Exploring the Potential of Wrist-Worn Gesture Sensing

This thesis aims to explore the potential of wrist-worn gesture sensing. There has been a large amount of work on gesture recognition in the past utilizing different kinds of sensors. However, gesture sets tested across different work were all different, making it hard to compare them. Also, there has not been enough work on understanding what types of gestures are suitable for wrist-worn devices. Our work addresses these two problems and makes two main contributions compared to previous work: the specification of larger gesture sets, which were verified through an elicitation study generated by combining previous work; and an evaluation of the potential of gesture sensing with wrist-worn sensors. We developed a gesture recognition system, WristRec, which is a low-cost wrist-worn device utilizing bend sensors for gesture recognition. The design of WristRec aims to measure the tendon movement at the wrist while people perform gestures. We conducted a four-part study to verify the validity of the approach and the extent of gestures which can be detected using a wrist-worn system. During the initial stage, we verified the feasibility of WristRec using the Dynamic Time Warping (DTW) algorithm to perform gesture classification on a group of 5 gestures, the gesture set of the MYO armband. Next, we conducted an elicitation study to understand the trade-offs between hand, wrist, and arm gestures. The study helped us understand the type of gestures which wrist-worn system should be able to recognize. It also served as the base of our gesture set and our evaluation on the gesture sets used in the previous research. To evaluate the overall potential of wrist-worn recognition, we explored the design of hardware to recognize gestures by contrasting an Inertial measurement unit (IMU) only recognizer (the Serendipity system of Wen et al.) with our system. We assessed accuracies on a consensus gesture set and on a 27-gesture referent set, both extracted from the result of our elicitation study. Finally, we discuss the implications of our work both to the comparative evaluation of systems and to the design of enhanced hardware sensing

An Assessment of Single-Channel EMG Sensing for Gestural Input

Wearable devices of all kinds are becoming increasingly popular. One problem that plagues wearable devices, however, is how to interact with them. In this paper we construct a prototype electromyography (EMG) sensing device that captures a single channel of EMG sensor data corresponding to user gestures. We also implement a machine learning pipeline to recognize gestural input received via our prototype sensing device. Our goal is to assess the feasibility of using a BITalino EMG sensor to recognize gestural input on a mobile health (mHealth) wearable device known as Amulet. We conduct three experiments in which we use the EMG sensor to collect gestural input data from (1) the wrist, (2) the forearm, and (3) the bicep. Our results show that a single channel EMG sensor located near the wrist may be a viable approach to reliably recognizing simple gestures without mistaking them for common daily activities such as drinking from a cup, walking, or talking while moving your arms

WatchTrace: Design and Evaluation of an At-Your-Side Gesture Paradigm

In this thesis, we present the exploration and evaluation of a gesture interaction paradigm performed with arms at rest at the side of one's body. This gesture stance is informed persisting challenges in mid-air arm gesture interactions in relation to fatigue and social acceptability. The proposed arms-down posture reduces physical effort by minimizing the shoulder torque placed on the user. While this interaction posture has been previously explored, the gesture vocabulary in previous research has been small and limited. The design of this gesture interaction is motivated by the ability to provide rich and expressive input; the user performs gestures by moving the whole arm at the side of the body to create two-dimensional visual traces, as in hand-drawing in a bounded plane parallel to the ground. Within this space, we present the results of two studies that investigate the use of side-gesture input for interaction. First, we explore the users' mental model for using this interaction by conducting an elicitation study on a set of everyday tasks one would perform on a large display in public to semi-public contexts. The takeaway from this study presents the need for a dynamic and expressive set of gesture vocabulary including ideographic and alphanumeric gesture constructs that can be combined or chained together. We then explore the feasibility of designing such a gesture recognition system using commodity hardware and recognition techniques, dubbed WatchTrace, which supports alphanumeric gestures of up to length three, providing a vibrant, dynamic, and feasible gestural vocabulary. Finally, we explore potential approaches to improve the recognition through the use of adaptive thresholds, n-best lists, and changing reject rates among other conventional techniques in the field of gesture classification

Smartwatch-based early gesture detection & trajectory tracking for interactive gesture-driven applications

Ministry of Education, Singapore under its Academic Research Funding Tier

On the role of gestures in human-robot interaction

This thesis investigates the gestural interaction problem and in particular the usage of gestures for human-robot interaction. The lack of a clear definition of the problem statement and a common terminology resulted in a fragmented field of research where building upon prior work is rare. The scope of the research presented in this thesis, therefore, consists in laying the foundation to help the community to build a more homogeneous research field. The main contributions of this thesis are twofold: (i) a taxonomy to define gestures; and (ii) an ingegneristic definition of the gestural interaction problem. The contributions resulted is a schema to represent the existing literature in a more organic way, helping future researchers to identify existing technologies and applications, also thanks to an extensive literature review. Furthermore, the defined problem has been studied in two of its specialization: (i) direct control and (ii) teaching of a robotic manipulator, which leads to the development of technological solutions for gesture sensing, detection and classification, which can possibly be applied to other contexts