
Jaakko MalmivuoTechnische Universität Berlin | TUB · Department of Energy and Automation Technology
Jaakko Malmivuo
Professor, Dr. Tech.
About
648
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Introduction
Home pages: www.bem.fi, www.bem.fi/malmivuo,
Internet education: www.evicab.eu,
International Society for Bioelectromagnetism: www.isbem.org,
International Congress of Bioelectromagnetism: www.isbem.org > Congresses,
Ragnar Granit Society: www.rgs.fi
Additional affiliations
Publications
Publications (648)
Proceedings of the International Conference on
Bioelectromagnetism, Electrical Bioimpedance, and
Electrical Impedance Tomography,
ICBEM-ICEBI-EIT 2022.
June 29 – July 1, 2022
Virtual / Kyung Hee University
Did you know that there are five Finnish Nobel laureates? In addition to F. E. Sillanpää,
A. I. Virtanen, Martti Ahtisaari, and Bengt Holmström, Ragnar Granit received the Nobel
Prize in 1967 for his research on the color vision of the eye. Granit conducted this
research at the Institute of Physiology of the University of Helsinki, located on the
S...
Bioelectromagnetism
Version in Vietnamese language
Hanoi University
Hanoi, Vietnam
With a clinical study of 313 subjects, we demonstrated that though the lead fields of ECG and MCG are fully independent, the recorded signals are only partially independent. We demonstrated that this principle is true also within the three orthogonal dipolar leads of ECG as well as MCG.
Ragnar Granit was born in 1900 in Helsinki, Finland. He went to school at Swedish Lyceum in Helsinki. His university studies he made at the University of Helsinki and he graduated from the faculty of medicine. He defended his doctoral thesis in 1926. He was a researcher at Oxford University and the University of Pennsylvania in the 1920s and 1930s....
Ragnar Granit was born in 1900 in Oulunkylä, the parish of Helsinge, Finland. He went to school at Swedish Lyceum in Helsinki. His university studies he made at the University of Helsinki and he graduated from the faculty of medicine. He defended his doctoral thesis in 1926. He was a researcher at Oxford University and the University of Pennsylvani...
In the modern society the cardiac diseases are the major cause of serious illnesses and death. The most popular diagnostic method for these is the recording of the activity of the cardiac muscle by recording its electric and/or magnetic field. These are called the electrocardiogram, ECG and magnetocardiogram, MCG, respectively. ECG and MCG have bee...
Biomagnetic fields are generated by the same phenomenon as the bioelectric fields. They are induced by the electric currents generated by the activating tissues. These are primarily nerve and muscle tissues. The theoretical difference between these fields is based on the distribution of the elements of the volume sources generating these fields. Bi...
Electrical impedance tomography (EIT) is an promising imaging technology for continuous bedside monitoring of ventilation and perfusion. However, due to the spatial and frequency overlapping of ventilation and cardiac components in the heart-lung interaction system, it's difficult to separate the components in spontaneous breathing subjects. We int...
Electrical impedance tomography (EIT) is an promising imaging technology for continuous bedside monitoring of ventilation and perfusion. However, due to the spatial and frequency overlapping of ventilation and cardiac components in the heart-lung interaction system, it's difficult to separate the components in spontaneous breathing subjects. We int...
In 1900s it was generally thought that Finland had only two Nobelists: Frans Emil Sillanpää, Literature 1939, and Artturi Ilmari Virtanen, Chemistry 1945. However, the fact is that since 1967 Finland had two science Nobelists. Ragnar Granit received the Nobel Prize in Physiology or Medicine in 1967. However, this has not always considered as Finnis...
Jos tavalliselta suomalaiselta kysyttiin sotien jälkeisenä aikana ennen 2000-lukua kuinka monta Nobel-palkintoa suomalaiset olivat saaneet, vastaus oli mitä todennäköisemmin: Suomalaisia nobelisteja on kaksi, Frans Emil Sillanpää ja Artturi I. Virtanen. Tiedenobelisteja näistä on siis vain yksi. Vaikka Suomen asukasluku on pieni, oltiin silti sitä...
Ragnar Arthur Granit was born on 30th October 1900 in the then Parish of Helsinki into the family of forestry officer Arthur Wilhelm Granit (born 1871) and his wife Bertie Granit (born 1878). The Granit family is originally from Korppoo, from the south-western archipelago of Finland. The family home for over 100 years was in Vikminne in Korpoström....
