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Laser doppler vibrometry

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https://www.readbyqxmd.com/read/28504937/ultrasonic-fingerprint-sensor-with-transmit-beamforming-based-on-a-pmut-array-bonded-to-cmos-circuitry
#1
Xiaoyue Jiang, Hao-Yen Tang, Yipeng Lu, Eldwin Ng, Julius Tsai, Bernhard Boser, David Horsley
In this paper, we present a single-chip 65x42 element ultrasonic pulse-echo fingerprint sensor with transmit beamforming based on piezoelectric micromachined ultrasonic transducers (PMUTs) directly bonded to a CMOS readout ASIC. The readout ASIC was realized in a standard 180 nm CMOS process with a 24V high voltage transistor option. Pulse-echo measurements are performed column-by-column in sequence using either one column or five columns to transmit the ultrasonic pulse at 20 MHz. Transmit beamforming is used to focus the ultrasonic beam at the imaging plane where the finger is located, increasing the ultrasonic pressure and narrowing the 3dB beam-width to 50 microns, a factor of 6...
May 11, 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/28372141/optical-imaging-of-propagating-mach-cones-in-water-using-refracto-vibrometry
#2
Nathan R Huber, Thomas M Huber, Matthew T Huber
Refracto-vibrometry was used to optically image propagating Mach cones in water. These Mach cones were produced by ultrasonic longitudinal and shear waves traveling through submerged 12.7 mm diameter metal cylinders. Full-field videos of the propagating wave fronts were obtained using refracto-vibrometry. A laser Doppler vibrometer, directed at a retroreflective surface, sampled time-varying water density at numerous scan points. Wave speeds were determined from the Mach cone apex angles; the measured longitudinal and shear wave speeds in steel (6060 ± 170 m/s and 3310 ± 110 m/s, respectively) and beryllium (12 400 ± 700 m/s and 8100 ± 500 m/s) agreed with published values...
March 2017: Journal of the Acoustical Society of America
https://www.readbyqxmd.com/read/28324990/indirect-measurement-of-the-carotid-arterial-pressure-from-vibrocardiographic-signal-calibration-of-the-waveform-and-comparison-with-photoplethysmographic-signal
#3
L Casacanditella, G Cosoli, S Casaccia, E P Tomasini, L Scalise
The detection of arterial Blood Pressure waveform provides important information about the subject health status. Laser Doppler Vibrometry (LDV) is a non-contact technique with high sensitivity able to detect mechanical movements of the arterial wall; several previous studies have shown that LDV is able to characterize cardiac activity. Photoplethysmogram (PPG) quantifies the digital volume artery pulse, which has been demonstrated to be closely related to the pressure signal measured by an arterial tonometer...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28320655/a-study-on-the-effects-of-release-area-on-the-quality-factor-of-contour-mode-resonators-by-laser-doppler-vibrometry
#4
Brian Gibson, Kamala Qalandar, Cristian Cassella, Gianluca Piazza, Kimberly L Foster
Through the use of a laser Doppler vibrometer, it is shown that a 31% variation in quality factor can occur due to the effect of undercutting of the device layers outside of the anchors of a 220-MHz aluminum nitride contour-mode resonator. This undercutting is a result of the isotropic etch process used to release the device from the substrate. This paper shows that the variation in Q is a function of the release distance, L , between the active region of the resonator and the edge of this released region. This paper also determined a design modification that eliminated this issue and achieved a Q of 3048, which is independent of L ...
May 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/28270971/multifrequency-swept-optical-coherence-microscopy-for-highspeed-full-field-tomographic-vibrometry-in-biological-tissues
#5
Samuel Choi, Keita Sato, Takeru Ota, Fumiaki Nin, Shogo Muramatsu, Hiroshi Hibino
Because conventional laser Doppler vibrometry or Doppler optical coherence tomography require mechanical scanning probes that cannot simultaneously measure the wide-range dynamics of bio-tissues, a multifrequency-swept optical coherence microscopy with wide-field heterodyne detection technique was developed. A 1024 × 1024 × 2000 voxel volume was acquired with an axial resolution of ~1.8 μm and an acquisition speed of 2 s. Vibration measurements at 10 kHz were performed over a wide field of view. Wide-field tomographic vibration measurements of a mouse tympanic membrane are demonstrated to illustrate the applicability of this method to live animals...
