Rubbing a Physics Based Synthesis Model: From Mouse Control to Frictional Haptic Feedback

This paper investigates three kinds of interactions for a friction based virtual music instrument. The sound synthesis model consists of a bank of mass-spring-dampers excited via rubbing. A nonlinear static friction model capable of reproducing the characteristic stick-slip phenomenon observed in frictional interaction is employed, allowing for dynamic variation of the sliding friction. The different controls developed allow for gradually increasing the interplay between performer and instrument. The key excitation parameters, e.g., the rubbing velocity and the rubbing normal force are controlled using three different interfaces: a standard mouse, a Sensel Morph, and a 3D Systems Touch X. The Sensel Morph is a touchpad with pressure sensitivity, allowing for a natural exertion of the normal force; the 3D Systems Touch X is a haptic device that renders both resistance to the applied normal force, as well as the stick-slip motion resulting from the friction interaction. A preliminary user study aiming to compare the experience of performing with the different interfaces was carried out. The results indicate that the haptic feedback provides a more intuitive and enjoyable experience. However, extra features do not necessarily improve the user interaction, as the results suggest a preference for the mouse over the Sensel

Keytar: Melodic control of multisensory feedback from virtual strings

A multisensory virtual environment has been designed, aiming at recreating a realistic interaction with a set of vibrating strings. Haptic, auditory and visual cues progressively istantiate the environment: force and tactile feedback are provided by a robotic arm reporting for string reaction, string surface properties, and furthermore defining the physical touchpoint in form of a virtual plectrum embodied by the arm stylus. Auditory feedback is instantaneously synthesized as a result of the contacts of this plectrum against the strings, reproducing guitar sounds. A simple visual scenario contextualizes the plectrum in action along with the vibrating strings. Notes and chords are selected using a keyboard controller, in ways that one hand is engaged in the creation of a melody while the other hand plucks virtual strings. Such components have been integrated within the Unity3D simulation environment for game development, and run altogether on a PC. As also declared by a group of users testing a monophonic Keytar prototype with no keyboard control, the most significant contribution to the realism of the strings is given by the haptic feedback, in particular by the textural nuances that the robotic arm synthesizes while reproducing physical attributes of a metal surface. Their opinion, hence, argues in favor of the importance of factors others than auditory feedback for the design of new musical interfaces

Bowing virtual strings with realistic haptic feedback

We present a music interface implementing a bowed string. The bow is realised using a commercially available haptic device, consisting of a stylus attached to a robotic arm. While playing the virtual strings with the stylus reproducing the bow, users feel both the elastic force from the strings and the friction resulting from the interaction with their surfaces. The audio-haptic feedback is obtained by a physical model: four stiff strings are simulated using a finite difference time domain method, modelled as 1-Delements in the virtual 3-D space. The bow is simply modelled as a rigid cylinder that can move free in this space, and interact with the strings. Finally, the frictional interaction between such elements is modelled by a nonlinear friction model capable of reproducing the characteristic stick-slip phenomenon observed during string bowing. Moreover, the model can be dynamically controlled in one parameter so as to become more sticky or slippery. By turning on and off the frictional feedback, users can appreciate the significance of this interaction. A real-time visualisation of the bowed strings complements the audio-haptic displa

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Can the Treatment of Dental Malocclusions Affect the Posture in Children?

Objective: The aim of this study was to investigate whether the treatment of the dental malocclusions can affect the postural attitude in children. Study design: Sixty patients aged 9-12 years in mixed dentition were enrolled. The patients underwent an orthodontic evaluation for dental malocclusion and a postural examination by means of a vertical laser line (VLL) and a stabilometric???baropodometric platform. The children were treated with a functional appliance according to the type of malocclusion for two years. The position of the head and of the atlanto-occipital joint (C0-C1) respects to the VLL, the typologies of podalic support and the distribution of the body weight on the feet were evaluated before and after the orthodontic treatment. Results: A significant correction of the position of the head, with a physiological extension of C0 -C1, a significant improvement of the typology of podalic support and a homogeneous distribution of the body weight on the feet were observed after the treatment of the malocclusions. Conclusion; From our results, the treatment of dental malocclusion can contribute to ameliorate the postural attitude in children

Whole-Body Cryostimulation: A Rehabilitation Booster in Post-COVID Patients? A Case Series

Given the severity and prevalence of post-COVID-19 symptoms in the general population, the identification of boosters for rehabilitation programs appears to be of paramount importance. The purpose of this case series is to provide some preliminary evidence about the role of whole-body cryostimulation (WBC) as an effective adjuvant for the recovery of patients with the post-COVID-19 condition (PCC). We recruited seven patients with previously confirmed SARS-CoV-2 infection and symptoms of PCC of different severities for a comprehensive rehabilitation program, including WBC. The main symptoms were dyspnea, chronic and muscular fatigue, chronic pain, and poor sleep quality. Moreover, some patients presented high levels of hematological markers of inflammation. Because we provided a range of interventions, including nutritional and psychological support along with physical exercise and physiotherapy, we could not determine to what extent WBC may per se have accounted for the clinical and functional improvements. However, for all reported cases, it was observed that the introduction of WBC sessions represented a turning point in the patient’s subjective and objective improvements related to health and functioning

No Strings Attached: Force and Vibrotactile Feedback in a Guitar Simulation

In this paper we propose a multisensory simulation of plucking guitar strings in virtual reality. The auditory feedback is generated by a physics-based simulation of guitar strings, and haptic feedback is provided by a combination of high fidelity vibrotactile actuators and a Phantom Omni haptic device. Moreover, we present a user study (n=29) exploring the perceived realism of the simulation and the relative importance of force and vibrotactile feedback for creating a realistic experience of plucking virtual strings. The study compares four conditions: no haptic feedback, vibrotactile feedback, force feedback, and a combination of force and vibrotactile feedback. The results indicate that the combination of vibrotactile and force feedback eliits the most realistic experience, and during this condition, the participants were less likely to inadvertently hit strings after the intended string had been plucked. Notably, no statistically significant differences were found between the conditions involving either vibrotactile or force feedback, which points towards an indication that haptic feedback is important but does not need to be high fidelity in order to enhance the quality of the experience

From phenotyping to the study of clonal relationship of microbial isolates

The term "typing" is generally used with two meanings: a methods to establish the correct taxonomic collocation of a genus/specie/biotype, b methods for discriminating different bacterial isolates of the same species in order to establish the genetic relationship among the microorganisms involved in a possible outbreak. In this paper we focus our attention on the second aspect, that represents a relevant epidemiological tools in infection prevention and control. Typing systems are traditionally based on two steps workup: the first is the study of phenotypes such as serotype, biotype, phage-type, or antimicrobial susceptibilities of the isolates and this can be easily performed in every microbiology laboratory; the second, examines the relatedness of isolates at a molecular level. Over the years many molecular methods have been developed and efficiently applied in several hospital settings. The large panorama of methods put the microbiologists in trouble to operate the proper choice. Thus, in the present paper, we have reviewed old as well new molecular typing methods in order to provide a useful guide that can represent an overview on molecular methods and particularly of their specific pro and cons