It is first introduced the principle of reciprocity, which is shown to be a very powerful tool in analysing the properties of bioelectric and biomagnetic fields and instruments. It makes it possible to solve the most fundamental problems in bioelectromagnetism. Then a short historical review of biomagnetic measurements is presented. This is followe...
Background: Delayed medical attendance is a leading cause of death in patients with ST elevation
myocardial infarction (STEMI).
Methods: We aimed to introduce, develop, and validate a novel method (RELF method) for detection of
transmural ischemia based on a new and easy-to-use 3-lead configuration and orthonormalization of ST
reference vectors (ST...
In the history of science it is usually listed who were the scientists who first made certain important contributions to the science. So it is in the field of bioelectro-magnetism as well. A typical example is Luigi Galvani as the first to do bimetallic stimulation of the frog muscle. Without attempting to take from Galvani the honor as famous scie...
Professor Robert Plonsey passed away in March 2015. He was a notable contributor to the discipline of bioelectromagnetism. He was founding member and Honorary President of the International Society for Bioelectromagnetism. Therefore this 10th International Conference on Bioelectromagnetism is a proper place to organize a session in his memory. In t...
Linear methods of reconstruction play an important role in medical electrical impedance tomography (EIT) and there is a wide variety of algorithms based on several assumptions. With the Graz consensus reconstruction algorithm for EIT (GREIT), a novel linear reconstruction algorithm as well as a standardized framework for evaluating and comparing me...
We have shown that the spatial resolution of electroencephalography EEG, is as good or better than that of magnetoencephalography MEG. In addition, the instrumentation for EEG is at least an order of magnitude cheaper than that for MEG. The positioning of the MEG recording dewar is far more simple and fast than fixing the traditional EEG-electrodes...
After the Baltic States regained their independence in the 1990s, I started to create contacts with them, especially with Estonia, to help in developing the education and research in biomedical engineering. During my first visit to Tallinn University of Technology in 1993 I recognized that they had a need for relevant study materials in biomedical...
Non-invasive estimation of bladder volume could help patients with impaired bladder volume sensation to determine the right moment for catheterisation. Continuous, non-invasive impedance measurement is a promising technology in this scenario, although influences of body posture and unknown urine conductivity limit wide clinical use today. We studie...
Introduction.
Professor Steffen Leonhardt presents the lecturer
1. Introduction to bioelectromagnetism, 1.1-1.3
Short history of bioelectromagnetism, 1.4
Nobel Prizes in bioelectromagnetism, 1.5
Lecture 2.
Part I. Anatomical and Physiological Basis of Bioelectromagnetism
2. Nerve and muscle cells
3. Subthreshold membrane phenomena
4. Active behavior of the membrane
5. Synapses, receptor cells and brain, 5.1-5.2
5. Synapses, receptor cells and brain (Cont.), 5.3-5.5
6. The heart
Appendix A. Consistent System of Rectangular and Spherical Coordinates for ECG and MCG
Part II. Bioelectric Sources and Conductors and Their Modeling
7. Volume source and volume conductor
Part III. Theoretical Methods in Bioelectromagnetism
11. Theoretical methods for analysing volume sources and volume conductors,
11.1-11.4.
11. Theoretical methods for analysing volume sources and volume conductors (Cont.), 11.4-11.8.
Bioelectromagnetism Education at the Helmholtz Institute, RWT Aachen University, Aachen, Germany.
11. Theoretical methods for analysing volume sources and volume conductors (Cont.), 11.7-11.8
12. Theory of biomagnetic measurements
Part IV. Electric and Magnetis Measurement of the Electric Activity of the Neural Tissue
13. Electroencephalography, 13...
Bioelectromagnetism Education at the Helmholtz Institute, RWT Aachen University, Aachen, Germany.
Part V. Electric and Magnetic Measurement of the Electric Activity of the Heart
15. 12-lead ECG-system
16. Vectorcardiographic lead systems, 16.1-16.2
16. Vectorcardiographic lead systems (Cont.), 16.3-16.4
17. Other ECG lead systems
18. Distortion factors in the ECG
19. The basis of ECG diagnosis
20. Magnetocardiography
Part VI. Electric and Magnetic Stimulation of Neural Tissue
21. Functional electrical stimulation
Theodore von Kármán Fellowship Lecture.
