MilliSonic: Pushing the Limits of Acoustic Motion Tracking

Recent years have seen interest in device tracking and localization using acoustic signals. State-of-the-art acoustic motion tracking systems however do not achieve millimeter accuracy and require large separation between microphones and speakers, and as a result, do not meet the requirements for many VR/AR applications. Further, tracking multiple concurrent acoustic transmissions from VR devices today requires sacrificing accuracy or frame rate. We present MilliSonic, a novel system that pushes the limits of acoustic based motion tracking. Our core contribution is a novel localization algorithm that can provably achieve sub-millimeter 1D tracking accuracy in the presence of multipath, while using only a single beacon with a small 4-microphone array.Further, MilliSonic enables concurrent tracking of up to four smartphones without reducing frame rate or accuracy. Our evaluation shows that MilliSonic achieves 0.7mm median 1D accuracy and a 2.6mm median 3D accuracy for smartphones, which is 5x more accurate than state-of-the-art systems. MilliSonic enables two previously infeasible interaction applications: a) 3D tracking of VR headsets using the smartphone as a beacon and b) fine-grained 3D tracking for the Google Cardboard VR system using a small microphone array

Towards System Agnostic Calibration of Optical See-Through Head-Mounted Displays for Augmented Reality

This dissertation examines the developments and progress of spatial calibration procedures for Optical See-Through (OST) Head-Mounted Display (HMD) devices for visual Augmented Reality (AR) applications. Rapid developments in commercial AR systems have created an explosion of OST device options for not only research and industrial purposes, but also the consumer market as well. This expansion in hardware availability is equally matched by a need for intuitive standardized calibration procedures that are not only easily completed by novice users, but which are also readily applicable across the largest range of hardware options. This demand for robust uniform calibration schemes is the driving motive behind the original contributions offered within this work. A review of prior surveys and canonical description for AR and OST display developments is provided before narrowing the contextual scope to the research questions evolving within the calibration domain. Both established and state of the art calibration techniques and their general implementations are explored, along with prior user study assessments and the prevailing evaluation metrics and practices employed within. The original contributions begin with a user study evaluation comparing and contrasting the accuracy and precision of an established manual calibration method against a state of the art semi-automatic technique. This is the first formal evaluation of any non-manual approach and provides insight into the current usability limitations of present techniques and the complexities of next generation methods yet to be solved. The second study investigates the viability of a user-centric approach to OST HMD calibration through novel adaptation of manual calibration to consumer level hardware. Additional contributions describe the development of a complete demonstration application incorporating user-centric methods, a novel strategy for visualizing both calibration results and registration error from the user’s perspective, as well as a robust intuitive presentation style for binocular manual calibration. The final study provides further investigation into the accuracy differences observed between user-centric and environment-centric methodologies. The dissertation concludes with a summarization of the contribution outcomes and their impact on existing AR systems and research endeavors, as well as a short look ahead into future extensions and paths that continued calibration research should explore

Design and Evaluation of a Contact-Free Interface for Minimally Invasive Robotics Assisted Surgery

Robotic-assisted minimally invasive surgery (RAMIS) is becoming increasingly more common for many surgical procedures. These minimally invasive techniques offer the benefit of reduced patient recovery time, mortality and scarring compared to traditional open surgery. Teleoperated procedures have the added advantage of increased visualization, and enhanced accuracy for the surgeon through tremor filtering and scaling down hand motions. There are however still limitations in these techniques preventing the widespread growth of the technology. In RAMIS, the surgeon is limited in their movement by the operating console or master device, and the cost of robotic surgery is often too high to justify for many procedures. Sterility issues arise as well, as the surgeon must be in contact with the master device, preventing a smooth transition between traditional and robotic modes of surgery. This thesis outlines the design and analysis of a novel method of interaction with the da Vinci Surgical Robot. Using the da Vinci Research Kit (DVRK), an open source research platform for the da Vinci robot, an interface was developed for controlling the robotic arms with the Leap Motion Controller. This small device uses infrared LEDs and two cameras to detect the 3D positions of the hand and fingers. This data from the hands is mapped to the da Vinci surgical tools in real time, providing the surgeon with an intuitive method of controlling the instruments. An analysis of the tracking workspace is provided, to give a solution to occlusion issues. Multiple sensors are fused together in order to increase the range of trackable motion over a single sensor. Additional work involves replacing the current viewing screen with a virtual reality (VR) headset (Oculus Rift), to provide the surgeon with a stereoscopic 3D view of the surgical site without the need for a large monitor. The headset also provides the user with a more intuitive and natural method of positioning the camera during surgery, using the natural motions of the head. The large master console of the da Vinci system has been replaced with an inexpensive vision based tracking system, and VR headset, allowing the surgeon to operate the da Vinci Surgical Robot with more natural movements for the user. A preliminary evaluation of the system is provided, with recommendations for future work

