Sami Nikkonen

Optimal Electroencephalogram and Electrooculogram Signal Combination for Deep Learning-based Sleep Staging

Tashakori, Masoumeh; Rusanen, Matias; Karhu, Tuomas; Huttunen, Riku; Leppanen, Timo; Nikkonen, Sami, 2025, IEEE journal of biomedical and health informatics, 29, 7, 4741-4747. A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

A comparative analysis of unsupervised machine‐learning methods in PSG‐related phenotyping

Ghorvei, Mohammadreza; Karhu, Tuomas; Hietakoste, Salla; Ferreira‐Santos, Daniela; Hrubos‐Strøm, Harald; Islind, Anna Sigridur; Biedebach, Luka; Nikkonen, Sami; Leppänen, Timo; Rusanen, Matias, 2024, Journal of sleep research, [First published: 24 October 2024], 1-13. A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Excessive daytime sleepiness is associated with relative delta frequency power among patients with mild OSA

Howarth, Timothy; Tashakori, Masoumeh; Karhu, Tuomas; Rusanen, Matias; Pitkänen, Henna; Oksenberg, Arie; Nikkonen, Sami, 2024, Frontiers in neurology, 15, 1367860. A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Interhemispheric differences of electroencephalography signal characteristics in different sleep stages

Tashakori, Masoumeh; Rusanen, Matias; Karhu, Tuomas; Grote, Ludger; Nath, Rajdeep Kumar; Leppänen, Timo; Nikkonen, Sami, 2024, Sleep medicine, 117, 201-208. A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Prolonged lung-to-finger circulation time indicates an increased risk of intermittent hypoxaemia in sleep apnoea patients

Pahari, Purbanka; Korkalainen, Henri; Arnardóttir, Erna Sif; Islind, Anna Sigridur; August, Elias; Oksenberg, Arie; Töyräs, Juha; Leppänen, Timo; Nikkonen, Sami, 2024, ERJ open research, 10, 4, 01051-2023. A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Respiratory event index underestimates severity of sleep apnea compared to apnea-hypopnea index

Pitkänen, Minna; Nath, Rajdeep Kumar; Korkalainen, Henri; Nikkonen, Sami; Mahamid, Alaa; Oksenberg, Arie; Duce, Brett; Töyräs, Juha; Kainulainen, Samu; Leppänen, Timo, 2024, Sleep advances, 5, 1, zpad054. A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Retrospective validation of automatic sleep analysis with grey areas model for human‐in‐the‐loop scoring approach

Rusanen, Matias; Jouan, Gabriel; Huttunen, Riku; Nikkonen, Sami; Sigurðardóttir, Sigríður; Töyräs, Juha; Duce, Brett; Myllymaa, Sami; Arnardottir, Erna Sif; Leppänen, Timo; Islind, Anna Sigridur; Kainulainen, Samu; Korkalainen, Henri, 2024, Journal of sleep research, [First published: 23 October 2024], 1-13. A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Temporal and sleep stage‐dependent agreement in manual scoring of respiratory events

Pitkänen, Minna; Pitkänen, Henna; Nath, Rajdeep Kumar; Nikkonen, Sami; Kainulainen, Samu; Korkalainen, Henri; Ólafsdóttir, Kristín Anna; Arnardottir, Erna Sif; Sigurdardottir, Sigridur; Penzel, Thomas; Fanfulla, Francesco; Anttalainen, Ulla; Saaresranta, Tarja; Grote, Ludger; Hedner, Jan; Staats, Richard; Töyräs, Juha; Leppänen, Timo, 2024, Journal of sleep research, [First published: 04 November 2024], 1-10. A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Verbal memory is linked to average oxygen saturation during sleep, not the apnea-hypopnea index nor novel hypoxic load variables

Thorisdottir, K; Hrubos-Strøm, H; Karhu, T; Nikkonen, S; Dammen, T; Nordhus, IH; Leppänen, T; Jónsdóttir, MK; Arnardottir, ES, 2024, Sleep medicine, 123, 29-36. A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Morbid obesity influences the nocturnal electrocardiogram wave and interval durations among suspected sleep apnea patients

Kainulainen, Samu; Suni, Aaron; Lipponen, Jukka A; Kulkas, Antti; Duce, Brett; Korkalainen, Henri; Nikkonen, Sami; Sillanmäki, Saara, 2023, Annals of noninvasive electrocardiology, 2024; 29, 1, e13101. A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Multicentre sleep-stage scoring agreement in the Sleep Revolution project