Short history of biomagnetism
22. Magnetic stimulation of the neural tissue
Part VII. Electric and Magnetic Stimulation of the Heart
23. Cardiac pacing
24. Cardiac defibrillation
Part VIII. Measurement of the Intrinsic Electric Properties of Biological Tissues
25. Impedance plethysmography, 25.1-25.3
Lecture 14. Introduction
25. Impedance plethysmography (Cont.), 25.4-25.6
26. Impedance tomography
27. The electrodermal response
Part IX. Other Bioelectromagnetic Phenomena
28. The electric signals originating in the eye
The course provides a general view of bioelectromagnetism and describes it as an independent discipline. It begins with a historical account of the many innovations and innovators on whose work the field rests. This is accompanied by a discussion of both the theories and experiments which were contributed to the development of the field.
The physio...
The advantages of the Internet in education are widely acknowledged by students and teachers all over the world. The authors have developed EVICAB as a free-access portal for e-learning with a full curriculum in biomedical engineering. It may be used as a virtual campus to support classroom lecturing or for distant learning. EVICAB provides educati...
It is generally believed that the first experiment on bimetallic electric stimulation of living body was made by Luigi Galvani with frog leg in 1786. Galvani however succeeded to produce electric stimulation of the frog leg already in 1781 with electricity produced with electric machine. It has been suggested by Rowbottom and Susskind that the firs...
The first solution for the independence/interdependence of the bioelectric and biomagnetic signals was made by Malmivuo. It was concluded, that even though the dipolar electric and magnetic lead fields where orthogonal, i.e. independent, the recorded signals are only partially independent. Actually, this is the case also with the three orthogonal d...
The theoretical solution for the independence of bioelectric and biomagnetic signals rising from volume sources was published by Jaakko Malmivuo in 1995 [1]. In 2000 his research group published a clinical study on electro- and magnetocardiography which confirmed this result [2, 3]. In 2005 Iwasaki and co-workers published a clinical study on the d...
Accurate source localization of the epileptogenic regions require EEG data that reflect only the epileptic activity. Isolating the ictal activity from the other artifacts and normal background activity of the brain is a challenge. In this work we apply independent component analysis to first obtain independent source signals from ictal recordings o...
In this work, we apply independent component analysis (ICA) to decompose the epileptic electroencephalographic (EEG) data into independent components. After computing the spectral coherence of IC, only components with high synchrony were retained while constructing the EEG. The reconstructed EEG was then used as an input for the source localization...
The Internet has been widely used as a powerful tool in education [1]. It gives the possibility to deliver teaching and learning material widely all over the world without the need for students or teachers to travel and be present at the same location. For this we have developed a free access e-learning portal European Virtual Campus for Biomedical...
The Internet has been widely used as a powerful educational tool. It gives the possibility to deliver the educational material widely all over the world without the need of the students or the teachers to travel and be present at the same location. For this we have developed the e-learning portal EVICAB (European VIrtual CAmpus for Biomedical engin...
- The well-documented success of deep brain stimulation (DBS) in treating movement disorders has gathered a lot of interest among epileptologists.
- However, treatment with DBS in epilepsy is poorly understood with respect to , 1) How DBS affects the epileptic networks, 2) What are the ideal parameters, 3) What seizures are best controlled.
- Local...
The principle of reciprocity is a general principle, which holds for all linear systems. It was first described by Hermann von Helmholtz over 150 years ago [1]. In brief, it may be described by noting, that the source and the measurement sites may be swapped without a change in the detected signal. For us, who work with bioelectromagnetic problems...
Though the principle of reciprocity was invented by Hermann von Helmholtz already over 150 years ago, and though it is a very powerful tool in solving various important problems in bioelectromagnetism, it is not generally used. In impedance tomography the measurement sensitivity distribution has generally been misunderstood. This can be easily demo...
Since the detection of the first biomagnetic signals in 1963 there has been continuous discussion on the properties and relative merits of bioelectric and biomagnetic measurements. In this review article it is briefly discussed the early history of this controversy. Then the theory of the independence and interdependence of bioelectric and biomagne...
