A pulsed terahertz (THz) imaging system and millimeter-wave reflectometer were used to acquire images point measurements, respectively, of five rabbit cornea in vivo. These results are the first ever produced vivo cornea. modified version a standard protocol using gentle stream air Mylar window was employed slightly dehydrate healthy The sensor data companion central corneal thickness (CCT) measurements acquired every 10-15 min over course two hours ultrasound pachymmetry.. Statistically...

This work introduces the potential application of terahertz (THz) sensing to field ophthalmology, where it is uniquely suited due its nonionizing photon energy and high sensitivity water content. Reflective THz imaging spectrometry data are reported on ex-vivo porcine corneas prepared with uniform concentrations using polyethylene glycol (PEG) solutions. At 79% concentration by mass, measured reflectivity cornea was 20.4%, 14.7%, 11.7%, 9.6%, 7.4% at 0.2, 0.4, 0.6, 0.8, 1 THz, respectively....

Terahertz (THz) imaging has shown great potential as a tool for in vivo of conditions which affect the hydration properties skin, including thermal burns, chemical irritation, and cancer. This work presents composite model skin based on gradients measured by confocal Raman spectroscopy. Bruggeman mixing theory is used to compute dielectric function profile stratified media calculations simulate reflection spectrum THz radiation from skin. The reflected power reflectometry measurement...

Accurate and early prediction of tissue viability is the most significant determinant flap survival in reconstructive surgery.Perturbation water content (TWC) a generic component response to such surgeries, and, therefore, may be an important diagnostic target for assessing extent vivo.We have previously shown that reflective terahertz (THz) imaging, non-ionizing technique, can generate spatially resolved maps TWC superficial soft tissues, as cornea wounds, on order minutes.Herein, we report...

In vivo visualization and quantification of edema, or 'tissue swelling' following injury, remains a clinical challenge. Herein, we investigate the ability reflective terahertz (THz) imaging to track changes in tissue water content (TWC)-the direct indicator edema-by comparison depth-resolved magnetic resonance (MRI) burn-induced model edema.A partial thickness full burns were induced an rat elicit unique TWC perturbations corresponding burn severity. Concomitant THz surface maps MRI images...

A method to register THz and visible images of cutaneous burn wounds calibrate image data is presented. Images partial full thickness in 9 rats were collected over 435 mins. = 7.25 hours following induction. two-step process was developed reference the unknown structure imaging contrast known features present injury. This enabled demarcation a wound center for each image, independent contrast. Threshold based segmentation automated identification air (0% reflectivity), brass (100% abdomen...

Terahertz spectroscopy is a promising method to diagnose ocular diseases, where the cornea typically imaged by Gaussian beams. However, beam’s mismatch with cornea’s spherical surface produces 5-10 % error in analysis. We investigate wavefront-modified vector beams, reducing original analysis less than 0.5 %. Vector beams are synthesized our developed 3D Angular Spectrum Method expanded harmonic presentation, allowing wavefront modification and scattering from 100-layer models. show that...

Terahertz medical imaging has emerged as a promising new field because of its non-ionizing photon energy and acute sensitivity to water concentration. To better understand the primary contrast mechanism in THz tissues, reflectivity varying concentrations was measured. Using pulsed reflective system, 0.3 mm thin paper sample with probed from measured data noise equivalent delta concentration (NEΔWC) 0.054% derived. The system is based on photoconductive source time-gated waveguide-mounted...

BACKGROUND Head and neck squamous cell carcinomas (HNSCCs) are debilitating diseases for which a patient's prognosis depends heavily on complete tumor resection. Currently, the surgeon's fingers determine location of tissue margins. This study evaluated diagnostic utility novel imaging modality, dynamic optical contrast (DOCI), in detection HNSCC. system generates by illuminating with pulsed light detecting variations endogenous fluorophore lifetimes. METHODS A total 47 fresh ex vivo samples...

Objective A cerebrospinal fluid leak is one of the most serious complications in otolaryngology. It may occur as a result injury to skull base, typically traumatic or iatrogenic. While presence often discerned emergent setting, distinguishing normal secretions from those containing can be difficult during postoperative visits clinic. As current laboratory‐based assays are labor intensive and require several days result, we aim develop more user‐friendly rapid point‐of‐care detection device....

Objective: The goal of this paper is to demonstrate and evaluate the potential efficacy laser-generated shockwave (LGS) therapy on biofilm infected tissue. Methods: To proof concept, Staphylococcus epidermidis was allowed proliferate ex vivo pigskin, until mature formation achieved, then subjected LGS. Bacterial load between control treated samples compared using swab technique colony counting. Scanning electron microscopy (SEM) used visualize growth resulting reduction in coverage from...

A system was built to test the efficacy of bacterial biofilm disruption using laser generated shockwaves. The is based on a Q-switched, ND:YAG pulsed operating at rep rate 10 Hz with 1500 mJ pulses centered 1064 nm. were used create shockwave in Al coated polycarbonate substrates and resulting peak stress greater than 50 MPa measured. These coupled bacteria grown confluence agar plates cell death as result assessed. results show 55% reduction number living between shocked control samples....

Currently, there is no curative treatment for advanced metastatic prostate cancer, and options, such as chemotherapy, are often nonspecific, harming healthy cells resulting in severe side effects. Attaching targeting ligands to agents used anticancer therapies has been shown improve efficacy reduce nonspecific toxicity. Furthermore, the use of triggered can enable spatial temporal control over treatment. Here, we combined an engineered cancer-specific ligand, A11 minibody, with a novel...

Coupling to longitudinal modes of thin spherical shells, under Gaussian-beam illumination, was explored with a theoretical method based on Fourier-optics analysis and vector harmonics scrutinized an experimental setup. For the theory part, illumination frequency band fixed between 100-600 GHz outer shell radius curvature thickness are 7.5 mm 0.5 mm, respectively. The material either lossless cornea or aqueous effective media representing cornea. Six different beam-target strategies were...

Mie theory is a powerful method to model electromagnetic scattering from multilayered sphere. Usually, the incident beam expanded its vector spherical harmonic representation defined by shape coefficients, and multilayer sphere obtained T-matrix method. However, obtaining coefficients for arbitrarily shaped beams has limitations on source locations requires different methods when inside or outside computational domain at scatterer surface. We propose 3D angular spectrum defining arbitrary...

Background and Objectives Bacterial biofilm formation within chronic wound beds, which provides an effective barrier against antibiotics, is a known cause of recalcitrant infections significant healthcare burden, often requiring repeated surgical debridements. Laser-generated shockwaves (LGS) novel, minimally invasive, nonthermal modality for mechanical debridement utilizes compressive stress waves, generated by photonic absorption in thin titanium films to mechanically disrupt the biofilm....

Research in THz imaging is generally focused on three primary application areas: medical, security, and nondestructive evaluation (NDE). While work security personnel screening populated by a number of different active passive system architectures, research medical performed with time-domain systems. These systems typically employ photoconductive or electro-optic source/detector pairs can acquire depth resolved data spectrally pixels synchronously sampling the electric field...

Terahertz (THz) imaging is an expanding area of research in the field medical due to its high sensitivity changes tissue water content. Previously reported vivo rat studies demonstrate that spatially resolved hydration mapping with THz illumination can be used rapidly and accurately detect fluid shifts following induction burns provide highly spatial temporal characterization edematous tissue. imagery partial full thickness burn wounds acquired by our group correlate well severity suggest...

A reflective THz imaging system sensitive to small variations in water concentrations has been developed. Biological tissues such as skin, eyes and teeth were imaged ascertain the systems response tissue hydration. Difference translated contrast images. Contrast was also seen images of skin cancer burns suggesting potential diagnostic capability clinical settings. All specimens analyzed freshly excised ex-vivo tissues. These encouraging preliminary results have motivated us explore vivo our system.

Terahertz (THz) imaging is a relatively new non-destructive analytical technique that transitioning from established application research areas such as defense and biomedicine to studies of cultural heritage artifacts. Our adopts THz medical system, originally designed for in vivo tissue hydration sensing, acquire high contrast imagery painted plaster samples order assess the ability system image Byzantine wall paintings at Enkleistra St. Neophytos Paphos, Cyprus. The original 12th century...

A reflective terahertz (THz) system has been under development for imaging and monitoring of skin hydration, through consideration attenuation, scattering, spatial resolution measurement sensitivity, the frequency band 0.4 - 0.7 THz determined optimal operation. THz, typically defined as range between 0.1-10 proposed hydration primarily due to being non-ionizing radiation highly sensitivity water concentrations. While it is important maximize changes in concentration, operational must...

We present a novel system for imaging burns and other lesions of human skin tissue utilizing the acute sensitivity THz radiation to water concentration. It is impulse radar that carries out reflective, 2D with photoconductive-switch wideband illuminator, Schottky-rectifying gated receiver, mechanical scanning. has been used image ~2 mm spatial resolution in ≈5 min over 1 KPixel sq inch.