Developing an Optical Microlever for Stable and Unsupported Force Amplification

Optical micromachines have the potential to improve the capabilities of optical tweezers by amplifying forces and allowing for indirect handling and probing of specimens. However, systematic design and testing of micromachine performance is still an emerging field. In this work we have designed and tested an unsupported microlever, suitable for...

Interfacial force measurements using atomic force microscopy

Atomic Force Microscopy (AFM) can not only image the topography of surfaces at atomic resolution, but can also measure accurately the different interaction forces, like repulsive, adhesive and lateral existing between an AFM tip and the sample surface. Based on AFM, various extended techniques have been developed such as colloidal probe AFM,...

The videolaryngoscope is less traumatic than the classic laryngoscope for a difficult airway in an obese patient

This report describes the anesthetic management of an obese patient with a difficult airway and the merits of videolaryngoscopy, specifically in terms of the reduced risk of dental damage during intubation. A 49-year-old woman (body mass index; BMI, 36 kg·m?2), was scheduled to undergo an elective laparoscopic cholecystectomy because of...

Suturing intraabdominal organs: When do we cause tissue damage?

It is generally assumed that safety of tissue manipulations during (laparoscopic) surgery is related to the magnitude of force that is exerted on the tissue. To provide trainees with performance feedback about tissuehandling skills, it is essential to define objective criteria for judging the safety of applied forces. To be of clinical relevance...

The Compressiometer: Towards a new skin tensiometer for research and surgical planning

After surgery, around 35% of patients experience problems of excessive scarring, causing disfiguring and impaired function. An incision placed in the wrong direction causes unnecessary skin tension on the wound, resulting in increased collagen disposition and potentially hypertrophic scars. Currently, skin tension lines are used for incision...

Force-based assessment of tissue handling skills in simulation training for robot-assisted surgery

Introduction: Although robotic-assisted surgery is increasingly performed, objective assessment of technical skills is lacking. The aim of this study is to provide validity evidence for objective assessment of technical skills for robotic-assisted surgery. Methods: An international multicenter study was conducted with participants from the...

Design, calibration and validation of a wheel-rail contact force measurement system in V-Track

An innovative downscale test rig called V-Track has been constructed for wheel-rail contact experiments under impact loading conditions. In this paper, a force measurement system termed a dynamometer was developed in V-Track to measure the wheel-rail contact forces. The dynamometer consists of four 3-component piezoelectric force sensors and...

Haptic guidance on demand: A grip-force based scheduling of guidance forces

In haptic shared control systems (HSC), a fixed strength of guidance force equates to a fixed level of control authority, which can be insufficient for complex tasks. An adaptable control authority based on operator input can allow the HSC system to better assist the operator under varied conditions. In this paper, we experimentally...

Improved analysis and visualization of friction loop data: unraveling the energy dissipation of meso-scale stick–slip motion

In this paper we demonstrate a new method for analyzing and visualizing friction force measurements of meso-scale stick–slip motion, and introduce a method for extracting two separate dissipative energy components. Using a microelectromechanical system tribometer, we execute 2 million reciprocating sliding cycles, during which we measure the...

Wireless instrumented klapskates for long-track speed skating

In the current project, we aim to provide speed skaters with real-time feedback on how to improve their skating performance within an individual stroke. The elite skaters and their coaches wish for a system that determines the mechanical power per stroke. The push-off force of the skater is a crucial variable in this power determination. In...

Push-off forces in elite short-track speed skating

This study performed an analysis of the push-off forces of elite-short-track speed skaters using a new designed instrumented short-track speed skate with the aim to improve short-track skating performance. Four different skating strokes were distinguished for short-track speed skaters at speed. The strokes differed in stroke time, force level...

Force-based learning curve tracking in fundamental laparoscopic skills training

Background: Within minimally invasive surgery (MIS), structural implementation of courses and structured assessment of skills are challenged by availability of trainers, time, and money. We aimed to establish and validate an objective measurement tool for preclinical skills acquisition in a basic laparoscopic at-home training program. Methods...

The influence of laparoscopic handle design parameters and grasping strategy on the haptic perception of variable tissue stiffness

Stiffness perception in laparoscopic surgery has an important role in achieving appropriate tissue manipulation. The need for haptic feedback to perceive tissue stiffness and the reduce in haptic feedback when using laparoscopic instruments suggest an inability to sufficiently experience stiffness perception during laparoscopic surgeries. Better...

Wave dissipation in a permeable structure: Experimental research on the physical processes causing energy dissipation inside an array of cylinders

Mangrove forests, which serve as a natural sea defence, have been degraded by human action during the last decades. To protect and recover these areas, different types of permeable structures consisting of bamboo have been proposed and applied. However, these structures are currently based on engineering judgement, as design rules are not...

Improving the filling jet schematisation through a lock door by taking into account the presence of a ship

This study treats the calculation of longitudinal forces on a ship in a lock chamber due to the levelling procedure. The focus will be on the force resulting from the filling jet through the levelling door in the lock, with the main point of interest being the interaction between the ship and the flow resulting from the jet. To understand more...

Evaluating the use of a piezo-resistive pressure sensor system for performance feedback in long track speed skating

In the sport of long track speed skating, in recent years there has been an increasing desire for training tools which provide deeper technical insight of the skating movement to the athlete and coaches. In previous literature a variety of measurement systems have been presented; one such system included the instrumented klapskate developed at...

Turbulent boundary layers over surfaces with streamwise-preferential permeability: Experimental investigation into the drag and flow mechanics

Turbulent drag is the largest source of fuel consumption in aviation and forms a significant contribution to climate warming. Recent numerical studies have suggested the ability of surfaces with streamwise-preferential permeability to reduce turbulent friction, and a theoretical framework behind the working mechanism has been proposed. This work...

A Hybrid Box Trainer for Training of Technical Skills in Laparoendoscopic Single Site Surgery (LESS)

The goal of this thesis is to design a hybrid trainer that can quantitatively measure the LESS performance while investigating the difference between LESS and CLS, finally propose a novel objective assessment tools for future research. A force platform is developed, which measures tissue manipulation force in the range of 0-20N with an accuracy...