The Twente humanoid head

This video shows the results of the project on the mechatronic development of the Twente humanoid head. The mechanical structure consists of a neck with four degrees of freedom (DOFs) and two eyes (a stereo pair system) which tilt on a common axis and rotate sideways freely providing a three more DOFs. The motion control algorithm is designed to receive, as an input, the output of a biological-inspired vision processing algorithm and to exploit the redundancy of the joints for the realization of the movements. The expressions of the humanoid head are implemented by projecting light from the internal part of the translucent plastic cover

Feasibility of joystick guided colonoscopy

The flexible endoscope is increasingly used to perform minimal invasive interventions. A novel add-on platform allows single-person control of both endoscope and instrument at the site of intervention. The setup changes the current routine of handling the endoscope. This study aims to determine if the platform allows effective and efficient manipulation to position the endoscope at potential intervention sites throughout the bowel. Five experts in flexible endoscopy first performed three colonoscopies on a computer simulator using the conventional angulation wheels. Next they trained with the joystick interface to achieve their personal level of intubation time with low pain score. 14 PhD students (novices) without hands-on experience performed the same colonoscopy case using either the conventional angulation wheels or joystick interface. Both novice groups trained to gain the average expert level. The cecal intubation time, pain score and visualization performance (% of bowel wall) were recorded. All experts reached their personal intubation time in 6 ± 6 sessions. Three experts completed their learning curve with low pain score in 8 ± 6 sessions. The novices required 11 ± 6 sessions using conventional angulation wheels, and 12 ± 6 sessions using the joystick interface. There was no difference in the visualization performance between the novice and between the expert groups. This study shows that the add-on platform enables endoscope manipulation required to perform colonoscopy. Experts need only a relatively short training period. Novices are as effective and as efficient in endoscope manipulation when comparing the add-on platform with conventional endoscope contro

Apunts d'avaluació de serveis socioeducatius

Podeu consultar la 2a edició a: http://hdl.handle.net/2445/101624Podeu consultar la 3a edició a: http://hdl.handle.net/2445/124743S'expliquen teòricament i amb exemples els següents aspectes relacionats amb l'avaluació de serveis socioeducatius: models i dimensions, procés avaluatiu d'un servei, i documents tècnics de proposta i difusió de l'avaluació

Evaluation of flexible endoscope steering using haptic guidance

Background Steering the tip of a flexible endoscope relies on the physician’s dexterity and experience. For complex flexible endoscopes, conventional controls may be inadequate. Methods A steering method based on a multi-degree-of-freedom haptic device is presented. Haptic cues are generated based on the endoscopic images. The method is compared against steering using the same haptic device without haptic cues, and against conventional steering. Human-subject studies were conducted in which 12 students and 6 expert gastroenterologists participated. Results Experts are significantly faster when using the conventional method compared with using the haptic device, either with or without haptic cues. However, it is expected that the performance of the subjects with the haptic device will increase with experience. Conclusions Using a haptic device may be a viable alternative to the conventional method for the control of complex flexible endoscopes. The results suggest that the use of haptic cues may reduce the patient discomfort

Bridging the gap between passivity and transparency

In this paper a structure will be given which in aremarkably simple way offers a solution to the implementationof different telemanipulation schemes for discrete time varyingdelays by preserving passivity and allowing the highest transparencypossible. This is achieved by splitting the communicationchannel in two separate ones, one for the energy balance whichwill ensure passivity and one for the haptic information betweenmaster and slave and which will address transparency. Theauthors believe that this structure is the most general up todate which preserves passivity under discrete time varying delaysallowing different control schemes to address transparency

3D position estimation of flexible instruments: marker-less and marker-based methods

Purpose Endoscopic images can be used to allow accurate flexible endoscopic instrument control. This can be implemented using a pose estimation algorithm, which estimates the actual instrument pose from the endoscopic images. Methods In this paper, two pose estimation algorithms are compared: a marker-less and a marker-based method. The marker-based method uses the positions of three markers in the endoscopic image to update the state of a kinematic model of the endoscopic instrument. The marker-less method works similarly, but uses the positions of three feature points instead of the positions of markers. The algorithms are evaluated inside a colon model. The endoscopic instrument is manually operated, while an X-ray imager is used to obtain a ground-truth reference position. Results The marker-less method achieves an RMS error of 1.5, 1.6, and 1.8 mm in the horizontal, vertical, and away-from-camera directions, respectively. The marker-based method achieves an RMS error of 1.1, 1.7, and 1.5 mm in the horizontal, vertical, and away-from-camera directions, respectively. The differences between the two methods are not found to be statistically significant. Conclusions The proposed algorithms are suitable to realize accurate robotic control of flexible endoscopic instruments, enabling the physician to perform advanced procedures in an intuitive way

Intuitive user interfaces increase efficiency in endoscope tip control

Background Flexible endoscopes are increasingly used to perform advanced intraluminal and transluminal interventions. These complex interventions demand accurate and efficient control, however, current endoscopes lack intuitiveness and ergonomic control of the endoscope tip. Alternative handheld controllers can improve intuitiveness and ergonomics, though previous studies are inconclusive concerning their effect on the efficiency of endoscope manipulation. The aim of this study is to determine the efficiency of a robotic system with intuitive user interface in controlling the tip of the flexible endoscope. Methods We compared the efficiency of time and tip trajectory when steering the endoscope tip using the conventional steering wheels and a robotic platform with three different user interfaces: a touchpad in combination with a position control algorithm, a joystick combined with linear rate control, and a joystick combined with non-linear rate control. Fourteen participants, without a medical background, used all four interfaces. They performed both large navigational and fine targeting tasks in a simulated environment which allowed objective cross-subject comparison. Afterward, the participants were asked to select their preferred steering method. Results Participants were significantly faster in steering the endoscope tip when using robotic steering compared to using the conventional steering method. Between the robotic interfaces, using the touchpad was significantly faster compared to the joystick with linear rate control. Use of the joystick with non-linear rate control led to a shorter tip trajectory compared to the touchpad. The majority of participants preferred the joystick with non-linear rate control over the other steering methods. Conclusions This work shows that intuitive user interfaces can improve the efficiency of endoscope tip steerin