Focused ultrasound has been shown to be effective at stimulating neurons in many animal models, both <i>in vivo</i> and <i>ex vivo</i>. Ultrasonic neuromodulation is the only noninvasive method of stimulation that could reach deep brain with high spatial-temporal resolution, thus potential for use clinical applications basic studies nervous system. Understanding physical mechanism by which energy a acoustic frequency wave delivered stimulate will important optimize this technology. We imaged...

Focused ultrasound (FUS) is a powerful tool for noninvasive modulation of deep brain activity with promising therapeutic potential refractory epilepsy; however, tools examining FUS effects on specific cell types within the do not yet exist. Consequently, how heterogeneous networks can be modulated and whether parameters identified to bias these in context complex behaviors remains unknown. To address this, we developed fiber Photometry Coupled focused Ultrasound System (PhoCUS)...

Identifying pathogens in complex samples such as blood, urine, and wastewater is critical to detect infection inform optimal treatment. Surface-enhanced Raman spectroscopy (SERS) machine learning (ML) can distinguish among multiple pathogen species, but processing fluid sensitively specifically remains an outstanding challenge. Here, we develop acoustic bioprinter digitize into millions of droplets, each containing just a few cells, which are identified with SERS ML. We demonstrate rapid...

A pseudospectral model of linear elastic wave propagation is described based on the first order stress-velocity equations elastodynamics. k-space adjustments to spectral gradient calculations are derived from dyadic Green’s function solution second-order equation and used (a) ensure exact for homogeneous timesteps arbitrarily large size, (b) also allows larger time steps without loss accuracy in heterogeneous media. The formulation wavefield be split easily into compressional shear parts....

Ultrasound can modulate action potential firing in vivo and vitro, but the mechanistic basis of this phenomenon is not well understood. To address problem, we used patch-clamp recording to quantify effects focused, high-frequency (43 MHz) ultrasound on evoked CA1 pyramidal neurons acute rodent hippocampal brain slices. We find that either inhibit or potentiate a spike frequency–dependent manner: at low (near-threshold) input currents frequencies, inhibits firing, while higher potentiates...

Capacitive micromachined ultrasonic transducers (CMUTs) have great potential to compete with traditional piezoelectric in therapeutic ultrasound applications. In this paper we designed, fabricated and developed an acoustic lens formed on the CMUT mechanically focus ultrasound. The was designed based paraxial theory made of silicone rubber for impedance matching encapsulation. local oxidation silicon (LOCOS) fusion-bonding. verified behave like electromechanical resonator air exhibited...

Touchscreen sensors are widely used in many devices such as smart phones, tablets, and laptops with diverse applications. We present the design, analysis, implementation of an ultrasonic touchscreen system that utilizes interaction transient Lamb waves objects contact screen. It attempts to improve on existing ultrasound technologies, potential addressing some weaknesses dominant capacitive or resistive ones. Compared acoustic modalities, among other advantages, it provides capability...

This paper presents a novel method to increase the bandwidth (BW) of airborne capacitive micromachined ultrasonic transducers (CMUTs). introduces gaseous squeeze film as damping mechanism, which induces stiffening effect that lowers pull-in voltage and improves sensitivity. The optimal behavior this versus mechanism can be controlled by creating optimized fluidic trenches various heights within gap. fractional BW from 0.89% 8.1% adjusting trench height while lowering less than 54 V at gap...

Photoacoustic imaging offers significant potential as a biomedical modality. For some applications, however, there is need for contrast enhancement. In this paper, theoretical comparison presented of the efficacy three different designs photoacoustic agents (PACAs), specifically, droplet dye, bubble filled with gas coated by dye loaded shell, and volatile dye. each case, governing equations describing dynamics single PACA in homogenous incompressible fluid are derived. The coupled sets...

Transcranial focused ultrasound is approved for non-invasive treatment of essential tremor, and being researched as a noninvasive means ablating brain tumors, neuromodulation, increasing delivery cancer therapeutics through the blood-brain barrier. Present technology relies on use an array transducers placed in helmet aimed at skull normal incidence, leading to inefficient transmission, excess heating skull, limited envelope center brain. We propose wedge capable efficiently delivering...