We have previously developed a weighted multielectrode lead (WMEL) method to improve the signal-to-noise ratio (SNR) of electroencephalography (EEG) signals generated deep in the brain.
The objective of this study was to compare the WMEL method to beamformers, which is a more commonly known spatial filtering method.
Internet is more and more frequently used in education. We have used Internet examination in the ordinary teaching in the Institute and in the courses given by the author in other universities in Finland and abroad. 2. Materials and Methods The European VIrtual CAmpus for Biomedical engineering, EVICAB, is a novel Internet portal located in the add...
Though the principle of reciprocity was invented by Hermann von Helmholtz already over 150 years ago, and though it is a very powerful tool in solving various important problems in bioelectromagnetism, it is not generally used. In impedance tomography the measurement sensitivity distribution has generally been misunderstood. This can be easily demo...
Electroencephalography (EEG) is a non-invasive way of measuring the electrical activity of the brain from the scalp using electrodes. The EEG offers excellent temporal resolution, but suffers due to limited spatial resolution. This is due to the volume conduction effects of the tissues present in the human head between the sources and sensors. Esti...
E-learning can provide many advantages for Biomedical Engineering (BME) educationt. An increasing number of applications of e-learning urges a need to find methods how to evaluate them. The aim of this study was to investigate how e-learning has been developing so far (during the years 2006-2009) among BME education offering centers in Europe and t...
This paper presents technologies and methods that have been used when developing a virtual campus for Biomedical Engineering. Modern educational technologies have been applied to produce video lectures for personal computers, iPods, media phones, and to integrate virtual communication system. It became possible to break traditional classroom bounda...
Background: The electroencephalography (EEG) is an attractive and a simple technique to measure the brain activity. It is attractive due its excellent temporal resolution and simple due to its non-invasiveness and sensor design. However, the spatial resolution of EEG is reduced due to the low conducting skull. In this paper, we compute the potentia...
Volume conductor head models contain thin tissue layers, some of which have highly contrasting conductivity values relative to neighboring tissues. We expound the cerebrospinal fluid (CSF) and the six cortical layers of the gray matter. The dual nature of the CSF competes with the well-known shunting behavior of the skull. The incorporation of the...
Though the principle of reciprocity was invented by Hermann von Helmholtz already over 150 years ago, and though it is a very powerful tool in solving various important problems in bioelectromagnetism, it is not generally used. In impedance tomography the measurement sensitivity distribution has generally been misunderstood. This can be easily
demo...
Learning objects are fundamental elements of e-learning content creation and distribution. High quality and pedagogically valuable learning objects can lead to better results in education. In this paper we briefly present several learning objects developed and applied for EVICAB, European Virtual Campus for Biomedical Engineering. Thus, implemented...
Bioelectric source measurements are influenced by the measurement location as well as the conductive
properties of the tissues. Volume conductor effects such as the poorly conducting bones or the moderately conducting skin are known to affect the measurement precision and accuracy of the surface electroencephalography (EEG) measurements. This paper...
This publication describes a measurement method where on the scalp (1) there are several measurement electrodes (2). The signals which they measure are weighed with amplifiers (3) so that the system has homogeneous measurement sensitivity (4) in the region of the brain. In a spherical head model the weighing is proportional to the cosine of the mea...
Our goal is to quantitatively analyze tissues thicknesses of the human head using two measurement trajectories. The results can aid in tissue atlases, creation of realistically shaped models, adapting generalized templates to reflect a more-personalized model, and studying the changes related to aging and morphologically-progressive diseases.
The main advantage of video lectures is being able to break spatial and temporal constrains when disseminating information. We briefly present the system used for recording and diffusing video lectures over the Internet. The process of recording and diffusing video lectures may be divided into 5 main steps: prepare, record, edit, produce, and share...
An ideal bioelectric measurement should be focused on and specific to the target region. Volume conductor effects such as the poorly conducting bones or the moderately conducting skin are known to affect the specificity and accuracy of the surface electroencephalography (EEG) measurements. This paper introduces a modeling study on the effect of bip...
Borrowing from the fields of paleoanthropology and cranial anthropology we mathematically transform a uni-versal head model to reflect the size of an average female of other ethnic groups. Our goal is to make deformable generic head models readily available for individuals who have not been medically imaged. We concluded that elliptical and exponen...