February 1, 2017: Biomedical Optics Express
https://www.readbyqxmd.com/read/28249534/a-novel-setup-for-wafer-curvature-measurement-at-very-high-heating-rates
#6
T Islam, J Zechner, M Bernardoni, M Nelhiebel, R Pippan
The curvature evolution of a thin film layer stack containing a top Al layer is measured during temperature cycles with very high heating rates. The temperature cycles are generated by means of programmable electrical power pulses applied to miniaturized polysilicon heater systems embedded inside a semiconductor chip and the curvature is measured by a fast wafer curvature measurement setup. Fast temperature cycles with heating duration of 100 ms are created to heat the specimen up to 270 °C providing an average heating rate of 2500 K/s...
February 2017: Review of Scientific Instruments
https://www.readbyqxmd.com/read/28227286/indirect-measurement-of-the-carotid-arterial-pressure-from-vibrocardiographic-signal-calibration-of-the-waveform-and-comparison-with-photoplethysmographic-signal
#7
L Casacanditella, G Cosoli, S Casaccia, E P Tomasini, L Scalise, L Casacanditella, G Cosoli, S Casaccia, E P Tomasini, L Scalise, G Cosoli, S Casaccia, E P Tomasini, L Casacanditella, L Scalise
The detection of arterial Blood Pressure waveform provides important information about the subject health status. Laser Doppler Vibrometry (LDV) is a non-contact technique with high sensitivity able to detect mechanical movements of the arterial wall; several previous studies have shown that LDV is able to characterize cardiac activity. Photoplethysmogram (PPG) quantifies the digital volume artery pulse, which has been demonstrated to be closely related to the pressure signal measured by an arterial tonometer...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28142401/functional-outcomes-of-heparin-binding-epidermal-growth-factor-like-growth-factor-for-regeneration-of-chronic-tympanic-membrane-perforations-in-mice
#8
Peter Luke Santa Maria, Peter Gottlieb, Chloe Santa Maria, Sungwoo Kim, Sunil Puria, Yunzhi Peter Yang
We aim to demonstrate that regeneration of chronic tympanic perforations with heparin-binding epidermal growth factor-like growth factor (HB-EGF) delivered by an injectable hydrogel restored hearing to levels similar to that of nonperforated tympanic membranes. Chronic tympanic membrane perforation is currently managed as an outpatient surgery with tympanoplasty. Due to the costs of this procedure in the developed world and a lack of accessibility and resources in developing countries, there is a great need for a new treatment that does not require surgery...
May 2017: Tissue Engineering. Part A
https://www.readbyqxmd.com/read/28008214/displacement-sensing-based-on-resonant-frequency-monitoring-of-electrostatically-actuated-curved-micro-beams
#9
Naftaly Krakover, B Robert Ilic, Slava Krylov
The ability to control nonlinear interactions of suspended mechanical structures offers a unique opportunity to engineer rich dynamical behavior that extends the dynamic range and ultimate device sensitivity. We demonstrate a displacement sensing technique based on resonant frequency monitoring of curved, doubly clamped, bistable micromechanical beams interacting with a movable electrode. In this configuration, the electrode displacement influences the nonlinear electrostatic interactions, effective stiffness and frequency of the curved beam...
November 2016: Journal of Micromechanics and Microengineering: Structures, Devices, and Systems
https://www.readbyqxmd.com/read/27857289/use-of-photoacoustic-excitation-and-laser-vibrometry-to-remotely-detect-trace-explosives
#10
C M Wynn, R W Haupt, J H Doherty, R R Kunz, W Bai, G Diebold
In this paper, we examine a laser-based approach to remotely initiate, measure, and differentiate acoustic and vibrational emissions from trace quantities of explosive materials against their environment. Using a pulsed ultraviolet laser (266 nm), we induce a significant (>100  Pa) photoacoustic response from small quantities of military-grade explosives. The photoacoustic signal, with frequencies predominantly between 100 and 500 kHz, is detected remotely via a wideband laser Doppler vibrometer. This two-laser system can be used to rapidly detect and discriminate explosives from ordinary background materials, which have significantly weaker photoacoustic response...
