Angular needle tracker and stabilizer for image-guided interventions

Introduction Minimally invasive image-guided interventions have changed the face of procedural medicine. For these procedures, safety and efficacy depend on precise needle placement. Needle targeting devices help improve the accuracy of needle placement, but their use has not seen broad penetration. Some of these devices are costly and require major modifications to the clinical workflow. In this article, we developed a low-cost, disposable, and easy-to-use angulation tracking device, which was based on a redesigned commercial passive needle holder. Material and methods The new design provided real-time angulation information for needle tracking. In this design, two potentiometers were used as angulation sensors, and they were connected to two axes of the passive needle holder’s arch structure through a 3 D-printed bridge structure. A control unit included an Arduino Pro Mini, a Bluetooth module, and two rechargeable batteries. The angulation was calculated and communicated in real time to a novel developed smartphone app, where real-time angulation information was displayed for guiding the operator to position the needle to the planned angles. Results The open-air test results showed that the average errors are 1.03° and 1.08° for left–right angulation and head–foot angulation, respectively. The animal cadaver tests revealed that the novel system had an average angular error of 3.2° and a radial distance error of 3.1 mm. Conclusions The accuracy was comparable with some commercially available solutions. The novel and low-cost needle tracking device may find a role as part of a real-time precision approach to both planning and implementation of image-guided therapies

Complete analytic solution to Brownian unicycle dynamics

This paper derives a complete analytical solution for the probability distribution of the configuration of a non-holonomic vehicle that moves in two spatial dimensions by satisfying the unicycle kinematic constraints and in presence of Brownian noises. In contrast to previous solutions, the one here derived holds even in the case of arbitrary linear and angular speed. This solution is obtained by deriving the analytical expression of any-order moment of the probability distribution. To the best of our knowledge, an analytical expression for any-order moment that holds even in the case of arbitrary linear and angular speed, has never been derived before. To compute these moments, a direct integration of the Langevin equation is carried out and each moment is expressed as a multiple integral of the deterministic motion (i.e., the known motion that would result in absence of noise). For the special case when the ratio between the linear and angular speed is constant, the multiple integrals can be easily solved and expressed as the real or the imaginary part of suitable analytic functions. As an application of the derived analytical results, the paper investigates the diffusivity of the considered Brownian motion for constant and for arbitrary time-dependent linear and angular speed.Comment: 22 pages, 6 figures, 2 table

Automatic multi-trajectory planning solution for steerable catheters

The present work describes a novel approach to trajectory planning for minimally invasive surgery consisting of an algorithm able to provide the surgeon with multiple curvilinear paths to connect an entry area defined on the brain cortex to a specific target point in the brain. A criterion based on the minimum distance from the safety-critical brain struc- tures (blood vessels, thalamus and ventricles) is used to rank the obtained trajectories. The solution is integrated onto the EDEN2020∗ programmable bevel-tip needle, a multi-segment probe whose steering ability derives from the offset generated on its tip, and provides a level of tolerance with respect to tracking errors arising from catheter model inaccuracies. The case of study of the work consists of a typical Deep Brain Stimulation scenario where tests have been performed in order to compare the result obtained from standard rectilinear trajectory planning against this novel curvilinear solution using the clearance from obstacles as an index of performance of the estimated solutions

Automatic optimized 3D path planner for steerable catheters with heuristic search and uncertainty tolerance

In this paper, an automatic planner for minimally invasive neurosurgery is presented. The solution can provide the surgeon with the best path to connect a user-defined entry point with a target in accordance with specific optimality criteria guaranteeing the clearance from obstacles which can be found along the insertion pathway. The method is integrated onto the EDEN2020∗ programmable bevel-tip needle, a multi-segment steerable probe intended to be used to perform drug delivery for glioblastomas treatment. A sample-based heuristic search inspired to the BIT* algorithm is used to define the optimal solution in terms of path length, followed by a smoothing phase required to meet the kinematic constraint of the catheter. To account for inaccuracies in catheter modeling, which could de- termine unexpected control errors over the insertion procedure, an uncertainty margin is defined so that to include a further level of safety for the planning algorithm. The feasibility of the proposed solution was demonstrated by testing the method in simulated neurosurgical scenarios with different degree of obstacles occupancy and against other sample-based algorithms present in literature: RRT, RRT* and an enhanced version of the RRT-Connect

Modeling and simulation of an active robotic device for flexible needle insertion

Master'sMASTER OF ENGINEERIN