Non-contact Interaction Research Articles

A non-contact interactive stereo display system for exploring human anatomy.

Stereoscopic display based on Virtual Reality (VR) can facilitate doctors to observe the 3 D virtual anatomical models with the depth cues, assist them in intuitively investigating the spatial relationship between different anatomical structures without mental imagination. However, there is few input device can be used in controlling the virtual anatomical models in the sterile operating room. This paper presents a cost-effective VR application system for demonstration of 3 D virtual anatomical models with non-contact interaction and stereo display. The system is integrated with hand gesture interaction and voice interaction to achieve non-contact interaction. Hand gesture interaction is implemented based on a Leap Motion controller mounted on the Oculus Rift DK2. Voice is converted into operation using Bing Speech for English language and Aitalk for Chinese language, respectively. A local relationship database is designed to record the anatomical terminologies to speech recognition engine to query these uncommon words. The hierarchical nature of these terminologies is also recorded in a tree structure. In the experiments, ten participants were asked to perform the evaluation on the proposed system. The results show that our system is more efficient than traditional interactive manner and verify the feasibility and practicability in the sterile operating room.

A non-contact interactive stereo display system for exploring human anatomy

Stereoscopic display based on Virtual Reality (VR) can facilitate clinicians observing 3 D anatomical models with the depth cue which lets them understand the spatial relationship between different anatomical structures intuitively. However, there are few input devices available in the sterile field of the operating room for controlling 3 D anatomical models. This paper presents a cost-effective VR application for stereo display of 3 D anatomical models with non-contact interaction. The system is integrated with hand gesture interaction and voice interaction to achieve non-contact interaction. Hand gesture interaction is based on Leap Motion. Voice interaction is implemented based on Bing Speech for English language and Aitalk for Chinese language. A local database is designed to record the anatomical terminologies organized in a tree structure, and provided to the speech recognition engine for querying these uncommon words. Ten participants were asked to practice the proposed system and compare it with the common interactive manners. The results show that our system is more efficient than the common interactive manner and prove the feasibility and practicability of the proposed system used in the sterile field.

A Light Implementation of a 3D Convolutional Network for Online Gesture Recognition

With the advancement of machine learning techniques and the increased accessibility to computing power, Artificial Neural Networks (ANNs) have achieved state-of-the-art results in image classification and, most recently, in video classification. The possibility of gesture recognition from a video source enables a more natural non-contact human-machine interaction, immersion when interacting in virtual reality environments and can even lead to sign language translation in the near future. However, the techniques utilized in video classification are usually computationally expensive, being prohibitive to conventional hardware. This work aims to study and analyze the applicability of continuous online gesture recognition techniques for embedded systems. This goal is achieved by proposing a new model based on 2D and 3D CNNs able to perform online gesture recognition, i.e. yielding a label while the video frames are still being processed, in a predictive manner, before having access to future frames of the video. This technique is of paramount interest to applications in which the video is being acquired concomitantly to the classification process and the issuing of the labels has a strict deadline. The proposed model was tested against three representative gesture datasets found in the literature. The obtained results suggest the proposed technique improves the state-of-the-art by yielding a quick gesture recognition process while presenting a high accuracy, which is fundamental for the applicability of embedded systems.

Flexible pressure sensor based on PVDF nanofiber

The development of wearable electronic devices has created a better blueprint for future human-computer interaction and intelligent living. Flexible pressure sensor is an important link to the development of wearable electronic devices. Despite significant progress made to date, there are still issues to be solved, including complex material synthesis, cumbersome preparation process and poor sensitivity response to human body signal. In this paper, we report flexible sensors that could be applied in different conditions. The sensors are fabricated by combination electrospinning-prepared PVDF nanofiber film with PDMS/Ag NWs and PET/ITO electrodes, respectively. The sensors based on PVDF nanofiber film feature good piezoelectric property with quantitative pressure measurement. Furthermore, they can act as a real-time monitor of human movement due to their conformal form factors. In addition, the sensors realize non-direct contact sensing, providing a broad design idea for future non-contact human-computer interaction. Our approach provides a new, simple, and cost-effective strategy for the development of wearable pressure sensors.

Non-contact tensile viscoelastic characterization of microscale biological materials

Many structures and materials in nature and physiology have important “meso-scale” structures at the micron length-scale whose tensile responses have proven difficult to characterize mechanically. Although techniques such as atomic force microscopy and micro- and nano-identation are mature for compression and indentation testing at the nano-scale, and standard uniaxial and shear rheometry techniques exist for the macroscale, few techniques are applicable for tensile-testing at the micrometre-scale, leaving a gap in our understanding of hierarchical biomaterials. Here, we present a novel magnetic mechanical testing (MMT) system that enables viscoelastic tensile testing at this critical length scale. The MMT system applies non-contact loading, avoiding gripping and surface interaction effects. We demonstrate application of the MMT system to the first analyses of the pure tensile responses of several native and engineered tissue systems at the mesoscale, showing the broad potential of the system for exploring micro- and meso-scale analysis of structured and hierarchical biological systems.

