Harvey Lui's research while affiliated with University of British Columbia - Vancouver and other places

Eczema (atopic eczema) is a common, chronic and recurrent inflammatory skin disease affecting 10‐15% of the population. A limited Canadian study based on a small survey sample reported that the annual cost of eczema is $CAD 1.4 billion dollars, with costs expected to rise further with the introduction of biologic therapies. Its growing global preva...

The study objective is to evaluate whether incorporating patient demographics into Raman spectral analysis can improve diagnostic performance. In vivo Raman spectra of 731 cases were analysed by dividing the data into two groups: skin cancers/precancers (malignant melanoma, basal cell carcinoma, squamous cell carcinoma, and actinic keratosis, n = 3...

The recent worldwide rise in idiopathic immune and inflammatory diseases such as multiple sclerosis (MS) and inflammatory bowel diseases (IBD) has been linked to Western society-based changes in lifestyle and environment. These include decreased exposure to sunlight/UVB light and subsequent impairment in the production of vitamin D, as well as dysb...

This issue of Photodermatology, Photoimmunology, and Photomedicine commemorates the contributions and legacy of Dr. Nikiforos Kollias, an outstanding skin biophysicist affectionately known as “Nik” to those who worked and trained with and under him. After Nik earned his PhD studying low temperature thermal transport properties of metals, he launche...

Linked editorial: Fuller and Hay. Br J Dermatol 2019; 180:1279–1280.

Androgenetic alopecia (AGA) is characterized by progressive miniaturization of hair follicles on the scalp from terminal (≥30 μm)to vellus (≥30 μm) types [1]. Under trichoscopy, hair shaft diameter variation (HSDV) is defined as the percentage of vellus hair shafts within a region of interest. HSDV>20% is characteristic of AGA and is considered as...

We report a novel approach to selectively close single blood vessels within tissue using multiphoton absorption–based photothermolysis (multiphoton photothermolysis) without the need of exogenous agents. The treatment process is monitored by in vivo reflectance confocal microscopy in real time. Closure of single targeted vessels of varying sizes ra...

Over the last decade new systemic drugs (e.g. biologics, apremilast, alitretinoin) have diversified the options for treating palmoplantar dermatoses such as psoriasis and dermatitis. Topical psoralen‐UVA (tPUVA) phototherapy nevertheless remains an important modality for hand and foot dermatoses that may be refractory to topicals, with the advantag...

Raman spectroscopy provides molecular finger-printing of biological tissues. To achieve high spatial resolution, confocal Raman spectroscopy (micro-Raman) has been developed. To guide where micro-Raman is acquired, imaging guidance is necessary, especially for high scattering biological tissue. Reflectance confocal microscopy (RCM) has been integra...

Skin cancer is the most common human malignancy with an ongoing continual increase in global incidence.1‐3 Despite their high prevalence, keratinocyte carcinomas (KCs), namely basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), are often excluded from population‐based cancer registries. As there are over 3000 defined skin disease varietie...

Background and Purpose Although cutaneous autofluorescence has been utilized for evaluation of skin conditions, there is a paucity of data on normal human skin autofluorescence and its dependence on anatomical site. The objective of this study is to use excitation‐emission matrix spectroscopy to quantify and characterize skin autofluorescence at di...

Background: Labial melanotic macules (LMMs) are benign hyperpigmented macules of unknown etiology. They can affect one or both lips. Their description in patients with atopic dermatitis (AD) is limited in the published literature. Objectives: The aim of the study was to describe the clinical characteristics of LMMs developing in Canadian patients w...

Determining the optical polarization properties of a skin lesion is a proposed method to differentiate melanoma from other skin lesions. We developed an in vivo Stokes polarimetry probe that fires a laser of known polarization at the skin and measures the Stokes parameters of the backscattered light in one shot. From these measured Stokes parameter...

Vascular structures of skin are important biomarkers in diagnosis and assessment of cutaneous conditions. Presence and distribution of lesional vessels are associated with specific abnormalities. Therefore, detection and localization of cutaneous vessels provide critical information towards diagnosis and stage status of diseases. However, cutaneous...

