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353 results on '"Lekkala, Jukka"'

3. Electrically Induced Blink for the Prevention of Ocular Symptoms and Blurred Vision in Patients With Acute Facial Nerve Palsy.

Author

Mäkelä, Eeva, Venesvirta, Hanna, Ilves, Mirja, Lylykangas, Jani, Rantanen, Ville, Uusitalo, Hannu, Verho, Jarmo, Vehkaoja, Antti, Lekkala, Jukka, Surakka, Veikko, and Rautiainen, Markus

Subjects
BELL'S palsy, VISION disorders, DATA analysis, T-test (Statistics), RESEARCH funding, QUESTIONNAIRES, DESCRIPTIVE statistics, TELEVISION, FACIAL nerve diseases, ELECTRIC stimulation, STATISTICS, ONE-way analysis of variance, DRY eye syndromes, VISUAL acuity, DATA analysis software, BLINKING (Physiology)
Abstract

Objectives : Facial nerve palsy causes blurred vision and ocular discomfort due to deficits in blinking and eye closure. The objective of this study was to determine whether eye-blinks could be elicited by electrical stimulation and whether electrically induced blink would have an effect on the visual acuity and ocular symptoms in patients with acute facial nerve palsy. Methods : The zygomatic branch of the facial nerve of fifteen participants with acute facial nerve palsy was electrically stimulated in order to elicit a blink. In successful cases, the participant proceeded with a two-hour TV watching session in which an electrically induced blink was delivered every 5 seconds. The control condition consisted of an otherwise similar TV watching session without electrically induced blinking. Subjective ocular symptoms were evaluated with a Dry Eye Questionnaire and visual acuity was assessed with a Logarithm of the Minimum Angle of Resolution (LogMAR) chart before and after both sessions. Results : The stimulation produced a blink in 8 participants (53%). The visual acuity in the affected eye decreased during the control session, whereas no significant change occurred during the stimulation session. The ocular symptoms were significantly reduced during the stimulation session. Conclusions : Electrically elicited blink is a promising method for reducing the eye symptoms in individuals with acute facial nerve palsy. [ABSTRACT FROM AUTHOR]

Published
2024
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5. Coercivity weighted Langevin magnetisation; A new approach to interpret superparamagnetic and nonsuperparamagnetic behaviour in single domain magnetic nanoparticles

Author

Rajan, Dhanesh Kattipparambil and Lekkala, Jukka

Subjects
Condensed Matter - Materials Science, Mathematical Physics, 35Qxx
Abstract

Superparamagnetism (SPM) is an attractive material property often appearing in nanoscaled single domain (SD) configurations. However, not all SD particles are superparamagnetic, which depends on a few parameters including material type, temperature, measurement time and magneto crystalline anisotropy. The non-linear magnetisation response of magnetic particles can be interpreted by classical Langevin approach but its applicability is limited to pure SD-SPM behaviour. The classical Langevin equation lacks parameters to account for possible remanence and coercivity in SD regime, resultantly, the SD-nonSPM possibility is left untreated. To solve this issue, we propose a new model by including SD coercivity parameters in classical Langevin equations. The new model 1) combines steady or time varying magnetisation dynamics and temperature or particle size dependent coercivity and 2) helps to calculate coercivity compensated magnetisations and susceptibilities directly. The model covers full spectrum of SD diameters and defines the switching between superparamagnetic and non-superparamagnetic states more precisely., Comment: 9 pages, 2012 HKICEAS conference, Thes paper proposes a theoretical approach for 'Differentiating superparamagnetic and non-superparamagnetic behaviour in single domain magnetic nanoparticles by coercivity weighted Langevin magnetisation'

Published
2013

6. Short-term stability of combined finger and toe photoplethysmogram analysis

Author

Peltokangas, Mikko, Huotari, Matti, Verho, Jarmo, Mattila, Ville M., Röning, Juha, Romsi, Pekka, Lekkala, Jukka, Vehkaoja, Antti, Oksala, Niku, Magjarevic, Ratko, Editor-in-chief, Ładyżyński, Piotr, Series editor, Ibrahim, Fatimah, Series editor, Lacković, Igor, Series editor, Rock, Emilio Sacristan, Series editor, Eskola, Hannu, editor, Väisänen, Outi, editor, Viik, Jari, editor, and Hyttinen, Jari, editor

Published
2018
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7. Temperature effect on the baseline noise in MEA measurements

Author

Ryynänen, Tomi, Lekkala, Jukka, Magjarevic, Ratko, Editor-in-chief, Ładyżyński, Piotr, Series editor, Ibrahim, Fatimah, Series editor, Lacković, Igor, Series editor, Rock, Emilio Sacristan, Series editor, Eskola, Hannu, editor, Väisänen, Outi, editor, Viik, Jari, editor, and Hyttinen, Jari, editor