LexiPal: Kinect-based application for dyslexia using multisensory approach and natural user interface

Considered as an effective learning strategy for dyslexia, multisensory approach demands visual, auditory, and kinesthetic activity. While development of software application implementing multisensory approach has shown promising result, previous applications did not accurately resemble multisensory strategy because there are no kinesthetic implementations. This research proposes a Kinect-based application, termed LexiPal, which incorporates kinesthetic activity in multisensory implementation by using Natural User Interface (NUI). NUI provides more intuitive ways of interacting with the application by using body movement and gesture. LexiPal implements NUI by fusing several technologies including Augmented/Mixed Reality (AR/MR), non-contact human-computer interaction, skeletal tracking, hand tracking, and gesture recognition. For evaluation purpose, LexiPal was tested on 40 dyslexic children and they considered LexiPal user interaction as easy to use and enjoyable, which attract them to play the learning content again in the near future.

Video-based arm motion estimation and interaction with fuzzy predictive control

Multi-projector display systems are gaining popularity for use in immersive virtual reality applications and scientific visualization. While recent work has addressed the issues of human interfaces to hide the distributed nature of those systems, there has been relatively little work on natural interactive modalities. In this paper, based on the discrete characteristics of nodes distribution and the spatio-temporal coherence of the user’s movement, we propose a non-contact interaction solution for multi-projector display system. Utilizing a virtual three-dimensional interactive rectangular parallelepiped, we establish correspondence between the virtual scene and the user’s arm position information. For robustly tracking the user’s arm position, an arm motion estimation method is designed based on the fuzzy predictive control theory. To verify the efficiency and accuracy of the proposed method, various motion estimation algorithms were tested with and without the fuzzy predictive control theory to stabilize the output.

Time-dependent restricted-active-space self-consistent-field theory for bosonic many-body systems

We develop an ab initio time-dependent wavefunction based theory for the description of a many-body system of cold interacting bosons. Like the multi-configurational time-dependent Hartree method for bosons (MCTDHB), the theory is based on a configurational interaction Ansatz for the many-body wavefunction with time-dependent self-consistent-field orbitals. The theory generalizes the MCTDHB method by incorporating restrictions on the active space of the orbital excitations. The restrictions are specified based on the physical situation at hand. The equations of motion of this time-dependent restricted-active-space self-consistent-field (TD-RASSCF) theory are derived. The similarity between the formal development of the theory for bosons and fermions is discussed. The restrictions on the active space allow the theory to be evaluated under conditions where other wavefunction based methods due to exponential scaling in the numerical effort cannot, and to clearly identify the excitations that are important for an accurate description, significantly beyond the mean-field approach. For ground state calculations we find it to be important to allow a few particles to have the freedom to move in many orbitals, an insight facilitated by the flexibility of the restricted-active-space Ansatz. Moreover, we find that a high accuracy can be obtained by including only even excitations in the many-body self-consistent-field wavefunction. Time-dependent simulations of harmonically trapped bosons subject to a quenching of their noncontact interaction, show failure of the mean-field Gross-Pitaevskii approach within a fraction of a harmonic oscillation period. The TD-RASSCF theory remains accurate at much reduced computational cost compared to the MCTDHB method. Exploring the effect of changes of the restricted-active-space allows us to identify that even self-consistent-field excitations are mainly responsible for the accuracy of the method.

上皮細胞集団間相互作用におけるパターン形成解析

上皮細胞集団間相互作用におけるパターン形成解析

Analysis of information characteristics of a dynamic displacement doppler transducer signal

The article discusses the main features of the analysis of the Doppler transducer output signal that allow conducting experiments to determine the parameters of the oscillation of rotating elements of power units. A Doppler discrete- phase method that has fewer restrictions as compared to the classical discrete-phase method is presented. The theoretical rationale for the formation of the Doppler transducer output signal in the case of its non-contact interaction with the surface of the object under control (characteristic information sections of the output signal are considered) is presented. An analysis of the output waveform near its extreme values in the presence and absence of vibration of the controlled object is carried out using the waveforms obtained in conducting the pilot study as an example. Distinctive features of the output signal due to the rotation of the rotor and the vibrational motion of the surface of the blade controlled are discussed.

