- 标题
- 摘要
- 关键词
- 实验方案
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Detection of Knot Defects on Coniferous Wood Surface Using Near Infrared Spectroscopy and Chemometrics
摘要： Lumber pieces usually contain defects such as knots, which strongly affect the strength and stiffness. To develop a model for rapid, accurate grading of lumbers based on knots, Douglas fir, spruce-pine-fir (SPF), Chinese hemlock, and Dragon spruce were used. The experiments explored the effects of modelling methods and spectral preprocess methods for knot detection, and investigated the feasibility of using a model built within one species to discriminate the samples from other species, using a novel variable selection method-random frog to select effective wavelengths. The results showed that least squares-support vector machines coupled with first derivative preprocessed spectra achieved best performance for both single and mixed models. Models built within Dragon spruce could be used to classify knot samples from SPF and Chinese hemlock but not Douglas fir, and vice versa. Eight effective wavelengths (1314 nm, 1358 nm, 1409 nm, 1340 nm, 1260 nm, 1586 nm, 1288 nm, and 1402 nm) were selected by RF to build effective wavelengths based models. The sensitivity, specificity, and accuracy in the validation set were 98.49%, 93.42%, and 96.30%, respectively. Good results could be obtained when using data at just eight wavelengths, as an alternative to evaluating the whole spectrum.
关键词： Coniferous wood,Knot detection,Near infrared spectroscopy (NIRS),Random frog algorithm,Least squares-support vector machines (LS-SVM)
更新于2025-09-23 15:23:52
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Wearable SiPM-based NIRS Interface Integrated with Pulsed Laser Source
摘要： We present the design of a miniaturized probe integrating silicon photomultiplier and light-pulsing electronics in a single 2x2mm2 CMOS chip which includes functional blocks such as a fast pulse-laser driver and synchronized single-photon detection circuit. The photon pulses can be either counted on-chip or processed by an external high-speed electronic module such as time-corelated single photon counting (TCSPC) unit. The integrated circuit was assembled on a printed circuit board (PCB) and also on a 2.5D silicon interposer platform of size 1 cm and interfaced with a silicon photomultiplier (SiPM), vertical cavity surface emitting laser (VCSEL) and other ancillary components such as capacitors and resistors. Our approach of integrating an optical interface to optimize light collection on the small active area and light emission from the vertical-cavity surface-emitting laser (VSCEL) will facilitate clinical adoption in many applications and change the landscape of Near Infrared Spectroscopy (NIRS) hardware commercially due to significant optode-size reduction and the elimination of optical fibers.
关键词： Near-Infrared Spectroscopy (NIRS),Time-Domain (TD),complementary metal-oxide-semiconductor (CMOS),Vertical Cavity Surface Emitting Laser (VCSEL),Silicon Photomultiplier (SiPM),Optical Probe
更新于2025-09-11 14:15:04
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Revolutionizing Tropical Medicine (Point-of-Care Tests, New Imaging Technologies and Digital Health) || The Use of Near-Infrared Spectroscopy to Monitor Tissue Oxygenation, Metabolism and Injury in Low Resource Settings
摘要： In a low resource setting there are many barriers for providing the standard of healthcare that is normal in developed countries. Modern healthcare largely depends on reliable and accurate medical devices that can diagnose disease, monitor treatment and provide accurate prognostic information. Often medical devices are associated with high costs for purchasing and maintenance that often includes costs for a large number of consumables. In addition, a particular infrastructure is required and highly trained staff are needed to operate these devices. To be successful and useful in low‐ and middle‐income countries (LMICs), a medical device needs to be inexpensive, portable, safe, non‐invasive, easy to use and interpret, and battery‐powered. Near‐infrared spectroscopy (NIRS) is a medical device that fulfills all of these requirements and thus has great potential to make an impact on healthcare in LMICs. Its most important use to date has been in neurological monitoring. Its success in this field is due to its low cost, ease of use and ability to be used in a low resource environment.
关键词： metabolism,Near‐Infrared Spectroscopy,NIRS,tissue oxygenation,injury,low resource settings
更新于2025-09-11 14:15:04