Oliver Amft's research while affiliated with University of Freiburg and other places
What is this page?
This page lists the scientific contributions of an author, who either does not have a ResearchGate profile, or has not yet added these contributions to their profile.
It was automatically created by ResearchGate to create a record of this author's body of work. We create such pages to advance our goal of creating and maintaining the most comprehensive scientific repository possible. In doing so, we process publicly available (personal) data relating to the author as a member of the scientific community.
If you're a ResearchGate member, you can follow this page to keep up with this author's work.
If you are this author, and you don't want us to display this page anymore, please let us know.
It was automatically created by ResearchGate to create a record of this author's body of work. We create such pages to advance our goal of creating and maintaining the most comprehensive scientific repository possible. In doing so, we process publicly available (personal) data relating to the author as a member of the scientific community.
If you're a ResearchGate member, you can follow this page to keep up with this author's work.
If you are this author, and you don't want us to display this page anymore, please let us know.
Publications (232)
We analyse the influence of reflective photoplethysmography (PPG) sensor positioning relative to blood vessels. A voxel based Monte Carlo simulation framework was developed and validated to simulate photon-tissue interactions. An anatomical model comprising a multi-layer skin description with a blood vessel is presented to simulate PPG sensor posit...
Introduction/purpose:
Wearables that include a color light sensor are a promising measure of electronic screen use in adults. However, to extend this approach to children, we need to understand feasibility of wear placement. The purpose of this study was to examine parent perceptions of children's acceptability of different sensor placements and f...
Monitoring dietary intake is essential to providing user feedback and achieving a healthier lifestyle. In the past, different approaches for monitoring dietary behavior have been proposed. In this position paper, we first present an overview of the state-of-the-art techniques grouped by image- and sensor-based approaches. After that, we introduce a...
Due to formal academic regulations, the affiliation of the university has been amended, and an “Acknowledgements” section has been added to the original publication [...]
We propose a novel knowledge extraction method based on Bayesian-inspired association rule mining to classify anxiety in heterogeneous, routinely collected data from 9,924 palliative patients. The method extracts association rules mined using lift and local support as selection criteria. The extracted rules are used to assess the maximum evidence s...
Much has changed in the landscape of wearables research since the first International Symposium on Wearable Computers (ISWC) was organized in 1997. The authors, many of whom were active in this community since the beginning, reflect now 25 years later on the role of the conference, emerging research methods, the devices, and ideas that have stood t...
This paper investigates a context-adaptive sample acquisition strategy at sub-Nyquist sampling rate for wearable embedded sensor devices. Our approach can be applied to compressive sensing frameworks to minimise sampling and transmission costs. We consider a context estimate to represent the local signal structure and a feed-forward response model...
The TELECOVID study (https://www.telecovid.de) is designed to remotely monitor the physiological health status of COVID-19 positive-risk patients in home isolation. Key vital parameters are measured day and night using an in-ear biosensor technology. These data are streamed to the clinic in real time to enable timely interaction in case of deterior...
Presents information on the ISWC 2020 Conference.
Differences in contact impedance of the ECG measurement electrodes lead to asymmetries of the signal paths and thus result in reduced common-mode rejection and artifacts. Here, the imbalance of contact impedance is investigated for
different types of electrodes with capacitive coupling in terms of static imbalance as well as dynamic variation durin...
Differences in contact impedance of the ECG measurement electrodes lead to asymmetries of the signal paths and thus result in reduced common-mode rejection and artifacts. Here, the imbalance of contact impedance is investigated for
different types of electrodes with capacitive coupling in terms of static imbalance as well as dynamic variation durin...
Differences in contact impedance of the ECG measurement electrodes lead to asymmetries of the signal paths and thus result in reduced common-mode rejection and artifacts. Here, the imbalance of contact impedance is investigated for
different types of electrodes with capacitive coupling in terms of static imbalance as well as dynamic variation durin...
We propose three novel digital biomarkers for the longitudinal performance monitoring and movement evaluation of hemiparetic patients, e.g. after stroke. We devised convergence points (CP) for the bilateral walking analysis based on gait parameters, e.g. stride duration using regression- modelling to estimate similarity between body sides. The phys...
THE NEW CORONAVIRUS pandemic has promoted the new development of mobile and wearable computing in unprecedented ways. We discuss how on-body devices can help to fight the pandemic and may stay as a toolset to effectively deal with infectious diseases in the future. WHY WEARABLES? Researchers and health policy managers turned to smartphones and on-b...
We describe a simulation-based Design Space Exploration procedure (DynDSE) for wearable IoT edge devices that retrieve events from streaming sensor data using context-adaptive pattern recognition algorithms. We provide a formal characterisation of the design space, given a set of system functionalities, components and their parameters. An iterative...
