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Highlights • Full mapping of carious degree status using novel 3D hyperspectral imaging system. • White spot lesion detection with high resolution at 488 nm light source. • Enamel and dentin carious detection with high resolution at 514 nm light source. • Integration of developed imaging system with laser drilling system to achieve precise carious removal. Abstract Early detection of carious is vital for demineralization reversal, offering less pain, as well as precise carious removal. In this study, the difference in optical properties of normal tissue and human carious lesion has been used for early diagnosis, using laser induced fluorescence spectroscopy. The optical system consists of light source in visible band and hyperspectral camera, associated with designed digital image processing algorithm. The human tooth sample was illuminated with visible band sources at 488, and 514 nm with energy of 5 m watt. The reflected and emitted light from the tested sample was captured using hyperspectral camera in an attempt to generate multispectral images (cubic image). The variation of reflected and emitted energy as function of wavelength was employed to generate characteristic spectrum of each tooth tissue. Human teeth carious tissue lesion releases its excess energy by emitting fluorescence light producing chemical footprint signature; this signature is dependent on the elemental composition of tooth elements and carious state. This non-invasive, non-contact and non-ionizing imaging system with associated novel pattern recognition algorithm was employed to diagnose and classify different carious types and stages. It was reported that the perceived fluorescence emission is function of the illuminating wavelength. While enamel and dentin carious were distinguished and characterized at 514 nm illuminating wavelength; white spot lesion were contoured and recognized at 488 nm. Therefore, full recognition could be achieved through generated cubic image after sample irradiation at 488 nm and 514 nm. In conclusion, this study reports on a customized optical image system that can offer high sensitivity, high resolution, and early carious detection with optimum performance at 514 nm and 488 nm. [ABSTRACT FROM AUTHOR]

Abstract Terrorism by means of explosive materials has become a serious threat. Instant identification of common explosive material is an urgent demand. Even though FTIR spectroscopy can offer signature based on chemical structure; this technology requires sample handling and processing. On the other hand, laser induced photoacoustic spectroscopy (LIPAS) can offer outstanding characteristic signatures. Common commercial explosive materials were subjected to LIPAS analysis via stimulating the tested material with pulsed Q-switched Nd:YAG laser. Generated photoacoustic signature was captured and processed via high response piezoelectric transducer and novel digital signal processing algorithm designed for time and frequency domain analysis respectively. Each explosive material demonstrated characteristic absorption coefficient as well as frequency response. The main finding of this study is that phase-resolved domain analysis offered an outstanding signature. This phase-shift signature is candidate for data-base operation mode. LIPAS offered superior identification signatures compared with FTIR spectroscopy with the advantages of standoff detection capabilities. Highlights • Characteristic optical properties of each explosive material via photoacoustic spectroscopy. • Photoacoustic frequency signature with stable base line and sharp characteristic peaks. • Photoacoustic phase-shift signature that can offer novel identification tool for explosive materials. • Novel photocoustic spectroscopy technique that eliminated sample preparation; with standoff detection capabilities. [ABSTRACT FROM AUTHOR]

Abstract Common fertilizers have the oxidizing and the reducing elements on the same molecule; therefore they have an explosiveness nature. Reliable approach for fast recognition of such compounds is an urgent need. Laser induced photoacoustic spectroscopy is an interesting technology as it can offer characteristic thermal, acoustical, and light absorption coefficient. The paper deals with a photoacoustic spectroscopy technique to record the characteristic photoacoustic frequency-response of common explosive-related materials. The proper stimulating light was generated using pulsed Q-switched Nd:YAG laser at 1064 nm. Photoacoustic signature for each investigated material was recorded using high response piezoelectric transducer. The captured signal was processed using novel digital algorithm designed for time and frequency domain analysis to achieve good discrimination between different explosive-related materials. Each investigated material demonstrated a characteristic absorption coefficient as well as frequency response with maximum amplitude at 47.9, 49, and 46 MHz for urea nitrate, ammonium nitrate, and ammonium perchlorate respectively. Graphical abstract Image 1 Highlights • Instant identification of explosive-related compounds. • Novel photoacoustic signal processing using time and frequency domain algorithms. • Original approaches to quantify characteristic absorption coefficient as well as frequency response. • Quantified thermal, optical, and acoustical properties that can act as a fingerprint of the material structure. [ABSTRACT FROM AUTHOR]

