Optical parameters (properties) of tissue-mimicking phantoms are determined through nonin-vasive optical imaging. Objective of this study is to decompose obtained diffuse reflectance into these optical properties such as absorption and scattering coefficients. To do so, transmission spectroscopy is firstly used to measure the coefficients via an experimental setup. Next, the optical properties of each characterized phantom are input for Monte Carlo (MC) simulations to get diffuse reflectance. Also, a surface image for each single phantom with its known optical properties is obliquely captured due to reflectance-based geometrical setup using CMOS camera that is positioned at 50 angle to the phantoms. For the illumination of light, a laser light source at 633 nm wavelength is preferred, because optical properties of different components in a biological tissue on that wavelength are nonoverlapped. During in vitro measurements, we prepared 30 different mixture samples adding clinoleic intravenous lipid emulsion (CILE) and evans blue (EB) dye into a distilled water. Finally, all obtained diffuse reflectance values are used to estimate theoptical coefficients by artificial neural networks (ANNs) in inverse modeling. For a biological tissue it is found that the simulated and measured values in our results are in good agreement.

Purpose: To evaluate the potential clinical usability of a new prototype of ophthalmic blue light filters developed by using electrochromic technology in pseudophakic patients complaining of glare. Methods: A prototype of electrochromic device was developed, with a specific frame that enclosed an electronic driver that allowed personalizing its function for each patient. A pro-spective, observational case series study was performed to test it. Five patients who had un-dergone cataract surgery with clear intraocular lenses and complaining of glare were included in the study. Main outcome measures were the results obtained in the satisfaction questionnaire that was delivered to patients. Then, visual acuity, contrast sensitivity, and reading ability data were evaluated with and without the prototype under different lighting conditions and different modes of the prototype after a complete month of use. Lens transmittance was also measured. Results: Visual acuity, contrast sensitivity and reading function did not change significantly with prototype use. The main activity for which the prototype was used was walking. Only one patient found that the dimming level was insufficient. No patients reported variable discomfort when passing tunnels, not sufficiently clear indoors, or put on and remove discomfort. The lenses slightly decreased their transmittance at the end of the study. Conclusion: Glasses based on electrochromic technology may be acceptable for outdoor/indoor use and for distance–near vision. Future studies with larger samples must be conducted to confirm the clinical usability of these glasses.

Teicoplanin (TCP) is an important lipoglycopeptide antibiotic produced by fermenting Acti-noplanes teichomyceticus. The change in TCP concentration is important to measure in the fermentation process. In this study, a reagent-free and rapid quantification method for TCP in the TCP–Tris–HCl mixture samples was developed using near-infrared (NIR) spectroscopy by focusing our attention on the fermentation process for TCP. The absorbance optimization (AO) partial least squares (PLS) was proposed and integrated with the moving window (MW) PLS, which is called AO–MW–PLS method, to select appropriate wavebands. A model set that includes various wavebands that were equivalent to the optimal AO–MW–PLS waveband was proposed based on statistical considerations. The public region of all equivalent wavebands was just one of the equivalent wavebands. The obtained public regions were 1540–1868 nm for TCP and 1114–1310 nm for Tris. The root-mean-square error and correlation coefficient for leave-one-out cross validation were 0.046 mg mL 1 and 0.9998 mg mL 1 for TCP, and 0.235 mg mL 1 and 0.9986 mg mL 1 for Tris, respectively. All the models achieved highly accurate prediction effects, and the selected wavebands provided valuable references for designing specialized spectrometers. This study provided a valuable reference for further application of the proposed methods to TCP fermentation broth and to other spectroscopic analysis fields.

Human serum albumin (HSA) injectable product is a severely afflicted area on drug safety due to its high price and restricted supply. Raman spectroscopy performances high specificity on HSA detection and it is even possible to determine HSA injectable products noninvasively. In this study, we developed a noninvasive rapid screening method for of HSA injectable products by using portable Raman spectrometer. Qualitative models were established by using principal component analysis combined with classical least squares (PCA-CLS) algorithm, while quanti-tative model was established by using partial least squares (PLS) algorithm. Model transfer in different instruments of both the same and different apparatus modules was further discussed in this paper. A total of 34 HSA injectable samples collected from markets were used for verification. The identification results showed 100% accuracy and the predicted concentrations of those identified as true HSA were consistent with their labeled concentrations. The quantitative results also indicated that model transfer was excellent in the same apparatus modules of Raman spectrometer at all concentration levels, and still good enough in the different apparatus modules although the relative standard deviation (RSD) value showed a little increasing trend at low HSA concentration level. In conclusion, the method was proved to be feasible and efficient for screening HSA injections, especially on its screening speed and the consideration of glass containers. Moreover, with inspiring results on the model transfer, the method could be used as a universal screening mean to different Raman instruments.

During neurosurgery, an optical probe has been used to guide the micro-electrode, which is punc-tured into the globus pallidus (GP) to create a lesion that can relieve the cardinal symptoms. Accurate target localization is the key factor to affect the treatment. However, considering the scattering nature of the tissue, the “look ahead distance (LAD)" of optical probe makes the boundary between the different tissues blurred and difficult to be distinguished, which is defined as artifact. Thus, it is highly desirable to reduce the artifact caused by LAD. In this paper, a real-time algorithm based on precise threshold was proposed to eliminate the artifact. The value of the threshold was determined by the maximum error of the measurement system during the calibration procession automatically. Then, the measured data was processed sequentially only based on the threshold and the former data. Moreover, 100 m double-fiber probe and two-layer and multi-layer phantom models were utilized to validate the precision of the algorithm. The error of the algorithm is one puncture step, which was proved in the theory and experiment. It was concluded that the present method could reduce the artifact caused by LAD and make the real boundary sharper and less blurred in real-time. It might be potentially used for the neurosurgery navigation.

