Luc Geurts

KU Leuven | ku leuven · Faculty of Engineering Technology

Wearable activity trackers are routinely applied in physical activity (PA) interventions in late life, but there is little research that focuses on older adults' perspectives on the technology. We conducted a qualitative study with 24 older persons to explore their perspective on wearables and PA. First, we discussed their relationship with PA and...

BACKGROUND Emotions and mood are important for our overall well-being. The search for continuous, effortless emotion prediction methods is, therefore, an important field of study. Mobile sensing provides a promising tool and can capture one of the most telling signs of emotions: language. OBJECTIVE The aim of this study is to examine the separate...

Background: Emotions and mood are important for overall well-being. Therefore, the search for continuous, effortless emotion prediction methods is an important field of study. Mobile sensing provides a promising tool and can capture one of the most telling signs of emotion: language. Objective: The aim of this study is to examine the separate an...

Amongst the various characteristics of a speech signal, the expression of emotion is one of the characteristics that exhibits the slowest temporal dynamics. Hence, a performant speech emotion recognition (SER) system requires a predictive model that is capable of learning sufficiently long temporal dependencies in the analysed speech signal. Theref...

BACKGROUND Glaucoma, the “silent thief of sight”, is a major cause of blindness worldwide. It is a burden for people in low-income countries specifically, where it accounts for 15% of the total blindness. More than half of the people living with glaucoma in low-income countries, are unaware of their disease until it progresses to an advanced stage,...

Background: Glaucoma, the silent thief of sight, is a major cause of blindness worldwide. It is a burden for people in low-income countries, specifically countries where glaucoma-induced blindness accounts for 15% of the total incidence of blindness. More than half the people living with glaucoma in low-income countries are unaware of the disease...

Chronic arthritis (CA) represents a group of musculoskeletal diseases that require frequent physical therapy and a well-monitored medication regime to improve or maintain disease status. To support patients in this disease management, health apps may provide a solution. However, patients with CA differ in their disease trajectory, needs and prefere...

Physical activity (PA) positively impacts the quality of life of older adults, with technology as a promising factor in maintaining motivation. Within Computer Science and Engineering, research investigates how to track PA of older adults for various purposes. We present a systematic review of 204 papers and discuss wearable tracking systems accord...

Purpose The aim of this study is to compare the performance of Glaucoma Easy Screener (GES), as a low cost and portable visual field screening tool to the glaucoma screening test (GST) from Octopus. Methods GES is comprised of a Moto G5 smartphone, Homido v1 virtual reality headset and a gaming joystick for user input. The screening app’s design i...

Sailing Skweezee is a game that explores squeeze interaction in virtual reality. Squeezing a soft controller stuffed with conductive wool steers a virtual boat through a course on water. The game is played with an Oculus Rift headset and is developed in Unity. An open source Skweezee library for Unity implements the squeeze interaction. Sailing Skw...

In recent years there has been major growth in the use of gamification in education. It can be utilized to develop assignments or learning environments. Lots of studies have already proven the positive impact of introducing such tools to students. This paper examines how gamification techniques can be used in the electrical engineering course. It d...

This research introduces a toolkit for creating interactive ob- jects as a strategy to observe and discuss their construction and experience as scientific, artistic, and social subjects. Interac- tive technology as toolkit is presented to be senseware (Hara, 2009), following three specific trajectories in depth: the de- sign and programming of inte...

Squeeze interaction, defined as squeezing a soft object that affects computed feedback, is a promising interaction technique due to its expressive character. Skweezee for Processing is a Processing library that allows makers to implement squeeze interactions in a lightweight manner. The library offers a set of features based on data extraction algo...

BACKGROUND Breastfeeding has many benefits for newborns, mothers, and wider society. WHO recommends mothers to feed newborns exclusively with breastmilk for the first six months after birth but breastfeeding rates in many countries fail to align with the recommendations due to various barriers. Breastfeeding success is associated with a number of d...

Background: Breastfeeding has many benefits for newborns, mothers, and the wider society. The World Health Organization recommends mothers to feed newborns exclusively with breastmilk for the first 6 months after birth, but breastfeeding rates in many countries fail to align with the recommendations because of various barriers. Breastfeeding succe...

Breastfeeding is widely promoted due to its health benefits for infants, but breastfeeding rates in many industrialised countries are low, and some mothers struggle to establish a positive feeding relationship with their child. We draw from breastfeeding research along with a qualitative enquiry into the lived experiences of breastfeeding mothers t...

The Phonoloco technology allows to repurpose a set of regular smartphones into a system that allows for playful interactions. The most important feature of the proposed system is the use of the front-facing camera and a pattern on the ceiling in order to sense the position of each device lying on a flat surface at centimeter precision. This way eac...

