213 research outputs found

    mHealth hyperspectral learning for instantaneous spatiospectral imaging of hemodynamics

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    Hyperspectral imaging acquires data in both the spatial and frequency domains to offer abundant physical or biological information. However, conventional hyperspectral imaging has intrinsic limitations of bulky instruments, slow data acquisition rate, and spatiospectral tradeoff. Here we introduce hyperspectral learning for snapshot hyperspectral imaging in which sampled hyperspectral data in a small subarea are incorporated into a learning algorithm to recover the hypercube. Hyperspectral learning exploits the idea that a photograph is more than merely a picture and contains detailed spectral information. A small sampling of hyperspectral data enables spectrally informed learning to recover a hypercube from an RGB image. Hyperspectral learning is capable of recovering full spectroscopic resolution in the hypercube, comparable to high spectral resolutions of scientific spectrometers. Hyperspectral learning also enables ultrafast dynamic imaging, leveraging ultraslow video recording in an off-the-shelf smartphone, given that a video comprises a time series of multiple RGB images. To demonstrate its versatility, an experimental model of vascular development is used to extract hemodynamic parameters via statistical and deep-learning approaches. Subsequently, the hemodynamics of peripheral microcirculation is assessed at an ultrafast temporal resolution up to a millisecond, using a conventional smartphone camera. This spectrally informed learning method is analogous to compressed sensing; however, it further allows for reliable hypercube recovery and key feature extractions with a transparent learning algorithm. This learning-powered snapshot hyperspectral imaging method yields high spectral and temporal resolutions and eliminates the spatiospectral tradeoff, offering simple hardware requirements and potential applications of various machine-learning techniques.Comment: This paper will appear in PNAS Nexu

    Spinal cord stimulator malfunction caused by radiofrequency neuroablation -A case report-

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    The implantation of spinal cord stimulators (SCSs) to treat chronic intractable pain is steadily increasing. And there is an increased likelihood of instances where other therapies or procedures are found to interfere with SCS function, which in turn may result in pain. Since SCS utilize electric impulses as well as magnets, special considerations need for patients with a SCS in situ who require these procedures. The present report describes a case where radiofrequency (RF) ablation of the third occipital nerve resulted in spontaneous activation of a cervical SCS device

    Clinical Experiences of Transforaminal Balloon Decompression for Patients with Spinal Stenosis

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    Lumbar spinal stenosis is a commonly treated with epidural injections of local anesthetics and corticosteroids, however, these therapies may relieve leg pain for weeks to months but do not influence functional status. Furthermore, the majority of patients report no substantial symptom change over the repeated treatment. Utilizing balloon catheters, we successfully treated with three patients who complained persistent symptoms despite repeated conventional steroid injections. Our results suggest that transforaminal decompression using a balloon catheter may have potential in the nonsurgical treatment of spinal stenosis by modifying the underlying pathophysiology

    The Effect of Stimulation Frequency on the Ionic Currents in Single Atrial Cells of the Rabbit

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    In single atrial cells isolated from rabbit hearts the calcium current and [Caj-dependent transient outward current were recorded using the whole-cell clamp technique and the effect of stimulation frequency on these currents was investigated. Voltage dependent transient outward current, which contributes the initial, rapid repolarization phase of the action potential and is frequency-dependent, was also investigated. Increasing the stimulation frequency from O. 025 Hz to 1 Hz had no effect on the calcium current and [Caj-dependent transient outward current and greatly inhibited voltage-dependent transient outward current. The amplitude of voltage dependent transient outward current increased as the membrane potential became depolarized, its steady-state inactivation spans the voltage range -70 mV to -10 mVand steady-state activation curve -30 mV to 30 mV. Within the range of the resting membrane potential (at -70 mV), the voltage-dependent recovery time constant was 1. 3 s. The reversal potential was about -50 mV. Voltage-dependent transient outward current was inhibited by K-channel blockers and not inhibited by modulation of [Cali. From the above findings, it is concluded that due to the amplitude and voltage-dependent recovery time constant which were the basic mechanisms for frequency-dependency, the voltage- dependent transient outward current contributes the initial, rapid repolarization phase and changed the action potential configuration according to stimulation frequency in the rabbit atrium

    Quasi 3D ECE imaging system for study of MHD instabilities in KSTAR

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    A second electron cyclotron emission imaging (ECEI) system has been installed on the KSTAR tokamak, toroidally separated by 1/16th of the torus from the first ECEI system. For the first time, the dynamical evolutions of MHD instabilities from the plasma core to the edge have been visualized in quasi-3D for a wide range of the KSTAR operation (B0 = 1.7???3.5 T). This flexible diagnostic capability has been realized by substantial improvements in large-aperture quasi-optical microwave components including the development of broad-band polarization rotators for imaging of the fundamental ordinary ECE as well as the usual 2nd harmonic extraordinary ECE.open1
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