Hepatocellular carcinoma (HCC) is a noteworthy health problem with a poor diagnosis due to limited detection techniques. Transcriptome studies can be used to classify cancer further away from anatomical location and histopathology. Recent studies demonstrated the novelty of numerous types of specific RNA biomarkers that differentially expressed both the normal liver and the HCC tissues, but those specific types overlapped with the detection of other types of cancers. In this study, total RNA was used to ensure the existence of differences between different cancer types. A multispectral light source (340-1000nm) interacted with the sample. Multi-wavelengths images were captured using a hyperspectral camera (wavelength 380-1000nm). The optimum wavelength to discriminate between the normal and HCC samples was selected by calculating the optical properties (transmission, absorption and scattered light). Results showed specific spectral signatures for total RNA within the red-band (633-700nm) that discriminate HCC from control. The amount of light scattering, transmission and absorption relatively changed due to the variations of size, shape, and concentration of total RNA. The spectral RNA signature that is dependent on the shape and size of total RNA may be utilized as the gold standard for HCC detection. [ABSTRACT FROM AUTHOR]

We present a method for the noninvasive determination of the size, position, and optical properties of tumors in the human breast. The tumor is first detected by photothermal imaging. It is then sized, located, and optically characterized using designed digital image processing and edge-detection pattern recognition. The method assumes that the tumor is spherical and inhomogeneous and embedded in an otherwise homogeneous tissue. Heat energy is deposited in the tissue by absorption of near-infrared (NIR) Nd:YAG laser radiation, and its subsequent conversion to heat via vibrational relaxation causes a rise in temperature of the tissue. The tumor absorbs and scatters NIR light more strongly than the surrounding healthy tissue. Heat will diffuse through the tissue, causing a rise in temperature of the surrounding tissue. Differentiation between normal and cancerous tissues is determined using IR thermal imaging. Results are presented on a 55-year-old patient with a papillary breast cancer. We found that these results provide the clinician with more detailed information about breast lesions detected by photothermal imaging and thereby enhance its potential for specificity. [ABSTRACT FROM AUTHOR]

• Hyperspectral imaging depends on the optical properties for ex-vivo breast tissues to provide different responses of normal vs tumorous tissue. • The spectral signatures of both malignant and normal ex-vivo breast tissue utilizing K-mean clustering for cancer tissue detection was evaluated. • Trials showed that the superimposed of spectral region 420∼620 nm was proposed as the optimum bandwidth. • The proposed system shows potential edge evaluation method for ex-vivo breast cancer detection with high sensitivity and specificity. Breast cancer is one of the most widely recognized tumors..Diagnosis made in the early stage of disease may imporve outcomes. The discovery of malignant growth utilizing noninvasive light intrusive methods in lieu of conventional excisional biopsy may assist in achieving this goal. The change of the optical properties of ex-vivo breast tissues provides different responses to light transmission, absorption, and particularly the reflection over the spectrum range. We offer the use of Hyperspectral imaging (HSI) with advanced image processing and pattern recognition in order to analyze HSI data for breast cancer detection. The spectral signatures were mined and evaluated in both malignant and normal tissue. K-mean clustering was designed for classifying hyperspectral data in order to evaluate and detection of cancer tissue. This method was used to detect ex-vivo breast cancer. Spatial spectral images were created to high spot the differences in the reflectance properties of malignant versus normal tissue. Trials showed that the superficial spectral reflection images within 500 nm wavelength showed high variance (214.65) between cancerous and normal breast tissues. On the other hand, image within 620 nm wavelength showed low variance (0.0020).However, the superimposed of spectral region 420–620 nm was proposed as the optimum bandwidth. Finally, the proposed HS imaging system was capable to discriminate the tumor region from normal tissue of the ex-vivo breast sample with sensitivity and a specificity of 95 % and 96 %. High sensitivity and specificity were achieved, which proposes potential for HSI as an edge evaluation method to enhance the surgical outcome compared to the presently available techniques in the clinics. [ABSTRACT FROM AUTHOR]