Broadband thermal imaging using meta-optics.

Subwavelength diffractive optics known as meta-optics have demonstrated the potential to significantly miniaturize imaging systems. However, despite impressive demonstrations, most meta-optical imaging systems suffer from strong chromatic aberrations, limiting their utilities. Here, we employ inverse-design to create broadband meta-optics operating in the long-wave infrared (LWIR) regime (8-12 µm). Via a deep-learning assisted multi-scale differentiable framework that links meta-atoms to the phase, we maximize the wavelength-averaged volume under the modulation transfer function (MTF) surface of the meta-optics. Our design framework merges local phase-engineering via meta-atoms and global engineering of the scatterer within a single pipeline. We corroborate our design by fabricating and experimentally characterizing all-silicon LWIR meta-optics. Our engineered meta-optic is complemented by a simple computational backend that dramatically improves the quality of the captured image. We experimentally demonstrate a six-fold improvement of the wavelength-averaged Strehl ratio over the traditional hyperboloid metalens for broadband imaging.

Acoustic analysis of normal voice patterns in North Indian population.

Acoustic analysis of voice provides objective values which can be used for treatment follow-up, comparison, and analysis. There are a variety of programs available for this purpose, but none of these provide a normative value. The reason being that the acoustic parameters vary with age, gender, and ethnicity. The study was done to create standardized values of acoustic parameters in north Indian Hindi speakers for clinical use. OBJECTIVE: To evaluate the characteristics of voice of the north Indian Hindi speakers across the adult population based on acoustic measures of fundamental frequency (F0), jitter, shimmer, and harmonic-to-noise ratio and to observe the gender differences in these measures. METHODS: A total of 62 (39 men and 23 women) voice samples from healthy normal voiced adults aged 18-40 years were included. RESULTS: Mean fundamental frequency in males and females in the age group 18-25 is 156 and 262, respectively. Similarly mean fundamental frequency in males and females in the age group 26-40 is 141 and 253, respectively. Shimmer in the women (18-25) group and jitter in the men (26-40) group is not normally distributed. Rest all parameters were normally distributed across all groups. Fundamental frequency showed statistically significant gender differences in both the age groups. Jitter and shimmer variables were statistically significant when compared between the two genders in the age group 26-40. Harmonic-to-noise ratio showed a statistically significant difference in the age group 18-25 among both genders. There exists statistically significant negative correlation between smoothed cepstral peak prominence and fundamental frequency, Pearson's r -0.479 (P-value <0.001). CONCLUSION: All acoustic parameters except intensity show a significant gender difference; however, the participants across each gender revealed no difference in acoustic parameters when segregated into age groups.

Large field-of-view thermal imaging via all-silicon meta-optics.

A broad range of imaging and sensing technologies in the infrared require large field-of-view (FoV) operation. To achieve this, traditional refractive systems often employ multiple elements to compensate for aberrations, which leads to excess size, weight, and cost. For many applications, including night vision eye-wear, air-borne surveillance, and autonomous navigation for unmanned aerial vehicles, size and weight are highly constrained. Sub-wavelength diffractive optics, also known as meta-optics, can dramatically reduce the size, weight, and cost of these imaging systems, as meta-optics are significantly thinner and lighter than traditional refractive lenses. Here, we demonstrate 80° FoV thermal imaging in the long-wavelength infrared regime (8-12 µm) using an all-silicon meta-optic with an entrance aperture and lens focal length of 1 cm.

To Determine the Prevalence of Laryngopharyngeal Reflux in Patients of Various Throat Disorders and to Evaluate the Efficacy of Anti-reflux Therapy.

To study the prevalence of Laryngopharyngeal reflux in individuals having throat complaints by applying the Reflux Symptom Index and Reflux finding score as a prognostic tool after anti reflux therapy. Materials and Methods: A Cross-sectional study of 75 patients of age 18 years and above with clinical diagnosis of Laryngopharyngeal reflux was conducted in ENT. Cases were examined with detailed history and thorough examination with indirect laryngoscopy and Hopkins 70 degree endoscope. Symptoms and findings of patients were assessed by Belafsky Reflux Symptom Index and Reflux Finding Score. Patients presenting Belafsky Reflux Symptom Index > 13 and also Reflux Finding Score > 7 were classified as having Laryngopharyngeal reflux. After 6 weeks of treatment, patients were reassessed and Reflux Symptom Index and Reflux finding score were calculated. Results: The mean age of the study subjects was 37.12 ± 12.39 years. Most common symptom reported based on RSI questionnaire was excessive throat mucus (81.33%) followed by clearing of throat (75%) and coughing on lying down and heartburn. Based on the Laryngoscopy, about 57.33% had thick endolarygeal mucus, 56% had diffuse erythema, 45.33% had granulations and 29.33% had subglottic edema. Based on the reflux symptom scores, we found 53.33% and 80% of patients based on reflux findings score to have Laryngopharyngeal Reflux. The mean Reflux Symptom Index scores were 16.25 ± 5.53 and 10.73 ± 4.40 and also the mean Reflux Finding scores were 13.81 ± 2.42 and 6.61 ± 2.16 respectively before and after the treatment which was statistically significant.

Severe iritis and choroidal effusion following selective laser trabeculoplasty.

A patient with uncontrolled primary open-angle glaucoma underwent selective laser trabeculoplasty and developed a significant anterior chamber reaction, shallow anterior chamber, and choroidal effusion. Common complications associated with selective laser trabeculoplasty include conjunctival injection, mild anterior chamber reaction, and post-treatment intraocular pressure elevation. The authors believe this is the first reported case of severe iritis and choroidal effusion following selective laser trabeculoplasty.