Development and evaluation of a fluidic facemask for airborne transmission mitigation.

Recently, a fluidic facemask concept was proposed to mitigate the transmission of virus-laden aerosol and droplet infections, such as SARS-CoV-2 (COVID-19). This paper describes an experimental investigation of the first practical fluidic facemask prototype, or "Air-Screen". It employs a small, high-aspect-ratio, crossflow fan mounted on the visor of a filter-covered cap to produce a rectangular air jet, or screen, in front of the wearer's face.

Energetic analysis and experiments of earthworm-like locomotion with compliant surfaces.

The energy consumption of worm robots is composed of three parts: heat losses in the motors, internal friction losses of the worm device and mechanical energy locomotion requirements which we refer to as the cost of transport (COT). The COT, which is the main focus of this paper, is composed of work against two types of external factors: (i) the resisting forces, such as weight, tether force, or fluid drag for robots navigating inside wet environments and (ii) sliding friction forces that may result from sliding either forward or backward. In a previous work, we determined the mechanical energy requirement of worm robot locomotion over compliant surfaces, independently of the efficiency of the worm device.

Validation of a stereo camera system to quantify brain deformation due to breathing and pulsatility.

Purpose: A new stereo vision system is presented to quantify brain shift and pulsatility in open-skull neurosurgeries.

Methods: The system is endowed with hardware and software synchronous image acquisition with timestamp embedding in the captured images, a brain surface oriented feature detection, and a tracking subroutine robust to occlusions and outliers. A validation experiment for the stereo vision system was conducted against a gold-standard optical tracking system, Optotrak CERTUS.

Accurate multi-robot targeting for keyhole neurosurgery based on external sensor monitoring.

Robotics has recently been introduced in surgery to improve intervention accuracy, to reduce invasiveness and to allow new surgical procedures. In this framework, the ROBOCAST system is an optically surveyed multi-robot chain aimed at enhancing the accuracy of surgical probe insertion during keyhole neurosurgery procedures. The system encompasses three robots, connected as a multiple kinematic chain (serial and parallel), totalling 13 degrees of freedom, and it is used to automatically align the probe onto a desired planned trajectory.

Conditions for worm-robot locomotion in a flexible environment: theory and experiments.

Biological vessels are characterized by their substantial compliance and low friction that present a major challenge for crawling robots for minimally invasive medical procedures. Quite a number of studies considered the design and construction of crawling robots; however, very few focused on the interaction between the robots and the flexible environment. In a previous study, we derived the analytical efficiency of worm locomotion as a function of the number of cells, friction coefficients, normal forces, and local (contact) tangential compliance.

Force feedback in a piezoelectric linear actuator for neurosurgery.

Background: Force feedback in robotic minimally invasive surgery allows the human operator to manipulate tissues as if his/her hands were in contact with the patient organs. A force sensor mounted on the probe raises problems with sterilization of the overall surgical tool. Also, the use of off-axis gauges introduces a moment that increases the friction force on the bearing, which can easily mask off the signal, given the small force to be measured.

Clinical acceptance and accuracy assessment of spinal implants guided with SpineAssist surgical robot: retrospective study.

Study Design: Retrospective, multicenter study of robotically-guided spinal implant insertions. Clinical acceptance of the implants was assessed by intraoperative radiograph, and when available, postoperative computed tomography (CT) scans were used to determine placement accuracy.

Objective: To verify the clinical acceptance and accuracy of robotically-guided spinal implants and compare to those of unguided free-hand procedures.

Analysis of wormlike robotic locomotion on compliant surfaces.

An inherent characteristic of biological vessels and tissues is that they exhibit significant compliance or flexibility, both in the normal and tangential directions. The latter in particular is atypical of standard engineering materials and presents additional challenges for designing robotic mechanisms for navigation inside biological vessels by crawling on the tissue. Several studies aimed at designing and building wormlike robots have been carried out, but little was done on analyzing the interactions between the robots and their flexible environment.

A self-propelled inflatable earthworm-like endoscope actuated by single supply line.

Design of a self-propelling endoscope has been of interest for decades, as it allows for simplified medical examination techniques and improved patient comfort, together with advanced analysis capacity. In this paper, we describe the development of a fully automatic, multiple-balloon system achieving peristaltic locomotion, controlled by a single supply channel. The system employs the nonlinear pressure-radius characteristics of elastic balloons to simultaneously control numerous balloons with a constant inlet pressure.

Ultrasound-guided robot for flexible needle steering.

The success rate of medical procedures involving needle insertion is often directly related to needle placement accuracy. Due to inherent limitations of commonly used freehand needle placement techniques, there is a need for a system providing for controlled needle steering for procedures that demand high positional accuracy. This paper describes a robotic system developed for flexible needle steering inside soft tissues under real-time ultrasound imaging.

Bone-mounted miniature robotic guidance for pedicle screw and translaminar facet screw placement: part 2--Evaluation of system accuracy.

Objective: To evaluate the accuracy of a novel bone-mounted miniature robotic system for percutaneous placement of pedicle and translaminar facet screws.

Methods: Thirty-five spinal levels in 10 cadavers were instrumented. Each cadaver's entire torso was scanned before the procedure.

Flexible needle steering for percutaneous therapies.

Objective: A robotic system is presented for flexible needle steering and control in soft tissue.

Materials And Methods: Flexible needle insertion into a deformable tissue is modeled as a linear beam supported by virtual springs, where the stiffness coefficients of the springs can vary along the needle. Using this simplified model, the forward and inverse kinematics of the needle are solved analytically, thus enabling both path planning and path correction in real time.

Feasibility study of a mini, bone-attached, robotic system for spinal operations: analysis and experiments.

Study Design: In this investigation, a new concept of a miniature, bone-attached, medical robotic system for spinal operations is presented. As part of the design parameters of the robot, the forces and moments applied by the physician during insertion of Kirschner wires to soft tissues and drilling in hard tissues were examined. A theoretical model for the expected error of the robotic system due to the applied force has been derived and verified experimentally.

Approximating Functions by Neural Networks: A Constructive Solution in the Uniform Norm.

A method for constructively approximating functions in the uniform (i.e., maximal error) norm by successive changes in the weights and number of neurons in a neural network is developed.