Collaborative robot control with hand gestures

Mestrado de dupla diplomação com a Université Libre de TunisThis thesis focuses on hand gesture recognition by proposing an architecture to control a collaborative robot in real-time vision based on hand detection, tracking, and gesture recognition for interaction with an application via hand gestures. The first stage of our system allows detecting and tracking a bar e hand in a cluttered background using skin detection and contour comparison. The second stage allows recognizing hand gestures using a Machine learning method algorithm. Finally an interface has been developed to control the robot over. Our hand gesture recognition system consists of two parts, in the first part for every frame captured from a camera we extract the keypoints for every training image using a machine learning algorithm, and we appoint the keypoints from every image into a keypoint map. This map is treated as an input for our processing algorithm which uses several methods to recognize the fingers in each hand. In the second part, we use a 3D camera with Infrared capabilities to get a 3D model of the hand to implement it in our system, after that we track the fingers in each hand and recognize them which made it possible to count the extended fingers and to distinguish each finger pattern. An interface to control the robot has been made that utilizes the previous steps that gives a real-time process and a dynamic 3D representation.Esta dissertação trata do reconhecimento de gestos realizados com a mão humana, propondo uma arquitetura para interagir com um robô colaborativo, baseado em visão computacional, rastreamento e reconhecimento de gestos. O primeiro estágio do sistema desenvolvido permite detectar e rastrear a presença de uma mão em um fundo desordenado usando detecção de pele e comparação de contornos. A segunda fase permite reconhecer os gestos das mãos usando um algoritmo do método de aprendizado de máquina. Finalmente, uma interface foi desenvolvida para interagir com robô. O sistema de reconhecimento de gestos manuais está dividido em duas partes. Na primeira parte, para cada quadro capturado de uma câmera, foi extraído os pontos-chave de cada imagem de treinamento usando um algoritmo de aprendizado de máquina e nomeamos os pontos-chave de cada imagem em um mapa de pontos-chave. Este mapa é tratado como uma entrada para o algoritmo de processamento que usa vários métodos para reconhecer os dedos em cada mão. Na segunda parte, foi utilizado uma câmera 3D com recursos de infravermelho para obter um modelo 3D da mão para implementá-lo em no sistema desenvolvido, e então, foi realizado os rastreio dos dedos de cada mão seguido pelo reconhecimento que possibilitou contabilizar os dedos estendidos e para distinguir cada padrão de dedo. Foi elaborado uma interface para interagir com o robô manipulador que utiliza as etapas anteriores que fornece um processo em tempo real e uma representação 3D dinâmica

Novel approaches in hand rehabilitation

Hand rehabilitation is a constructive activity to gradually restore health and functionality of hand and fingers. Motion disabilities of hand and fingers are a common problem and can be a result of a wide variety of diseases and traumas. This problem is especially emphasized in the elderly population. Common methods in hand rehabilitation include physical therapy that should be performed frequently. However, patients tend not to follow the program strictly and perform exercises the wrong way, making progress slower or even stagnant. With the development of novel contactless and noninvasive sensors for tracking hand and finger motion the hand rehabilitation can be further upgraded. In this paper we looked into existing hand rehabilitation systems and presented a concept of a novel system by empowering capabilities of new sensors with virtual reality (VR) environment. The existing hand rehabilitation exercises were analysed, adapted and verified in order to be implemented into the system

Novel approaches in hand rehabilitation

Hand rehabilitation is a constructive activity to gradually restore health and functionality of hand and fingers. Motion disabilities of hand and fingers are a common problem and can be a result of a wide variety of diseases and traumas. This problem is especially emphasized in the elderly population. Common methods in hand rehabilitation include physical therapy that should be performed frequently. However, patients tend not to follow the program strictly and perform exercises the wrong way, making progress slower or even stagnant. With the development of novel contactless and noninvasive sensors for tracking hand and finger motion the hand rehabilitation can be further upgraded. In this paper we looked into existing hand rehabilitation systems and presented a concept of a novel system by empowering capabilities of new sensors with virtual reality (VR) environment. The existing hand rehabilitation exercises were analysed, adapted and verified in order to be implemented into the system

