scholarly journals EyeLoop: An Open-Source System for High-Speed, Closed-Loop Eye-Tracking

2021 ◽  
Vol 15 ◽  
Author(s):  
Simon Arvin ◽  
Rune Nguyen Rasmussen ◽  
Keisuke Yonehara
Keyword(s):  
Eye Tracking ◽  
Open Source ◽  
High Speed ◽  
Closed Loop ◽  
Low Cost ◽  
Open Loop ◽  
Eye Tracker ◽  
High Resource ◽  
Real Time Analysis ◽  
Loop Design

Eye-trackers are widely used to study nervous system dynamics and neuropathology. Despite this broad utility, eye-tracking remains expensive, hardware-intensive, and proprietary, limiting its use to high-resource facilities. It also does not easily allow for real-time analysis and closed-loop design to link eye movements to neural activity. To address these issues, we developed an open-source eye-tracker – EyeLoop – that uses a highly efficient vectorized pupil detection method to provide uninterrupted tracking and fast online analysis with high accuracy on par with popular eye tracking modules, such as DeepLabCut. This Python-based software easily integrates custom functions using code modules, tracks a multitude of eyes, including in rodents, humans, and non-human primates, and operates at more than 1,000 frames per second on consumer-grade hardware. In this paper, we demonstrate EyeLoop’s utility in an open-loop experiment and in biomedical disease identification, two common applications of eye-tracking. With a remarkably low cost and minimum setup steps, EyeLoop makes high-speed eye-tracking widely accessible.

scholarly journals EyeLoop: An open-source, high-speed eye-tracker designed for dynamic experiments

2020 ◽  
Author(s):  
Simon Arvin ◽  
Rune Rasmussen ◽  
Keisuke Yonehara
Keyword(s):  
Eye Tracking ◽  
Open Source ◽  
High Speed ◽  
Closed Loop ◽  
Tracking System ◽  
Open Loop ◽  
Eye Tracker ◽  
High Resource ◽  
Dynamic Experiments ◽  
Post Hoc

AbstractEye-tracking is a method for tracking the position of the eye and size of the pupil, often employed in neuroscience laboratories and clinics. Eye-trackers are widely used, from studying brain dynamics to investigating neuropathology and disease models. Despite this broad utility, eye-trackers are expensive, hardware-intensive, and proprietary, which have limited this approach to high-resource facilities. Besides, experiments have largely been confined to static open-loop designs and post hoc analysis due to the inflexibility of current systems. Here, we developed an open-source eye-tracking system, named EyeLoop, tailored to dynamic experiments. This Python-based software easily integrates custom functions via a modular logic, tracks a multitude of eyes, including rodent, human, and non-human primate eyes, and it operates well on inexpensive consumer-grade hardware. One of the most appealing applications of EyeLoop is closed-loop experiments, in which the eyes evoke stimulus feedback, such as rapid neuronal optogenetic stimulation. By using EyeLoop, we demonstrate its utility in an open-loop, a closed-loop, and a biomedical experiment. With a remarkably low minimal hardware cost amounting to 29 USD, EyeLoop makes dynamic eye-tracking accessible to low-resource facilities, such as high schools, small laboratories, and small clinics.

scholarly journals A Fast and Effective System for Analysis of Optokinetic Waveforms with a Low-Cost Eye Tracking Device

Healthcare ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 10
Author(s):  
Chong-Bin Tsai ◽  
Wei-Yu Hung ◽  
Wei-Yen Hsu
Keyword(s):  
Eye Movements ◽  
Eye Tracking ◽  
Eye Movement ◽  
Low Cost ◽  
Saccadic Eye Movements ◽  
Slow Phase ◽  
Eye Tracker ◽  
Effective System ◽  
Tracking Device ◽  
Traditional Approaches