ABSTRACT Ultrasound (US) can modulate the electrical activity of excitable tissues but mechanisms underlying this effect are not understood at molecular level or in terms physical modality through which US exerts its effects. Here we report an experimental system that allows for stable patch-clamp recording presence 43 MHz, a frequency known to stimulate neural activity. We describe effects on two ion channels proposed be involved response cells US: mechanosensitive Piezo1 channel and...

Transient Lamb waves induced by finite piezoelectric transducers have been widely used in ultrasonic touch systems, where a tactile object is localized through its interaction with the waves. However, this problem has not looked in-depth theoretically, which essential for development of robust systems. The two-dimensional theory often fails to provide true picture as diffraction effects are great significance these technologies. Reduced order models such plate theories, on other hand, can...

This paper reports vented CMUTs with wide bandwidth and high sensitivity, optimized by multi-parameter optimization method. The dominated parameters, including the radius thickness of flexible plate, gap height, size distribution holes have been individually optimized. impedance measurements well-match simulation results. Then method in place individual parameter is used to optimize design parameters all together. Finally, keeping approximate bandwidth, makes sensitivity improved 11% at same...

This paper presents a novel multilayer masking technology for fabricating airborne capacitive micromachined ultrasonic transducers (CMUTs) with multi-depth fluidic trenches, in which plurality of layers different etch depths are selectively patterned prior to the real etching keep planar wafer surface. The trenches utilized effectively control squeeze film within CMUT gap and tune fractional bandwidth (FBW) CMUT. As such, FBW can be changed over wide range by only adjusting trench height....

Transcranial focused ultrasound (FUS) is a noninvasive treatment for brain tumors and neuromodulation. Based on normal incidence, conventional FUS techniques use or an array of ultrasonic transducers to overcome the attenuation absorption in skull; however, this remains main limitation using FUS. A dual-mode conversion technique based Lamb waves proposed achieve high transmission efficiency. This concept was validated finite element analysis (FEA) experiments changes incident angle....

We developed a fully-populated 2-D capacitive micromachined ultrasonic transducer (CMUT) array for high intensity focused ultrasound (HIFU) treatment. The CMUT array, which consists of 20 × square elements with an element-to-element pitch 1 mm, was designed and fabricated using the thick-buried-oxide (BOX) fabrication process. It then assembled on custom interface board that can provide various configurations depending desired applications. In this study, groups into eight channels, based...

Photoacoustic imaging has shown great promise for medical imaging, where optical energy absorption by blood haemoglobin is used as the contrast mechanism. A numerical method was developed in-silico assessment of photoacoustic image reconstruction brain. Image segmentation techniques were to prepare a digital phantom from MR images. Light transport through brain tissue modelled using Finite Element approach. The resulting acoustic pressure then estimated pulsed photoacoustics considerations....

Abstract Focused ultrasound has been shown to be effective at stimulating neurons in vivo, ex vivo and vitro preparations. Ultrasonic neuromodulation is the only non-invasive method of stimulation that could reach deep brain with high spatial-temporal resolution, thus potential for use clinical applications basic studies nervous system. Understanding physical mechanism by which energy a acoustic frequency wave delivered stimulate will important optimize this technology. Two primary...

Abstract Objective . Although recent studies have shown that mechanical stress plays an important role in ultrasound neuromodulation, the magnitude and distribution of generated tissues by focused transducers not been adequately examined. Various acoustic radiation force (ARF) equations used previous evaluated based on tissue displacement results are suitable for estimating displacement. However, it is unclear whether can be accurately determined. This study evaluates predicted various AFR...

This paper presents the theory of k -space method generalized to model elastic wave propagation in heterogeneous anisotropic media. The methods are promising time integration techniques giving, conjunction with collocation spectral methods, accurate and efficient numerical schemes for problems In this paper, operator is derived a spatially continuous form using Fourier analysis displacement formalism elastodynamics. An algorithm then constructed by applying method, leading define discrete...

This paper presents a novel method to significantly broaden the bandwidth of airborne capacitive micromachined ultrasonic transducers (CMUTs) by introducing gaseous squeeze film as damping mechanism. The and stiffening effects can be tuned lower pull-in voltage while improving sensitivity optimizing fluidic trenches various heights within gap. By only adjusting trench height, we control from 0.89% 8.1% keeping under 55 V achieving minimum detectable pressure (MDP) 2.2 μPa/√Hz 4.88 μPa/√Hz....