19 research outputs found

    Improvements in Remote Cardiopulmonary Measurement Using a Five Band Digital Camera

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    Remote measurement of the blood volume pulse via photoplethysmography (PPG) using digital cameras and ambient light has great potential for healthcare and affective computing. However, traditional RGB cameras have limited frequency resolution. We present results of PPG measurements from a novel five band camera and show that alternate frequency bands, in particular an orange band, allowed physiological measurements much more highly correlated with an FDA approved contact PPG sensor. In a study with participants (n = 10) at rest and under stress, correlations of over 0.92 (p <; 0.01) were obtained for heart rate, breathing rate, and heart rate variability measurements. In addition, the remotely measured heart rate variability spectrograms closely matched those from the contact approach. The best results were obtained using a combination of cyan, green, and orange (CGO) bands; incorporating red and blue channel observations did not improve performance. In short, RGB is not optimal for this problem: CGO is better. Incorporating alternative color channel sensors should not increase the cost of such cameras dramatically

    BioWatch: Estimation of Heart and Breathing Rates from Wrist Motions

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    Continued developments of sensor technology including hardware miniaturization and increased sensitivity have enabled the development of less intrusive methods to monitor physiological parameters during daily life. In this work, we present methods to recover cardiac and respiratory parameters using accelerometer and gyroscope sensors on the wrist. We demonstrate accurate measurements in a controlled laboratory study where participants (n = 12) held three different positions (standing up, sitting down and lying down) under relaxed and aroused conditions. In particular, we show it is possible to achieve a mean absolute error of 1.27 beats per minute (STD: 3.37) for heart rate and 0.38 breaths per minute (STD: 1.19) for breathing rate when comparing performance with FDA-cleared sensors. Furthermore, we show comparable performance with a state-of-the-art wrist-worn heart rate monitor, and when monitoring heart rate of three individuals during two consecutive nights of in-situ sleep measurements.National Science Foundation (U.S.) (CCF-1029585)Samsung (Firm). Think Tank TeamMIT Media Lab Consortiu

    Crowdsourced data collection of facial responses

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    In the past, collecting data to train facial expression and affect recognition systems has been time consuming and often led to data that do not include spontaneous expressions. We present the first crowdsourced data collection of dynamic, natural and spontaneous facial responses as viewers watch media online. This system allowed a corpus of 3,268 videos to be collected in under two months. We characterize the data in terms of viewer demographics, position, scale, pose and movement of the viewer within the frame, and illumination of the facial region. We compare statistics from this corpus to those from the CK+ and MMI databases and show that distributions of position, scale, pose, movement and luminance of the facial region are significantly different from those represented in these datasets. We demonstrate that it is possible to efficiently collect massive amounts of ecologically valid responses, to known stimuli, from a diverse population using such a system. In addition facial feature points within the videos can be tracked for over 90% of the frames. These responses were collected without need for scheduling, payment or recruitment. Finally, we describe a subset of data (over 290 videos) that will be available for the research community.Things That Think ConsortiumProcter & Gamble Compan

    Exploring Temporal Patterns in Classifying Frustrated and Delighted Smiles

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    We create two experimental situations to elicit two affective states: frustration, and delight. In the first experiment, participants were asked to recall situations while expressing either delight or frustration, while the second experiment tried to elicit these states naturally through a frustrating experience and through a delightful video. There were two significant differences in the nature of the acted versus natural occurrences of expressions. First, the acted instances were much easier for the computer to classify. Second, in 90 percent of the acted cases, participants did not smile when frustrated, whereas in 90 percent of the natural cases, participants smiled during the frustrating interaction, despite self-reporting significant frustration with the experience. As a follow up study, we develop an automated system to distinguish between naturally occurring spontaneous smiles under frustrating and delightful stimuli by exploring their temporal patterns given video of both. We extracted local and global features related to human smile dynamics. Next, we evaluated and compared two variants of Support Vector Machine (SVM), Hidden Markov Models (HMM), and Hidden-state Conditional Random Fields (HCRF) for binary classification. While human classification of the smile videos under frustrating stimuli was below chance, an accuracy of 92 percent distinguishing smiles under frustrating and delighted stimuli was obtained using a dynamic SVM classifier.MIT Media Lab ConsortiumProcter & Gamble Compan

    BioInsights: Extracting personal data from "Still" wearable motion sensors

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    During recent years a large variety of wearable devices have become commercially available. As these devices are in close contact with the body, they have the potential to capture sensitive and unexpected personal data even when the wearer is not moving. This work demonstrates that wearable motion sensors such as accelerometers and gyroscopes embedded in head-mounted and wrist-worn wearable devices can be used to identify the wearer (among 12 participants) and his/her body posture (among 3 positions) from only 10 seconds of “still” motion data. Instead of focusing on large and apparent motions such as steps or gait, the proposed methods amplify and analyze very subtle body motions associated with the beating of the heart. Our findings have the potential to increase the value of pervasive wearable motion sensors but also raise important privacy concerns that need to be considered.National Science Foundation (U.S.). (CCF-1029585

    Acume: A New Visualization Tool for Understanding Facial Expression and Gesture Data

