Petri Laarne, Martha Arbayani Zaidan, Tuomo Nieminen,
We present ennemi, a Python package for correlation analysis based on mutual information (MI). MI is a measure of relationship between variables. Unlike Pearson correlation it is valid also for non-linear relationships, yet in the linear case the two are equivalent. The effect of other variables can be removed like with partial correlation, with the same equivalence. These features make MI a better correlation measure for exploratory analysis of many variable pairs. Our package provides methods for ...
Tópico(s): Blind Source Separation Techniques
2021 - Elsevier BV | SoftwareX
H Järvinen, Raija Seuri, Mika Kortesniemi, Atte Lajunen, Elina Hallinen, Päivi Savikurki-Heikkilä, P. Laarne, Marja Perhomaa, Erja Tyrväinen,
Indication-based national diagnostic reference levels (DRLs) for a few most common paediatric computed tomography (CT) examinations are proposed. Patient dose data (CTDI vol and dose length product) were collected for over 1000 patients in 4 university hospitals with best experiences in paediatric CT. Four indications for chest CT and two for abdomen (abdomen + pelvis), chest + abdomen and head CT were considered. The DRLs for the body examinations are proposed as exponential DRL-curves, where CTDI vol ...
Tópico(s): Cardiac, Anesthesia and Surgical Outcomes
2015 - Oxford University Press | Radiation Protection Dosimetry
Outi Ryynanen, Jari Hyttinen, P. Laarne, Jaakko Malmivuo,
The purpose of the present study was to examine the spatial resolution of electroencephalography (EEG) by means of inverse cortical EEG solution. The main interest was to study how the number of measurement electrodes and the amount of measurement noise affects the spatial resolution. A three-layer spherical head model was used to obtain the source-field relationship of cortical potentials and scalp EEG field. Singular value decomposition was used to evaluate the spatial resolution with various measurement ...
Tópico(s): Functional Brain Connectivity Studies
2004 - Institute of Electrical and Electronics Engineers | IEEE Transactions on Biomedical Engineering
P. Laarne, Jari Hyttinen, Silke Dodel, Jaakko Malmivuo, Hannu Eskola,
Two inverse algorithms were applied for solving the EEG inverse problem assuming a single dipole as a source model. For increasing the efficiency of the forward computations the lead field approach based on the reciprocity theorem was applied. This method provides a procedure to calculate the computationally heavy forward problem by a single solution for each EEG lead. A realistically shaped volume conductor model with five major tissue compartments was employed to obtain the lead fields of the ...
Tópico(s): EEG and Brain-Computer Interfaces
2000 - Elsevier BV | Computers and Biomedical Research
Tópico(s): EEG and Brain-Computer Interfaces
2000 - Springer Science+Business Media | Brain Topography
P. Laarne, P. Kauppinen, Jari Hyttinen, Jaakko Malmivuo, Hannu Eskola,
Tópico(s): Neonatal and fetal brain pathology
1999 - Springer Science+Business Media | Medical & Biological Engineering & Computing
P. Kauppinen, Jari Hyttinen, P. Laarne, Jaakko Malmivuo,
There is an evolving need for new information available by employing patient tailored anatomically accurate computer models of the electrical properties of the human body. Because construction of a computer model can be difficult and laborious to perform sufficiently well, devised models have varied greatly in the level of anatomical accuracy incorporated in them. This has restricted the validity of conducted simulations. In the present study, a versatile software package was developed to transform ...
Tópico(s): Electrical and Bioimpedance Tomography
1999 - Elsevier BV | Computer Methods and Programs in Biomedicine
T. Heinonen, Hannu Eskola, Prasun Dastidar, P. Laarne, Jaakko Malmivuo,
This paper describes a segmentation method primarily developed for reconstructing resistive head models for electroencephalographic modelling purposes. The method was implemented by combining several image processing techniques, such as amplitude segmentation, region growing, and image fusion. Also a graphical user interface was developed to enable semiautomatic approach to the segmentation process. This method was developed especially for segmentation of the brain and skull from T1-weighted magnetic ...
