AI Article Synopsis
Article Abstract
We report successful real-time three-channel self-mixing laser-Doppler measurements with extreme optical sensitivity using a laser-diode-pumped thin-slice Nd:GdVO(4) laser in the carrier-frequency-division-multiplexing scheme with three pairs of acoustic optical modulators (i.e., frequency shifters) and a three-channel FM-wave demodulation circuit. We demonstrate (1) simultaneous independent measurement of three different nanometer-vibrating targets, (2) simultaneous measurements of small particles in Brownian motion from three directions, and (3) identification of the velocity vector of small particles moving in water flowing in a small-diameter glass pipe.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1364/ao.48.000609 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Noninvasive therapeutic ultrasound to increase perfusion in chronic limb-threatening ischemia: An early feasibility study.
Vasc Med
December 2024
Vascular & Interventional Specialists of Orange County, Orange, CA, USA.
Background: Preclinical studies have demonstrated that therapeutic ultrasound (TUS) increases perfusion in peripheral artery disease (PAD). This pilot study assessed the safety and effectiveness of a noninvasive TUS device in patients with advanced PAD.
Methods: A phased array of TUS transducers was fabricated on a wearable sleeve, designed to sonicate the posterior and anterior tibial arteries (and their collaterals) at the calf level.
Changes in wing resonance in dried preserved crickets.
R Soc Open Sci
December 2024
School of Life and Environmental Sciences, Green Lane, Lincoln LN6 7DL, UK.
Male crickets sing to attract females for mating. Sound is produced by tegminal stridulation, where one wing bears a plectrum and the other a wing vein modified with cuticular teeth. The carrier frequency ( ) of the call is dictated by the wing resonance and the rate of tooth strikes.
View Article and Find Full Text PDFA heterodyne laser Doppler vibrometer (LDV) with a Bragg cell has a stationary signal carrier at a frequency of at least 35 MHz. The expensive Bragg cell with the restricted shift frequency is not an optimal solution to meet the requirements for many measurement scenarios. For vibrations with low frequencies and small amplitudes, a tens-of-megahertz carrier frequency not only wastes bandwidth at the photodetector but also requires a fast and expensive analog-to-digital converter (ADC).
View Article and Find Full Text PDFNegative pressure breathing: the response of human respiration and circulation to different levels of rarefaction during inspiration.
Front Physiol
November 2024
Department of Cardiovascular and Respiratory Physiology in Extreme Environments, Institute of Biomedical Problems of the Russian Academy of Sciences, Moscow, Russia.
Article Synopsis
- - Negative pressure breathing (NPBin) is a technique that lowers pressure in the respiratory tract during inhalation, aiming to boost blood flow to the heart and counteract fluid shifts in space.
- - This study analyzed the effects of NPBin for 25 minutes at pressure reductions of -10 to -25 cmHO, using various non-invasive measurement techniques to assess changes in circulation and respiration in healthy volunteers.
- - Results showed that NPBin increased tidal volume and decreased respiratory rate without significantly affecting overall minute ventilation, while circulatory parameters showed increased amplitude during breathing cycles, indicating a complex interaction between respiration and circulation.
A New Approach to Retinal Oxygen Extraction Measurement Based on Laser Speckle Flowgraphy and Retinal Oximetry.
Transl Vis Sci Technol
December 2024
Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria.
Purpose: Currently, no standard for the measurement of retinal oxygen extraction exists. Here, we present a novel approach for measurement of retinal oxygen extraction based on two commercially available devices, namely laser speckle flowgraphy (LSFG) and retinal oximetry.
Methods: The study was conducted in a randomized, double-masked design.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!