Nikkonen, Sami; Somaskandhan, Pranavan; Korkalainen, Henri; Kainulainen, Samu; Terrill, Philip I; Gretarsdottir, Heidur; Sigurdardottir, Sigridur; Olafsdottir, Kristin Anna; Islind, Anna Sigridur; oskarsdottir, Maria; Arnardottir, Erna Sif; Leppänen, Timo, 2023, Journal of sleep research, 2024; 33, 1, e13956. A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Multi‐centre arousal scoring agreement in the Sleep Revolution

Pitkänen, Henna; Nikkonen, Sami; Rissanen, Marika; Islind, Anna Sigridur; Gretarsdottir, Heidur; Arnardottir, Erna Sif; Leppänen, Timo; Korkalainen, Henri, 2023, Journal of sleep research, 2024; 33, 4, e14127. A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Obstructive Sleep Apnea Patients With Atrial Arrhythmias Suffer From Prolonged Recovery From Desaturations

Rissanen, Marika; Korkalainen, Henri; Duce, Brett; Sillanmaki, Saara; Pitkanen, Henna; Suni, Aaron; Nikkonen, Sami; Kulkas, Antti; Toyras, Juha; Leppanen, Timo; Kainulainen, Samu, 2023, IEEE transactions on biomedical engineering, 70, 7, 2122-2130. A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Reaction time in psychomotor vigilance task is related to hypoxic load in males with sleep apnea

Pahari, Purbanka; Korkalainen, Henri; Karhu, Tuomas; Arnardottir, Erna Sif; Töyräs, Juha; Leppänen, Timo; Nikkonen, Sami, 2023, Journal of sleep research, 2024; 33, 2, e13988. A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Review and perspective on sleep-disordered breathing research and translation to clinics

Korkalainen, Henri; Kainulainen, Samu; Islind, Anna Sigridur; Óskarsdóttir, María; Strassberger, Christian; Nikkonen, Sami; Töyräs, Juha; Kulkas, Antti; Grote, Ludger; Hedner, Jan; Sund, Reijo; Hrubos-Strom, Harald; Saavedra, Jose M.; Ólafsdóttir, Kristín Anna; Ágústsson, Jón S.; Terrill, Philip I.; McNicholas, Walter T.; Arnardóttir, Erna Sif; Leppänen, Timo, 2023, Sleep medicine reviews, 2024; 73, 101874. A2 Katsausartikkeli tieteellisessä aikakauslehdessä

Towards a Deeper Understanding of Sleep Stages through their Representation in the Latent Space of Variational Autoencoders

Biedebach, Luka; Rusanen, Matias; Pórðarson, Benedikt Hólm; Arnardóttir, Erna Sif; Óskarsdóttir, María; Nikkonen, Sami; Korkalainen, Henri; Myllymaa, Sami; Töyräs, Juha; Kainulainen, Samu; Leppänen, Timo; Islind, Anna Sigridur, 2023, Bui, Tung, Proceedings of the 56th Annual Hawaii International Conference on System Sciences, 3111-3120. A4 Artikkeli konferenssijulkaisussa

Utilizing Envelope Analysis of a Nasal Pressure Signal for Sleep Apnea Severity Estimation

Varis, Mikke; Karhu, Tuomas; Leppänen, Timo; Nikkonen, Sami, 2023, Diagnostics, 13, 10, 1776. A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

A Comparison of Signal Combinations for Deep Learning-Based Simultaneous Sleep Staging and Respiratory Event Detection

Huttunen, Riku; Leppanen, Timo; Duce, Brett; Arnardottir, Erna S.; Nikkonen, Sami; Myllymaa, Sami; Toyras, Juha; Korkalainen, Henri, 2022, IEEE transactions on biomedical engineering, [Date of Publication: 28 November 2022], 1-12. A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

ABOSA – Freely available automatic blood oxygen saturation signal analysis software: Structure and validation

Karhu, Tuomas; Leppänen, Timo; Töyräs, Juha; Oksenberg, Arie; Myllymaa, Sami; Nikkonen, Sami, 2022, Computer methods and programs in biomedicine, 226, 107120. A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Deep Learning Enables Accurate Automatic Sleep Staging Based on Ambulatory Forehead EEG

