scholarly journals Non-invasive programmed stimulation vs. electrophysiological study in patients with pacemaker

2016 ◽  
Vol 13 ◽  
pp. 26-27
Author(s):  
Márcio Galindo Kiuchi ◽  
Shaojie Chen
Keyword(s):  
Electrophysiological Study ◽  
Non Invasive ◽  
Programmed Stimulation

scholarly journals Evidence of activation of vagal afferents by non-invasive vagus nerve stimulation: An electrophysiological study in healthy volunteers

Cephalalgia ◽  
2017 ◽  
Vol 37 (13) ◽  
pp. 1285-1293 ◽  
Author(s):  
Romain Nonis ◽  
Kevin D’Ostilio ◽  
Jean Schoenen ◽  
Delphine Magis
Keyword(s):  
Vagus Nerve ◽  
Healthy Volunteers ◽  
Nerve Stimulation ◽  
Vagus Nerve Stimulation ◽  
Electrophysiological Study ◽  
Vagal Afferents ◽  
Response Analysis ◽  
Bipolar Electrode ◽  
Non Invasive ◽  
Vagal Afferent

Background Benefits of cervical non-invasive vagus nerve stimulation (nVNS) devices have been shown in episodic cluster headache and preliminarily suggested in migraine, but direct evidence of vagus nerve activation using such devices is lacking. Vagal somatosensory evoked potentials (vSEPs) associated with vagal afferent activation have been reported for invasive vagus nerve stimulation (iVNS) and non-invasive auricular vagal stimulation. Here, we aimed to show and characterise vSEPs for cervical nVNS. Methods vSEPs were recorded for 12 healthy volunteers who received nVNS over the cervical vagus nerve, bipolar electrode/DS7A stimulation over the inner tragus, and nVNS over the sternocleidomastoid (SCM) muscle. We measured peak-to-peak amplitudes (P1-N1), wave latencies, and N1 area under the curve. Results P1-N1 vSEPs were observed for cervical nVNS (11/12) and auricular stimulation (9/12), with latencies similar to those described previously, whereas SCM stimulation revealed only a muscle artefact with a much longer latency. A dose-response analysis showed that cervical nVNS elicited a clear vSEP response in more than 80% of the participants using an intensity of 15 V. Conclusion Cervical nVNS can activate vagal afferent fibres, as evidenced by the recording of far-field vSEPs similar to those seen with iVNS and non-invasive auricular stimulation.

scholarly journals Use of aVR and Jastrzębski algorithms in the classification of wide complex tachycardia in dogs – a preliminary study

2018 ◽  
Vol 62 (3) ◽  
pp. 365-369
Author(s):  
Marcin Michałek ◽  
Piotr Frydrychowski ◽  
Jakub Adamowicz ◽  
Agnieszka Sławuta ◽  
Urszula Pasławska ◽  
...  
Keyword(s):  
Veterinary Medicine ◽  
Retrospective Analysis ◽  
Cardiac Electrophysiology ◽  
Electrophysiological Study ◽  
Qrs Complex ◽  
Algorithmic Approach ◽  
Non Invasive ◽  
Wide Complex Tachycardia ◽  
Common Criterion

AbstractIntroductionVentricular rhythm disturbances are a common pathology in human and veterinary medicine. In humans, the algorithmic approach is used to differentiate wide QRS complex tachycardia. The most commonly used are the aVR and Brugada algorithms as well as the ventricular tachycardia (VT) score developed by Jastrzębski and coworkers. In veterinary medicine, no such algorithms are available and the only parameter used to describe VT abnormalities is the duration of the QRS complexes. The aim of this analysis was determining whether human medicine algorithms for VT are applicable in veterinary medicine to differentiate wide QRS complex tachycardia in dogs.Material and MethodsA retrospective analysis was performed on 11 dogs of both sexes and various breeds and age diagnosed with VT. The diagnosis was based on ambulatory ECG, further established based on the reaction to lidocaine or adenosine or an invasive electrophysiological study.ResultsOf the 11 tracings passed through the aVR algorithm, 10 met the VT criteria. The most common criterion was the Vi/Vt ratio (8 out of 11 tracings). Based on the VT score, seven out of eight dogs had a high probability of VT.ConclusionRetrospective analysis of ECGs by aVR and VT score indicates that the applied algorithms may be useful in differentiating wide QRS complex tachycardia as a quick, easy, and non-invasive alternative to cardiac electrophysiology.

