Continuum Robot with Follow the Leader Motion for Endoscopic Third Ventriculostomy and Tumor Biopsy
This paper presents a miniature wire-driven multisection continuum robot (diameter of 3.4 mm/length of 60 mm) which performs a combined endoscopic third ventriculostomy (ETV) and endoscopic tumor biopsy (ETB). Key contributions are the miniature continuum robot including push-pull wires (0.15 mm in diameter) which control six bending subsections of the robot, a kinetic model to control the individual subsections of the robot by follow-the-leader (FTL) motion, and a clinical strategy to design a curved path for FTL motion. This robot can introduce surgical tools to ETV/ETB sites by a single curved trajectory through a single incision, unlike the current conventional approach which requires multiple tool placement through multiple trajectories and incisions.
Qualitative and Quantitative Assessment of Technical Skills in Percutaneous Coronary Intervention: In Vivo Porcine Studies
In this study, a natural-behavior-based assessment framework is proposed to qualitatively and quantitatively assess technical skills in PCI. In vivo porcine studies were conducted to deliver a medical guidewire to two target coronaries. Simultaneously, four types of natural behaviors were acquired from the subjects’ dominant hand and arm. The effective behavior features were applied in Gaussian-mixture-model-based qualitative assessment and Mahalanobis-distance-based quantitative assessment. The qualitative assessment achieves an accuracy of 92% to distinguish the novice and expert attempts. Furthermore, the quantitative assessment can assign objective scores for all attempts, indicating high correlation (R=0.9225) to those obtained by traditional methods.
Perceptual Limits of Optical See-Through Visors for Augmented Reality Guidance of Manual Tasks
The current generation of consumer-level Optical-See Trough (OST) Head-Mounted Displays (HMDs) generally renders the virtual content on a fixed focal plane located at a distance of 2 meters or more from the user. As a consequence, during manual task, the user not only experiences a vergence-accommodation conflict, but also a mismatch in the ocular accommodation stimulus for the virtual content and the real-world scene (his/her eyes can’t focus on both virtual and real objects simultaneously). This work presents a mathematical formulation of this latter optical issue and experimentally shows that such conflict can affect the accuracy of Augmented Reality (AR) guided manual tasks.
Low-Voltage Irreversible Electroporation Using a Comb-Shaped Contact Electrode
This study examined the feasibility of low-voltage contact IRE (irreversible electroporation) using a new comb-shaped miniature electrode. The electrode was designed to perforate cutaneous and subcutaneous tumor cells by touching it to the lesion surface of skin or gastrointestinal tract to apply electric pulses. Experiments using 3-D cultured cells showed that the maximum ablation depth reached 400 µm at 20 V. Insulation of lateral spaces between electrode teeth as well as administration of adjuvants to modify the cell membrane were effective and increased the ablation depth by 26% and the ablation area by 40%.
Image-based Artefact Removal in Laser Scanning Microscopy
Advances in laser scanning microscopy (LSM) have greatly extended its applicability in cancer imaging not only to observe dynamic biological processes, but also to quantitatively measure them. The fast acquisition with increased spatial resolution and field of view enables scanning of larger areas of the specimen. However in practice, image quality is compromised by the motion of specimen and the motion of the microscope laser. In this paper, we present a framework for efficient removal of jaggedness artefacts caused by the varying speeds of the laser. Our framework compensates for the local displacements and reduces the level of noise, demonstrating substantial improvement over other state-of-the-art acquisition methods.
An Ankle-Foot Prosthesis Emulator Capable of Modulating Center of Pressure
Difficulty balancing is one of the most commonly reported challenges following lower limb amputation. Active prosthetic limbs could be used to assist with balance by better controlling interactions with the ground. This work describes the design of a prosthesis emulator with two forefoot digits and a heel digit. Independent actuation of these digits modulates the origin and magnitude of the ground reaction force vector. During standing and walking, the emulator was able to control center of pressure along a prescribed pattern with errors of about 10% of pattern length, similar to human control.