Leino, Akseli; Korkalainen, Henri; Kalevo, Laura; Nikkonen, Sami; Kainulainen, Samu; Ryan, Alexander; Duce, Brett; Sipila, Kirsi; Ahlberg, Jari; Sahlman, Johanna; Miettinen, Tomi; Westeren-Punnonen, Susanna; Mervaala, Esa; Toyras, Juha; Myllymaa, Sami; Leppanen, Timo; Myllymaa, Katja, 2022, IEEE access, 10, 26554-26566. A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Desaturation event scoring criteria affect the perceived severity of nocturnal hypoxic load

Karhu, Tuomas; Leppänen, Timo; Korkalainen, Henri; Myllymaa, Sami; Duce, Brett; Töyräs, Juha; Nikkonen, Sami, 2022, Sleep medicine, 100, 479-486. A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Novel oxygen desaturation parameters are associated with cardiac troponin I: Data from the Akershus Sleep Apnea Project

Sigurdardottir, Fjola D.; Øverby, Caroline Tonje; Nikkonen, Sami; Karhu, Tuomas; Dammen, Toril; Nordhus, Inger Hilde; Thorshov, Thea; Einvik, Gunnar; Kainulainen, Samu; Leppänen, Timo; Arnardottir, Erna Sif; Töyräs, Juha; Omland, Torbjørn; Hrubos‐Strøm, Harald, 2022, Journal of sleep research, 31, 5, e13581. A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Obstructive sleep apnea‐related intermittent hypoxaemia is associated with impaired vigilance

Pahari, Purbanka; Korkalainen, Henri; Karhu, Tuomas; Rissanen, Marika; Arnardottir, Erna Sif; Hrubos‐Strøm, Harald; Duce, Brett; Töyräs, Juha; Leppänen, Timo; Nikkonen, Sami, 2022, Journal of sleep research, [First published: 08 December 2022], e13803. A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Pulse Oximetry: The Working Principle, Signal Formation, and Applications

Leppänen, Timo; Kainulainen, Samu; Korkalainen, Henri; Sillanmäki, Saara; Kulkas, Antti; Töyräs, Juha; Nikkonen, Sami, 2022, Penzel, T; Hornero, R, Advances in the Diagnosis and Treatment of Sleep Apnea, 205-218. A3 Kirjan tai muun kokoomateoksen osa

QTc prolongation is associated with severe desaturations in stroke patients with sleep apnea

Sillanmäki, Saara; Lipponen, Jukka A; Korkalainen, Henri; Kulkas, Antti; Leppänen, Timo; Nikkonen, Sami; Töyräs, Juha; Duce, Brett; Suni, Aaron; Kainulainen, Samu, 2022, Bmc pulmonary medicine, 22, 1, 204. A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

STAR sleep recording export software for automatic export and anonymization of sleep studies

Nikkonen, Sami; Korkalainen, Henri; Töyräs, Juha; Leppänen, Timo, 2022, Scientific reports, 12, 1, 15859. A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

The severity and morphology of intermittent hypoxemias are related to impaired daytime alertness

Pahari, P; Korkalainen, H; Karhu, T; Rissanen, M; Arnardottir, ES; Strøm, HH; Duce, B; Töyräs, J; Leppänen, T; Nikkonen, S, 2022, Sleep medicine. Abstrakti

Automatic Respiratory Event Scoring in Obstructive Sleep Apnea Using a Long Short-Term Memory Neural Network

Nikkonen, Sami; Korkalainen, Henri; Leino, Akseli; Myllymaa, Sami; Duce, Brett; Leppänen, Timo; Töyräs, Juha, 2021, IEEE journal of biomedical and health informatics, 25, 8, 2917-2927. A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Diabetes and cardiovascular diseases are associated with the worsening of intermittent hypoxaemia

Karhu, T; Myllymaa, S; Nikkonen, S; Mazzotti, DR; Kulkas, A; Töyräs, J; Leppänen, T, 2021, Journal of sleep research, 2022; 31, 1, e13441. A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Longer and Deeper Desaturations Are Associated With the Worsening of Mild Sleep Apnea: The Sleep Heart Health Study

Karhu, Tuomas; Myllymaa, Sami; Nikkonen, Sami; Mazzotti, Diego R; Töyräs, Juha; Leppänen, Timo, 2021, Frontiers in neuroscience, 15, 657126. A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Neural network analysis of nocturnal SpO2 signal enables easy screening of sleep apnea in patients with acute cerebrovascular disease

