Haptic User Interface of a Cable-Driven Input Device to Control the End Effector of a Surgical Telemanipulation System

In robotic telemanipulation for minimally-invasive surgery, lack of haptic sensation and non-congruent movement of input device and manipulator are major drawbacks. Input devices based on cable-driven parallel mechanisms have the potential to be a stiff alternative to input devices based on rigid parallel or serial kinematics by offering low inertia and a scalable workspace. In this paper, the haptic user interface of a cable-driven input device and its technical specifications are presented and assessed. The haptic user interface allows to intuitively control the gripping movement of the manipulator’s end effector by providing a two-finger precision grasp. By design, the interface allows to command input angles between 0° and 45°. Furthermore, interaction forces from the manipulator’s end effector can be displayed to the user’s twofinger grasp in a range from 0 N to 6 N with a frequency bandwidth of 17 Hz.

The Critical View Of Safety : Une Attitude Pour Prévenir L’erreur D’identification Dans Les Cholécystectomies Laparoscopiques.

Résumé: Avec la généralisation de la cholécystectomie laparoscopique, l’incidence des traumatismes opératoires des voies biliaires a augmentée de façon significative. La perte de la sensation haptique, la vision bidimensionnelle, et l’éclairage centré favorisent l’illusion aboutissant à des erreurs d’identifications, où le chirurgien confond voie biliaire principale et canal cystique. Ce phénomène explique l’augmentation des traumatismes biliaires à l’ère de la laparoscopie.Récemment, et grâce aux recommandations des sociétés savantes comme la SAGES sur les bonnes pratiques chirurgicales, l’incidence de ces traumatismes est en régression et tend a rejoindre celle décrite à l’ère de la chirurgie ouverte. Parmi ses recommandations, la SAGES met l’accent sur l’adoption par tous les chirurgiens de la « Critical View of Safety » durant la réalisation de la cholécystectomie par voie laparoscopique. L’objectif de cette mise au point est de décrire cette attitude, mais surtout analyser son efficacité et ses limites dans la prévention des traumatismes opératoires des voies biliaires.Abstract:With the generalization of laparoscopic cholecystectomy, the incidence of operative bile ducts injury has increased significantly, the loss of haptic sensation, the two-dimensional vision, and the centered lighting favor the illusion leading to misidentifications, as consequences the surgeon confuses the main bile duct and the cystic duct. This phenomenon explains this increase in the incidence of bile duct injuries in the era of laparoscopy.Recently, and thanks to the recommendations of some learned societies such as SAGES on good surgical practices, the incidence of these complications is declining and tends to join that described in the era of open surgery. Among its many recommendations, SAGES recommends the adoption by all surgeons of the “Critical View of Safety” during the performance of laparoscopic cholecystectomy, an attitude that we will describe, and analyze its effectiveness and its limits in prevention of operative bile ducts injury.

Sense of Resistance for a Cursor Moved by User’s Keystrokes

Haptic sensation of a material can be modulated by its visual appearance. A technique that utilizes this visual-haptic interaction is called as pseudo-haptic feedback. Conventional studies have investigated pseudo-haptic feedback in situations, wherein a user manipulated a virtual object using a computer mouse, a force-feedback device, etc. The present study investigated whether and how it was possible to offer pseudo-haptic feedback to a user who manipulated a virtual object using keystrokes. Participants moved a cursor toward a destination by pressing a key. While the cursor was moving, the cursor was temporarily slowed down on a square area of the screen. The participants’ task was to report, on a five-point scale, how much resistance they felt to the cursor’s movement. In addition to the basic speed of the cursor, the ratio of the basic speed to the speed within the square area was varied. In Experiment 1, we found that these two factors interacted significantly with each other, but further analysis showed that the cursor speed within the square area was the most important determinant of perceived resistance. In Experiment 2, consistent with the results of the previous experiment, it was found that the cursor movement outside of the square area was not required to generate the sense of resistance. Counterintuitively, in Experiment 3, the sense of resistance was apparent even without user’s keystrokes. We discuss how the sense of resistance for a cursor moved by keystrokes can be triggered visually, but interpreted by the brain as a haptic impression.

Sense of resistance for a cursor moved by user’s keystrokes

Haptic sensation of a material can be modulated by its visual appearance. A technique that utilizes this visual-haptic interaction is called pseudo-haptic feedback. Conventional studies have investigated pseudo-haptic feedback in situations wherein a user manipulated a virtual object using a computer mouse, a force-feedback device, etc. The present study investigated whether and how it was possible to offer pseudo-haptic feedback to a user who manipulated a virtual object using keystrokes. Participants moved a cursor toward a destination by pressing a key. While the cursor was moving, the cursor was temporarily slowed down on a square area of the screen. The participants' task was to report, on a 5-point scale, how much resistance they felt to the cursor's movement. In addition to the basic speed of the cursor, the ratio of the basic speed to the speed within the square area was varied. In Experiment 1, we found that these two factors interacted significantly with each other, but further analysis showed that the cursor speed within the square area was the most important determinant of perceived resistance. In Experiment 2, consistent with the results of the previous experiment, it was found that the cursor movement outside of the square area was not required to generate the sense of resistance. Counterintuitively, in Experiment 3, the sense of resistance was apparent even without user's keystrokes. We discuss how the sense of resistance for a cursor moved by keystrokes can be triggered visually, but interpreted by the brain as a haptic impression.

Introduction of a New In-Situ Measurement System for the Study of Touch-Feel Relevant Surface Properties

The touch-feel sensation of product surfaces arouses growing interest in various industry branches. To entangle the underlying physical and material parameters responsible for a specific touch-feel sensation, a new measurement system has been developed. This system aims to record the prime physical interaction parameters at a time, which is considered a necessary prerequisite for a successful physical description of the haptic sensation. The measurement setup enables one to measure the dynamic coefficient of friction, the macroscopic contact area of smooth and rough surfaces, the angle enclosed between the human finger and the soft-touch surfaces and the vibrations induced in the human finger during relative motion at a time. To validate the measurement stand, a test series has been conducted on two soft-touch surfaces of different roughness. While the individual results agree well with the literature, their combination revealed new insights. Finally, the investigation of the haptics of polymer coatings with the presented measuring system should facilitate the design of surfaces with tailor-made touch-feel properties.

Development of MEMS Tactile Sensation Device for Haptic Robot

A tactile sensation device using micro-electromechanical system (MEMS) has been developed. This device is integrated with a haptic sensation robot for use as fingers. The tactile device must be miniaturized to enable attachment of the actuator mechanism to the fingers. Therefore, we used MEMS technology for this device. The device is composed of an interface part fabricated by 3D printing, pins, and MEMS cantilever-type actuators. It has the ability to stimulate the mechanoreceptors of the fingertips. The device and robot can display not only high-resolution images of the fingertips but also the repulsion force during finger operations such as tool holding and rotation. We have not yet achieved the final device because of fabrication problems. In this paper, we explain the details, progress of development, and results of trials on the prototype device.