For the intelligence of metamaterials, the -sensing mechanism and programmable reaction units are two important components for self-recognition and -determination. However, their realization still face great challenges. Here, we propose a smart sensing metasurface to achieve self-defined functions in the framework of digital coding metamaterials. A sensing unit that can simultaneously process the sensing channel and realize phase-programmable capability is designed by integrating radio frequency (RF) power detector and PIN diodes. Four sensing units distributed on the metasurface aperture can detect the microwave incidences in the x- and y-polarizations, while the other elements can modulate the reflected phase patterns under the control of a field programmable gate array (FPGA). To validate the performance, three schemes containing six coding patterns are presented and simulated, after which two of them are measured, showing good agreements with designs. We envision that this work may motivate studies on smart metamaterials with high-level recognition and manipulation.

PURPOSE To investigate changes of whole eye axial biometry during accommodation using ultra-long scan depth optical coherence tomography (UL-OCT). DESIGN Prospective, observational case series. METHODS Twenty-one adult subjects were enrolled. Using UL-OCT, the left eye of each subject was imaged with relaxed (0 D) and accommodative stimuli (+6 D). Full eye biometry included central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness, vitreous length and axial length (AL). RESULTS During accommodation (+6 D), the axial biometry of the whole eye changed significantly. Compared to the rest state, ACD at the accommodative state decreased significantly from 3.128 ± 0.305 mm to 2.961 ± 0.298 mm (paired t-test, P < 0.001). The lens thickness increased significantly from 3.723 ± 0.237 mm to 3.963 ± 0.234 mm (P < 0.001). The vitreous length decreased significantly from 17.129 ± 0.864 mm to 17.057± 0.848 mm (P < 0.001). AL was 24.519 ± 0.917 mm at the rest state and increased to 24.545±0.915 mm with +6 D accommodation stimulus. The elongated AL of 26.1 ± 13.4 μm between the rest and accommodative states was significant (P < 0.001). CONCLUSIONS During accommodation, whole eye axial biometry changed, including a decrease in ACD and vitreous length, and an increase in lens thickness and AL. UL-OCT provides an alternative method that is suitable for full eye biometry during accommodation.

The goal was to determine the variability of the quantitative measurement of the bulbar conjunctival microvascular morphology and hemodynamics by testing the repeatability and variation during office hours. Functional slit-lamp biomicroscopy (FSLB) was used to image the bulbar conjunctival microvasculature, including the vessel diameter, blood flow velocity/rate and fractal dimensions of the microvascular network. The temporal side of the bulbar conjunctiva in 20 healthy subjects was imaged. The subject was imaged at 9AM to test the measurement repeatability by two independent graders. The intraclass correlation coefficient (ICC) and coefficient of repeatability (CoR) were calculated. These same subjects were then imaged every two hours from 9AM to 5PM to test the variation during office hours. Custom software was used to semi-automatically process all measurements. The CoR% and ICC values between two graders for measuring the vessel diameter were 4.87% and 0.989, respectively. For the axial blood flow velocity, the CoR% and ICC were 11.49% and 0.997, respectively. From 9AM to 5PM, There were no significant variations in the vessel diameter and hemodynamics (P > 0.05). Whereas, the fractal dimensions of the non-invasive microvascular perfusion maps (nMPMs) were significantly increased at 3PM and 5PM compared with the baseline obtained at 9AM (P < 0.05). FSLB appears to be capable of measuring vessel diameter, blood flow velocity and fractal dimension of the microvascular network in the bulbar conjunctiva. Slight variations over office hours were observed in the microvascular network, while the blood flow velocity remained stable.

Purpose-To analyze quantitatively the alterations in the microvascular network of the upper tarsal conjunctiva, lid wiper, and bulbar conjunctiva relative to ocular discomfort after contact lens wear.Design-A prospective, cross-over clinical study.Methods-Functional slit-lamp biomicroscopy (FSLB) was used to image the microvascular network of the upper tarsal conjunctiva, lid wiper, and bulbar conjunctiva. The microvascular network was automatically segmented, and fractal analyses were performed to yield the fractal dimension (D box ) that represented vessel density. Sixteen healthy subjects (nine female and seven male) with an average age of 35.5 ± 6.7 years old (mean ± standard deviation) were recruited. The right eye was imaged at 9 AM and 3 PM at the first visit (Day 1) when the subject was not wearing contact lenses. During the second visit (Day 2), the right eye was fit with a contact lens for 6 h. Microvascular imaging was performed before (at 9 AM) and after lens wear (at 3 PM). Ocular comfort was rated using a 50-point visual analogue scale before and after 6 h of lens wear, and its relationships with microvascular parameters were analyzed.Results-There were no significant differences in D box among the upper tarsal conjunctiva, lid wiper, and bulbar conjunctiva among the measurements at 9 AM (Day 1 and Day 2) and 3 PM Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Financial Disclosures HHS Public AccessAuthor manuscript Am J Ophthalmol. Author manuscript; available in PMC 2017 October 01. Author Manuscript Author ManuscriptAuthor Manuscript Author Manuscript (Day 1) when the subjects were not wearing the lenses (P > 0.05), whereas after 6 h of lens wear, the microvascular network densities were increased in all three of these locations. D box of the lid wiper increased from 1.411 ± 0.116 to 1.548 ± 0.079 after 6 h of contact lens wear (P < 0.01). D box of the tarsal conjunctiva was 1.731 ± 0.026 at baseline and increased to 1.740 ± 0.030 (P < 0.05). D box of the bulbar conjunctiva increased from 1.587 ± 0.059 to 1.632 ± 0.060 (P < 0.001). The decrease in ocular discomfort was strongly related to the D box change in the lid wiper (r = 0.61, P < 0.05). There were no correlations between the changes of ocular comfort and the microvascular network densities of either the tarsal or bulbar conjunctivas (P > 0.05).Conclusion-This study is the first to show that the microvascular network of the lid wiper can be quantitatively analyzed in contact lens wearers. The microvascular responses of the lid wiper were significantly correlated with contact lens discomfo...

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