IEEE transactions on bio-medical engineering
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A long-term implantable photoplethysmographic sensor system is proposed. The system employs an elastic cuff which is directly wrapped around an arterial blood vessel. ⋯ The sensor will permit real-time, continuous monitoring of important vital parameters such as arterial blood oxygen saturation and pulse rate over a long-term period in vivo. We emphasize on the specific requirements for design and instrumentation of the implantable sensor and discuss first in vitro data acquired with that new photonics-based sensor.
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IEEE Trans Biomed Eng · Feb 2008
Validation of non-rigid registration between functional and anatomical magnetic resonance brain images.
This paper presents a set of validation procedures for nonrigid registration of functional EPI to anatomical MRI brain images. Although various registration techniques have been developed and validated for high-resolution anatomical MRI images, due to a lack of quantitative and qualitative validation procedures, the use of nonrigid registration between functional EPI and anatomical MRI images has not yet been deployed in neuroimaging studies. ⋯ Bound constraints, resolution level and cross-validation issues have been discussed to show the degree of accuracy and effectiveness of the nonrigid registration technique. The analyses performed reveal that the nonrigid approach provides a more accurate registration, in particular when the functional regions of interest lie in regions distorted by susceptibility artifacts.
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IEEE Trans Biomed Eng · Feb 2008
Investigation of optimum electrode locations by using an automatized surface electromyography analysis technique.
Identification of the innervation zone is widely used to optimize the accuracy and precision of noninvasive surface electromyography (EMG) signals because the EMG signal is strongly influenced by innervation zones. However, simply structured fusiform muscle, such as biceps brachii muscle, has been employed mainly due to the simplicity with which the propagation from raw EMG signals can be observed. In this study, the optimum electrode location (OEL), free from innervational influence, was investigated by the propagation pattern of action potentials for brachii muscles and more complicated deltoid muscle structures using an automatized signal analysis technique. ⋯ The propagation patterns and OEL were examined from biceps brachii muscles for all subjects and from deltoid muscles for seven subjects. The estimated locations were partially confirmed by comparing the root mean squares of the EMG signals. These results show that propagation patterns and OEL could be estimated simply and automatically even from the surface EMG signals of deltoid muscles.
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IEEE Trans Biomed Eng · Feb 2008
Online classification of single EEG trials during finger movements.
Many offline studies have explored the feasibility of EEG potentials related to single limb movements for a brain-computer interface (BCI) control signal. However, only few functional online single-trial BCI systems have been reported. We investigated whether inexperienced subjects could control a BCI accurately by means of visually-cued left versus right index finger movements, performed every 2 s, after only a 20-min training period. ⋯ They could choose the correct target in 84%-100% of the cases, 3.5-7.7 times a minute. Their mean single trial classification rate was 80% and bit rate 10 bits/min. These results encourage the development of BCIs for paralyzed persons based on detection of single-trial movement attempts.