Investigation on Deep Layer Measurements in the Cerebral Cortex within the Adult Head by near Infrared Spectroscopy Using an Absorbance Difference Technique

Ohnishi, Michihiro; Kusakawa, Naoki; Shimizu, Masaki; Honda, Kiyoshi; Shimada, Yasuhiro; Fujimoto, Ichiro; Hirao, Konomu

doi:10.1255/jnirs.351

Cited by 9 publications

(3 citation statements)

References 14 publications

(27 reference statements)

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“…While light emitted by the Diagnodent pen has a wavelength of 655 nm, DRS uses a broader range of wavelengths (400-1600 nm), which should allow for deeper penetration through hard dental tissues. However, the penetration depth also depends on the distance between the optical fibers-the larger the distance, the higher the detection depth [58][59][60]. In this study, the distance between the optical fibers was 0.85 mm, which seems to be suitable for the detection of demineralization within the enamel, as DRS outperformed the Diagnodent pen and visual inspection in D1 and D2 lesions.…”

Section: Discussionmentioning

confidence: 64%

Diffuse Reflectance Spectroscopy as a Novel Method of Caries Detection—An In Vitro Comparative Study in Permanent Teeth

et al. 2023

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This in vitro study aimed to compare outcomes of dental caries detection using visual inspection classified according to the International Caries Detection and Assessment System (ICDAS) with objective assessments using a well-established laser fluorescence system (Diagnodent pen) and a novel diffuse reflectance spectroscopy (DRS) device. One hundred extracted permanent premolars and molars were utilized, including sound teeth, teeth with non-cavitated caries, or teeth with small cavitated lesions. A total of 300 regions of interest (ROIs) were assessed using each detection method. Visual inspection, being a subjective method, was performed by two independent examiners. The presence and extent of caries were histologically verified according to Downer’s criteria, serving as a reference for other detection methods. Histological results revealed 180 sound ROIs and 120 carious ROIs, categorized into three different extents of caries. Overall, there was no significant difference between the detection methods in sensitivity (0.90–0.93) and false negative rate (0.05–0.07). However, DRS exhibited superior performance in specificity (0.98), accuracy (0.95), and false positive rate (0.04) compared to other detection methods. Although the tested DRS prototype device exhibited limited penetration depth, it shows promise as a method, particularly for the detection of incipient caries.

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Section: Discussionmentioning

confidence: 64%

Diffuse Reflectance Spectroscopy as a Novel Method of Caries Detection—An In Vitro Comparative Study in Permanent Teeth

et al. 2023

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“…Spatially resolved spectroscopy (SRS) acquires the reflectance from objects at different spatial distances between the illumination and detectors, and it enables the obtaining of information from the sample at different depths as the transport path of photons generally forms a "banana-shape" in the tissue of the biological materials [28]. There are various configurations for SRS, including single-fiber-based, multi-fiber-based, and hyperspectral imaging-based, for measuring the optical absorption and scattering properties of food products [29][30][31].…”

Section: Introductionmentioning

confidence: 99%

Identification of Apple Varieties Using a Multichannel Hyperspectral Imaging System

Huang

Yang

Sun

et al. 2020

Sensors

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This paper reports the nondestructive detection of apple varieties using a multichannel hyperspectral imaging system consisting of an illumination fiber and 30 detection fibers arranged at source–detector distances of 1.5–36 mm over the spectral range of 550–1650 nm. Spatially resolved (SR) spectra were obtained for 1500 apples, 500 each of three varieties from the same orchard to avoid environmental and geographical influences. Partial least squares discriminant analysis (PLSDA) models were developed for single SR spectra and spectral combinations to compare their performance of variety detection. To evaluate the effect of spectral range on variety detection, three types of spectra (i.e., visible region: 550–780 nm, near-infrared region: 780–1650 nm, full region: 550–1650 nm) were analyzed and compared. The results showed that the single SR spectra presented a different accuracy for apple variety classification, and the optimal SR spectra varied with spectral types. Spectral combinations had better accuracies for variety detection with best overall classifications of 99.4% for both spectral ranges in the NIR and full regions; however, the spectral combination could not improve the results over the optimal single SR spectra in the visible region. Moreover, the recognition of golden delicious (GD) was better than those of the other two varieties, with the best classification accuracy of 100% for three types of spectra. Overall, the multichannel hyperspectral imaging system provides more spatial-spectral information for the apples, and the results demonstrate that the technique gave excellent classifications, which suggests that the multichannel hyperspectral imaging system has potential for apple variety detection.

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“…Spatially-resolved spectroscopy is an emerging spectroscopic technique for measuring reflectance from the sample at different spatial distances between a point light source and detectors. Spatially-resolved (SR) spectra contain information about the sample at different layers (or depths) since the transport path of photons generally forms a “banana-shape” in biological tissues [ 20 ], shown in Figure 1 . Short spatial distances between the illumination and detectors would provide top layer information of the sample, while large source-detector distances is useful to obtain deep layer information of the sample [ 21 ].…”

Section: Introductionmentioning

confidence: 99%

Assessment of Tomato Maturity in Different Layers by Spatially Resolved Spectroscopy

Huang

Chen

et al. 2020

Sensors

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Tomato maturity is important to determine the fruit shelf life and eating quality. The objective of this research was to evaluate tomato maturity in different layers by using a newly developed spatially resolved spectroscopic system over the spectral region of 550–1650 nm. Thirty spatially resolved spectra were obtained for 600 tomatoes, 100 for each of the six maturity stages (i.e., green, breaker, turning, pink, light red, and red). Support vector machine discriminant analysis (SVMDA) models were first developed for each of individual spatially resolved (SR) spectra to compare the classification results of two sides. The mean spectra of two sides with the same source-detector distances were employed to determine the model performance of different layers. SR combination by averaging all the SR spectra was also subject to comparison with the classification model performance. The results showed large source-detector distances would be helpful for evaluating tomato maturity, and the mean_SR 15 obtained excellent classification results with the total classification accuracy of 98.3%. Moreover, the classification results were distinct for two sides of the probe, which demonstrated even if in the same source-detector distances, the classification results were influenced by the measurement location due to the heterogeneity for tomato. The mean of all SR spectra could only improve the classification results based on the first three mean_SR spectra, but could not obtain the accuracy as good as the following mean_SR spectra. This study demonstrated that spatially resolved spectroscopy has potential for assessing tomato maturity in different layers.

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Investigation on Deep Layer Measurements in the Cerebral Cortex within the Adult Head by near Infrared Spectroscopy Using an Absorbance Difference Technique

Cited by 9 publications

References 14 publications

Diffuse Reflectance Spectroscopy as a Novel Method of Caries Detection—An In Vitro Comparative Study in Permanent Teeth

Diffuse Reflectance Spectroscopy as a Novel Method of Caries Detection—An In Vitro Comparative Study in Permanent Teeth

Identification of Apple Varieties Using a Multichannel Hyperspectral Imaging System

Assessment of Tomato Maturity in Different Layers by Spatially Resolved Spectroscopy

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