Background: There is no accepted method to objectively assess the visual appearance of sunscreens on the skin. Methods: We present a method for sunscreen application, digital photography, and computer analysis to quantify the appearance of the skin after sunscreen application. Four sunscreen lotions were applied randomly at densities of 0.5, 1.0...

Background: Basal cell carcinoma (BCC) is the most common skin cancer, which is highly damaging in its advanced stages. Computer-aided techniques provide a feasible option for early detection of BCC. However, automated BCC detection techniques immensely rely on handcrafting high-level precise features. Such features are not only computationally co...

Raman spectroscopy provides a noninvasive bedside tool that captures unique optical signals via molecular vibrations in tissue samples. Raman theory was discovered at the beginning of the twentieth century, but it was not until the past few decades that it has been used to differentiate skin neoplasms. We provide a brief description of Raman spectr...

Scalp imaging techniques are necessary tools for the trichological practice and for visualization of permeation, penetration and absorption processes into and through the scalp and for the research on drug delivery and toxicology. The present letter reviews different scalp imaging techniques and discusses their utility. Moreover, two different stud...

Phototherapy with ultraviolet A-1 (UVA1) can induce durable remissions in sclerosing disorders such as morphea(1) . Optimal UVA1 dosing remains an area of research(2-4) . Acute adverse reactions to UVA1 include erythema, pruritus and polymorphic light eruption (PMLE)(5) . The acute adverse reaction rate during UVA1 phototherapy has been reported to...

Movie S1. Multimode imaging video of the treatment process. Blue channel, RCM; Green channel, SHG; Red channel, TPF. The bottom part of the frame at 2.03 s is black because the shutter is closing.

The successful application of lasers in the treatment of skin diseases and cosmetic surgery is largely based on the principle of conventional selective photothermolysis which relies strongly on the difference in the absorption between the therapeutic target and its surroundings. However, when the differentiation in absorption is not sufficient, col...

Blood vessels are important biomarkers in skin lesions both diagnostically and clinically. Detection and quantification of cutaneous blood vessels provide critical information towards lesion diagnosis and assessment. In this paper, a novel framework for detection and segmentation of cutaneous vasculature from dermoscopy images is presented and the...

Raman spectroscopy is a noninvasive optical technique under investigation for skin disease diagnosis. In this chapter, we present a rapid real-time Raman system and an imaging-guided confocal Raman system and their applications for in vivo skin evaluation. The rapid Raman system, obtaining signals from millimeter size tissue volume, has been evalua...

Interference and polarization techniques provide the highest sensitivity and precision in optical metrology. The recently introduced polarization speckle method, incorporating both techniques, is a promising biomedical tool. In this chapter we demonstrate how the method could be used in dermatology. Measuring the polarization properties of coherent...

Scanning speed and coupling efficiency of excitation light to optic fibres are two major technical challenges that limit the potential of fluorescence excitation-emission matrix (EEM) spectrometer for on-line applications and in vivo studies. In this paper, a novel EEM system, utilizing a supercontinuum white light source and acousto-optic tunable...

Porphyrins produced by Propionibacterium acnes represent the principal fluorophore associated with acne, and appear as orange-red luminescence under the Wood’s lamp. Assessment of acne based on Wood’s lamp (UV) or visible light illumination is limited by photon penetration depth and has limited sensitivity for earlier stage lesions. Inducing fluore...

Reflectance confocal microscopy (RCM) and multiphoton microscopy (MPM) are non-invasive methods of acquiring morphological images of the skin in vivo. Most research in this area focuses on instruments that are configured for two-dimensional imaging in a horizontal plane parallel to the skin surface. In contrast, conventional histopathologic evaluat...

Photothermolysis induced by femtosecond (fs) lasers may be a promising modality in dermatology because of its advantages of high precision due to multiphoton absorption and deeper penetration due to the use of near infrared wavelengths. Although multiphoton absorption nonlinear effects are capable of precision targeting, the femtosecond laser photo...

