19,431 research outputs found
Deepr: A Convolutional Net for Medical Records
Feature engineering remains a major bottleneck when creating predictive
systems from electronic medical records. At present, an important missing
element is detecting predictive regular clinical motifs from irregular episodic
records. We present Deepr (short for Deep record), a new end-to-end deep
learning system that learns to extract features from medical records and
predicts future risk automatically. Deepr transforms a record into a sequence
of discrete elements separated by coded time gaps and hospital transfers. On
top of the sequence is a convolutional neural net that detects and combines
predictive local clinical motifs to stratify the risk. Deepr permits
transparent inspection and visualization of its inner working. We validate
Deepr on hospital data to predict unplanned readmission after discharge. Deepr
achieves superior accuracy compared to traditional techniques, detects
meaningful clinical motifs, and uncovers the underlying structure of the
disease and intervention space
Chronic-Pain Protective Behavior Detection with Deep Learning
In chronic pain rehabilitation, physiotherapists adapt physical activity to
patients' performance based on their expression of protective behavior,
gradually exposing them to feared but harmless and essential everyday
activities. As rehabilitation moves outside the clinic, technology should
automatically detect such behavior to provide similar support. Previous works
have shown the feasibility of automatic protective behavior detection (PBD)
within a specific activity. In this paper, we investigate the use of deep
learning for PBD across activity types, using wearable motion capture and
surface electromyography data collected from healthy participants and people
with chronic pain. We approach the problem by continuously detecting protective
behavior within an activity rather than estimating its overall presence. The
best performance reaches mean F1 score of 0.82 with leave-one-subject-out cross
validation. When protective behavior is modelled per activity type, performance
is mean F1 score of 0.77 for bend-down, 0.81 for one-leg-stand, 0.72 for
sit-to-stand, 0.83 for stand-to-sit, and 0.67 for reach-forward. This
performance reaches excellent level of agreement with the average experts'
rating performance suggesting potential for personalized chronic pain
management at home. We analyze various parameters characterizing our approach
to understand how the results could generalize to other PBD datasets and
different levels of ground truth granularity.Comment: 24 pages, 12 figures, 7 tables. Accepted by ACM Transactions on
Computing for Healthcar
Understanding and Measuring Psychological Stress using Social Media
A body of literature has demonstrated that users' mental health conditions,
such as depression and anxiety, can be predicted from their social media
language. There is still a gap in the scientific understanding of how
psychological stress is expressed on social media. Stress is one of the primary
underlying causes and correlates of chronic physical illnesses and mental
health conditions. In this paper, we explore the language of psychological
stress with a dataset of 601 social media users, who answered the Perceived
Stress Scale questionnaire and also consented to share their Facebook and
Twitter data. Firstly, we find that stressed users post about exhaustion,
losing control, increased self-focus and physical pain as compared to posts
about breakfast, family-time, and travel by users who are not stressed.
Secondly, we find that Facebook language is more predictive of stress than
Twitter language. Thirdly, we demonstrate how the language based models thus
developed can be adapted and be scaled to measure county-level trends. Since
county-level language is easily available on Twitter using the Streaming API,
we explore multiple domain adaptation algorithms to adapt user-level Facebook
models to Twitter language. We find that domain-adapted and scaled social
media-based measurements of stress outperform sociodemographic variables (age,
gender, race, education, and income), against ground-truth survey-based stress
measurements, both at the user- and the county-level in the U.S. Twitter
language that scores higher in stress is also predictive of poorer health, less
access to facilities and lower socioeconomic status in counties. We conclude
with a discussion of the implications of using social media as a new tool for
monitoring stress levels of both individuals and counties.Comment: Accepted for publication in the proceedings of ICWSM 201
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