The articles in this special section focus on personalized pervasive health. For over more than two decades, mobile, wearable, and ambient sensor and interaction devices have grown into today’s plethora of computing platforms and tools for pervasive health. Pervasive computing is now assimilating into medicine, from disease risk prevention to diagn...
We present a fundamentally new approach to design and assess wearable motion systems based on biomechanical simulation and sensor data synthesis. We devise a methodology of personal biomechanical models and virtually attach sensor models to body parts, including sensor positions frequently considered for wearable devices. The simulation enables us...
Day to day interactions with wearable and pervasive systems lead to collected data that capture various aspects of human behavior and enable machine learning algorithms to extract extensive information about users. We discuss privacy risk awareness, and ways to preserve privacy and integrate it in current frameworks.
BACKGROUND
Mobile Health (mHealth) defines the support and practice of health care using mobile devices and promises to improve the current treatment situation of patients with chronic diseases. Little is known about mHealth usage and digital preferences of patients with chronic rheumatic diseases (RMD).
OBJECTIVE
To explore mHealth usage, eHealth...
Background:
Mobile Health (mHealth) defines the support and practice of health care using mobile devices and promises to improve the current treatment situation of patients with chronic diseases. Little is known about mHealth usage and digital preferences of patients with chronic rheumatic diseases (RMD).
Objective:
To explore mHealth usage, pre...
In this article, we provide a concise overview on how the skills and dexterity of our upper and lower limbs, acquired and trained in interacting with the physical world, can be transferred to the interaction with HMD. We present the vision of around-body interaction, in which we use the space around our body, defined by the reach of our limbs, for...
We present an eating detection algorithm for wearable sensors based on first detecting chewing cycles and subsequently estimating eating phases. We term the corresponding algorithm class as a bottom-up approach. We evaluated the algorithm using electromyographic (EMG) recordings from diet-monitoring eyeglasses in free-living and compared the bottom...
The International Symposium on Wearable Computers (ISWC) has been the leading research venue for wearable technology research since 1997. In 2019, the 23rd ISWC was held in London, U.K., from Sep. 9th–13th. Following on the last eight years of successful collaboration, ISWC was colocated with the 2019 ACM International Joint Conference on Pervasive...
In this paper, we introduce the increasing belief criterion in association rule mining. The criterion uses a recursive application of Bayes' theorem to compute a rule's belief. Extracted rules are required to have their belief increase with their last observation. We extend the taxonomy of association rule mining algorithms with a new branch for Ba...
Multiprocess Additive Manufacturing (AM) offers system designers new, exciting computational tools to rapidly realise smart wearable sensing devices in two-dimensional (2D) and 3D shapes. We guide readers through the novel development and fabrication process based on a digital co-design framework and highlight AM techniques, functional materials, a...
We recently had the pleasure of interviewing researchers in electronics and materials for pervasive systems, as well as researchers, practitioners, and digital tool builders in crafts such as music and food. We have separated the conversations into two interview digests. The first highlights important topics for future research in pervasive systems...
Electronic miniaturization has driven pervasive computing for decades. With the rapid progress of digital manufacturing however, new tools and methods are maturing that enrich the possibilities for ambient and wearable system design. While miniaturized technology remains a key feature, now pervasive system designers work holistically across enginee...
Animation: Wolfgang Rheindt .
Graphics: Michael Noack.
This work has been partially funded by the EU H2020 MSCA ITN ACROSSING project (GA no. 616757) and by the Chair of Digital Health at Friedrich-Alexander-Universität Erlangen-Nürnberg.
This paper presents an attention-based adaptive sampling for EMG-data streams. Our sampling strategy is based on dynamically tuning the duty cycle of an EMG monitoring and recognition system. A proportional forward response model was used to keep a high sampling rate in case of potential target patterns. The adaptive behaviour of the response model...
We propose a motion sensor data synthesis approach to investigate the performance effect of sensor placement and orientation variation on health marker estimation. Using OpenSim, we simulate walking motion of patients after stroke and synthesise inertial sensor data. We analyse 384 sensor positions with 192 sensors simulated at each leg's thigh. To...
Reports on major events and exhibitions that were part of the 2018 ACM International Symposium on Wearable Computers (ISWC) in Singapore in October 2018.
We design and 3D print conductive lines and EMG electrodes on eyeglasses temples. We evaluate the electrical property and the EMG signal quality of the printed components and report line resistance, electrode surface resistance, and EMG signal quality. We found that the signal quality is comparable to non-printed lines and electrodes. Our work show...
Background: Physical activity (PA) is essential in stroke rehabilitation of hemiparetic patients to avoid health risks, and moderate to vigorous PA could promote patients' recovery. However, PA assessments are limited to clinical environments. Little is known about PA in unguided free-living. Wearable sensors could reveal patients' PA during rehabi...
