6: planar Hall-effect sensor array.

[0015] Figure 3 is the illustration of the reconfigurable Hall-effect sensor array unit, (a) Explosive view of the reconfigurable mechanism, (b) The planform view of the reconfigurable mechanism, (c) The self-developed FPC-Hall-effect sensor. 3-1: Step motor; 3-2: mounting base; 3-3: roller; 3-4: bearing; 3-5: revolving shaft; 3-6: coupling; 3-7: encoder; 3-8: elastic backbone; 3-9: cable wire; 3-10: flexible Hall-effect sensor; 3- 11: eyelet.

[0016] Figure 4 is the illustration of different configuration regarding to different curvature. 4-1: The configuration of big curvature; 4-2: the configuration of small curvature;

[0017] Figure s is the block diagram illustrating the wirelessly magnetic location- aware algorithm, which formulates and solves an optimization problem based on the fusion of magnetic fields measured by the planar Hall-effect sensor array and reconfigurable Halleffect sensor array.

[0018] Figure 6A and 6B are simulation results about the measurement accuracy of said planar magnetic sensor array and reconfigurable magnetic sensor array. 6-1: Planar magnetic sensor array; 6-2: reconfigurable magnetic sensor array; 6-3: curvature of elastic backbone; 6-4: the trajectory of said magnetic devices, which is divided into different block in sub-space of overall space; 6-5: localization mean error in different blocks by reconfigurable magnetic sensor array; 6-6: localization mean error in different blocks by planar Hall-effect sensor array.DETAILED DESCRIPTION OF THE INVENTION

[0019] This invention is concerned with the development of a magnetic location- aware system using reconfigurable magnetic sensor array, which is utilized for the pose estimation of magnetic devices like magnetic capsule endoscopes, magneticcolonoscopes and likewise magnetic-actuated medical devices in surgery. More specifically, this system is developed by the co-design of the Hall-effect sensor array approach and the cable-driven mechanism to achieve the fulfilment of reconfigurable function from the technique perspective. Moreover, based on the developed system, the overall system workflow, including the kinematic modelling methodology of the reconfigurable system, visual frame calibration scheme and magnetic location-aware algorithm, is constructed.

[0020] A magnetic location-aware system is first designed and prototyped by codesigning the cable-driven reconfigure mechanism and Hall-effect sensing technique. Compared to the former works, the developed system makes a forward step in the real application of magnetic location-aware technology toward the body dimension.

[0021] Based on the developed system, the overall system workflow including the visual frame calibration method and location-aware algorithm, is constructed.

[0022] The validation of the developed system and proposed overall system workflow strategy, are verified by means of conducting experiments. Further, serval technical essentials about the location-aware algorithm for Hall-effect sensing are indicated by the virtual fulfillment of the simulation experiments.

[0023] This invention provides a reconfigurable Hall-effect sensor array unit. In one embodiment, said reconfigurable Hall-effect sensor array unit comprises: (a) a mounting rack; (b) a plurality of elastic backbones connected to said mounting rack, comprising a bending mechanism; (c) flexible Hall-effect sensors distributed on said plurality of elastic backbones; wherein said bending mechanism controls curvature of said plurality of elastic backbones to provide a configuration suitable for magnetic localization in a measurement space.

[0024] In one embodiment, said bending mechanism comprises a step motor, a shaft, wires connected to said elastic backbones and a first microcontroller, wherein said firstmicrocontroller controls said step motor to tighten or release said wires to induce said elastic backbones to change curvature.

[0025] In one embodiment, said plurality of elastic backbones comprises a mechanism for connecting elastic rods to enhance stiffness.

[0026] In one embodiment, said reconfigurable Hall-effect sensor array unit further comprises a movement unit for adjusting position of said reconfigurable Hall-effect sensor array unit.

[0027] This invention further provides a system for magnetic localization of a magnetic object. In one embodiment, said system comprises: (a) said reconfigurable Hall-effect sensor array unit; (b) a planar Hall-effect sensor array unit; and (c) a computer unit comprising: (i) a processor; (ii) memory; and (iii) program instructions, stored in the memory, that upon execution by the processor cause the computing unit to perform operations for implementing a magnetic localization algorithm based on measurements from said planar Hall-effect sensor array and said reconfigurable Hall-effect sensor array to obtain a 5-DOF pose of said magnetic object.