Leino, Akseli; Nikkonen, Sami; Kainulainen, Samu; Korkalainen, Henri; Töyräs, Juha; Myllymaa, Sami; Leppänen, Timo; Ylä-Herttuala, Salla; Westeren-Punnonen, Susanna; Muraja-Murro, Anu; Jäkälä, Pekka; Mervaala, Esa; Myllymaa, Katja, 2021, Sleep medicine, 79, 71-78. A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Self-Applied Home Sleep Recordings: The Future of Sleep Medicine

Korkalainen, Henri; Nikkonen, Sami; Kainulainen, Samu; Dwivedi, Amit Krishna; Myllymaa, Sami; Leppänen, Timo; Töyräs, Juha, 2021, Sleep medicine clinics, 16, 4, 545-556. A2 Katsausartikkeli tieteellisessä aikakauslehdessä

Deep learning enables sleep staging from photoplethysmogram for patients with suspected sleep apnea

Korkalainen, H; Aakko, J; Duce, B; Kainulainen, S; Leino, A; Nikkonen, S; Afara, I O; Myllymaa, S; Töyräs, J; Leppänen, T, 2020, Sleep, 43, 11, zsaa098. A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Estimating daytime sleepiness with previous night EEG, EOG and EMG spectrograms in patients with suspected sleep apnea using a convolutional neural network

Nikkonen, Sami; Korkalainen, Henri; Kainulainen, Samu; Myllymaa, Sami; Leino, Akseli; Kalevo, Laura; Oksenberg, Arie; Leppänen, Timo; Töyräs, Juha, 2020, Sleep, 43, 12, zsaa106. A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Longer apneas and hypopneas are associated with greater ultra-short-term HRV in obstructive sleep apnea

Hietakoste, Salla; Korkalainen, Henri; Kainulainen, Samu; Sillanmäki, Saara; Nikkonen, Sami; Myllymaa, Sami; Duce, Brett; Töyräs, Juha; Leppänen, Timo, 2020, Scientific reports, 10, 21556. A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Novel computational tools for enhanced diagnostics of obstructive sleep apnea

Nikkonen, Sami, 2020, Publications of the University of Eastern Finland. Dissertations in Forestry and Natural Sciences. G5 Artikkeliväitöskirja

Power spectral densities of nocturnal pulse oximetry signals differ in OSA patients with and without daytime sleepiness

Kainulainen, Samu; Töyräs, Juha; Oksenberg, Arie; Korkalainen, Henri; Afara, Isaac O; Leino, Akseli; Kalevo, Laura; Nikkonen, Sami; Gadoth, Natan; Kulkas, Antti; Myllymaa, Sami; Leppänen, Timo, 2020, Sleep medicine, 73, 231-237. A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Accurate Deep Learning-Based Sleep Staging in a Clinical Population with Suspected Obstructive Sleep Apnea

Korkalainen, Henri; Aakko, Juhani; Nikkonen, Sami; Kainulainen, Samu; Leino, Akseli; Duce, Brett; Afara, Isaac Oluwaseun; Myllymaa, Sami; Töyräs, Juha; Leppänen, Timo, 2019, IEEE journal of biomedical and health informatics, 24, 7, 2073-2081. A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Artificial neural network analysis of the oxygen saturation signal enables accurate diagnostics of sleep apnea

Nikkonen, S; Afara, IO; Leppänen, T; Töyräs, J, 2019, Scientific reports, 9, 1, 13200. A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Intra-night variation in apnea-hypopnea index affects diagnostics and prognostics of obstructive sleep apnea

Nikkonen, S; Töyräs, J; Mervaala, E; Myllymaa, S; Terrill, P; Leppänen, T, 2019, Sleep and breathing, 2020; 24, 379-386. A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Mortality-risk-based apnea-hypopnea index thresholds for diagnostics of obstructive sleep apnea

Korkalainen, H; Töyräs, J; Nikkonen, S; Leppänen, T, 2019, Journal of sleep research, 28, 6, e12855. A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Required CPAP usage time to normalize AHI in obstructive sleep apnea patients: a simulation study

Kulkas, Antti; Leppänen, Timo; Nikkonen, Sami; Oksenberg, Arie; Duce, Brett; Mervaala, Esa; Töyräs, Juha, 2018, Physiological measurement, 39, 11, 115009. A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Simulation of Required CPAP Usage to Normalize AHI in Obstructive Sleep Apnea Patients