We propose a novel optical method for glucose measurement based on diffuse photon-pair density wave (DPPDW) in a multiple scattering medium (MSM) where the light scattering of photon-pair is induced by refractive index mismatch between scatters and phantom solution. Experi-mentally, the DPPDW propagates in MSM via a two-frequency laser (TFL) beam wherein highly correlated pairs of linear polarized photons are generated. The reduced scattering coefficient 0 2s and absorption coefficient 2a of DPPDW are measured simultaneously in terms of the amplitude and phase measurements of the detected heterodyne signal under arrangement at different dis-tances between the source and detection fibers in MSM. The results show that the sensitivity of glucose detection via glucose-induced change of reduced scattering coefficient ( 0 2s) is 0.049% mM 1 in a 1% intralipid solution. In addition, the linear range of 0 2s vs glucose concentration implies that this DPPDW method can be used to monitor glucose concentration continuously and noninvasively subcutaneously.

Dialysis hypotension is one of the most prevalence symptoms of dialysis and occurs in 40% of treatment sessions. Detection and prediction of hypotension is important for the well-being of the patient and for optimizing treatment. The aim of this study was to construct optical system to monitor blood pressure (BP) continuously and without cuff in hemodialysis based on pulse transit time (PTT) method. To measure the BP changes, dual-channel optical system were developed. In this study, individuals were classified into two groups of normal and hemodialysis. In both groups, BP and consequently PTT were earned three times in different positions. After the initial calibration, the regression equation was drawn for each subject. In normal group, each subject was placed in the supine position and BP was measured both by designed system and sphyg-momanometer cuff. During BP measurements, in addition to BP, blood pressure decline was also monitored by optical system. For hemodialysis group, the same measurement setup was adopted. In both groups, the error between cuff method and PTT was calculated. Correlation coefficients for BPcuff vs BPPTT were calculated and Bland–Altman plot was performed for the normal and hemodialysis groups. In this study 16 subjects participated. The results for normal group showed that maximum difference between cuff method and the present method was 14 mmHg and for dialysis group was 16 mmHg. Bland–Altman plot in normal group revealed limits of agreement from 13.98 to 13.18 mmHg. Considering hemodialysis group, limits of agreement were from -15.94 to 13.88 mmHg. The correlation coefficient was 0.74 for normal group and was 0.72 for hemodialysis group. The proposed system can monitor BP continuously and diagnose sudden hypotension. So it can be recommended as a useful method to indicate hypotension and can be used for dialysis unit.

Usually, only focused femtosecond (fs) lasers at near-infrared (NIR) range can induce photo-damage to transparent cells, making it difficult to treat large amount of cells by such optical methods for photostimulation. In this study, we clarify the mechanism of photodamage to cells that are co-cultured with gold nanorods (GNRs) by fs laser. The pulse duration and repetition rate of the fs laser play a key role in cell damage suggesting that the heat accumulation con-tributes to the major part for the cell damage rather than the high peak power which mainly determines the efficiency of multiphoton excitation. We further show that cellular Ca2t can also be released in this scheme, but the process is more sensitive to peak power. Our results can provide a large-scale GNR-mediated photostimulation for cell signaling modulation.

In this paper, we studied the effects of physical factors, such as, acoustic pulses of laser-induced hydrodynamics (ALIH) and extremely-high frequencies (EHF) radiation, on the formation of heterotopic bone marrow organs. A suspension of precipitated bone marrow cells from CBA mice were exposed to ALIH pulses and EHF radiation separately and in their combination tissue engineering constructs, presenting gelatin sponges 2 by 2 by 2 mm in size containing 107 nucleated bone marrow cells, were exposed to physical factors and were implanted under the renal capsules of syngeneic mice. The newly formed hematopoietic organs were examined in three and five months later after treatment. The five months old transplants were bigger in size than the three months old transplants. The number of hematopoietic cells in the rest of the groups increased during this period by a factor from 3 to 10, the increase being as high as 20-fold in the ALIHtEHF group. Maximal concentration of multipotent stromal cells (MSCs) was in the EHFtALIH, and minimal concentration was in the ALIHtEHF. The accumulation rate of bone capsule weight was highest for the transplants of EHFtALIH and ALIH-sponge groups during the first three months. These data showed that the combined impact of the EHFtALIH on MSCs is the most effective for the formation of bone marrow transplantation.

It is necessary to know the distribution of the Chinese eye's aberrations in clinical environment to guide high-resolution retinal imaging system design for large Chinese population application. We collected the monochromatic wave aberration of 332 healthy eyes and 344 diseased eyes in Chinese population across a 6.0-mm pupil. The aberration statistics of Chinese eyes including healthy eyes and diseased eyes were analyzed, and some differences of aberrations between the Chinese and European race were concluded. On this basis, the requirement for adaptive optics (AO) correction of the Chinese eye's monochromatic aberrations was analyzed. The result showed that a stroke of 20
m and ability to correct aberrations up to the 8th Zernike order were needed for reflective wavefront correctors to achieve near diffraction-limited imaging in both groups for a reference wavelength of 550 nm and a pupil diameter of 6.0 mm. To verify the analysis mentioned above, an AO flood-illumination system was established, and high-resolution retinal imaging in vivo was achieved for Chinese eye including both healthy and diseased eyes.

A method for investigating the optical properties of human tissues is suggested. The method is based on the measurement of Cherenkov radiation produced by relativistic electrons passing through the tissue. Monte-Carlo simulation of visible photon emission and propagation is carried out taking into account multiple electron and photon scattering processes. Sensitivity of the Cherenkov radiation to the optical characteristics of human tissues is demonstrated.