Abstract:
:Currently, simulations of the induced currents in the brain produced by transcranial magnetic stimulation (TMS) are used to elucidate the regions reached by stimuli. However, models commonly found in the literature are too general and neglect imperfections in the windings. Aiming to predict the stimulation sites in patients requires precise modeling of the electric field (E-field), and a proper calibration to adequate to the empirical data of the particular coil employed. Furthermore, most fabricators do not provide precise information about the coil geometries, and even using X-ray images may lead to subjective interpretations. We measured the three components of the vector magnetic field induced by a TMS figure-8 coil with spatial resolutions of up to 1 mm. Starting from a computerized tomography-based coil model, we applied a multivariate optimization algorithm to automatically modify the original model and obtain one that optimally fits the measurements. Differences between models were assessed in a human brain mesh using the finite-elements method showing up to 6% variations in the E-field magnitude. Our calibrated model could increase the precision of the estimated E-field induced in the brain during TMS, enhance the accuracy of delivered stimulation during functional brain mapping, and improve dosimetry for repetitive TMS. Graphical Abstract Geometrical model of TMS coil based on TAC images is optimally deformed to match magnetic field measurements. The calibrated model's induced electric field in the brain differs from the original.
journal_name
Med Biol Eng Computjournal_title
Medical & biological engineering & computingauthors
Mancino AV,Milano FE,Bertuzzi FM,Yampolsky CG,Ritacco LE,Risk MRdoi
10.1007/s11517-020-02156-2subject
Has Abstractpub_date
2020-07-01 00:00:00pages
1499-1514issue
7eissn
0140-0118issn
1741-0444pii
10.1007/s11517-020-02156-2journal_volume
58pub_type
杂志文章abstract::Many studies concerning the internal work of human motion have used two-dimensional kinematic models to estimate kinetic energy of the segments. The generalised co-ordinate concept has been applied here to a simultaneous and bilateral gait analysis. A three-dimensional kinematic model based on quaternions has been dev...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/BF02523852
更新日期:1996-11-01 00:00:00
abstract::We introduce a novel method for an automatic classification of subjects to those with or without neuromuscular disorders. This method is based on multiscale entropy of recorded surface electromyograms (sEMGs) and support vector classification. The method was evaluated on a single-channel experimental sEMGs recorded fr...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/s11517-010-0629-7
更新日期:2010-08-01 00:00:00
abstract::It is proposed that myo-electric signals can be used to augment conventional speech-recognition systems to improve their performance under acoustically noisy conditions (e.g. in an aircraft cockpit). A preliminary study is performed to ascertain the presence of speech information within myo-electric signals from facia...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/BF02345373
更新日期:2001-07-01 00:00:00
abstract::Pre-operative diagnosis of chest-wall deformity is important for successful surgical correction and post-operative evaluation of funnel chest patients. However, conventional indices that define the severity of deformity have several limitations; manually calculated and cannot supply information about asymmetry. We dev...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/s11517-008-0367-2
更新日期:2008-08-01 00:00:00
abstract::Single-ventricle anomaly is a hereditary heart disease that is characterized by anatomical malformations. The main consequence of this malformation is desaturated blood flow, which without proper treatment increases the risk of death. The classical treatment is based on a three-stage palliative procedure which should ...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/s11517-016-1499-4
更新日期:2017-02-01 00:00:00
abstract::The aim of the study was to develop a method for investigating how interictal epileptic discharges in temporal epilepsy patients are activated spatially. The activity was measured using magneto-encephalography (MEG). The MEG data were used to produce a current-arrow map that reflected the topographic distribution of t...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/BF02344215
更新日期:2002-05-01 00:00:00
abstract::We present an analytical solution for the electrical potential and activating function (AF) established by cylindrical needle electrodes in anisotropic tissue. We compare this activating function to (1) AF computed assuming line-source electrodes and (2) AF computed using a finite element program. The results show tha...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/s11517-009-0508-2