Published
2018
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8. Low-latency EMG Onset and Termination Detection for Facial Pacing

Author

Kontunen, Anton, Rantanen, Ville, Vehkaoja, Antti, Ilves, Mirja, Lylykangas, Jani, Mäkelä, Eeva, Rautiainen, Markus, Surakka, Veikko, Lekkala, Jukka, Magjarevic, Ratko, Editor-in-chief, Ładyżyński, Piotr, Series editor, Ibrahim, Fatimah, Series editor, Lacković, Igor, Series editor, Rock, Emilio Sacristan, Series editor, Eskola, Hannu, editor, Väisänen, Outi, editor, Viik, Jari, editor, and Hyttinen, Jari, editor

Published
2018
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9. Artificial Eye Blink Pacemaker - A First Investigation into the Blink Production Using Constant-Interval Electrical Stimulation

Author

Lylykangas, Jani, Ilves, Mirja, Venesvirta, Hanna, Rantanen, Ville, Mäkelä, Eeva, Vehkaoja, Antti, Verho, Jarmo, Lekkala, Jukka, Rautiainen, Markus, Surakka, Veikko, Magjarevic, Ratko, Editor-in-chief, Ładyżyński, Piotr, Series editor, Ibrahim, Fatimah, Series editor, Lacković, Igor, Series editor, Rock, Emilio Sacristan, Series editor, Eskola, Hannu, editor, Väisänen, Outi, editor, Viik, Jari, editor, and Hyttinen, Jari, editor

Published
2018
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10. Day-to-day repeatability of the results of the finger-toe-plot analysis

Author

Peltokangas, Mikko, Telembeci, Anca A., Verho, Jarmo, Lekkala, Jukka, Vehkaoja, Antti, Oksala, Niku, Magjarevic, Ratko, Editor-in-chief, Ładyżyński, Piotr, Series editor, Ibrahim, Fatimah, Series editor, Lacković, Igor, Series editor, Rock, Emilio Sacristan, Series editor, Eskola, Hannu, editor, Väisänen, Outi, editor, Viik, Jari, editor, and Hyttinen, Jari, editor

Published
2018
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17. Prosthetic Pacing Device for Unilateral Facial Paralysis

Author

Rantanen, Ville, Vehkaoja, Antti, Verho, Jarmo, Veselý, Petr, Lylykangas, Jani, Ilves, Mirja, Mäkelä, Eeva, Rautiainen, Markus, Surakka, Veikko, Lekkala, Jukka, Magjarevic, Ratko, Editor-in-chief, Ładyżyński, Piotr, Series editor, Ibrahim, Fatimah, Series editor, Lacković, Igor, Series editor, Rock, Emilio Sacristan, Series editor, Kyriacou, Efthyvoulos, editor, Christofides, Stelios, editor, and Pattichis, Constantinos S., editor

Published
2016
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24. Wearable System for EKG Monitoring - Evaluation of Night-Time Performance

Author

Vehkaoja, Antti, Verho, Jarmo, Cömert, Alper, Honkala, Markku, Lekkala, Jukka, Akan, Ozgur, Series editor, Bellavista, Paolo, Series editor, Cao, Jiannong, Series editor, Dressler, Falko, Series editor, Ferrari, Domenico, Series editor, Gerla, Mario, Series editor, Kobayashi, Hisashi, Series editor, Palazzo, Sergio, Series editor, Sahni, Sartaj, Series editor, Shen, Xuemin (Sherman), Series editor, Stan, Mircea, Series editor, Xiaohua, Jia, Series editor, Zomaya, Albert, Series editor, Coulson, Geoffrey, Series editor, Nikita, Konstantina S., editor, Lin, James C., editor, Fotiadis, Dimitrios I., editor, and Arredondo Waldmeyer, Maria-Teresa, editor

Published
2012
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36. Prosthetic Pacing Device for Unilateral Facial Paralysis

Author

Rantanen, Ville, primary, Vehkaoja, Antti, additional, Verho, Jarmo, additional, Veselý, Petr, additional, Lylykangas, Jani, additional, Ilves, Mirja, additional, Mäkelä, Eeva, additional, Rautiainen, Markus, additional, Surakka, Veikko, additional, and Lekkala, Jukka, additional

Published
2016
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41. Microfabricated porous SU-8 membranes as innervation interfaces for hiPSC-neurons in microfluidic devices

Author

Salpavaara, Timo, Joki, Tiina, Skogberg, Anne, Rebelo Calejo, Teresa, Lekkala, Jukka, Narkilahti, Susanna, Kallio, Pasi, Tampere University, BioMediTech, and Clinical Medicine