We present a sleep timing estimation approach that combines data-driven estimators with an expert model and uses smartphone context data. Our data-driven methodology comprises a classifier trained on features from smartphone sensors. Another classifier uses time as input. Expert knowledge is incorporated via the human circadian and homeostatic two...
Background: Longitudinal movement parameter analysis of hemiparetic patients over several months could reveal potential recovery trends and help clinicians adapting therapy strategies to maximize recovery outcome. Wearable sensors offer potential for day-long movement recordings in realistic rehabilitation settings including activities of daily liv...
In this work, we use data acquired longitudinally, in free-living, to provide accurate estimates of running performance. In particular, we used the HRV4Training app and integrated APIs (e.g. Strava and TrainingPeaks) to acquire different sets of parameters, either via user input, morning measurements of resting physiology, or running workouts to es...
This chapter provides an introduction to the field of automatic dietary monitoring (ADM) that intends to derive diet-related behaviour information from unobtrusive sensors and data analysis algorithms. A conceptual gap found in most literature reviews on the relation of physiology and dietary activities is filled. A consistent knowledge-based physi...
Wearable computing enables more personalized healthcare through a distributed information sharing model that puts patients and users rather than providers, insurers, and other industry stakeholders at the center. It also fosters the creation of new health knowledge and more effective prevention and treatment techniques by integrating vital-sign dat...
With wearable computing research recently passing the 20-year mark, this survey looks back at how the field developed and explores where it’s headed. According to the authors, wearable computing is entering its most exciting phase yet, as it transitions from demonstrations to the creation of sustained markets and industries, which in turn should dr...
Screen use can influence the circadian phase and cause eye strain. Smart eyeglasses with an integrated color light sensor can detect screen use. We present a screen use detection approach based on a light sensor embedded into the bridge of smart eyeglasses. By calculating the light intensity at the user's eyes for different screens and content type...
We propose to 3D-print personal fitted, regular-look smart eyeglasses frames equipped with bilateral Electromyography (EMG) recording to monitor Temporalis muscles' activity for automatic dietary monitoring. Personal fitting supported electrode-skin contact at temple ear bend and temple end positions. We evaluated the smart monitoring eyeglasses du...
We described physical activity measures and hourly patterns in patients with chronic obstructive pulmonary disease (COPD) after stratification for generic and COPD-specific characteristics and, based on multiple physical activity measures, we identified clusters of patients. In total, 1001 patients with COPD (65% men; age, 67 years; forced expirato...
This chapter introduces fundamental concepts related to wearable computing, smart textiles, and context awareness. The history of wearable computing is summarized to illustrate the current state of smart textile and garment research. Subsequently, the process to build smart textiles from fabric production, sensor and actuator integration, contactin...
Textiles are pervasive in our life, covering human body and objects, as well as serving in industrial applications. In its everyday use of individuals, smart textile becomes a promising medium for monitoring, information retrieval, and interaction. While there are many applications in sport, health care, and industry, the state-of-the-art smart tex...
Personalized 3D-printed eyeglasses equipped with sensing functions can enhance daily life through augmenting applications that enable wearers to monitor their vitals and behavior.
In this work, we propose to use anthropometrics and physiological data to estimate cardiorespiratory fitness (CRF) in free-living and analyze the relation between estimated CRF and running performance. In particular, we use the ratio between running speed and heart rate (HR) as predictor for CRF estimation in free-living. The ratio is representativ...
From a holistic perspective, this handbook explores the design, development and production of smart textiles and textile electronics, breaking with the traditional silo-structure of smart textile research and development.
Leading experts from different domains including textile production, electrical engineering, interaction design and human-compu...
We present an approach to infer relative position and orientation of ubiquitous building-installed low-resolution spatial sensors using real-life measurements. Commercial buildings accumulate a "zoo" of heterogeneous devices, as new generations of sensors and emerging modalities become available. The increasing number of building sensors pose chall...
Ideally, building devices should be installed in a set-and-forget manner with minimum device configuration. In practice however, the correct interaction between all devices must be assured in order for the building to function properly, e.g., each motion detector has to be associated to the correct ceiling lamps. Currently, the initial commissionin...
We monitor chewing using 3D-printed eyeglasses with surface Electromyography (EMG) and skull vibration sensors integrated at the eyeglasses frame. We demonstrate the feasibility of recording chewing of different foods using the prototype. Users can explore the effect on EMG and vibration when chewing different food samples, e.g. apples, potato chip...
We investigate a generic fabric material as basis for resistive pressure and bio-impedance sensors and apply the fabric in a shirt collar for swallowing spotting. A pilot study confirmed the signal performance of both sensor types.
We monitor chewing using 3D-printed smart eyeglasses with Electromyography (EMG) electrodes and bone vibration sensors attached at the eyeglasses frame. We recorded intake of different foods and non-chewing activities and analysed signal waveforms and signal performance. Our prototype showed promising results towards detecting chewing and compensat...