更新日期:2009-09-01 00:00:00
abstract::Past decades witnessed the expansion of linear signal processing methods in numerous biomedical applications. However, the nonlinear behavior of biomedical signals revived the interest in nonlinear signal processing methods such as higher-order statistics, in particular higher-order cumulants (HOC). In this paper, HOC...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/s11517-015-1394-4
更新日期:2015-11-01 00:00:00
abstract::In this study, the shape and the configuration of smooth muscle cells (SMCs) within the arterial wall are altered to investigate their influence on molecular transport across the media layer of the thoracic aorta wall. In a 2D geometry of the media layer containing SMCs, the finite-element method has been employed to ...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/s11517-007-0219-5
更新日期:2007-11-01 00:00:00
abstract::The fraction of repolarization variability independent of RR interval variability is of clinical interest. It has been linked to direct autonomic nervous system (ANS) regulation of the ventricles in healthy subjects and seems to reflect the instability of the ventricular repolarization process in heart disease. In thi...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/s11517-019-01998-9
更新日期:2019-08-01 00:00:00
abstract::Neurofilaments are organised into parallel bundles in axons through crossbridges formed by lateral projections of neurofilament subunits. Pure neurofilaments form gels in vitro, consisting of interconnected parallel arrays of filaments regulated by the phosphorylation level of neurofilament subunits. Neurofilament-ass...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/BF02522486
更新日期:1998-05-01 00:00:00
abstract::Electroencephalography (EEG) has been widely utilized to measure the depth of anaesthesia (DOA) during operation. However, the EEG signals are usually contaminated by artifacts which have a consequence on the measured DOA accuracy. In this study, an effective and useful filtering algorithm based on multivariate empiri...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/s11517-016-1598-2
更新日期:2017-08-01 00:00:00
abstract::An eye pointer was developed as a new line-of-sight displacement analyser. It analyses an observer's eye movements and superimposes their line of vision on a TV image which is the same as their view. A newly developed miniature colour field camera and very compact eye-movement sensors are attached to a translucent rei...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/BF02446149
更新日期:1990-07-01 00:00:00
abstract::The paper describes an investigation in which it is shown that small positive voltage pulses applied to an external conductor placed against the photocathode of a photomultiplier tube can be used to switch the photocathode completely off for the duration of the pulses. This suggests that a photomultiplier tube with a ...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/BF02441486
更新日期:1989-05-01 00:00:00
abstract::Electromyography (EMG) in a bio-driven system is used as a control signal, for driving a hand prosthesis or other wearable assistive devices. Processing to get informative drive signals involves three main modules: preprocessing, dimensionality reduction, and classification. This paper proposes a system for classifyin...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/s11517-018-1857-5
更新日期:2018-12-01 00:00:00
abstract::Abnormal localization of immature precursors (ALIP) aggregating and clustering in bone marrow biopsy appears earlier than that of bone marrow smears in detection of the relapse of acute myelocytic leukemia (AML). But traditional manual ALIP recognition has many shortcomings such as prone to false alarms, neglect of di...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/s11517-014-1223-1
更新日期:2015-03-01 00:00:00
abstract::Tissue hardness is related to tissue composition, and this is often changed by disease. It is therefore of interest to measure the hardness in an objective and non-invasive way. A tactile sensor based on a vibrating piezoelectric ceramic element in a feedback loop is described. When the sensor touches an object it pro...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/BF02513357
更新日期:1999-09-01 00:00:00
abstract::A rapid-access but limited vocabulary communication aid for the non-vocal and speech impaired is useful in some well defined situations. The design and construction of such a device is described. Three distinct situations have been identified where an aid is essential and an initial evaluation has shown the Pocket Spe...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/BF02441487
更新日期:1989-05-01 00:00:00