scholarly journals Psychophysical measures of tonotopic selectivity in cats and humans

2021 ◽  
Author(s):  
Robert P. Carlyon ◽  
John C. Middlebrooks ◽  
Matthew L. Richardson ◽  
Robin Gransier ◽  
François Guérit ◽  
...  
Keyword(s):  
Cochlear Implants ◽  
Pure Tone ◽  
Electrophysiological Study ◽  
Center Frequency ◽  
Auditory Prosthesis ◽  
Auditory Filter ◽  
Non Invasive ◽  
Spread Of Excitation ◽  
Novel Approaches ◽  
Electrophysiological Methods

Sound spectra are represented by patterns of activity along the tonotopic axis ofthe cochlea. Cochlear implants can transmit spectra by stimulating tonotopicallyappropriate electrodes, but fidelity is limited by intracochlear spread of excitation. We aim to better evaluate present-day experimental stimulation procedures and, potentially, to improve transmission of spectra with novel stimulation modalities. As a first step, we are developing non-invasive measures of tonotopic spread of excitation that can be compared between normal-hearing cats and humans. These measures include psychophysics in the present study and scalp-recorded electrophysiology in a companion study (Guérit et al., 2021). Cats and humans detected pure-tone probes presented in continuous 1/8- and 1-oct noise-band maskers. Masker bandwidths were readily discernable in both species by the dependence of masked thresholds on probe frequencies. Thresholds were largely constant across the bandwidth of the 1-oct masker, whereas thresholds dropped markedly at frequencies away from the center of the 1/8-oct masker. Cats and humans differed in that the feline auditory filter centered on 8 kHz, which we measured using a notched-noise procedure, was 22% wider than published values for humans at the same center frequency. Also, thresholds for the cats in the 1-octmasker condition consistently were 1.0 to 3.2 dB higher than expected based on the estimated masker power in the feline auditory filter. The present psychophysical results parallel those in our companion electrophysiological study, thereby providing perceptual validation for that study. These psychophysical and electrophysiological methods will be valuable for future investigations of novel approaches for auditory prosthesis.

X-ray microtomography

1988 ◽  
Vol 46 ◽  
pp. 998-999
Author(s):  
H.W. Deckman ◽  
B.F. Flannery ◽  
J.H. Dunsmuir ◽  
K.D' Amico
Keyword(s):  
Computed Tomography ◽  
Internal Structure ◽  
Imaging Technique ◽  
Three Dimensional ◽  
Tissue Structure ◽  
Individual Element ◽  
X Ray ◽  
Non Invasive ◽  
Panoramic Imaging ◽  
Three Dimensional Images

We have developed a new X-ray microscope which produces complete three dimensional images of samples. The microscope operates by performing X-ray tomography with unprecedented resolution. Tomography is a non-invasive imaging technique that creates maps of the internal structure of samples from measurement of the attenuation of penetrating radiation. As conventionally practiced in medical Computed Tomography (CT), radiologists produce maps of bone and tissue structure in several planar sections that reveal features with 1mm resolution and 1% contrast. Microtomography extends the capability of CT in several ways. First, the resolution which approaches one micron, is one thousand times higher than that of the medical CT. Second, our approach acquires and analyses the data in a panoramic imaging format that directly produces three-dimensional maps in a series of contiguous stacked planes. Typical maps available today consist of three hundred planar sections each containing 512x512 pixels. Finally, and perhaps of most import scientifically, microtomography using a synchrotron X-ray source, allows us to generate maps of individual element.

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