November 10, 2016: Applied Optics
https://www.readbyqxmd.com/read/27802716/approaching-attometer-laser-vibrometry
#11
C Rembe, L Kadner, M Giesen
The heterodyne two-beam interferometer has been proven to be the optimal solution for laser-Doppler vibrometry (LDV) regarding accuracy and signal robustness. The theoretical resolution limit for a two-beam interferometer of laser class 3R (up to 5 mW visible measurement-light) is in the regime of a few femtometer per square-root Hertz and well suited to study vibrations in microstructures. However, some new applications of radio-frequency microelectromechanical (RF-MEM) resonators, nanostructures, and surface-nano-defect detection require resolutions beyond that limit...
October 2016: Review of Scientific Instruments
https://www.readbyqxmd.com/read/27802700/response-measurement-by-laser-doppler-vibrometry-in-vibration-qualification-tests-with-non-gaussian-random-excitation
#12
M Troncossi, R Di Sante, A Rivola
In the field of vibration qualification testing, random excitations are typically imposed on the tested system in terms of a power spectral density (PSD) profile. This is the one of the most popular ways to control the shaker or slip table for durability tests. However, these excitations (and the corresponding system responses) exhibit a Gaussian probability distribution, whereas not all real-life excitations are Gaussian, causing the response to be also non-Gaussian. In order to introduce non-Gaussian peaks, a further parameter, i...
October 2016: Review of Scientific Instruments
https://www.readbyqxmd.com/read/27802696/features-of-the-non-contact-carotid-pressure-waveform-cardiac-and-vascular-dynamics-during-rebreathing
#13
S Casaccia, E J Sirevaag, E J Richter, J A O'Sullivan, L Scalise, J W Rohrbaugh
This report amplifies and extends prior descriptions of the use of laser Doppler vibrometry (LDV) as a method for assessing cardiovascular activity, on a non-contact basis. A rebreathing task (n = 35 healthy individuals) was used to elicit multiple effects associated with changes in autonomic drive as well as blood gases including hypercapnia. The LDV pulse was obtained from two sites overlying the carotid artery, separated by 40 mm. A robust pulse signal was obtained from both sites, in accord with the well-described changes in carotid diameter over the blood pressure cycle...
October 2016: Review of Scientific Instruments
https://www.readbyqxmd.com/read/27749749/a-new-intraoperative-real-time-monitoring-system-for-reconstructive-middle-ear-surgery-an-experimental-and-clinical-feasibility-study
#14
Thomas Zahnert, Marie-Luise Metasch, Hannes Seidler, Matthias Bornitz, Nicoloz Lasurashvili, Marcus Neudert
HYPOTHESIS: Electromagnetical excitation of ossicular vibration is suitable for middle ear transmission measurements in the experimental and clinical setting. Thereby, it can be used as a real-time monitoring system for quality control in ossiculoplasty. BACKGROUND: Positioning and coupling of middle ear prosthesis are a precondition for good postoperative hearing results, but at the same time completely dependent upon the surgeon's subjective judgment during surgery...
December 2016: Otology & Neurotology
https://www.readbyqxmd.com/read/27683000/auditory-mechanics-in-a-bush-cricket-direct-evidence-of-dual-sound-inputs-in-the-pressure-difference-receiver
#15
Thorin Jonsson, Fernando Montealegre-Z, Carl D Soulsbury, Kate A Robson Brown, Daniel Robert
The ear of the bush-cricket, Copiphora gorgonensis, consists of a system of paired eardrums (tympana) on each foreleg. In these insects, the ear is backed by an air-filled tube, the acoustic trachea (AT), which transfers sound from the prothoracic acoustic spiracle to the internal side of the eardrums. Both surfaces of the eardrums of this auditory system are exposed to sound, making it a directionally sensitive pressure difference receiver. A key feature of the AT is its capacity to reduce the velocity of sound propagation and alter the acoustic driving forces at the tympanum...