BACKGROUND Patients with Chronic Arthritis (CA) ideally apply self-management behaviors between consultations. This enduring, tedious task of keeping track of disease-related parameters, adhering to medication schemes, and engaging in physical therapy might be supported by using an mHealth application. However, which self-management features are va...

Background Patients with chronic arthritis (CA) ideally apply self-management behaviors between consultations. This enduring, tedious task of keeping track of disease-related parameters, adhering to medication schemes, and engaging in physical therapy may be supported by using a mobile health (mHealth) app. However, further research is needed to de...

In a participatory design process, patients as well as care providers play a critical role in the design and development of healthcare apps. However, special attention should be given to problematic group dynamics that may arise from unequal power across participants. In this paper, we present Turning Tables, a focus group method, inspired by socia...

INTRODUCTION: Low income countries bear 90% of the burden of avoidable blindness. In particular, glaucoma is one of the major causes of visual impairment. Early detection is critical to avoid irreversible blindness due to this underdiagnoseddisease. Mobile and connected technologies yield potential to support early detection. However, to realize th...

Excessive uninterrupted sitting, also known as sedentary behavior, has been detrimentally associated with several health outcomes. However, the general population is often unaware of these health risks. Mobile phone technology offers great potential to increase awareness and to initiate behavior change. This study examined the short-term effects of...

With the rise in smartphones, many mobile health apps are released that are not grounded in theory [1]. Several theories that catalog persuasive and/or behavior change principles exist, however these theories are not adapted for mHealth apps. The principles or techniques cataloged in these theories are described and often interpreted in an additive...

Background Chronic arthritis (CA), an umbrella term for inflammatory rheumatic and other musculoskeletal diseases, is highly prevalent. Effective disease-modifying antirheumatic drugs for CA are available, with the exception of osteoarthritis, but require a long-term commitment of patients to comply with the medication regimen and management progra...

Skweezees are soft objects filled with conductive padding, which are capable of detecting different squeeze gestures using electrodes dispersed all over the object. This paper presents a case-study on the design and development of a tangible product based on the Skweezee system, namely a cushion remote. Squeeze-based gestures for soft user interfac...

This paper first presents a critical analysis of an existing game (APEX), designed by researchers in psychoacoustics only, to measure psychoacoustic thresholds in preschoolers. Next it presents another game (DIESEL-X), designed by dyslexia researchers and game designers, to remediate the shortcomings of the former game. Via a repeated measures expe...

We present an evaluation of a DIY-toolkit, designed to empower caregivers to create tailor-made, unique assistive solutions for their clients. More specifically, the toolkit aims to enable occupational therapists to turn everyday soft objects into smart devices that can be programmed to recognize certain manipulations. These smart objects can then...

Psychological experiments on visual attention are repetitive, and can become tedious for test participants. This is not only an unpleasant experience but can be harmful for the reliability of the results as well. In this study we investigated whether a game-based version of the Posner cueing test (measuring visual attention shifts) can provide a mo...

DIESEL-X is a computer game that was developed to detect a high risk for developing dyslexia in preschoolers. The game includes three mini-games that test the player on three skills that are considered to yield outcome measures that predict the onset of dyslexia: the detection threshold of frequency modulated tones, a test on phonological awareness...

In this paper we describe the design, development and testing of two computer games using Sifteo Cubes that help children to train their visual perspective taking (VPT) skills, i.e. the ability to see the world from another person's perspective. The challenge was to design an enjoyable and usable game that takes into account the huge variability in...

Skweezees are soft, deformable objects that recognize their shape deformation. Typically, a Skweezee has a fabric 'skin' and is filled with conductive padding. Several fabric electrodes are dispersed over the shape, and a small electronic circuit measures the resistance between each possible pair of electrodes. As the shape is deformed as a result...

Often, logging data while playing a game-based health application is of specific interest, not only to the players themselves, but equally to therapists, health counselors, coaches, researchers, etc. Therefore, designing and developing a health game on its own is not enough; one also needs to foresee a health game data management system (DMS). In t...

The Skweezee System is an easy, flexible and open system for designing and developing squeeze-based, gestural interactions. It consists of Skweezees, which are soft objects, filled with conductive padding, that can be deformed or squeezed by applying pressure. These objects contain a number of electrodes that are dispersed over the shape. The elect...

Over the past decades, preschoolers emerged as frequent and experienced users of new digital media. As this trend continues, it is important for game designers to address the gratifications of this new gaming audience. Unfortunately, existing theoretical frameworks on meaningful gameplay for preschoolers are rare, outdated, or they lack a comprehen...

