High Sensitive FBG Based Muscular Strain Sensor

Assessment of biomechanical behavior of human musculoskeletal structure is essential to recognize bone diseases and to design proper medical devices.  The skeleton system basically adapts to mechanical loadings. Thus, monitoring the bone deformation under load is of great importance to attain better analysis and interpretation.  In recent years, Fiber Bragg Grating sensing devices have been developed and used to monitor strain and temperature of skeleton system.  In this work a Fiber Bragg Grating sensor is designed holding a 1.54 pmµε-1 axial strain sensitivity which is almost 30% higher than the one achieved so far.  The improvement in sensitivity is achieved by adjusting single-mode optical fiber parameters of the structure

Macular thickness measurements in healthy Norwegian volunteers: an optical coherence tomography study

<p>Abstract</p> <p>Background</p> <p>Ethnic, intersubject, interoperator and intermachine differences in measured macular thickness seem to exist. Our purpose was to collect normative macular thickness data in Norwegians and to evaluate the association between macular thickness and age, gender, parity, and contraception status.</p> <p>Methods</p> <p>Retinal thickness was measured by Stratus Optical Coherence Tomography in healthy subjects. Mean macular thickness (MMT) was analyzed by repeated measures ANOVA with three dependent regional MMT-variables for interaction with age, gender, parity and oral contraception use. Exploratory correlation with age by the Pearson correlation test, both before and after stratification by gender was performed. Differences in MMT between older and younger subjects, between oral contraception users and non-users, as well as parous and nulliparous women were studied by post-hoc Student's t-tests.</p> <p>Results</p> <p>Central MMT in Norwegians was similar to values earlier reported in whites. MMT in central areas of 1 and 2.25 mm in diameter were higher in males than in females. In younger subjects (≤43 years) differences in MMT between genders were larger than in the mixed age group, whereas in older subjects (>43 years) the small differences did not reach the set significance level. No differences were found in minimal foveolar thickness (MMFT) between the genders in any age group.</p> <p>Mean foveal thickness (1 mm in diameter) was positively associated with age in females (r = 0.28, p = 0.03). MMFT was positively associated with age in all groups and reached significance both in females and in mixed gender group (r = 0.20, p = 0.041 and r = 0.26, p = 0.044 respectively).</p> <p>Mean foveal thickness and MMFT were significantly higher in parous than in nulliparous women, and age-adjusted ANOVA for MMFT revealed a borderline effect of parity.</p> <p>Conclusions</p> <p>Age and gender should be taken into consideration when establishing normal ranges for MMT in younger subjects. The gender difference in retinal thickness in young, but not older adults suggests a gonadal hormonal influence. The possible association between parity and retinal structure and its clinical relevance, should be studied further.</p

Association of Optic Nerve Head Drusen with Best Vitelliform Macular Dystrophy: A Case Series

Purpose: To report the association of optic nerve head (ONH) drusen with Best vitelliform macular dystrophy (BVMD). Methods: Chart review. Patients: Five patients from 3 families. Results: Multimodal imaging and ophthalmic examination demonstrated findings consistent with ONH drusen, in association with BVMD, in 5 patients. Conclusion: We report the association of BVMD with ONH drusen in 5 patients. This combination has previously been reported only once. We recommend that patients with a diagnosis of BVMD undergo autofluorescence and ultrasound imaging of the optic nerve to help facilitate this diagnosis, as some ONH drusen can be buried

Sustained Control of Serpiginous Choroiditis with the Fluocinolone Acetonide 0.18 mg Intravitreal Implant

Purpose. To describe an alternative treatment for a patient with serpiginous choroiditis (SC) who was not tolerant to systemic therapies. Methods. Case report of a patient with serpiginous choroiditis with their clinical course followed with ophthalmic examinations and multimodal imaging overtime. Patients and Results. A 57-year-old female with serpiginous choroiditis was treated for seven years with numerous therapies including systemic steroids, immunosuppressive agents, and repeated dexamethasone intravitreal implants. The patient was intolerant of systemic therapies and would flare if dexamethasone injections were performed less frequently than every 8 weeks, making a viable long-term treatment plan problematic. Following one injection of the fluocinolone acetonide 0.18 mg intravitreal implant, she has experienced sustained control for 20 months. Discussion and Conclusions. Real-world treatment of SC is complex as long-term control is necessary, and associated side effects of the therapies provided may limit sustained use. The fluocinolone acetonide implant lasts 36 months and may be an alternative long-term management option, especially in the setting of systemic medication intolerance for some patients with SC

Segmentation of the Surfaces of the Retinal Layer from OCT Images

We have developed a method for the automated segmentation of the internal limiting membrane and the pigment epithelium in 3-D OCT retinal images. Each surface was found as a minimum s-t cut from a geometric graph constructed from edge/regional information and a priori-determined surface constraints. Our approach was tested on 18 3-D data sets (9 from patients with normal optic discs and 9 from patients with papilledema) obtained using a Stratus OCT-3 scanner. Qualitative analysis of surface detection correctness indicates that our method consistently found the correct surfaces and outperformed the proprietary algorithm used in the Stratus OCT-3 scanner. For example, for the internal limiting membrane, 4% of the 2-D scans had minor failures with no major failures using our approach, but 19% of the 2-D scans using the Stratus OCT-3 scanner had minor or complete failures

Parameters for weight computation in RPE.

<p>Parameters for weight computation in RPE.</p