abstract::To evaluate the possibility of respiratory-volume measurement using photoplethysmography (PPG), PPG signals from 16 normal volunteers are collected, and the respiratory-induced intensity variations (RIIV) are digitally extracted. The RIIV signals are studied while respiratory volume is varied. Furthermore, respiratory...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/BF02513264
更新日期:1999-01-01 00:00:00
abstract::The first in vivo evaluation of a pO2 sensor constructed with a novel copolymer is described. The performance of the sensor is assessed under dynamic conditions in vitro and in vivo. This sensor is more stable and reliable than the control sensor with a heparin-treated polyethylene membrane. ...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/BF02511245
更新日期:1996-07-01 00:00:00
abstract::Nowadays, acoustic emission (AE) has its applications in various areas, including mechanical, civil, underwater acoustics, and biomedical engineering. It is a non-destructive evaluation (NDE) and a non-intrusive method to detect active damage mechanisms such as crack growth, delamination, and processes such as frictio...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章,评审
doi:10.1007/s11517-020-02202-z
更新日期:2020-08-01 00:00:00
abstract::Breast cancer is the most common cancer among women globally, and the number of young women diagnosed with this disease is gradually increasing over the years. Mammography is the current gold-standard technique although it is known to be less sensitive in detecting tumors in woman with dense breast tissue. Detecting a...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/s11517-015-1403-7
更新日期:2016-09-01 00:00:00
abstract::Several recent studies have quantified abnormalities in Parkinsonian gait. However, few studies have attempted to quantify the regularity of body motion during walking in patients with Parkinson's disease. The aim of the paper was to characterise body motion patterns in healthy, elderly subjects and patients with Park...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/BF02351008
更新日期:2004-01-01 00:00:00
abstract::To make picture archiving and communication systems (PACS) a practical reality for small-scale structures, it appears necessary to build a network that integrates and optimises production management, analysis and storage of images, and to include the ability to communicate with other similar remote structures. To solv...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/BF02458046
更新日期:1993-05-01 00:00:00
abstract::The visco-elastic properties of living cells, measured to date by various authors, vary considerably, depending on the experimental methods and/or on the theoretical models used. In the present study, two mechanisms thought to be involved in cellular visco-elastic responses were analysed, based on the idea that the cy...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/BF02349982
更新日期:2003-11-01 00:00:00
abstract::The regulation of cerebral blood flow (CBF) following changes in arterial blood pressure (ABP) and end-tidal pCO2 (EtCO2) are of clinical interest in assessing cerebrovascular reserve capacity. Linear finite-impulse-response modelling is applied to ABP, EtCO2 and CBF velocity (CBFV, from transcranial Doppler measureme...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/BF02345749
更新日期:2000-09-01 00:00:00
abstract::Tooth mobility examination is important in planning dental treatment, as it may give an indication of alveolar bone loss and the condition of the periodontal ligament. In clinical dental diagnosis a manual tooth mobility examination is useful. However, its determination of tooth mobility is subjective and depends on t...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/BF02442173
更新日期:1989-01-01 00:00:00
abstract::This work addresses the problem of estimating the conduction velocity (CV) of single motor unit (MU) action potentials from surface EMG signals detected with linear electrode arrays during voluntary muscle contractions. In ideal conditions, that is without shape or scale changes of the propagating signals and with add...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/BF02344807
更新日期:2001-03-01 00:00:00
abstract::We investigate a new framework of surgical instrument detection based on power-varying ultrasound images with simple and efficient pixel-wise intensity processing. Without using complicated feature extraction methods, we identified the instrument with an estimated optimal power level and by comparing pixel values of v...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/s11517-017-1695-x
更新日期:2018-03-01 00:00:00
abstract::The mechanism of brain contusion has been investigated using a series of three-dimensional (3D) finite element analyses. A head injury model was used to simulate forward and backward rotation around the upper cervical vertebra. Intracranial pressure and shear stress responses were calculated and compared. The results ...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/BF02347044
更新日期:2000-05-01 00:00:00