We describe an approach to support athletes at various fitness levels in their training load analysis using heart rate (HR) and heart rate variability (HRV). A smartphone-based application (HRV4Training) was developed that captures heart activity over one to five minutes using photoplethysmography (PPG) and derives HR and HRV features. HRV4Training...
We describe an approach to support athletes at various fitness levels in their training load analysis using heart rate (HR) and heart rate variability (HRV). A smartphone-based application (HRV4Training) was developed that captures heart activity over one to five minutes using photoplethysmog-raphy (PPG) and derives HR and HRV features. HRV4Trainin...
Introduction
Les capteurs portables sont des instruments prometteurs pour contrôler certains mouvements du patient pendant les exercices et le quotidien ainsi que pour interpréter en continu son état et ses tendances de récupération. La recherche a également démontré que les scores d’évaluation clinique des fonctions motrices (Wolf-Motor Function p...
We present and evaluate measurement fusion and decision fusion for recognising apnea and periodic limb movement in sleep episodes. We used an in-bed sensor system composed of an array of strain gauges to detect pressure changes corresponding to respiration and body movement. The sensor system was placed under the bed mattress during sleep and conti...
Altini M, Casale P, Penders J, ten Velde G, Plasqui G, Amft O. Cardiorespiratory fitness estimation using wearable sensors: Laboratory and free-living analysis of context-specific submaximal heart rates..—In this work, we propose to use pattern recognition methods to determine submaximal heart rate (HR) during specific contexts, such as walking at...
Objective:
In this paper we propose artificial intelligence methods to estimate cardiorespiratory fitness (CRF) in free-living using wearable sensor data.
Methods:
Our methods rely on a computational framework able to contextualize heart rate (HR) in free-living, and use context-specific HR as predictor of CRF without need for laboratory tests....
In this work, we propose to use pattern recognition methods to determine submaximal heart rate (HR) during specific contexts, such as walking at a certain speed, using wearable sensors in free-living, and use context-specific HR to estimate cardiorespiratory fitness (CRF). CRF of 51 participants was assessed by a maximal exertion test (VO2max). Par...
In this article, the authors investigate a new source of information for dietary monitoring: pressure distribution on the surface underneath dining plates. Pressure sensing has been used to consider the weight of the eaten food. The core idea behind their work is that dynamic pressure information can also be used to distinguish between various cutl...
We present a framework to relate variables as they occur in a modern building management system (BMS) that processes data from building-installed sensor and actuators. Our group mining framework extracts a unified event time series as changes in building management variables, derives prepositional variable association rules, and extracts hierarchic...
We extend regular eyeglasses with multi-modal sensing and processing functions for context awareness. Our aim was to leverage eyeglasses as a platform to acquire and process context information according to the wearer's needs. The eyeglasses provide inertial motion, environmental light, and pulse sensors, data processing and wireless functionality,...
Smart textiles have been researched in the lab over the last 20 years. However, the gap between research and available mass-market products is huge. We identify challenges that are the core reasons for this gap. To tackle these challenges, we present our work towards a multipurpose smart textile with different sensing modalities. It separates the c...
We investigated how regular eyeglasses fitted with sensing and processing capabilities can be used as a wearable game controller. For this purpose we built a demo based on our smart eyeglasses prototype. WISEglass allows the wearer to control the game Pac-Man through head motions. The control signals are extracted from a gyroscope mounted in the te...
We estimate the Extended Barthel Index (EBI) in patients after stroke using inertial sensor measurements acquired during daily activity, rather than specific assessments. The EBI is a standard clinical assessment showing patient independence in handling everyday tasks. Our work aims at providing a continuous ability estimate for patients and therap...
We present a novel sensor system for the support of nutrition monitoring. The system is based on smart table cloth equipped with a fine grained pressure textile matrix and a weight sensitive tablet. Unlike many other nutrition monitoring approaches, our system is unobtrusive, non privacy invasive and easily deployable in every day life. It allows t...
We introduce a hierarchical nonparametric topic modeling approach to infer activity routines from context sensor data streams based on a distance dependent Chinese restaurant process (ddCRP). Our approach does not require labeled data at any stage. Neither does our approach depend on time-invariant sliding windows to sample context word statistics....
The authors discuss the vast application potential of multipurpose smart eyeglasses that integrate into the form factor of traditional spectacles and provide frequently needed sensing and interaction. In combination with software apps running on smart eyeglasses, the authors develop universal assistance systems that remain unobtrusive and thus can...
Ubiquitous body-worn sensors and mobile devices have extensive applications in health monitoring and user guidance when combined with advanced algorithms. This special issue includes 13 papers, presenting novel approaches and trends in both sensor integration and data processing algorithms. It features some of the best papers from the International...