Cited by 21Non-Invasive Vital Sign MonitoringEpilepsy research and treatmentEEG and Brain-Computer Interfaces

Identification of Ictal Tachycardia in Focal Motor- and Non-Motor Seizures by Means of a Wearable PPG Sensor

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Glasstetter, Martin, Böttcher, Sebastian, Zabler, Nicolas, Epitashvili, Nino, Dümpelmann, Matthias, Richardson, Mark P., Schulze-Bonhage, Andreas·2021·Sensors

Abstract

Photoplethysmography (PPG) as an additional biosignal for a seizure detector has been underutilized so far, which is possibly due to its susceptibility to motion artifacts. We investigated 62 focal seizures from 28 patients with electrocardiography-based evidence of ictal tachycardia (IT). Seizures were divided into subgroups: those without epileptic movements and those with epileptic movements not affecting and affecting the extremities. PPG-based heart rate (HR) derived from a wrist-worn device was calculated for sections with high signal quality, which were identified using spectral entropy. Overall, IT based on PPG was identified in 37 of 62 (60%) seizures (9/19, 7/8, and 21/35 in the three groups, respectively) and could be found prior to the onset of epileptic movements affecting the extremities in 14/21 seizures. In 30/37 seizures, PPG-based IT was in good temporal agreement (<10 s) with ECG-based IT, with an average delay of 5.0 s relative to EEG onset. In summary, we observed that the identification of IT by means of a wearable PPG sensor is possible not only for non-motor seizures but also in motor seizures, which is due to the early manifestation of IT in a relevant subset of focal seizures. However, both spontaneous and epileptic movements can impair PPG-based seizure detection.

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  • The quality of data can be expressed in many different ways, and data quality measures may also depend on the aims of the related analysis and project.

    “the quality of data can be expressed in many different ways, and data quality measures may also depend on the aims of the related analysis and project8–13”

    From Data quality evaluation in wearable monitoring (2022) · cites this paper as [8]

  • A clean BVP signal from the Empatica E4 without noise from motion artifacts has a smooth quasi-periodic signature, which can be separated from random noise or motion artifacts by analyzing the entropy of the signal spectrum.

    “A clean BVP signal from the Empatica E4 without noise from motion artifacts has a smooth quasi-periodic signature, which can be separated from random noise or, more importantly, from motion artifacts by analyzing the entropy of the signal spectrum.”

    From Data quality evaluation in wearable monitoring (2022) · cites this paper as [8]

  • Signal quality assessments have been done under more general circumstances, but wearable data quality in the context of epilepsy has not been a widely researched topic so far.

    “Signal quality assessments have been done under more general circumstances10,34–37, but wearable data quality in the context of epilepsy has not been a widely researched topic so far8,9,38.”

    From Data quality evaluation in wearable monitoring (2022) · cites this paper as [8]

  • The Empatica E4 has been shown to facilitate seizure detection by heart rate estimation from PPG despite its susceptibility to motion artifacts.

    “Moreover, the E4 has been shown to facilitate seizure detection by heart rate estimation from PPG despite its susceptibility to motion artifacts8,72.”

    From Data quality evaluation in wearable monitoring (2022) · cites this paper as [8]

  • There is cursory evidence that the BVP signal quality measure correctly maps periods of good and poor signal quality to estimations of the heart rate.

    “While there is cursory evidence that it correctly maps periods of good and poor signal quality to estimations of the heart rate8,9”

    From Data quality evaluation in wearable monitoring (2022) · cites this paper as [8]

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Authors
Glasstetter, M., Böttcher, S., Zabler, N., Epitashvili, N., Dümpelmann, M., Richardson, M. P., & Schulze-Bonhage, A.
Affiliations
  • University of Freiburg (DE)
  • King's College London (GB)
  • Epilepsy Center, Department of Neurosurgery, Medical Center—University of Freiburg, 79106 Freiburg im Breisgau, Germany
Corresponding author
Glasstetter, Martin
Venue
Sensors
Publisher
MDPI AG
Published
2021-09-08
Volume
21
Issue
18
Pages
6017
ISSN
1424-8220 (ISSN-L)
OpenAlex
W3196706059
Cited by
21
References
62
Citations by year
2026: 2 · 2025: 5 · 2024: 6 · 2023: 2 · 2022: 5 · 2021: 1
FWCI
1.06
Type
journal article
Language
en
Open access
Locations
  • Sensors (publishedVersion, cc-by)
  • Europe PMC (PubMed Central) (publishedVersion, other-oa)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
  • Research Portal (King's College London) (submittedVersion, other-oa)
Funders
Innovative Medicines Initiative (115902)
Topics
  • Physical Sciences › Engineering › Biomedical Engineering › Non-Invasive Vital Sign Monitoring
  • Health Sciences › Medicine › Psychiatry and Mental health › Epilepsy research and treatment
  • Life Sciences › Neuroscience › Cognitive Neuroscience › EEG and Brain-Computer Interfaces
Keywords
focal seizures, photoplethysmography, wearable sensors, heart rate, seizure detection, motor seizures, motion artifacts, spectral entropy, wrist-worn devices
MeSH terms
Wearable Electronic Devices, Electrocardiography, Electroencephalography, Heart Rate, Humans, Seizures, Signal Processing, Computer-Assisted, Tachycardia, Photoplethysmography

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