In this study, we develop a complete microwave-induced thermoacoustic imaging (TAI) model for potential breast cancer application. Acoustic pressures generated by different tissue targets are investigated finite-difference time-domain simulations of the entire TAI process including feeding antenna, matching mechanism, fluidic environment, 3-D model, and acoustic transducer. Simulation results achieve quantitative relationships between input microwave peak power resulting specific absorption...

Recent clinical studies have demonstrated that photoacoustic imaging (PAI) provides important diagnostic information during a routine breast exam for cancer. PAI enhances contrast between blood vessels and background tissue, which can help characterize suspicious lesions. However, most systems are either not compatible with commercial ultrasound or inefficiently deliver light to the region of interest, effectively reducing sensitivity technique. To address potentially overcome these...

The feasibility of contrast-enhanced thermoacoustic imaging (CETAI) for breast cancer detection is investigated by a systematic computational study using realistic numerical phantoms with tumors. Single-walled carbon nanotubes nontoxic concentration are applied as the contrast agents to increase dielectric properties tumors and enhance their detectability. Complete CETAI models developed solved generated signals techniques. Back-projection differential performed visualize It shown that...

Surgery to correct severe heart arrhythmias usually requires detailed maps of the cardiac activation wave prior ablation. The pinpoint electrical mapping procedure is laborious and limited by its spatial resolution (5-10 mm). We propose ultrasound current source density imaging (UCSDI), a direct 3-D technique that potentially facilitates existing procedures with superior resolution. based on pressure-induced change in resistivity known as acoustoelectric (AE) effect, which spatially confined...

During clinical studies, thermoacoustic imaging (TAI) failed to reliably identify malignant breast tissue. To increase detection capability, we propose spectroscopic TAI differentiate samples based on the slope of their dielectric absorption. Phantoms composed different ratios water and fat were imaged using excitation frequencies between 2.7 3.1 GHz. The frequency-dependent TA signal was highly correlated with that its absorption coefficient (R2 = 0.98 p < 0.01), indicating can...

Ultrasound current source density imaging (UCSDI) exploits the acoustoelectric (AE) effect, an interaction between ultrasound pressure and electrical resistivity, to map conduction in heart. The conversion efficiency for UCSDI is determined by AE constant K, a fundamental property of all materials; K directly affects magnitude detected voltage signal UCSDI. This paper describes technique measuring biological tissue, reports its value first time cadaver hearts. A custom chamber was designed...

Wireless communications from an airborne device to underwater receiver is challenging because the conductivity of water severely dampens magnitude electromagnetic waves in spectrum commonly used for wireless applications. In this paper, microwave-induced thermoacoustic (TAC), a hybrid technique communications, investigated and experimentally demonstrated provide potential solution deficiency. TAC based on effect directly converts energy air into acoustic water. Experimental demonstration...

We characterized the thermoacoustic and photoacoustic properties of large-area, few-layer graphene by pulsed microwave optical excitations. Due to its high electric conductivity low heat capacity per unit area, lends itself excellent energy absorption acoustic signal emanation due effect. When exposed or radiation, distinct signals generated are obtained laser graphene, respectively. Clear images large-area sample achieved. A numerical model is developed simulated results in good accordance...

Ultrasound traversing a biologic fluid or tissue generates local change in electrical conductivity known as the acoustoelectric effect. The authors exploit this interaction to image ionic current injected into abdominal segment of lobster nerve cord. A pair recording electrodes detected signal induced by pulses focused ultrasound (1.4 7.5MHz). was linear with at 2MPa (0.7μV∕mAcm2) and pressure 75mA∕cm2 (23μV∕MPa). Acoustoelectric imaging biocurrents potentially enhances spatial resolution...

We describe the first mapping of biological current in a live heart using ultrasound source density imaging (UCSDI). Ablation procedures that treat severe arrhythmias require detailed maps cardiac activation wave. The conventional procedure is time-consuming and limited by its poor spatial resolution (5-10 mm). UCSDI can potentially improve on existing procedures. It based pressure-induced change resistivity known as acousto-electric (AE) effect, which spatially confined to focus. Data from...

A clinical ultrasound scanner and 14 MHz linear array collected real-time photoacoustic images (PAI) during an injection of gold nanorods (GNRs) near the region a mature PC-3 prostate tumor in mice implanted with skin flap window chamber. Three dimensional spectroscopic PAI (690-900 nm) was also performed to investigate absorption changes enhance specific detection GNRs. Whereas GNRs improved contrast (+18 dB), spectrum consistent elevated infrared The versatile imaging platform potentially...