In this paper the design and testing of an active electrode are presented. The purpose was to design a low noise small sized active electrode that can be used to measure electroencephalography (EEG) and increase the signal-to-noise ratio of the measured signal. During the design process a unity gain active electrode was developed. It acts as a volt...
The main advantage of video lectures is being able to break spatial and temporal constrains when disseminating information. We briefly present the system used for recording and diffusing video lectures over the Internet. The process of recording and diffusing video lectures may be divided into 5 main steps: prepare, record, edit, produce,, and shar...
In this paper the design and testing of an active electrode are presented. The purpose was to design a low noise small sized active electrode that can be used to measure electroencephalography (EEG) and increase the signal-to-noise ratio of the measured signal. During the design process a unity gain active electrode was developed. It acts as a volt...
We have developed a multielectrode lead technique to improve the signal-to-noise ratio (SNR) of scalp-recorded electroencephalography (EEG) signals generated deep in the brain. The basis of the method lies in optimization of the measurement sensitivity distribution of the multielectrode lead. We claim that two factors improve the SNR in a multielec...
New portable electrocardiogram (ECG) measurement systems are emerging into market. Some use nonstandard bipolar electrode montage and sometimes very small interelectrode distances to improve the usability of the system. Modeling could provide a straightforward method to test new electrode systems. The aim of this study was to assess whether modelin...
Our goal is to explain the influence of thin tissue layers so that we can determine the consequence of including or excluding such tissues in our head models
Stimulation of peripheral nerves by electric impulses offers a new and elegant way to help patient suffering from nerve disorders (both peripheral and central). The purpose of this study is to test the applicability of the commercial transcutaneous electrical stimulator (TCES) in a different types of peroneal weakness (central and peripheral nerve...
We present the four key areas of research—preprocessing, the volume conductor, the forward problem, and the inverse problem—that affect the performance of EEG and MEG source
imaging. In each key area we identify prominent approaches and methodologies that have open
issues warranting further investigation within the community, challenges associated...
High-resolution medical images coupled with advanced image processing techniques enable an accurate quantitative analysis of the human head tissues. In this work we measured the scalp/skin, cranial muscles, fat, connective tissue, skull, cerebrospinal fluid (CSF), gray matter and white matter thicknesses beneath the standard 10-20 EEG locations on...
Replacing damaged neural tissue with stem cells in the brain is a seriously invasive procedure. We present ways of monitoring the bioelectric changes with some types of electroencephalography (EEG). The larger implantations of 1 cm 3 are much easier to monitor, whereas the smaller 0.5 mm 3 volumes are more difficult to detect. We show that traditio...
Bioelectric measurements are influenced by the measurement location as well as the conductive properties of the tissue. Volume conductor effects such as the poorly conducting bones or the moderately conducting skin are known to affect the specificity and accuracy of the surface electroencephalography (EEG) measurements. This paper investigates the...
The goal of this paper is to evaluate students' attitudes towards virtual learning objects for biomedical engineering (BME). Students were able to attend traditional classroom lectures, learn virtually, or both. We developed questionnaire to collect students' feedback and analyzed web log-ins. It is envisioned that results of this study will inform...
Volume conductor head models contain thin tissue layers, some of which have highly contrasting conductivity values relative to neighboring tissues. We expound upon the often excluded cerebrospinal fluid (CSF) to relate the similar effects of the diploe i.e. the soft table of the skull. The CSF introduces such a high conductivity ratio relative to i...
Internet is more and more used as an educational tool. We have developed the EVICAB platform which provides a curriculum in Biomedical Engineering. EVICAB includes the educational material in various formats eg. lecture videos, lecture slides, textbook, exercises and examination. The video material is available in various formats to be viewed on th...
Internet is more and more used as an educational tool. We have developed the EVICAB platform which provides a curriculum in Biomedical Engineering. EVICAB includes the educational material in various formats eg. lecture videos, lecture slides, textbook, exercises and examination. The video material is available in various formats to be viewed on th...
The aim of this study is to develop a new multielectrode lead method to improve the SNR of EEG signals generated deep in the brain. This method is based on modifying the measurement sensitivity distribution with the aid of the lead field and reciprocity theorems.