A Generalized Tracking Wall Approach to the Haptic Simulation of Tip Forces During Needle Insertion.

Haptic simulation of needle insertion requires both a needle-tissue interaction model and a method to render the outputs of this model into real-time force feedback for the user. In comparison with interaction models, rendering methods in the literature have seen little development and are either oversimplified or too computationally complex. Therefore, this study introduces the Generalized Tracking Wall (GTW) approach, a haptic rendering method inspired by the proxy approach.

Multimodal Haptic Simulation for Ventriculostomy Training.

Freehand ventriculostomy is a frequent surgical procedure and is among the first ones that junior neurosurgery residents learn. Although training simulators exist, none has been adopted in the clinical routine to train junior residents. This paper focuses on a novel multimodal haptic training simulator that will lift the limitations of current simulators.

Real Time Estimator to Perform Targeted Biopsies With a Free-Wrist Robot Despite Large Deformations of the Insertion Orifice.

In the context of keyhole surgery, and more particularly of uterine biopsy, the fine automatic movements of a surgical instrument held by a robot with 3 active DOF's require an exact knowledge of the point of rotation of the instrument. However, this center of rotation is not fixed and moves during an examination. This paper deals with a new method of detecting and updating the interaction matrix linking the movements of the robot with the surgical instrument.

Precisely positioning the tip of an instrument inserted through an orifice with a free wrist robot: application to prostate biopsies.

Purpose: Robots with a spherical unactuated wrist can be used for minimally invasive surgery. With such a robot, positioning the wrist center controls the instrument tip position when assuming that the insertion site behaves like a lever with a fixed and known fulcrum. In practice, this assumption is not always respected.

Overexpression of transcription factor Sp1 leads to gene expression perturbations and cell cycle inhibition.

Background: The ubiquitous transcription factor Sp1 regulates the expression of a vast number of genes involved in many cellular functions ranging from differentiation to proliferation and apoptosis. Sp1 expression levels show a dramatic increase during transformation and this could play a critical role for tumour development or maintenance. Although Sp1 deregulation might be beneficial for tumour cells, its overexpression induces apoptosis of untransformed cells.