[0028] In one embodiment, said magnetic localization algorithm comprises the steps of:(a) Measuring magnetic field of said magnetic object using said reconfigurable Halleffect sensor array and representing in a stacked matrix form:Eqn (1);(b) Measuring magnetic field of said magnetic object using said planar Hall-effect sensor array and representing in a stacked matrix form:Eqn (2);(c) Expressing modelled magnetic field in each of said flexible Hall-effect sensor in said reconfigurable Hall-effect sensor array in a stacked matrix form where is said 5-DOFpose, P is position of ij flexible Hall-effect sensor:Eqn (3);(d) Expressing modelled magnetic field in each of said Hall-effect sensor in said planar Hall-effect sensor array in a stacked matrix form where % is said 5-DOF pose, P,y is position of ij Hall-effect sensor:Eqn (4);(e) Obtaining said 5-DOF pose, , by solving an optimalization function:Eqn (5);

[0029] In one embodiment, said system further comprises a shape sensing unit for obtaining position of each flexible Hall-effect sensor and / or each Hall-effect sensor.

[0030] In one embodiment, said shape sensing unit comprises one or more selected from the group consisting of visual sensor module, fibre optic shape sensing module, and model-based shape sensing module.

[0031] In one embodiment, said shape sensing unit calibrates said position of each flexible Hall-effect sensor and / or each Hall-effect sensor prior to implementing said magnetic localization algorithm.

[0032] In one embodiment, said shape sensing unit obtains position of each flexible Hall-effect sensor and / or each Hall-effect sensor by data-based kinematics.

[0033] In one embodiment, said bending mechanism comprises a step motor, a shaft, wires connected to said elastic backbones and a first microcontroller, wherein said first microcontroller controls said step motor to tighten or release said wires to induce said elastic backbones to change curvature.

[0034] In one embodiment, said plurality of elastic backbones comprises a mechanism for connecting elastic rods to enhance stiffness.

[0035] In one embodiment, said system further comprises a movement unit for adjusting position of said reconfigurable Hall-effect sensor array unit.

[0036] In one embodiment, said movement unit is controlled by a second microcontroller to move said reconfigurable Hall-effect sensor array unit to within a desired distance to said measurement space.

[0037] In one embodiment, said measurement space is a space surrounded by said planar Hall-effect sensor array unit and said reconfigurable Hall-effect sensor array unit.

[0038] In one embodiment, this invention provides a system for simultaneous magnetic localization, comprising a planar Hall-effect sensor array unit, a reconfigurable Halleffect sensor array unit, a cable-driven mechanism unit, a linear movement unit, and an information processing computer unit, shape sensing unit, wherein (a) said planar Halleffect sensor array unit contains m X n, m, n G N+Hall-effect sensors for sensing the magnetic field, a planar mounting base for the accuracy location distribution of these m X n Hall-effect sensors; (b) said reconfigurable Hall-effect sensor array unit comprises m, m G N+self-developed flexible printed circuits Hall-effect sensors, which is distributed on an elastic backbone, an elastic backbone comprising 3-D print eyelets for the installation of cable wires and snap joint-like 3-D print parts for the installation of elastic rods, which are utilized for the enhancement of the stiffness of the elastic backbone; (c) said cable-driven mechanism unit comprises a rack for mounting, a step motor for the actuation, a self-design revolving shaft, two couplings, two bearings for the actuated force transmission, sets of self-design rollers and soft-iron wires for the transmission, further the bending of said reconfigurable Hall-effect sensor array unit; (d) said a linear movement unit contains two sets of linear movement modules including linear guideway and step motor, for the conduction of the horizontal movement of thecable-driven mechanism unit so that said reconfigurable Hall-effect sensor array unit could narrows to the desired distant that approaches to the specific measurement space, and microcontrollers and motor drivers to control the step motors of both said linear movement modules and said cable-driven mechanism unit; (e) said information processing computer unit for implementing magnetic localization strategy comprises a localization algorithm with program instructions based on magnetic fields measured by said planar Hall-effect sensor array and said reconfigurable Hall-effect sensor array for obtaining 5-DOF pose of magnetic devices to be measured, a calibration algorithm based on visual modules to calibrate the configurations collection of said elastic backbone and the pose of said planar Hall-effect sensor array unit; (f) said shape sensing unit is utilized to measure the shape of said elastic backbone.

[0039] In one embodiment, said Hall-effect sensors includes printed circuit boards and flexible printed circuits, and the sensors can be triaxial and multi-axial magnetic sensor.

[0040] In one embodiment, said distribution of said Hall-effect sensors is a combination strategy of planar array method and reconfigurable array method.

[0041] In one embodiment, plurality of said planar / reconfigurable Hall-effect sensor array can be optionally adjusted.

[0042] In one embodiment, said all Hall-effect sensors are connected in series and i Halleffect sensors as a group, i G N+, which is collected via one Inter- Integrated Circuit (IIC).

[0043] In one embodiment, said flexible printed circuit Hall-effect sensors are attached upon the said elastic backbone and could be bent into different shapes regarding the configuration of said cable-driven mechanism unit.

[0044] In one embodiment, said cable-driven mechanism bends said elastic backbone, generating different curvature of said elastic backbone, which further changes the pose of said reconfigurable Hall-effect sensor array unit.