Tópico(s): Advanced MRI Techniques and Applications
1997 - Elsevier BV | Computer Methods and Programs in Biomedicine
P. Laarne, Hannu Eskola, Jari Hyttinen, V. Suihko, Jaakko Malmivuo,
A computer model has been designed for the calculation of the electrical fields in the head, based on the finite difference method. This method has not previously been applied for head modelling. The model was validated by using three concentric spheres and comparing it with an analytic model. Three levels of accuracy were tested. The forward solutions show that the finite difference algorithm works correctly and, by selecting the size of the volume elements properly, accurate results are obtained. ...
Tópico(s): Optical Imaging and Spectroscopy Techniques
1995 - Taylor & Francis | Journal of Medical Engineering & Technology
Petri Laarne, Emil Amnell, Martha Arbayani Zaidan, Santtu Mikkonen, Tuomo Nieminen,
Relations between atmospheric variables are often non-linear, which complicates research efforts to explore and understand multivariable datasets. We describe a mutual information approach to screen for the most significant associations in this setting. This method robustly detects linear and non-linear dependencies after minor data quality checking. Confounding factors and seasonal cycles can be taken into account without predefined models. We present two case studies of this method. The first ...
Tópico(s): Air Quality Monitoring and Forecasting
2022 - Multidisciplinary Digital Publishing Institute | Atmosphere
Milla Laarne, Ali Oghabian, Jenni Laitila, Pirjo Isohanni, Olli Tynninen, Fang Zhao, Fanny Rostedt, J. Sarparanta, Lydia Sagath, Michael W. Lawlor, Carina Wallgren‐Pettersson, Vilma‐Lotta Lehtokari, Katarina Pelin,
Tópico(s): Cardiovascular Effects of Exercise
2025 - IOS Press | Journal of Neuromuscular Diseases
Jose Mari Louis Alforque, Lovelyn Tipon, Jillian A. Bejoc, Laarne Pontillas, Julius C. Daño, Alberich F. Machacon, Esperidion B. Corvera, Alain Kenneth S. Ragay, Hazel L. Cañeda,
The COVID-19 Outbreak has compelled many universities and any other learning institutions to immediately switch to the online platform in the continued delivery of lessons. Pandemic Teaching has allowed many to rethink how much course content is enough to achieve course learning objectives, and to reimagine traditional assessments as new and different learning opportunities. This study explored on the lived experience of university educators as they transition from the online learning to face-to- ...
Tópico(s): Healthcare Education and Workforce Issues
2024 - | International journal of research and scientific innovation
M. Laarne, J. Sarparanta, Carina Wallgren‐Pettersson, Manu Jokela, B. Udd, P. Hackman, Vilma‐Lotta Lehtokari, Katarina Pelin,
Tópico(s): 14-3-3 protein interactions
2024 - Elsevier BV | Neuromuscular Disorders
Rut Christiani, Hannu Eskola, Florentino Luciano Caetano dos Santos, P. Laarne,
Conclusions.Our results show that demographic factors including mean breast thickness and breast prosthesis affect MGD of patients in our region.Finally, our findings show a modest increase of radiation dose to the breast by digital mammography due to the average breast thickness of our patients.
Tópico(s): Medical Imaging Techniques and Applications
2018 - Elsevier BV | Physica Medica
T. Heinonen, Antti Lahtinen, Prasun Dastidar, Pertti Ryymin, Paeivi Laarne, Jaakko Malmivuo, E. M. Laasonen, Harry Frey, Hannu Eskola,
After the introduction of digital imagin devices in medicine computerized tissue recognition and classification have become important in research and clinical applications. Segmented data can be applied among numerous research fields including volumetric analysis of particular tissues and structures, construction of anatomical modes, 3D visualization, and multimodal visualization, hence making segmentation essential in modern image analysis. In this research project several PC based software were ...
Tópico(s): Medical Imaging Techniques and Applications
1999 - SPIE | Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE