Joseph E Hayward

Joseph E Hayward
McMaster University | McMaster · Department of Radiology and The School of Interdisciplinary Sciences

Doctor of Philosophy (Engineering Physics)

About

74
Publications
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Introduction
Biophotonics; in particular the role of light-based techniques for the diagnoses of biological tissue and the use of light-based techniques for therapeutic applications.

Publications

Publications (74)
Article
Skin cancer (SC) is a widely spread disease in the USA, Canada, and Australia. Skin cancer patients are mostly of advanced age and therefore more likely to be treated with radiation therapy as many are comorbid and not surgical candidates. However, radiation therapy has side effects, which may range from skin erythema to skin necrosis. As erythema...
Article
Full-text available
An optical phantom model with stable oxygen saturation (StO2) and optical properties (OPs) is the key for quick and accurate calibration of spectral imaging devices. Toward this goal, we have developed gel-based phantoms using Agarose, polystyrene microsphere, purified hemoglobin, and yeast. Theoretical values of OPs were calculated by applying Bee...
Conference Paper
Full-text available
Surveillance and assessment of radiation-induced erythema is an important aspect of managing skin toxicity in radiation therapy treated patients. Upon receiving the early fractions of radiation, an inflammatory response and vascular dilation takes place due to damage of basal cells in the skin’s epidermal layer. This process of skin reddening known...
Article
Full-text available
Erythema is an inflammatory condition of the skin that is commonly used as a feature to monitor the progression of cutaneous diseases or treatment induced side effects. In radiation therapy, skin erythema is routinely assessed visually by an expert using standardized grading criteria. However, visual assessment (VA) is subjective and commonly used...
Conference Paper
Full-text available
We document a comparison of an acousto-optic tunable filter (AOTF), and a liquid crystal tunable filter (LCTF) based on hyperspectral imaging (HSI). The purpose of this work is to highlight each tunable filter, in order to ease filter choice in HSI design. Three factors are evaluated including spectral resolution, and image quality. The results ver...
Article
Full-text available
Glioma itself accounts for 80% of all malignant primary brain tumors, and glioblastoma multiforme (GBM) accounts for 55% of such tumors. Diffuse reflectance and fluorescence spectroscopy have the potential to discriminate healthy tissues from abnormal tissues and therefore are promising noninvasive methods for improving the accuracy of brain tissue...
Article
PURPOSE: To investigate non-targeted radiation effects in esophageal adenocarcinoma cell lines (OE19 and OE33) using human keratinocyte and colorectal cancer cell reporters following γ-ray exposure. MATERIALS AND METHODS: Both clonogenic assays and ratiometric calcium endpoints were used to check for the occurrence of bystander signals in reporter...
Article
Optical spectroscopy of human tissue has been widely applied within the field of biomedical optics to allow rapid, in vivo characterization and analysis of the tissue. When designing an instrument of this type, an imaging spectrometer is often employed to allow for simultaneous analysis of distinct signals. This is especially important when perform...
Article
Full-text available
Time-resolved fluorescence (TRF) and diffuse reflectance (DR) spectroscopy are two optical biopsy modalities that have been studied in tumor diagnosis. Combination of TRF and DR spectroscopy allows us to obtain more features such as fluorescence intensity, lifetime, and optical properties, thus potentially improving the tissue diagnostic accuracy....
Article
Full-text available
The ability to recover the intrinsic fluorescence of biological fluorophores is crucial to accurately identify the fluorophores and quantify their concentrations in the media. Although some studies have successfully retrieved the fluorescence spectral shape of known fluorophores, the techniques usually came with heavy computation costs and did not...
Article
Full-text available
To test whether blood, urine, and tissue based colony-forming assays are a useful clinical detection tool for assessing fractionated treatment responses and non-targeted radiation effects in bystander cells. To assess patients' responses to radiation treatments, blood serum, urine, and an esophagus explant-based in vivo colony-forming assay were us...
Article
Radiation therapy (RT) may pose acute and long-term risks for patients with cardiovascular implantable electronic devices (CIEDs), including pacemakers (PMs) and implantable cardiac defibrillators (ICDs) However, the frequency of these problems has not been accurately defined. To determine the prevalence of CIEDs among patients requiring RT and rep...
Article
The ability to monitor changes in the concentration of hemoglobin in the blood of the skin in real time is a key component to personalized patient care. Since hemoglobin has a unique absorption spectrum in the visible light range, diffuse reflectance spectroscopy is the most common approach. Although the collection of the diffuse reflectance spectr...
Article
High-grade dysplasia (HGD) in Barrett's esophagus (BE) poses increased risk for developing esophageal adenocarcinoma. To date, early detection and treatment of HGD regions are still challenging due to the sampling error from tissue biopsy and relocation error during the treatment after histopathological analysis. In this study, CP-A (metaplasia) an...
Article
Full-text available
Photodynamic therapy (PDT) has been used clinically for treating various diseases including malignant tumors. The main advantages of PDT over traditional cancer treatments are attributed to the localized effects of the photochemical reactions by selective illumination, which then generate reactive oxygen species and singlet oxygen molecules that le...
Article
Full-text available
The measurement of changes in blood volume in tissue is important for monitoring the effects of a wide range of therapeutic interventions, from radiation therapy to skin-flap transplants. Many systems available for purchase are either expensive or difficult to use, limiting their utility in the clinical setting. A low-cost system, capable of measur...
Article
Full-text available
The fluorescence of Intralipid and polystyrene microspheres with sphere diameter of 1 µm at a representative lipid and microsphere concentration for simulation of mucosal tissue scattering has not been a subject of extensive experimental study. In order to elucidate the quantitative relationship between lipid and microsphere concentration and the r...
Article
Optical biopsy techniques offer a minimally invasive, real-time alternative to traditional biopsy and pathology during tumor resection surgery. Diffuse reflectance spectroscopy (DRS) is a commonly used technique in optical biopsy. Optical property recovery from spatially resolved DRS data allows quantification of the scattering and absorption prope...
Article
A hyperspectral fluorescence lifetime imaging (FLIM) instrument is developed to study endogenous fluorophores in biological tissue as an optical biopsy tool. This instrument is able to spectrally, temporally, and spatially resolve fluorescence signal, thus providing multidimensional information to assist clinical tissue diagnosis. An acousto-optic...
Article
Full-text available
When using ultrafast laser ablation in some ortho-pedic applications where precise cutting/drilling is required with minimal damage to collateral tissue, it is challenging to produce large-sized and deep holes using a tightly focused laser beam. The feasibility of producing deep, millimeter-size structures under different ablation strategies is inv...
Article
Purpose: A 2D∕3D registration algorithm is proposed for registering orthogonal x-ray images with a diagnostic CT volume for high dose rate (HDR) lung brachytherapy. Methods: The algorithm utilizes a rigid registration model based on a pixel∕voxel intensity matching approach. To achieve accurate registration, a robust similarity measure combining...
Article
Background: The time until maximal cutaneous vasoconstriction after injection of lidocaine with epinephrine is often given in textbooks and multiple choice examinations as 7 to 10 minutes. However, in our experience, there is significantly less cutaneous bleeding if one waits considerably longer than 7 to 10 minutes after injection of local anesth...
Article
Full-text available
Photodynamic Therapy (PDT) provides an opportunity for treatment of various invasive tumors by the use of a cancer targeting photosensitizing agent and light of specific wavelengths. However, real-time monitoring of drug localization is desirable because the induction of the phototoxic effect relies on interplay between the dosage of localized drug...
Article
Purpose: The primary goal of this investigation was to observe whether measurable levels of bystander factor(s) can be detected in esophageal carcinoma patients' urine samples taken after undergoing high dose rate (HDR) intraluminal brachytherapy (ILBT). However, a small pilot study was developed to evaluate whether serotonin [5-Hydroxytryptamine...
Article
A novel fibre optic probe design and Monte Carlo based optical property recovery algorithm for use in the optical biopsy of brain tissue are described. The algorithm’s performance is characterized when subjected to random noise.
Article
Full-text available
Ultrashort pulsed lasers in bone ablation show promise for many orthopedic applications. To minimize collateral tissue damage and control the ablation process, the ablation threshold fluence must be well characterized. Using an amplified femtosecond laser (170 fs, 800 nm, 1 kHz), the ablation threshold on unaltered porcine cortical bone was measure...
Article
Purpose: To quantitatively characterize the time sequence of skin erythema in head and neck patients undergoing intensity modulated radiation therapy(IMRT)treatments using optical reflectance spectroscopy. The overall goal is to identify patients who will develop extreme skin responses earlier than is possible by visual inspection alone. Methods: T...
Article
The prescribed radiant exposures for photodynamic therapy (PDT) of superficial skin cancers are chosen empirically to maximize the success of the treatment while minimizing adverse reactions for the majority of patients. They do not take into account the wide range of tissue optical properties for human skin, contributing to relatively low treatmen...
Article
An optical system using diffuse reflectance spectroscopy (DRS) and time‐resolved laser induced fluorescencespectroscopy (TR‐LIFS) is being developed to identify surgical margins during braintumour resection. Since initial trials will be performed ex vivo on small samples, we investigated our ability to perform DRS for these small sample volumes. We...
Article
The treatment of superficial skin cancers with photodynamic therapy (PDT) relies on uniformly covering the treatment target with sufficient light fluence using an externally applied source. Incorporating an integrating sphere into the treatment procedure makes this easier to achieve. A prototype sphere was characterized using a 1% Intralipid phanto...
Article
Full-text available
Photodynamic therapy (PDT) is an effective treatment option for various types of invasive tumors. The efficacy of PDT treatment depends strongly on selective cell uptake and selective excitation of the tumor. The characterization of fluorescence lifetimes of photosensitizers localized inside living cells may provide the basis for further investigat...
Article
An integrating sphere system has been developed to non-invasively study the optical properties of biological tissues over a broad spectral range. Using the integrating sphere as both a diffuse illumination source and a detector provides a technically simple measurement apparatus with numerous advantages. A primary advantage is the reduction of the...
Article
We report the investigation of fluorescence lifetime of delta-aminolevulinic acid (ALA) induced protoporphyrin IX (PpIX) and Photofrin© in vitro in MAT-LyLu (MLL) rat prostate adenocarcinoma cells. Photodynamic therapy (PDT) has been extensively investigated in the past decade as an effective treatment option for various types of invasive tumors. T...
Article
To demonstrate the viability of radiochromic film as an in vivo, two-dimensional dosimeter for the measurement of underdosed areas in patients undergoing total skin electron beam (TSEB) radiotherapy. The results were compared with thermoluminescent dosimeter measurements. Dosimetry results are reported for an inframammary fold of 2 patients treated...
Article
GE Lightspeed‐RT CT scanner was introduced to address Radiation Therapy limitations by increasing the bore of conventional CT scanners from 70cm to 85cm, and increasing the reconstruction field of view (FOV) from 50cm to 65cm. However, the gantry detectors were not increased and still only covers a 50cm circle in the bore. The additional 7.5cm FOV...
Article
The effect of photodynamic therapy treatments depends on the concentration of photosensitizer at the treatment site; thus a simple method to quantify concentration is desirable. This study compares the concentration of a fluorophore and sensitizer, aluminum phthalocyanine tetrasulfonate (AlPcS4), measured by two simple fluorescence-based techniques...
Article
Total skin electron (TSE) radiotherapy is routinely used to treat cutaneous T-cell lymphomas and can be implemented using a modified Stanford technique. In our centre, the composite depth dose for this technique is achieved by a combination of two patient positions per day over a three-day cycle, and two gantry angles per patient position. Due to p...
Conference Paper
Relatively inexpensive, commercially available components are used to image skin cancer using polarized light. The resultant images are easily resolved into separate red, green and blue images. The polarization-resolved images eliminate glare and improve the resolution of subsurface skin structures. The polarization photography set-up can be used t...
Article
A dual wavelength time-resolved reflectance system was developed for monitoring haemoglobin saturation noninvasively. At each wavelength, the time-resolved reflectance data were fitted to a diffusion model of light propagation in a homogeneous, semi-infinite medium to yield the absolute scattering and absorption coefficients. The absorption coeffic...
Article
This study compares the photosensitizer concentration measured noninvasively in vivo by diffuse reflectance spectroscopy with the results of postmortem tissue solubilization and fluorometric assay. The reflectance spectrometer consists of a fiber optic surface probe, spectrometer and charge-coupled device (CCD) array detector. The surface probe has...
Article
A near infrared spectrometer has been constructed which is capable of performing spatially resolved diffuse reflectance measurements in the wavelength range of 0.9 - 1.6 micrometer. In this technique, broadband light is delivered by an optical fiber to a point on the tissue surface and diffusely reflected light is collected by 300 micrometer fibers...
Article
This study compares the photosensitizer concentration measured non-invasively in vivo by diffuse reflectance spectroscopy with the results of post mortem tissue solubilization and fluorometric assay. The reflectance spectrometer consists of a fiber optic surface probe, spectrometer, and CCD array detector. The surface probe has eight fibers separat...
Article
Full-text available
Diabetics would benefit greatly from a device capable of providing continuous noninvasive monitoring of their blood glucose levels. The optical scattering coefficient of tissue depends on the concentration of glucose in the extracellular fluid. A feasibility study was performed to evaluate the sensitivity of the tissue reduced scattering coefficien...
Article
Full-text available
Diabetics would benefit from a device capable of providing continuous non-invasive monitoring of their blood glucose levels. A feasibility study was performed to determine wheiher a technique applying spatially resolved diffuse reflectance measurements could be used to detect changes in the blood glucose levels of diabetic volunteers by monitoring...
Article
We describe a general purpose instrument capable of a wide range of noninvasive measurements potentially useful for PDT dosimetry. Examples of applications are presented along with some limitations of the approach.
Article
The effect of nonlinear gain on the steady-state spectral output of 1.3 μm InGaAsP semiconductor diode lasers was investigated by measuring the spectral output of lasers that were operated in a short external cavity (SXC). For the SXC lasers, an increase in the powers in both the long- and short-wavelength modes that are adjacent to the resonant mo...
Article
We describe an instrument which will permit simultaneous collection of radial resolved reflectance over the spectral range 600-1000 nm and a neural network algorithm which permits real- time analysis of the data. The in vivo performance of the instrument is presently under investigation. Data will be presented illustrating the performance of the in...
Article
Data obtained from two techniques on light scattering centers that are distributed along the length of the active region of 1.3-μm InGaAsP/InP diode lasers are presented and discussed. Light scattering characteristics were obtained for 16 lasers by analyzing light detected through the substrate (using spatially and polarization resolved electrolumi...
Article
Physical mechanisms responsible for the above -threshold spectral output of 1.3 mum InGaAsP semiconductor diode lasers are presented and discussed. Measurements of the facet emission of a large number of devices indicate modulations in the below-threshold R_{ rm m}G_{rm m} product which can be used to predict and explain the shape of the above-thre...
Article
Physical mechanisms responsible for the above-threshold spectral output of 1.3 $\mu$m InGaAsP semiconductor diode lasers are presented and discussed. Measurements of the facet emission of a large number of devices indicate modulations in the below-threshold R$\sb{\rm m}$G$\sb{\rm m}$ product which can be used to predict and explain the shape of the...
Article
A residue that is characteristic of internal scattering is extracted from the below-threshold spectra of 1.3-μm semiconductor diode lasers by fitting a smooth function to the measured gain profile. The residue is found to be correlated with the above-threshold spectral output and can be used to predict and explain the above-threshold spectral tunin...
Article
A residue which is characteristic of internal scattering is extracted from the below threshold spectra of 1.3 μm semiconductor diode lasers by fitting a smooth function to the measured gain profile. The residue is found to be correlated with the above threshold spectral output. This suggests that the amount of scattering in the active region is an...
Article
Experimental techniques have been developed to monitor transient infrared absorptions using lead-salt tunable diode lasers. The techniques are easily implemented, yield sensitivities which are limited by detector noise at 10–5 level of absorbance, and have a response time on the order of one microsecond. The transient absorption detection technique...

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