[0045] In one embodiment, said curvature of said elastic backbone can be optionally adjusted.

[0046] In one embodiment, said reconfigurable Hall-effect sensor array unit could be moved in horizon under the actuation of said linear movement unit.

[0047] In one embodiment, said horizonal position of said reconfigurable Hall-effect sensor array unit can be optionally adjusted.

[0048] In one embodiment, said information processing computer unit has the functions of controlling the different configuration of said reconfigurable Hall-effect sensor array unit, data collection of both planar Hall-effect sensor array unit and said reconfigurable Hall-effect sensor array unit, and visual modules, the implement of said localization algorithm.

[0049] In one embodiment, said measurement space includes the space that is surrounded by both said planar Hall-effect sensor array unit and said reconfigurable Hall-effect sensor array unit.

[0050] In one embodiment, said measurement space can be determined via the size design of both said planar Hall-effect sensor array unit and said reconfigurable Halleffect sensor array unit.

[0051] In one embodiment, said magnetic source includes the magnetic field produced by permanent magnet, electromagnet, the combination or extruded-cut of magnets, and the hybrid magnets containing the combination of permanent magnet and electromagnet.

[0052] In one embodiment, said magnetic devices to be measured include the embedded magnetic source to generate the magnetic field.

[0053] In one embodiment, said system works in a workflow framework by the following steps: (a) Sensor modules conduct calibration of both the configuration of said elastic backbone and the pose of said planar Hall-effect sensor array unit; (b) Linear movement unit works to change the horizontal position of said cable-driven mechanismunit, in the meanwhile, cable-driven mechanism works to change the configuration of said reconfigurable Hall-effect sensor array unit; (c) Both planar and reconfigurableHall-effect sensor array units measure the magnetic field generated by magnetic device;(d) Information processing computer unit collect magnetic field data and implement said magnetic localization algorithm; (e) Information processing computer unit publish the5-DOF pose information of magnetic devices; (f) Information processing computer unit checks if the magnetic localization process is complete. If yes, linear movement unit and cable-driven mechanism back to the initial state. Otherwise, turn to step (c).

[0054] In one embodiment, said localization strategy further comprises program instructions for implementing the steps of: (a) magnetic field generated by said permanent magnet embedded inside the said magnetic devices is measured by the said reconfigurable Hall-effect sensor array and further represented as a stacked matrix formBRasEqn (1);(b) magnetic field generated by said permanent magnet embedded inside the said magnetic devices is measured by the said planar Hall-effect sensor array and further represented as a stacked matrix form BPasEqn (2);(c) modelled magnetic field in each Hall-effect sensor is expressed as the stacked matrix form BRx, Pij') and BP(x, Pij) which relative to the 5-DOF pose of the said magnetic devices and said position of ij Hall-effect sensor P . More specifically,Eqn (3);Eqn (4);(d) An optimization functionEqn (5);is constructed and the said 5-DOF pose x isobtained by solving the said optimization function.

[0055] In one embodiment, said shape sensing unit includes visual sensor module, fibre optic shape sensing module, model-based shape sensing and other shape sensing techniques.

[0056] In one embodiment, said sensor’s position and orientation are obtained by data- based kinematics. The data is acquired by the virtual data collection of said shape sensing unit.

[0057] In one embodiment, based on the simulation experiments, can be included in that compared to the planar magnetic sensor array method, the average measurement accuracy of said reconfigurable magnetic sensor array method is better.

[0058] On the bottom of the whole system, there is a planar Hall-effect sensor array attaching to the back of the human. An nxn Hall-effect sensors array is distributed on the lying bed, covering the projected area of the abdomen. Therefore, the measured endoscopic robots which are embed with the magnet could be induced by the planar Hall-effect sensor array. With the aid of the location-aware algorithm, the position of the measured endoscopic robots could be further calculated.

[0059] There are two set of self-developed flexible printed circuits (FPC) which are embed with the Hall-effect sensors, locating on the backbone of the cable-driven mechanism. The backbone could be blended by the planar cable-driven mechanism, further achieving different configurations to satisfy different application scenarios.Compared to the planar Hall-effect sensor array, the distribution of the reconfigurable Hall-effect sensor array changes via the actuation of the planar the planar cable-driven mechanism, which means that the pose of the Hall-effect sensor is not fixed but reconfigurable.

[0060] In order to satisfy the requirement of different sagittal abdominal diameters for different people, two sets of linear movement units are designed in the both sides of the whole system. When the linear movement unit works, the base of the reconfigurable Hall-effect sensor array could narrow to the desired distant that approaches to the specific sagittal abdominal diameter.