Optokinetic nystagmus (OKN) is an involuntary eye movement induced by motion of a large proportion of the visual field. It consists of a “slow phase (SP)” with eye movements in the same direction as the movement of the pattern and a “fast phase (FP)” with saccadic eye movements in the opposite direction. Study of OKN can reveal valuable information in ophthalmology, neurology and psychology. However, the current commercially available high-resolution and research-grade eye tracker is usually expensive. Methods & Results: We developed a novel fast and effective system combined with a low-cost eye tracking device to accurately quantitatively measure OKN eye movement. Conclusions: The experimental results indicate that the proposed method achieves fast and promising results in comparisons with several traditional approaches.

scholarly journals The Modelling, Simulation and FPGA-Based Implementation for Stepper Motor Wide Range Speed Closed-Loop Drive System Design

Machines ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 56 ◽  
Author(s):  
Chiu-Keng Lai ◽  
Jhang-Shan Ciou ◽  
Chia-Che Tsai
Keyword(s):  
Embedded System ◽  
High Speed ◽  
Closed Loop ◽  
Open Loop ◽  
Drive System ◽  
Stepper Motor ◽  
Motor Drive ◽  
Digital Controllers ◽  
Loop Control ◽  
Wide Range

Owing to the benefits of programmable and parallel processing of field programmable gate arrays (FPGAs), they have been widely used for the realization of digital controllers and motor drive systems. Furthermore, they can be used to integrate several functions as an embedded system. In this paper, based on Matrix Laboratory (Matlab)/Simulink and the FPGA chip, we design and implement a stepper motor drive. Generally, motion control systems driven by a stepper motor can be in open-loop or closed-loop form, and pulse generators are used to generate a series of pulse commands, according to the desired acceleration/run/deceleration, in order to the drive system to rotate the motor. In this paper, the speed and position are designed in closed-loop control, and a vector control strategy is applied to the obtained rotor angle to regulate the phase current of the stepper motor to achieve the performance of operating it in low, medium, and high speed situations. The results of simulations and practical experiments based on the FPGA implemented control system are given to show the performances for wide range speed control.

Modeling and Analysis for Thermal Control of Spindles for Reconfigurable Machines

2001 ◽  
Author(s):  
Jeffrey L. Stein ◽  
John E. Harder
Keyword(s):  
High Speed ◽  
Metal Cutting ◽  
Closed Loop ◽  
Dynamic Performance ◽  
Thermal Control ◽  
Open Loop ◽  
Limiting Factor ◽  
Process Conditions ◽  
Bearing Load ◽  
Bearing Loads

Abstract Control of thermally induced bearing loads remains an important but unsolved problem for precision, high-speed, metal cutting, machining spindles. Spindle dynamic performance, as well as spindle life, depends on bearing loads. Because these loads can change drastically with a change in process conditions, poor spindle dynamic performance, and dramatically reduced bearing life can result. The purpose of this paper is to evaluate the feasibility of controlling bearing loads by controlling the heat generated by a thermal actuator placed around the housing of the spindle. A mathematical model of the open loop response of a laboratory prototype spindle is developed and validated. The model is then used to evaluate the closed loop performance. The results show that closed loop control of the bearing load is achievable in steady state and under bandwidth limited transient conditions. The proposed system has reasonable command authority when additional heat is required, however, it is possible for the system to lose control when the heater is required to “provide” negative heat. This situation can be mitigated by proper choice of initial preload. As expected, measurement noise limits the control gain but is not a limiting factor. More open loop tests are suggested to validate the model under a broader set of conditions. In addition, closed loop validation is suggested. However, based on results obtained it appears bearing load control is achievable by controlling the thermal field around the spindle.

scholarly journals SnakeStrike: A Low-Cost Open-Source High-Speed Multi-Camera Motion Capture System