A non-contact human-computer interaction application design based on electrostatic current of human body

This paper puts forward a non-contact Human-Computer Interaction HCI method applied to game control based on electrostatic current of human body. By setting an electrode array, the induced current signals generated on the electrodes caused by hand motions can be measured by detection circuit and collected into PC by NI series M high-speed data acquisition device PXI6259. The direction of a hand motion can be figured out by processing the signals with LabVIEW programming. Furthermore, a game Mary programmed by LabVIEW can be played with this non-contact HCI technique, the corresponding hand motions: up, down, left and right can control the jump, squat, backward and forward motions of the game object Mary. After repeated experiments, the feasibility of this method has been proved. Namely, a non-contact controlling of a game can be realised with the HCI method based on electrostatic current of human body.

Passively-Switched, Non-Contact Energy Harvester for Broad Operational Range and Enhanced Durability

Impact-based vibrational energy harvesters that switch passively among dynamical modes to best match the ambient conditions and perform frequency up-conversion to maximize power output can increase the operational range over which harvesters output useful power. The disadvantage of impact-based harvesting is that it can lead to premature system failure. This paper presents modelling and experimental validation of a harvester with passively- switched dynamics in which a magnetic non-contact interaction replaces the impact-based interaction of previous systems for greater robustness. A low-frequency driving beam couples to a higher-frequency generating beam via tip magnets. Simulations predict that the noncontact interaction drives a diversity of dynamical modes in which the tip of the driving beam variously is repelled from and passes the tip of generating beam. Experiments validate the predicted dynamical behaviour of the system. Output power levels are similar to predictions, with a power of 903 μW on the primary resonance at 1 g acceleration.

A Stable and Transparent Microscale Force Feedback Teleoperation System

Scaled force feedback teleoperation is a promising approach to assist an operator engaged in a microscale task. Several systems were previously described to achieve such purpose, but much room was left for improvement, especially with regard to the specificities of bilateral coupling with very large scaling coefficients. Here, the objective is to render at human-scale haptic information available at the microscale, and to provide scaled teleoperation that simultaneously achieves stability and transparency. An active force sensor and a novel haptic interface were interconnected to form a complete teleoperation chain through a direct, two-channel scheme. Stability was ensured by enforcing passivity in the slave and in the master subsystems. Several experiments were carried out to demonstrate the capabilities of the system. The first experiment involved noncontact magnetic interaction. A second set of experiments demonstrated the penetration of a thin-glass probe in a water droplet where the operator interactively felt capillary forces.

Flow of magnetic repelling grains in a two-dimensional silo

During a typical silo discharge, the material flow rate is determined by the contact forces between the grains. Here, we report an original study concerning the discharge of a two-dimensional silo filled with repelling magnetic grains. This non-contact interaction leads to a different dynamics from the one observed with conventional granular materials. We found that, although the flow rate dependence on the aperture size follows roughly the power-law with an exponent 3/2 found in non-repulsive systems, the density and velocity profiles during the discharge are totally different. New phenomena must be taken into account. Despite the absence of contacts, clogging and intermittence were also observed for apertures smaller than a critical size determined by the effective radius of the repulsive grains. Received: 10 July 2015, Accepted: 7 August 2015; Edited by: L. A. Pugnaloni; Reviewed by: J. R. Darias, Universidad Simón o Bolívar, Caracas, Venezuela; DOI: http://dx.doi.org/10.4279/PIP.070013Cite as: G Lumay, J Schockmel, D Henández-Enríquez, S Dorbolo, N Vandewalle, F Pacheco-Vázquez, Papers in Physics 7, 070013 (2015)This paper, by G Lumay, J Schockmel, D Henández-Enríquez, S Dorbolo, N Vandewalle, F Pacheco-Vázquez, is licensed under the Creative Commons Attribution License 3.0.

A Multimedia System for Breath Regulation and Relaxation

In the hectic life today, detrimental stress has caused numerous illness. To adjust mental states, breath regulation plays a core role in multiple relaxation techniques. In this paper, we introduce a multimedia system supporting breath regulation and relaxation. Features of this system include non-contact respiration detection, bio-signal monitoring, and breath interaction. In addition to illustrating this system, we also propose a novel form of breath interaction. Through this form of breath interaction, the system effectively influenced user breath such that their breathing features turned into patterns that appeared when people were relaxed. An experiment was conducted to compare the effects of three forms of regulation, the free breathing mode, the pure guiding mode, and the local-mapping mode. Experiment results show that multimedia-assisted breath interaction successfully deepened and slowed down user breath, compared with free breathing mode. Besides objective breathing feature changes, subjective feedback also showed that participants were satisfied and became relaxed after using this system.

