Differentiating between the early stages of Parkinson's Disease (PD) and other diseases with parkinsonian symptoms is difficult from analyzing motor degeneration symptoms alone. For this reason, a commonly used di...
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Differentiating between the early stages of Parkinson's Disease (PD) and other diseases with parkinsonian symptoms is difficult from analyzing motor degeneration symptoms alone. For this reason, a commonly used di...
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Differentiating between the early stages of Parkinson's Disease (PD) and other diseases with parkinsonian symptoms is difficult from analyzing motor degeneration symptoms alone. For this reason, a commonly used diagnostic marker for PD is the hyperechogenicity of the Substantia Nigra (SN), which can help to make an early differential diagnosis of PD. Current practice for determining if an image displays hyper-echogenicty relies on clinician experience heavily because of the difficulty of discerning features in standard B-mode imaging. Harmonic imaging has been studied extensively, and while it does improve the image quality, it suffers from spectral overlap with the noisy fundamental component. Our approach uses an adaptive Third Order Volterra Filter (ToVF), which avoids this problem by completely separating an image into its linear, quadratic, and cubic components with no overlap. One of the standard implementations of the ToVF is through an adaptive Recursive Least Squares (RLS) algorithm. This paper examines two algorithms developed through applying an ℓ 0 constraint on the standard RLS cost function. The two algorithms approximate this cost function in different ways, one using a Slow Time Varying (STV) approximation and the other using a Taylor Series Expansion (TSE) approximation. Theoretically the ℓ 0 constraint will shorten the number of iterations to reach steady state without sacrificing image quality. Our results confirm that these theoretical results hold on an in vivo application.
Organic field‐effect transistors (OFETs) were fabricated using pentacene thin layer, and the effects of inserted Lewis‐acid thin layers on electrical properties were investigated. The OFETs have active layers of pen...
Organic field‐effect transistors (OFETs) were fabricated using pentacene thin layer, and the effects of inserted Lewis‐acid thin layers on electrical properties were investigated. The OFETs have active layers of pentacene and vanadium pentoxide (V2O5) as a Lewis‐acid layer. Typical source‐drain current (IDS) vs. source‐drain voltage (VDS) curves were observed under negative gate voltages (VGS) application, and the shift of the threshold voltage for FET driving (Vt) to positive side was also observed by V2O5 layer insertion, that is, ‐2.5 V for device with V2O5 layer and ‐5.7 V for device without V2O5 layer. It was thought that charge transfer (CT) complexes which were formed at the interface between pentacene and V2O5 layer were dissociated by the applied gate voltage, and the generated holes seem to contribute to drain current and the apparent Vt improvement.
In this study, we carried out development of non‐invasive optical transcutaneous partial pressure of carbon dioxide, pCO2, monitoring system. The purpose of this system is to detect CO2 from outer skin, not from the ...
In this study, we carried out development of non‐invasive optical transcutaneous partial pressure of carbon dioxide, pCO2, monitoring system. The purpose of this system is to detect CO2 from outer skin, not from the arterial blood‐gathering method. There are advantages about a reduction of analysis time and real‐time monitoring that this system might be available. The measurement system is composed of the IR lamp, the pyroelectric sensor including a 4.26 μm optical filter, the optical gas reaction chamber and the signal processing circuit. The optical reaction length of chamber was reduced by 1 mm using the soft‐lithography method which CO2 is exhausted in human body as we considered. The fabricated pCO2 monitoring system showed linear result of 6.50×10−6 absorbance/ppm sensitivity for CO2 concentration from 0 ∼5,000 ppm by MFC and about 2 seconds of fast response time. The proposed system can be used in the optical biosensor field for the medical diagnosis such as pCO2 monitoring system and environment monitoring systems.
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