Establishing a Framework for the development of Multimodal Virtual Reality Interfaces with Applicability in Education and Clinical Practice

The development of Virtual Reality (VR) and Augmented Reality (AR) content with multiple sources of both input and output has led to countless contributions in a great many number of fields, among which medicine and education. Nevertheless, the actual process of integrating the existing VR/AR media and subsequently setting it to purpose is yet a highly scattered and esoteric undertaking. Moreover, seldom do the architectures that derive from such ventures comprise haptic feedback in their implementation, which in turn deprives users from relying on one of the paramount aspects of human interaction, their sense of touch. Determined to circumvent these issues, the present dissertation proposes a centralized albeit modularized framework that thus enables the conception of multimodal VR/AR applications in a novel and straightforward manner. In order to accomplish this, the aforesaid framework makes use of a stereoscopic VR Head Mounted Display (HMD) from Oculus Rift©, a hand tracking controller from Leap Motion©, a custom-made VR mount that allows for the assemblage of the two preceding peripherals and a wearable device of our own design. The latter is a glove that encompasses two core modules in its innings, one that is able to convey haptic feedback to its wearer and another that deals with the non-intrusive acquisition, processing and registering of his/her Electrocardiogram (ECG), Electromyogram (EMG) and Electrodermal Activity (EDA). The software elements of the aforementioned features were all interfaced through Unity3D©, a powerful game engine whose popularity in academic and scientific endeavors is evermore increasing. Upon completion of our system, it was time to substantiate our initial claim with thoroughly developed experiences that would attest to its worth. With this premise in mind, we devised a comprehensive repository of interfaces, amid which three merit special consideration: Brain Connectivity Leap (BCL), Ode to Passive Haptic Learning (PHL) and a Surgical Simulator

Prefrontal cortex activation upon a demanding virtual hand-controlled task: A new frontier for neuroergonomics

open9noFunctional near-infrared spectroscopy (fNIRS) is a non-invasive vascular-based functional neuroimaging technology that can assess, simultaneously from multiple cortical areas, concentration changes in oxygenated-deoxygenated hemoglobin at the level of the cortical microcirculation blood vessels. fNIRS, with its high degree of ecological validity and its very limited requirement of physical constraints to subjects, could represent a valid tool for monitoring cortical responses in the research field of neuroergonomics. In virtual reality (VR) real situations can be replicated with greater control than those obtainable in the real world. Therefore, VR is the ideal setting where studies about neuroergonomics applications can be performed. The aim of the present study was to investigate, by a 20-channel fNIRS system, the dorsolateral/ventrolateral prefrontal cortex (DLPFC/VLPFC) in subjects while performing a demanding VR hand-controlled task (HCT). Considering the complexity of the HCT, its execution should require the attentional resources allocation and the integration of different executive functions. The HCT simulates the interaction with a real, remotely-driven, system operating in a critical environment. The hand movements were captured by a high spatial and temporal resolution 3-dimensional (3D) hand-sensing device, the LEAP motion controller, a gesture-based control interface that could be used in VR for tele-operated applications. Fifteen University students were asked to guide, with their right hand/forearm, a virtual ball (VB) over a virtual route (VROU) reproducing a 42 m narrow road including some critical points. The subjects tried to travel as long as possible without making VB fall. The distance traveled by the guided VB was 70.2 ± 37.2 m. The less skilled subjects failed several times in guiding the VB over the VROU. Nevertheless, a bilateral VLPFC activation, in response to the HCT execution, was observed in all the subjects. No correlation was found between the distance traveled by the guided VB and the corresponding cortical activation. These results confirm the suitability of fNIRS technology to objectively evaluate cortical hemodynamic changes occurring in VR environments. Future studies could give a contribution to a better understanding of the cognitive mechanisms underlying human performance either in expert or non-expert operators during the simulation of different demanding/fatiguing activities.openCarrieri, Marika; Petracca, Andrea; Lancia, Stefania; Basso Moro, Sara; Brigadoi, Sabrina; Spezialetti, Matteo; Ferrari, Marco; Placidi, Giuseppe; Quaresima, ValentinaCarrieri, Marika; Petracca, Andrea; Lancia, Stefania; BASSO MORO, Sara; Brigadoi, Sabrina; Spezialetti, Matteo; Ferrari, Marco; Placidi, Giuseppe; Quaresima, Valentin