A significant proportion of research in the field of human-computer interaction has been devoted to game design. Yet, a multitude of good ideas and enthusiastic game design initiatives exist, where the games never see the light of day. Unfortunately, the causes of these failures remain often unexplored and unpublished. The challenges faced by resea...

The goal of the DYSL-X project is to develop a tool to predict whether a preschooler (5 yrs) shows high risks for developing dyslexia. This tool is a tablet game that incorporates tests to take specific performance measures that allow for this prediction. The game will thus serve as an assessment tool to be used in school psychology services and cl...

Controlling computer games and other applications with motion-based gestures has become common in the last decade. In this paper we present a method to recognize relatively complex gestures with a simple, fast and yet reliable classifier algorithm. More specifically, the purpose of the classifier is to recognize large gestures, as measured with the...

We present the Boneshaker framework, a generic framework developed to facilitate the design of physical therapy games with the Unity 3D engine. The Boneshaker framework lowers the threshold for developing a variety of physical therapy games as it allows both developer and therapist to quickly add input devices and change specific game dynamics/ther...

In this paper we extend the field of organic user interfaces and introduce the Splash Controller. The main concept of a Splash Controller is that a user interacts with computing technology by manipulation of water in some kind of receptacle. To this end we highlight the possibilities of Splash Controllers, specifically as game controllers. Next, we...

While reconciling a creative game design process with a complex software engineering process is already a daunting task, serious games add another ingredient to an already volatile mixture: the challenge of crafting an effective learning experience. In order to achieve this strenuous objective, Group T’s e-Media Lab and the Centre for User Experien...

With the advent of computer games involving the movement of the player's whole body or body parts, an opportunity arises to develop games for people with motor disabilities. In this paper we present four minigames developed for people suffering from spasticity and loss of motor control. We thereby focus on the input devices, sensor signal processin...

In current cochlear implant systems, the fundamental frequency F0 of a complex sound is encoded by temporal fluctuations in the envelope of the electrical signals presented on the electrodes. In normal hearing, the lower harmonics of a complex sound are resolved, in contrast with a cochlear implant system. In the present study, it is investigated w...

In recent years many technical evolutions have been applied in hearing aids. In this paper differences between analog, programmable and fully digital hearing aids, the basic and supplementary functions of a hearing aid, and some important issues and future directions for digital hearing aids will be mentioned.

In this study the perception of the fundamental frequency (F0) of periodic stimuli by cochlear implant users is investigated. A widely used speech processor is the Continuous Interleaved Sampling (CIS) processor, for which the fundamental frequency appears as temporal fluctuations in the envelopes at the output. Three experiments with four users of...

APEX, an acronym for computer Application for Psycho-Electrical eXperiments, is a user friendly tool used to conduct psychophysical experiments and to investigate new speech coding algorithms with cochlear implant users. Most common psychophysical experiments can be easily programmed and all stimuli can be easily created without any knowledge of co...

Five post-lingually deafened users of the LAURA cochlear implant were presented with two trains of biphasic pulses applied concurrently to two widely separated channels. They could all discriminate between stimuli where pulses on the two channels were nearly synchronous (inter-channel delay=0.1 ms) and those where there was a longer delay applied t...

A new method to code the speech envelope in continuous interleaved sampling (CIS) processors for cochlear implants is proposed. In this enhanced envelope, the rapid adaptation seen in the response of auditory nerves to sound stimuli is incorporated. Two strategies, one using the standard envelope (CIS) and one using the enhanced envelope (EECIS), w...

Five post‐lingually deafened users of the LAURAflex cochlear implant detected temporal asynchronies between two 400‐ms, 100‐Hz trains of 40‐μs biphasic pulses, applied to two ‘‘target’’ electrode pairs. The pulses in the signal stimulus of each 2IFC trial were delayed by between 0.3 and 4.8 ms on either the basal or apical target, relative to those...

The status of speech processing for cochlear implants is reviewed. Points of interest to enhance further speech intelligibility based on improved signal processing, are discussed.

The purpose of the Spellbinder project is the development and the testing of a Brain Computer Interface, consisting of a diadem with electrodes to measure electroencephalogram signals, and several interactive computer programs, that allow the user to communicate with others through brainwaves, without using speech, facial expressions or other muscl...

With the advent of motion-based controllers, such as Nintendo's Wii remote, the online community has brought forth many libraries to connect such devices to a personal computer. In this paper we present a toolkit for the Wii MotionPlus, comprising of a calibration, a recording and a visualization tool. The purpose of the calibration tool is to calc...