Detection of Membrane Puncture with Haptic Feedback using a Tip-Force Sensing Needle.

This paper presents calibration and user test results of a 3-D tip-force sensing needle with haptic feedback. The needle is a modified MRI-compatible biopsy needle with embedded fiber Bragg grating (FBG) sensors for strain detection. After calibration, the needle is interrogated at 2 kHz, and dynamic forces are displayed remotely with a voice coil actuator.

A Passive Parallel Master-Slave Mechanism for Magnetic Resonance Imaging-Guided Interventions.

A passive, parallel master-slave mechanism is presented for magnetic resonance imaging (MRI)-guided interventions in the pelvis. The mechanism allows a physician to stand outside the MRI scanner while manipulating a needle inside the bore and, unlike a powered robot, does not place actuators in proximity to the patient. The manipulator combines two parallel mechanisms based on the Delta robot architecture.

Autonomous real-time interventional scan plane control with a 3-D shape-sensing needle.

This study demonstrates real-time scan plane control dependent on three-dimensional needle bending, as measured from magnetic resonance imaging (MRI)-compatible optical strain sensors. A biopsy needle with embedded fiber Bragg grating (FBG) sensors to measure surface strains is used to estimate its full 3-D shape and control the imaging plane of an MR scanner in real-time, based on the needle's estimated profile. The needle and scanner coordinate frames are registered to each other via miniature radio-frequency (RF) tracking coils, and the scan planes autonomously track the needle as it is deflected, keeping its tip in view.

MR-compatible biopsy needle with enhanced tip force sensing.

We describe an instrumented biopsy needle that provides physicians the capability to sense interaction forces directly at the tip of the needle's inner stylet. The sensors consist of optical fiber Bragg gratings (FBGs), and are unaffected by electromagnetic fields; hence the needle is suitable for MR-guided procedures. In comparison to previous instrumented needles that measure bending strains, the new design has additional sensors and a series of micro-machined holes at the tip.

Real-Time Estimation of 3-D Needle Shape and Deflection for MRI-Guided Interventions.

We describe a MRI-compatible biopsy needle instrumented with optical fiber Bragg gratings for measuring bending deflections of the needle as it is inserted into tissues. During procedures, such as diagnostic biopsies and localized treatments, it is useful to track any tool deviation from the planned trajectory to minimize positioning errors and procedural complications. The goal is to display tool deflections in real time, with greater bandwidth and accuracy than when viewing the tool in MR images.

Biomechanical analysis of penile erections: penile buckling behaviour under axial loading and radial compression.

Objective: To characterize the biomechanics of erectile function, as contrary reports have modelled the penis as an isotropic material and state that only axial buckling tests can effectively predict penile rigidity; that assumption is questioned and an alternative structure proposed and validated.

Methods: Three experimental physical cylindrical models of diameters 1.9, 2.