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    Facial and head actions contain significant affective information. To date, these actions have mostly been studied in isolation because the space of naturalistic combinations is vast. Interactive visualization tools could enable new explorations of dynamically changing combinations of actions as people interact with natural stimuli. This paper describes a new open-source tool that enables navigation of and interaction with dynamic face and gesture data across large groups of people, making it easy to see when multiple facial actions co-occur, and how these patterns compare and cluster across groups of participants. We share two case studies that demonstrate how the tool allows researchers to quickly view an entire corpus of data for single or multiple participants, stimuli and actions. Acume yielded patterns of actions across participants and across stimuli, and helped give insight into how our automated facial analysis methods could be better designed. The results of these case studies are used to demonstrate the efficacy of the tool. The open-source code is designed to directly address the needs of the face and gesture research community, while also being extensible and flexible for accommodating other kinds of behavioral data. Source code, application and documentation are available at http://affect.media.mit.edu/acume.Procter & Gamble Compan

    Predicting Online Media Effectiveness Based on Smile Responses Gathered Over the Internet

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    We present an automated method for classifying “liking” and “desire to view again” based on over 1,500 facial responses to media collected over the Internet. This is a very challenging pattern recognition problem that involves robust detection of smile intensities in uncontrolled settings and classification of naturalistic and spontaneous temporal data with large individual differences. We examine the manifold of responses and analyze the false positives and false negatives that result from classification. The results demonstrate the possibility for an ecologically valid, unobtrusive, evaluation of commercial “liking” and “desire to view again”, strong predictors of marketing success, based only on facial responses. The area under the curve for the best “liking” and “desire to view again” classifiers was 0.8 and 0.78 respectively when using a challenging leave-one-commercial-out testing regime. The technique could be employed in personalizing video ads that are presented to people whilst they view programming over the Internet or in copy testing of ads to unobtrusively quantify effectiveness.MIT Media Lab Consortiu

    Measuring Voter's Candidate Preference Based on Affective Responses to Election Debates

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    In this paper we present the first analysis of facial responses to electoral debates measured automatically over the Internet. We show that significantly different responses can be detected from viewers with different political preferences and that similar expressions at significant moments can have very different meanings depending on the actions that appear subsequently. We used an Internet based framework to collect 611 naturalistic and spontaneous facial responses to five video clips from the 3rd presidential debate during the 2012 American presidential election campaign. Using this framework we were able to collect over 60% of these video responses (374 videos) within one day of the live debate and over 80% within three days. No participants were compensated for taking the survey. We present and evaluate a method for predicting independent voter preference based on automatically measured facial responses and self-reported preferences from the viewers. We predict voter preference with an average accuracy of over 73% (AUC 0.779)

    Predicting Ad Liking and Purchase Intent: Large-Scale Analysis of Facial Responses to Ads

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    Billions of online video ads are viewed every month. We present a large-scale analysis of facial responses to video content measured over the Internet and their relationship to marketing effectiveness. We collected over 12,000 facial responses from 1,223 people to 170 ads from a range of markets and product categories. The facial responses were automatically coded frame-by-frame. Collection and coding of these 3.7 million frames would not have been feasible with traditional research methods. We show that detected expressions are sparse but that aggregate responses reveal rich emotion trajectories. By modeling the relationship between the facial responses and ad effectiveness, we show that ad liking can be predicted accurately (ROC AUC = 0.85) from webcam facial responses. Furthermore, the prediction of a change in purchase intent is possible (ROC AUC = 0.78). Ad liking is shown by eliciting expressions, particularly positive expressions. Driving purchase intent is more complex than just making viewers smile: peak positive responses that are immediately preceded by a brand appearance are more likely to be effective. The results presented here demonstrate a reliable and generalizable system for predicting ad effectiveness automatically from facial responses without a need to elicit self-report responses from the viewers. In addition we can gain insight into the structure of effective ads.MIT Media Lab ConsortiumNEC CorporationMAR

    Affectiva-MIT Facial Expression Dataset (AM-FED): Naturalistic and Spontaneous Facial Expressions Collected In-the-Wild

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    Computer classification of facial expressions requires large amounts of data and this data needs to reflect the diversity of conditions seen in real applications. Public datasets help accelerate the progress of research by providing researchers with a benchmark resource. We present a comprehensively labeled dataset of ecologically valid spontaneous facial responses recorded in natural settings over the Internet. To collect the data, online viewers watched one of three intentionally amusing Super Bowl commercials and were simultaneously filmed using their webcam. They answered three self-report questions about their experience. A subset of viewers additionally gave consent for their data to be shared publicly with other researchers. This subset consists of 242 facial videos (168,359 frames) recorded in real world conditions. The dataset is comprehensively labeled for the following: 1) frame-by-frame labels for the presence of 10 symmetrical FACS action units, 4 asymmetric (unilateral) FACS action units, 2 head movements, smile, general expressiveness, feature tracker fails and gender; 2) the location of 22 automatically detected landmark points; 3) self-report responses of familiarity with, liking of, and desire to watch again for the stimuli videos and 4) baseline performance of detection algorithms on this dataset. This data is available for distribution to researchers online, the EULA can be found at: http://www.affectiva.com/facial-expression-dataset-am-fed/
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