Kulkas, Antti; Nikkonen, Sami; Töyräs, Juha; Mervaala, Esa; Leppänen, Timo, 2018, Lhotska, L; Sukupova, L; Lackovic, I; Ibbott, G, World Congress on Medical Physics and Biomedical Engineering 2018, June 3-8, 2018, Prague, Czech Republic (Vol.2), 129-132. A4 Artikkeli konferenssijulkaisussa

Tarkenna hakuasi

Tutkimusryhmät

Optimal Electroencephalogram and Electrooculogram Signal Combination for Deep Learning-based Sleep Staging

A comparative analysis of unsupervised machine‐learning methods in PSG‐related phenotyping

Excessive daytime sleepiness is associated with relative delta frequency power among patients with mild OSA

Interhemispheric differences of electroencephalography signal characteristics in different sleep stages

Prolonged lung-to-finger circulation time indicates an increased risk of intermittent hypoxaemia in sleep apnoea patients

Respiratory event index underestimates severity of sleep apnea compared to apnea-hypopnea index

Retrospective validation of automatic sleep analysis with grey areas model for human‐in‐the‐loop scoring approach

Temporal and sleep stage‐dependent agreement in manual scoring of respiratory events

Verbal memory is linked to average oxygen saturation during sleep, not the apnea-hypopnea index nor novel hypoxic load variables

Morbid obesity influences the nocturnal electrocardiogram wave and interval durations among suspected sleep apnea patients

Multicentre sleep-stage scoring agreement in the Sleep Revolution project

Multi‐centre arousal scoring agreement in the Sleep Revolution

Obstructive Sleep Apnea Patients With Atrial Arrhythmias Suffer From Prolonged Recovery From Desaturations

Reaction time in psychomotor vigilance task is related to hypoxic load in males with sleep apnea

Review and perspective on sleep-disordered breathing research and translation to clinics

Towards a Deeper Understanding of Sleep Stages through their Representation in the Latent Space of Variational Autoencoders

Utilizing Envelope Analysis of a Nasal Pressure Signal for Sleep Apnea Severity Estimation

A Comparison of Signal Combinations for Deep Learning-Based Simultaneous Sleep Staging and Respiratory Event Detection

ABOSA – Freely available automatic blood oxygen saturation signal analysis software: Structure and validation

Deep Learning Enables Accurate Automatic Sleep Staging Based on Ambulatory Forehead EEG

Desaturation event scoring criteria affect the perceived severity of nocturnal hypoxic load

Novel oxygen desaturation parameters are associated with cardiac troponin I: Data from the Akershus Sleep Apnea Project

Obstructive sleep apnea‐related intermittent hypoxaemia is associated with impaired vigilance

Pulse Oximetry: The Working Principle, Signal Formation, and Applications

QTc prolongation is associated with severe desaturations in stroke patients with sleep apnea

STAR sleep recording export software for automatic export and anonymization of sleep studies

The severity and morphology of intermittent hypoxemias are related to impaired daytime alertness

Automatic Respiratory Event Scoring in Obstructive Sleep Apnea Using a Long Short-Term Memory Neural Network

Diabetes and cardiovascular diseases are associated with the worsening of intermittent hypoxaemia

Longer and Deeper Desaturations Are Associated With the Worsening of Mild Sleep Apnea: The Sleep Heart Health Study

Neural network analysis of nocturnal SpO2 signal enables easy screening of sleep apnea in patients with acute cerebrovascular disease

Self-Applied Home Sleep Recordings: The Future of Sleep Medicine

Deep learning enables sleep staging from photoplethysmogram for patients with suspected sleep apnea

Estimating daytime sleepiness with previous night EEG, EOG and EMG spectrograms in patients with suspected sleep apnea using a convolutional neural network

Longer apneas and hypopneas are associated with greater ultra-short-term HRV in obstructive sleep apnea

Novel computational tools for enhanced diagnostics of obstructive sleep apnea

Power spectral densities of nocturnal pulse oximetry signals differ in OSA patients with and without daytime sleepiness

Accurate Deep Learning-Based Sleep Staging in a Clinical Population with Suspected Obstructive Sleep Apnea

Artificial neural network analysis of the oxygen saturation signal enables accurate diagnostics of sleep apnea

Intra-night variation in apnea-hypopnea index affects diagnostics and prognostics of obstructive sleep apnea

Mortality-risk-based apnea-hypopnea index thresholds for diagnostics of obstructive sleep apnea

Required CPAP usage time to normalize AHI in obstructive sleep apnea patients: a simulation study

Simulation of Required CPAP Usage to Normalize AHI in Obstructive Sleep Apnea Patients