[0061] As the brain of the whole system, the computer and microcontrollers are utilized to conduct the location-aware algorithm and the data receive, respectively. Besides, another micro-controller is used to control the linear movement unit as well as the planar cable-driven mechanism.

[0062] To achieve magnetic localization, first constructing the magnetic field model for the magnetic devices, EPM and electromagnet array using the magnetic dipole model asBy packing the magnetic fields of all Hall-effect sensors in a vector form, the followings are obtained:Eqn (11);Then by solving an optimization problem with the measured fields vsfrom the Halleffect sensor array, the 5-D pose of the magnetic robots (except the rotation around its magnetic moment) is calculated. The optimization is formulated asEqn (12);s. t p- < pc< pc+mc< mc< mcwhere ||-||Frepresents the Frobenius norm, (■) and (-)+are the lower and upper bounds of the vector, respectively, < is element-wise (general) inequality symbol.

Claims

What is claimed is:

1. A reconfigurable Hall-effect sensor array unit, comprising: a. a mounting rack; b. a plurality of elastic backbones connected to said mounting rack, comprising a bending mechanism, c. flexible Hall-effect sensors distributed on said plurality of elastic backbones; wherein said bending mechanism controls curvature of said plurality of elastic backbones to provide a configuration suitable for magnetic localization in a measurement space.

2. The reconfigurable Hall-effect sensor array unit of claim 1, wherein said bending mechanism comprises a step motor, a shaft, wires connected to said elastic backbones and a first microcontroller, wherein said first microcontroller controls said step motor to tighten or release said wires to induce said elastic backbones to change curvature.

3. The reconfigurable Hall-effect sensor array unit of claim 1, wherein said plurality of elastic backbones comprises a mechanism for connecting elastic rods to enhance stiffness.

4. The reconfigurable Hall-effect sensor array unit of claim 1 , further comprises a movement unit for adjusting position of said reconfigurable Hall-effect sensor array unit.

5. A system for magnetic localization of a magnetic object, comprising: a. said reconfigurable Hall-effect sensor array unit of claim 1 ; b. a planar Hall-effect sensor array unit; and c. a computer unit comprising: i. a processor; ii. memory; and iii. program instructions, stored in the memory, that upon execution by the processor cause the computing unit to perform operations for implementing a magnetic localization algorithm based on measurements from said planar Hall-effect sensor array and saidreconfigurable Hall-effect sensor array to obtain a 5-DOF pose of said magnetic object.

6. The system of claim 5, wherein said magnetic localization algorithm comprises the steps of: a. Measuring magnetic field of said magnetic object using said reconfigurable Hall-effect sensor array and representing in a stacked matrix form:Eqn (1);b. Measuring magnetic field of said magnetic object using said planarHall-effect sensor array and representing in a stacked matrix form:Bp = Eqn (2);c. Expressing modelled magnetic field in each of said flexible Hall-effect sensor in said reconfigurable Hall-effect sensor array in a stacked matrix form where x is sa'^ 5-DOF pose, P,y is position of ij flexible Hall-effect sensor:Eqn (3);d. Expressing modelled magnetic field in each of said Hall-effect sensor in said planar Hall-effect sensor array in a stacked matrix form where is said 5-DOF pose, P^- is position of ij Hall-effect sensor:Eqn (4);e. Obtaining said 5-DOF pose, , by solving an optimalization function: Eqn (5).

7. The system of claim 6, further comprises a shape sensing unit for obtaining position of each flexible Hall-effect sensor and / or each Hall-effect sensor.

8. The system of claim 7, wherein said shape sensing unit comprises one or more selected from the group consisting of visual sensor module, fibre optic shape sensing module, and model-based shape sensing module.

9. The system of claim 7, wherein said shape sensing unit calibrates said position of each flexible Hall-effect sensor and / or each Hall-effect sensor prior to implementing said magnetic localization algorithm.

10. The system of claim 7, wherein said shape sensing unit obtains position of each flexible Hall-effect sensor and / or each Hall-effect sensor by data-based kinematics.

11. The system of claim 5, wherein said bending mechanism comprises a step motor, a shaft, wires connected to said elastic backbones and a first microcontroller, wherein said first microcontroller controls said step motor to tighten or release said wires to induce said elastic backbones to change curvature.

12. The system of claim 5, wherein said plurality of elastic backbones comprises a mechanism for connecting elastic rods to enhance stiffness.

13. The system of claim 5, wherein further comprises a movement unit for adjusting position of said reconfigurable Hall-effect sensor array unit.

14. The system of claim 13, wherein said movement unit is controlled by a second microcontroller to move said reconfigurable Hall-effect sensor array unit to within a desired distance to said measurement space.

15. The system of claim 5, wherein said measurement space is a space surrounded by said planar Hall-effect sensor array unit and said reconfigurable Hall-effect sensor array unit.

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