Fluorescence signals depend on the intensity of the exciting light, the absorption properties of the constituent molecules, and the efficiency with which the absorbed photons are converted to fluorescence emission. The optical features and appearance of vitiligo have been explained primarily on the basis of reduced epidermal pigmentation, which res...

Real-time Raman spectroscopy can be used to assist in assessing skin lesions suspicious for cancer. Most of the diagnostic algorithms are based on full band of the Raman spectra, either in the fingerprint region or the high wavenumber region. In this paper we explored wavenumber selection based analysis in Raman spectroscopy for skin cancer diagnos...

A platform technology for real-time in vivo tissue Raman spectroscopy was developed that takes 1-2 seconds to obtain a spectrum. The system was tested over 900 skin patients and 80 lung patients, achieved high diagnostic sensitivity (90%) and good specificities (73%, 65%) for skin cancer and lung cancer detection.

In a recent study, we have demonstrated that real-time Raman spectroscopy could be used for skin cancer diagnosis. As a translational study, the objective of this study is to validate previous findings through a completely independent clinical test. In total, 645 confirmed cases were included in the analysis, including a cohort of 518 cases from a...

Glycerol-induced optical clearing of the skin is limited by the barrier effect of the stratum corneum (SC). Application of hyperosmotic glycerol on human skin following SC removal substantially increased light penetration, but altered skin morphology.

A customized confocal Raman spectroscopy system was used to measure the Raman spectra of porcine skin irradiated by high power ultrafast laser. The changes in Raman spectra indicate that the collagen was denatured and carbonized after high power ultrafast laser irradiation.

Vascular structures are one of the most important features in the diagnosis and assessment of skin disorders. The presence and clinical appearance of vascular structures in skin lesions is a discriminating factor among different skin diseases. In this paper, we address the problem of segmentation of vascular patterns in dermoscopy images. Our propo...

Recent advances in biomedical optics have enabled dermal and epidermal components to be visualized at subcellular resolution and assessed non-invasively. Multiphoton microscopy (MPM) and reflectance confocal microscopy (RCM) are non-invasive imaging modalities that have demonstrated promising results in imaging skin micromorphology, and which provi...

Non-invasive cellular imaging of the skin in vivo can be achieved in reflectance confocal microscopy (RCM) and multiphoton microscopy (MPM) modalities to yield complementary images of the skin based on different optical properties. One of the challenges of in vivo microscopy is the delineation (i.e., segmentation) of cellular and subcellular archit...

Cutaneous malignant melanoma is one of the most frequent types of cancer in the world; but if the malignancy is detected and treated early, it can be cured. Many dermatologists promote dermoscopy as an early detection tool; however, dermoscopy requires formal training with a steep learning curve. In this chapter, we introduce a novel tree-based fra...

One challenge in facing the application of biomedical Raman spectroscopy is that the Raman signal is acquired in a dark operation room. It is inconvenient for both the operator and the patient because it is difficult for the operator to accurately and precisely locate the target in the dark environment, and the patient feels uncomfortable in such a...

The Journal of Investigative Dermatology publishes basic and clinical research in cutaneous biology and skin disease.

We describe the importance of identifying pigment networks in lesions which may be melanomas, and survey methods for identifying pigment networks (PN) in dermoscopic images. We then give details of how machine learning can be used to classify images into three classes: PN Absent, Regular PN and Irregular PN.

Raman photon generation inside human skin and escaping to skin surface were modeled in an eight-layered skin optical model. Intrinsic Raman spectra of different skin layers were determined by microscopy measurements of excised skin tissue sections. Monte Carlo simulation was used to study the excitation light distribution and intrinsic Raman signal...

One-photon absorption based traditional laser treatment may not necessarily be selective at the microscopic level, thus could result in un-intended tissue damage. Our objective is to test whether two-photon absorption (TPA) could provide highly targeted tissue alteration of specific region of interest without damaging surrounding tissues. TPA based...

Fiber delivery of ultrashort pulses is important for multiphoton endoscopy. A chirped photonic crystal fiber (CPCF) is first characterized for its transmission bandwidth, propagation loss, and dispersion properties. Its extremely low dispersion ( 2 ~ 150 fs m ) enables the delivery of sub-30 fs pulses through a ~1 m-long CPCF. The CPCF is then...

Stem cells offer tremendous opportunities for regenerative medicine. Over the past decade considerable research has taken place to identify and characterize the differentiation states of stem cells in culture. Raman micro-spectroscopy has emerged as an ideal technology since it is fast, nondestructive, and does not require potentially toxic dyes. R...

Skin surface roughness is an important clinical property for aging process and pathological changes of the outmost organ of the body. Physicians use skin roughness as the key diagnostic feature to detect warts, actinic keratoses, and psoriases, and to differentiate benign seborrheic keratoses from malignant melanomas. Additionally, skin roughness h...

Skin phantoms are often used to study and model light propagation. However, existing skin phantoms overlook the important effect of surface roughness on light propagation patterns. This paper reports the construction of durable phantoms with controllable surface roughness and bulk optical properties. With silica microspheres as the scattering parti...

Skin cancer is the most common cancer in the Western world. In order to accurately detect the disease, especially malignant melanoma-the most fatal form of skin cancer-at an early stage when the prognosis is excellent, there is an urgent need to develop noninvasive early detection methods. We believe that polarization speckle patterns, defined as a...

Supplementary Video 2

The movement from the subjects during in vivo confocal Raman spectral measurements could change the measurement volume, leading to non-specific signals and inaccurate interpretation of the acquired spectrum. Here we introduce a generally applicable method that includes (1) developing a multimodal system to achieve real-time monitoring of every spec...

Supplementary Information

Supplementary Video 1

We present a multimodal in vivo skin imaging instrument that is capable of simultaneously acquiring multiphoton and reflectance confocal images at up to 27 frames per second with 256 × 256 pixel resolution without the use of exogenous contrast agents. A single femtosecond laser excitation source is used for all channels ensuring perfect image regis...

Multiphoton microscopy (MPM) is a powerful technique for high resolution imaging of biological tissues. A specially-designed chirped photonic crystal fiber (CPCF) is introduced for MPM applications. The CPCF eliminates most pulse broadening effects in a broad transmission window because its cell-size radial chirp in the cladding structure localizes...

Polymorphous light eruption (PMLE) is the most common photodermatosis and is characterized by the development of a pruritic skin eruption within a few hours to days after sun or artificial light exposure. The eruption usually takes up to two weeks to resolve in the absence of further ultraviolet radiation. PMLE has been reported as a side effect of...

Laser (or light) hair removal, also referred to as photoepilation, is the most commonly used laser or light-based cosmetic medical procedure. The extended theory of selective photothermolysis is the basic principle for destruction of hair follicles using light. In this type of laser application the chromophore is follicular melanin. Several types o...

Hair loss has a high prevalence in the general population and can have significant medical and psychological sequelae. Pattern hair loss and alopecia areata represent the major reasons patients present to dermatologists in relation to hair loss. Because conventional treatment options are generally incompletely effective, novel methods for hair grow...

Irregular streaks are important clues for Melanoma (a potentially fatal form of skin cancer) diagnosis using dermoscopy images. This paper extends our previous algorithm to identify the absence or presence of streaks in a skin lesions, by further analyzing the appearance of detected streak lines, and performing a three-way classification for streak...

Patients often present with clinical skin features that may resemble a variety of similar but distinct conditions. A 41-year-old Asian woman was referred to the dermatology clinic for evaluation of dyspigmentation on the hands and feet that was first noted at the age of 6 years. Physical examination revealed a combination of hyper- and hypopigmente...

We have successfully developed a platform technology for real-time in vivo Raman spectroscopy of human tissues. Spectra can be obtained within 1-2 seconds. Clinical applications have been implemented for skin cancer and lung cancer detection.