2020 ◽  
Vol 14 ◽  
Author(s):  
Grady W. Jensen ◽  
Patrick van der Smagt ◽  
Egon Heiss ◽  
Hans Straka ◽  
Tobias Kohl
Keyword(s):  
Open Source ◽  
Motion Capture ◽  
High Speed ◽  
Low Cost ◽  
Camera Motion ◽  
Motion Capture System

scholarly journals Eye-tracking Analysis of Interactive 3D Geovisualization

2017 ◽  
Vol 10 (3) ◽  
Author(s):  
Lukas Herman ◽  
Stanislav Popelka ◽  
Vendula Hejlova
Keyword(s):  
Eye Tracking ◽  
Low Cost ◽  
3D Models ◽  
Main Function ◽  
Eye Tracker ◽  
Virtual Camera ◽  
Interactive 3D Models ◽  
Interactive 3D ◽  
3D Scene

This paper describes a new tool for eye-tracking data and their analysis with the use of interactive 3D models. This tool helps to analyse interactive 3D models easier than by time-consuming, frame-by-frame investigation of captured screen recordings with superimposed scanpaths. The main function of this tool, called 3DgazeR, is to calculate 3D coordinates (X, Y, Z coordinates of the 3D scene) for individual points of view. These 3D coordinates can be calculated from the values of the position and orientation of a virtual camera and the 2D coordinates of the gaze upon the screen. The functionality of 3DgazeR is introduced in a case study example using Digital Elevation Models as stimuli. The purpose of the case study was to verify the functionality of the tool and discover the most suitable visualization methods for geographic 3D models. Five selected methods are presented in the results section of the paper. Most of the output was created in a Geographic Information System. 3DgazeR works with generic CSV files, SMI eye-tracker, and the low-cost EyeTribe tracker connected with open source application OGAMA. It can compute 3D coordinates from raw data and fixations.

scholarly journals Open source modules for tracking animal behavior and closed-loop stimulation based on Open Ephys and Bonsai

2018 ◽  
Author(s):  
Alessio Paolo Buccino ◽  
Mikkel Elle Lepperød ◽  
Svenn-Arne Dragly ◽  
Philipp Häfliger ◽  
Marianne Fyhn ◽  
...  
Keyword(s):  
Open Source ◽  
Real Time ◽  
Closed Loop ◽  
Low Cost ◽  
Data Formats ◽  
Behavioral Tracking ◽  
Real Time Tracking ◽  
Set Up ◽  
And Behavior ◽  
Closed Loop Stimulation

AbstractObjectiveA major goal in systems neuroscience is to determine the causal relationship between neural activity and behavior. To this end, methods that combine monitoring neural activity, behavioral tracking, and targeted manipulation of neurons in closed-loop are powerful tools. However, commercial systems that allow these types of experiments are usually expensive and rely on non-standardized data formats and proprietary software which may hinder user-modifications for specific needs. In order to promote reproducibility and data-sharing in science, transparent software and standardized data formats are an advantage. Here, we present an open source, low-cost, adaptable, and easy to set-up system for combined behavioral tracking, electrophysiology and closed-loop stimulation.ApproachBased on the Open Ephys system (www.open-ephys.org) we developed multiple modules to include real-time tracking and behavior-based closed-loop stimulation. We describe the equipment and provide a step-by-step guide to set up the system. Combining the open source software Bonsai (bonsai-rx.org) for analyzing camera images in real time with the newly developed modules in Open Ephys, we acquire position information, visualize tracking, and perform tracking-based closed-loop stimulation experiments. To analyze the acquired data we provide an open source file reading package in Python.Main resultsThe system robustly visualizes real-time tracking and reliably recovers tracking information recorded from a range of sampling frequencies (30-1000Hz). We combined electrophysiology with the newly-developed tracking modules in Open Ephys to record place cell and grid cell activity in the hippocampus and in the medial entorhinal cortex, respectively. Moreover, we present a case in which we used the system for closed-loop optogenetic stimulation of entorhinal grid cells.SignificanceExpanding the Open Ephys system to include animal tracking and behavior-based closed-loop stimulation extends the availability of high-quality, low-cost experimental setup within standardized data formats serving the neuroscience community.

scholarly journals Student’s Reading of Thematic Maps from Czech School World Atlas – an Eye-tracking Study