September 2016: Journal of the Royal Society, Interface
https://www.readbyqxmd.com/read/27610377/differential-intracochlear-sound-pressure-measurements-in-human-temporal-bones-with-an-off-the-shelf-sensor
#16
Martin Grossöhmichen, Rolf Salcher, Klaus Püschel, Thomas Lenarz, Hannes Maier
The standard method to determine the output level of acoustic and mechanical stimulation to the inner ear is measurement of vibration response of the stapes in human cadaveric temporal bones (TBs) by laser Doppler vibrometry. However, this method is reliable only if the intact ossicular chain is stimulated. For other stimulation modes an alternative method is needed. The differential intracochlear sound pressure between scala vestibuli (SV) and scala tympani (ST) is assumed to correlate with excitation. Using a custom-made pressure sensor it has been successfully measured and used to determine the output level of acoustic and mechanical stimulation...
2016: BioMed Research International
https://www.readbyqxmd.com/read/27579835/a-preliminary-investigation-of-the-air-bone-gap-changes-in-intracochlear-sound-pressure-with-air-and-bone-conducted-stimuli-after-cochlear-implantation
#17
Renee M Banakis Hartl, Jameson K Mattingly, Nathaniel T Greene, Herman A Jenkins, Stephen P Cass, Daniel J Tollin
HYPOTHESIS: A cochlear implant electrode within the cochlea contributes to the air-bone gap (ABG) component of postoperative changes in residual hearing after electrode insertion. BACKGROUND: Preservation of residual hearing after cochlear implantation has gained importance as simultaneous electric-acoustic stimulation allows for improved speech outcomes. Postoperative loss of residual hearing has previously been attributed to sensorineural changes; however, presence of increased postoperative ABG remains unexplained and could result in part from altered cochlear mechanics...
October 2016: Otology & Neurotology
https://www.readbyqxmd.com/read/27546727/development-of-a-novel-completely-in-the-canal-direct-drive-hearing-device
#18
Hamid R Djalilian, Hossein Mahboubi, Yarah M Haidar, Peyton Paulick, Mark W Merlo, Mark Bachman
OBJECTIVES/HYPOTHESIS: To develop a novel completely-in-the-canal device capable of directly driving the tympanic membrane (TM) and ossicular chain from the ear canal. STUDY DESIGN: Development and feasibility study. METHODS: A voice coil actuator design was developed to drive the TM. Bench testing of the device using laser Doppler vibrometry (LDV) and sound recording was performed. Temporal bone studies using LDV were performed using different designs of the contact tip-TM interface to find the most efficient method of sound transmission...
April 2017: Laryngoscope
https://www.readbyqxmd.com/read/27500399/direct-acoustic-stimulation-at-the-lateral-canal-an-alternative-route-to-the-inner-ear
#19
Nicolas Verhaert, Joris Walraevens, Christian Desloovere, Jan Wouters, Jean-Marc Gérard
Severe to profound mixed hearing loss is associated with hearing rehabilitation difficulties. Recently, promising results for speech understanding were obtained with a direct acoustic cochlear implant (DACI). The surgical implantation of a DACI with standard coupling through a stapedotomy can however be regarded as challenging. Therefore, in this experimental study, the feasibility of direct acoustic stimulation was investigated at an anatomically and surgically more accessible inner ear site. DACI stimulation of the intact, blue-lined and opened lateral semicircular canal (LC) was investigated and compared with standard oval window (OW) coupling...
2016: PloS One
https://www.readbyqxmd.com/read/27496538/controlled-exploration-of-the-effects-of-conductive-hearing-loss-on-wideband-acoustic-immittance-in-human-cadaveric-preparations
#20
Gabrielle R Merchant, Saumil N Merchant, John J Rosowski, Hideko Heidi Nakajima
Current clinical practice cannot distinguish, with any degree of certainty, the multiple pathologies that produce conductive hearing loss in patients with an intact tympanic membrane and a well-aerated middle ear without exploratory surgery. The lack of an effective non-surgical diagnostic procedure leads to unnecessary surgery and limits the accuracy of information available during pre-surgical consultations with the patient. A non-invasive measurement to determine the pathology responsible for a conductive hearing loss prior to surgery would be of great value...
August 3, 2016: Hearing Research
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