A comprehensive evaluation of pretraining strategies for channel-agnostic contrastive self-supervision of biosignals

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Brüsch, Thea, Schmidt, Mikkel N., Alstrøm, Tommy S.
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866913153470693376
author Brüsch, Thea
Schmidt, Mikkel N.
Alstrøm, Tommy S.
author_facet Brüsch, Thea
Schmidt, Mikkel N.
Alstrøm, Tommy S.
contents Contrastive learning yields impressive results for self-supervision in computer vision. The approach relies on the creation of positive pairs, something which is often achieved through augmentations. However, for multivariate time series effective augmentations can be difficult to design. Additionally, the number of input channels for biosignal datasets often varies from application to application, limiting the usefulness of large self-supervised models trained with specific channel configurations. Motivated by these challenges, we set out to investigate strategies for creation of positive pairs for channel-agnostic self-supervision of biosignals. We introduce contrastive random lead coding (CRLC), where random subsets of the input channels are used to create positive pairs and compare with using augmentations and neighboring segments in time as positive pairs. We validate our approach by pre-training models on EEG and ECG data, and then fine-tuning them for downstream tasks. CRLC outperforms competing strategies in both scenarios in the channel-agnostic setting. Notably, for EEG tasks CRLC surpasses the current state-of-the-art reference model. While, the state-of-the-art reference model is superior in the ECG task, incorporating CRLC allows us to obtain comparable results. In conclusion, CRLC helps generalization across variable channel setups when training our channel-agnostic model. The code is available at https://github.com/theabrusch/Multiview_TS_SSL.
format Preprint
id arxiv_https___arxiv_org_abs_2410_19842
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle A comprehensive evaluation of pretraining strategies for channel-agnostic contrastive self-supervision of biosignals
Brüsch, Thea
Schmidt, Mikkel N.
Alstrøm, Tommy S.
Signal Processing
Machine Learning
Contrastive learning yields impressive results for self-supervision in computer vision. The approach relies on the creation of positive pairs, something which is often achieved through augmentations. However, for multivariate time series effective augmentations can be difficult to design. Additionally, the number of input channels for biosignal datasets often varies from application to application, limiting the usefulness of large self-supervised models trained with specific channel configurations. Motivated by these challenges, we set out to investigate strategies for creation of positive pairs for channel-agnostic self-supervision of biosignals. We introduce contrastive random lead coding (CRLC), where random subsets of the input channels are used to create positive pairs and compare with using augmentations and neighboring segments in time as positive pairs. We validate our approach by pre-training models on EEG and ECG data, and then fine-tuning them for downstream tasks. CRLC outperforms competing strategies in both scenarios in the channel-agnostic setting. Notably, for EEG tasks CRLC surpasses the current state-of-the-art reference model. While, the state-of-the-art reference model is superior in the ECG task, incorporating CRLC allows us to obtain comparable results. In conclusion, CRLC helps generalization across variable channel setups when training our channel-agnostic model. The code is available at https://github.com/theabrusch/Multiview_TS_SSL.
title A comprehensive evaluation of pretraining strategies for channel-agnostic contrastive self-supervision of biosignals
topic Signal Processing
Machine Learning
url https://arxiv.org/abs/2410.19842