Understanding the tumor microenvironment is critical to characterizing how cancers operate and predicting their response treatment. We describe a novel, high-resolution coregistered photoacoustic (PA) pulse echo (PE) ultrasound system used image microenvironment. Compared traditional optical systems, platform provides complementary contrast important depth information. Three mice are implanted with dorsal skin flap window chamber injected PC-3 prostate cells transfected green fluorescent...

Ultrasound current source density imaging (UCSDI) potentially transforms conventional electrical mapping of excitable organs, such as the brain and heart. For this study, we demonstrate volume a time-varying field by scanning focused ultrasound beam detecting acoustoelectric (AE) interaction signal. A pair electrodes produced an alternating distribution in special chamber filled with 0.9% NaCl solution. pulsed 1 MHz was scanned near sink, while AE signal detected on remote recording...

Thermoacoustic imaging is a promising modality for breast cancer detection. Acoustic signals generated by tumor targets with different sizes subject to microwave pulses various widths and waveforms are analytically studied in this letter. Time- frequency-domain profiles of the acoustic achieved. Some key parameters signals, including peak value peak-to-peak time interval time-domain pressure frequency global magnitude ratio second highest pressure, discussed. Impact pulse width on signal...

We present a novel two-dimensional (2D) MAET scanner, with rotating object of interest and two fixed pairs electrodes. Such an acquisition scheme, our reconstruction techniques, recovers the boundaries regions constant conductivity uniformly well, regardless their orientation. also general image algorithm for 2D in circular chamber point-like electrodes immersed into saline surrounding object. An alternative linearized procedure is developed, suitable recovering material interfaces...

Ultrasound current source density imaging (UCSDI), based on the acoustoelectric (AE) effect, is a noninvasive method for mapping electrical in 4-D (space + time). This technique potentially overcomes limitations with conventional procedures typically used during treatment of sustained arrhythmias. However, weak AE signal associated electrocardiogram major challenge advancing this technology. In study, we examined effects electrode configuration and ultrasound frequency magnitude quality...

Thermoacoustic imaging (TAI) is a non-ionizing, high-contrast and high-resolution modality for biomedical applications. The resolution of the reconstructed image by traditional algorithm, such as back-projection (BP), dependent on input microwave pulse width. In this work, it experimentally demonstrated that quality images based compressive sensing (CS), novel algorithm can reconstruct using fewer measurements, largely independent width which taken into account when building dictionary....

Objective. New innovations in deep brain stimulation (DBS) enable directional current steering—allowing more precise electrical of the targeted structures for Parkinson's disease, essential tremor and other neurological disorders. While intra-operative navigation through MRI or CT approaches millimeter accuracy placing DBS leads, no existing modality provides feedback currents as they spread from contacts tissue. In this study, we investigate transcranial acoustoelectric imaging (tAEI) a new...

Abstract Injuries caused by surgical incisions or traumatic lacerations compromise the structural and functional integrity of skin. Immediate approximation robust repair skin are critical to minimize occurrences dehiscence infection that can lead impaired healing further complication. Light‐activated sealing has emerged as an alternative sutures, staples, superficial adhesives, which do not integrate with tissues prone scarring infection. Here, we evaluate both shorter‐ longer‐term efficacy...

Thermal strain imaging (TSI) is demonstrated in two model systems mimicking potential clinical applications. First, a custom ultrasound (US) microscope produced high-resolution TSI images of an excised porcine coronary artery. Samples were placed temperature-controlled water chamber and scanned transversely longitudinally. Phase-sensitive, correlation-based speckle tracking was applied to map the spatial distribution temporal across sample. differentiated fatty tissue from water-based...

Thin polymer etalons are demonstrated as high-frequency ultrasound sensors for three-dimensional (3-D) high-resolution photoacoustic imaging. The etalon, a Fabry-Perot optical resonator, consists of thin slab sandwiched between two gold layers. It is probed with scanning continuous-wave (CW) laser array detection. Detection bandwidth 20-microm-diam element exceeds 50 MHz, and the sensitivity comparable to polyvinylidene fluoride (PVDF) equivalents similar size. In typical imaging setup,...