Numerical simulation of hemodynamic interactions of red blood cells in micro-capillary flow

The hemodynamic interactions of red blood cells (RBCs) in a microcapillary flow are investigated in this paper. This kind of interaction is considered as the non-contact mutual interaction of cells, which is important in the suspension flow of blood, but not sufficiently understood. The distributed Lagrange multiplier/fictitious domain method in the lattice Boltzmann framework is used to solve the suspension of the RBCs. The modification of the flow due to the cells, the dependence of the cell deformation on the flow and the cell-cell interaction via the fluid are discussed. It is revealed that the long-range hydrodynamic interaction with a long interacting distance, more than about 5 times of the RBC equivalent radius, mainly has effect on the rheology properties of the suspension, such as the mean velocity, and the short-range interaction is sensitive to the shape of the cell in the microcapillary flow. The flow velocity around the cell plays a key role in the cell deformation. In the current configuration of the flow and cells, the cells repel each other along the capillary.

The Research of the Driver Attention Field Modeling

For expanding the application scope of car-following, based on the basic idea of the noncontact interaction of the objects in physics, establish an attention field model to describe the driving behavior. Firstly, propose the time distance concept to describe the degree of driver perception to the front one-dimensional space and extend its application range to the two-dimensional space. Secondly, connect the point which has the same time distance to constitute the equipotential line of drivers’ attention field equipotent, and establish a model to describe it. Thirdly, define the effective range of the driver’s psychological field with the feature of the driver’s visual distance range increasing and the angle decreasing. Finally, design the calculation method to collect projection of the object in the psychological field scope and calculate the curve points to determine the object’s intensity of psychological field. Preliminarily build the driving behavior model and use the numerical simulation method to simulate the simple transport scenarios; initially verify the validity of the model.

Modeling Leukocyte-Leukocyte Non-Contact Interactions in a Lymph Node

The interaction among leukocytes is at the basis of the innate and adaptive immune-response and it is largely ascribed to direct cell-cell contacts. However, the exchange of a number of chemical stimuli (chemokines) allows also non-contact interaction during the immunological response. We want here to evaluate the extent of the effect of the non-contact interactions on the observed leukocyte-leukocyte kinematics and their interaction duration. To this aim we adopt a simplified mean field description inspired by the Keller-Segel chemotaxis model, of which we report an analytical solution suited for slowly varying sources of chemokines. Since our focus is on the non-contact interactions, leukocyte-leukocyte contact interactions are simulated only by means of a space dependent friction coefficient of the cells. The analytical solution of the Keller-Segel model is then taken as the basis of numerical simulations of interactions between leukocytes and their duration. The mean field interaction force that we derive has a time-space separable form and depends on the chemotaxis sensitivity parameter as well as on the chemokines diffusion coefficient and their degradation rate. All these parameters affect the distribution of the interaction durations. We draw a successful qualitative comparison between simulated data and sets of experimental data for DC-NK cells interaction duration and other kinematic parameters. Remarkably, the predicted percentage of the leukocyte-leukocyte interactions falls in the experimental range and depends (≅25% increase) upon the chemotactic parameter indicating a non-negligible direct effect of the non-contact interaction on the leukocyte interactions.

CONDENSATION STATE OF ULTRA-COLD BOSE ATOMIC GASES WITH NONCONTACT INTERACTION

Within the framework of quantum field theory, we find that uniform Bose atomic gases with noncontact interaction can undergo a Bardeen–Cooper–Schrieffer (BCS) condensation below a critical temperature. In the BCS condensation state, bare atoms with opposite wave vectors are bound into pairs, and unpaired bare atoms are transformed into a new kind of quasi-particle, i.e., the dressed atom. The atom-pair system is a condensate or a superfluid and the dressed-atom system is a normal fluid. At absolute zero temperature the condensate possesses a lowest negative energy. The critical temperature and the effective mass of dressed atoms are derived analytically. The transition from the BCS condensation state to the normal state is a first-order phase transition.

Non-Contact Interaction of Ultrasonic Wave on Laser Beam

The article presents the results of Matlab simulations and experimental studies of non-contact influence of ultrasonic wave on laser beam. A role of the air-gap and the influence of the air-gap on laser-ultrasonic transmission in optical fiber were examined. Two optical fibers were used with air-gap between them. One fiber was attached to a laser diode and positioned to pass through a hole in a sandwich type transducer and in a velocity transformer. In the velocity transformer (at its end), after leaving small air-gap, to the end of the transformer, the other optical fiber is attached. The second fiber can interact with a given biological structure.