Physical inactivity is one of the main risk factors for mortality,
and its relationship with the main chronic diseases has experienced
intensive medical research. A well-known method for assessing people’s
activity is the use of accelerometers implanted in wearables and mobile
phones. However, a series of main critical issues arise in the healthcare
context related to the limited amount of available labeled data to build
a classification model. Moreover, the discrimination ability of activities
is often challenging to capture since the variety of movement patterns
in a particular group of patients (e.g. obesity or geriatric patients) is
limited over time. Consequently, the proposed work presents a novel approach
for Human Activity Recognition (HAR) in healthcare to avoid
this problem. This proposal is based on semi-supervised classification
with Encoder-Decoder Convolutional Neural Networks (CNNs) using a
combination strategy of public labeled and private unlabeled raw sensor
data. In this sense, the model will be able to take advantage of the large
amount of unlabeled data available by extracting relevant characteristics
in these data, which will increase the knowledge in the innermost layers.
Hence, the trained model can generalize well when used in real-world use
cases. Additionally, real-time patient monitoring is provided by Apache
Spark streaming processing with sliding windows. For testing purposes,
a real-world case study is conducted with a group of overweight patients
in the healthcare system of Andalusia (Spain), classifying close to 30
TBs of accelerometer sensor-based data.