Subjects
3111 Biomedicine
Abstract

In this study, we developed microfabricated porous membranes aimed at facilitating innervation in 3D cell culture models. The aim of the paper is to introduce a fabrication method for porous membranes with adjustable size, shape and location of the pores without obstructing imaging or the connectivity of the cells. The method is based on making a patterned SU-8 layer on a sacrificial aluminium layer by UV lithography and releasing it with etching. With the proposed method, we were able to produce single-layer self-supporting membranes that were used as interfaces in compartmentalized microfluidic devices. The functionality of the membranes and their cytocompatibility were tested by culturing human pluripotent stem cell (hPSC)-derived neurons on their surfaces. In vitro experiments demonstrated that a dense neural network develops on top of the proposed membranes within a week. Neurites were able to migrate through the pores to the bottom side of the membranes. We achieved partial, but still significant, axonal isolation. The results of this study will pave the way for the development of optimized innervated tissue models by using the combination of porous SU-8 membrane substrates, microelectrode arrays and hPSC-derived neurons in compartmentalized cell cultivation devices. publishedVersion

Published
2021

45. Transparent Microelectrode Arrays Fabricated by Ion Beam Assisted Deposition for Neuronal Cell in Vitro Recordings

Author

Ryynänen, Tomi, Mzezewa, Ropafadzo, Meriläinen, Ella, Hyvärinen, Tanja, Lekkala, Jukka, Narkilahti, Susanna, Kallio, Pasi, Tampere University, BioMediTech, and Clinical Medicine

Subjects
indium tin oxide (ITO), lcsh:Mechanical engineering and machinery, ion beam assisted electron beam deposition (IBAD), neurons, lcsh:TJ1-1570, 217 Medical engineering, titanium nitride (TiN), transparent, microelectrode array (MEA), Article
Abstract

Microelectrode array (MEA) is a tool used for recording bioelectric signals from electrically active cells in vitro. In this paper, ion beam assisted electron beam deposition (IBAD) has been used for depositing indium tin oxide (ITO) and titanium nitride (TiN) thin films which are applied as transparent track and electrode materials in MEAs. In the first version, both tracks and electrodes were made of ITOto guarantee full transparency and thus optimal imaging capability. In the second version, very thin (20 nm) ITO electrodes were coated with a thin (40 nm) TiN layer to decrease the impedance of O30 μm electrodes to one third (1200 kΩ → 320 kΩ) while maintaining (partial) transparency. The third version was also composed of transparent ITO tracks, but the measurement properties were optimized by using thick (200 nm) opaque TiN electrodes. In addition to the impedance, the optical transmission and electric noise levels of all three versions were characterized and the functionality of the MEAs was successfully demonstrated using human pluripotent stem cell-derived neuronal cells. To understand more thoroughly the factors contributing to the impedance, MEAs with higher IBAD ITO thickness as well as commercial sputter-deposited and highly conductive ITO were fabricated for comparison. Even if the sheet-resistance of our IBAD ITO thin films is very high compared to the sputtered one, the impedances of the MEAs of each ITO grade were found to be practically equal (e.g., 300-370 kΩ for O30 μm electrodes with 40 nm TiN coating). This implies that the increased resistance of the tracks, either caused by lower thickness or lower conductivity, has hardly any contribution to the impedance of the MEA electrodes. The impedance is almost completely defined by the double-layer interface between the electrode top layer and the medium including cells. publishedVersion

Published
2020

47. Piezo- and pyroelectrictiy of a polymer-foam space-charge electret

Author

Neugschwandtner, Gerhard S., Schwodiauer, Reinhard, Bauer-Gogonea, Simona, Bauer, Siegfried, Paajanen, Mika, and Lekkala, Jukka

Subjects
Polymers -- Research, Pyroelectricity -- Research, Physics
Abstract

Piezo- and pyroelectricity are demonstrated in charged polymer foams, with a focus on determining pyroelectric, anisotropic elastic and piezolectric properties.

Published
2001

49. Effect of pulse waveforms on movement amplitudes and perceived discomfort in electric muscle stimulation in unresolved facial nerve palsy

Author

Mäkelä, Eeva A, primary, Ilves, Mirja K, additional, Venesvirta, Hanna M, additional, Lylykangas, Jani K, additional, Rantanen, Ville T, additional, Vehkaoja, Antti T, additional, Verho, Jarmo A, additional, Lekkala, Jukka, additional, Surakka, Veikko V, additional, and Rautiainen, Markus E P, additional

Published
2020
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50. Transferring scents over a communication network

Author

Isokoski, Poika, primary, Salminen, Katri, additional, Müller, Philipp, additional, Rantala, Jussi, additional, Nieminen, Ville, additional, Karjalainen, Markus, additional, Väliaho, Jari, additional, Kontunen, Anton, additional, Savia, Marjaana, additional, Leivo, Joni, additional, Telembeci, Anca, additional, Lekkala, Jukka, additional, Kallio, Pasi, additional, and Surakka, Veikko, additional

Published
2020
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