2020 ◽  
Vol 2 ◽  
pp. 1-1
Author(s):  
Marketa Beitlova ◽  
Stanislav Popelka ◽  
Vit Vozenilek
Keyword(s):  
Eye Tracking ◽  
Low Cost ◽  
Research Question ◽  
Empirical Studies ◽  
Eye Tracker ◽  
Thematic Maps ◽  
School Students ◽  
Trial Duration ◽  
Cartographic Visualization ◽  
The One

Abstract. According to the cartographic communication models, the map is intended as a product which helps people to understand the world. Usually, the first systematic cartographic product which pupils and students met in their lives is a school world atlas. In the Czech Republic, these atlases are used in almost every geography lesson. Thus, school atlases should be understandable, well-arranged, intelligible and easy to use by students. However, almost no empirical studies focused on this type of product exist.This presentation summarizes the results of the experiment, where the task was to find some object on the thematic map. The research aimed on two main issues: if the students are able to read thematic maps from school world atlas (Q1) and if the used cartographic visualization methods are properly selected (Q2).For finding answers to these research questions, the eye-tracking study conducted on 30 grammar school students was performed. This study contained ten tasks on the thematic world maps from the Czech school world atlas. Depending on the type of information displayed, visualization method and legend style, the tasks were formulated for each map. Eyemovement data were recorded using low-cost GazePoint eye-tracker with sampling frequency of 60 Hz. The first research question – if students can work with the thematic maps from school world atlas – was analysed using the correctness of answers and Trial Duration – the metric that shows how much time respondents needed to find the answer. For answering the second research question – if the cartographic methods used in the atlas are understandable –qualitative data visualization methods were used.At the beginning of the recorded data analysis, the correctness of answers and trial duration was ïnvestigated. These results helped us to find out, how the students were able to read the maps, if their answers were correct and how much time they needed for task solving. The results showed that generally, the students could read thematic maps (Q1). The most problematic task was the one where students had to estimate the pie-chart value according to the logarithmic scale.In the next step, the behaviour of students while solving each task was qualitatively described and problematic cartographic visualization methods were identified (Q2). For example, in some cases, used symbols were difficult to distinguish. The most serious problems were in the task, where students had to estimate the value of the bar chart. The scale of the legend was designed so that one millimetre of the bar corresponds to 50 million USD of export volume. This cartographic method was hard to understand for the students.The conducted eye-tracking study pointed out to maps where the cartographic methods were misused and caused problems to the students. The results might help the cartographers and map publishers who can modify the maps to be more understandable for the readers.

scholarly journals Piezoelectric MEMS Resonators for Cigarette Particle Detection

Micromachines ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 145 ◽  
Author(s):  
Javier Toledo ◽  
Víctor Ruiz-Díez ◽  
Maik Bertke ◽  
Hutomo Suryo Wasisto ◽  
Erwin Peiner ◽  
...  
Keyword(s):  
Resonance Frequency ◽  
Closed Loop ◽  
Low Cost ◽  
Open Loop ◽  
Piezoelectric Resonator ◽  
Particle Detection ◽  
Interface Circuit ◽  
Mems Resonators ◽  
Loading Effects ◽  
Working Principle

In this work, we demonstrate the potential of a piezoelectric resonator for developing a low-cost sensor system to detect microscopic particles in real-time, which can be present in a wide variety of environments and workplaces. The sensor working principle is based on the resonance frequency shift caused by particles collected on the resonator surface. To test the sensor sensitivity obtained from mass-loading effects, an Aluminum Nitride-based piezoelectric resonator was exposed to cigarette particles in a sealed chamber. In order to determine the resonance parameters of interest, an interface circuit was implemented and included within both open-loop and closed-loop schemes for comparison. The system was capable of tracking the resonance frequency with a mass sensitivity of 8.8 Hz/ng. Although the tests shown here were proven by collecting particles from a cigarette, the results obtained in this application may have interest and can be extended towards other applications, such as monitoring of nanoparticles in a workplace environment.

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