Purpose To assess the repeatability of a new swept-source optical coherence tomography (SS-OCT) biometer (IOLMaster 700) and evaluate the agreement with an optical low-coherence reflectometry (OLCR) ...biometer (Lenstar 900) in cataractous eyes. Setting Tertiary eyecare facility. Design Prospective evaluation of a diagnostic test. Methods Eyes of patients had 3 consecutive scans acquired by the same operator. The repeatability of measurements was assessed using the within-subject standard deviation and coefficient of variation (CoV). Agreement between the mean measurements of each machine was evaluated. Results The study comprised 100 eyes of 100 patients. The median lens thickness and axial length (AL) measurements were significantly greater ( P < .001) with SS-OCT (4.29 mm and 23.5 mm, respectively, versus 4.25 mm and 23.4 mm, respectively); anterior chamber depth (ACD) was greater with OLCR (2.72 mm versus 2.70 mm, respectively) ( P < .001). The within-subject standard deviation and CoV of the AL (0.01 and 0.05, respectively) and the ACD (0.04 and 1.22, respectively) measurements showed lower variability with SS-OCT (0.05 and 0.21, respectively, for AL; 0.06 and 1.99, respectively, for ACD) than with OLCR. Good agreement was seen for anterior segment measurements between the 2 devices. The 95% limits of agreement of most parameters fell within the test–retest variability of the parameters. The SS-OCT biometer also showed better penetration in dense posterior subcapsular cataracts, measuring AL successfully in 96% of cases. Conclusions The new SS-OCT biometer showed good repeatability and agreement with the OLCR biometer. The SS-OCT biometer measured the AL with fewer dropouts compared with the OLCR even in dense cataracts. Financial Disclosure None of the authors has a financial or proprietary interest in any material or method mentioned.
Study objectives Diagnostic errors in the emergency department (ED) are an important patient safety concern, but little is known about their cause. We identify types and causes of missed or delayed ...diagnoses in the ED. Methods This is a review of 122 closed malpractice claims from 4 liability insurers in which patients had alleged a missed or delayed diagnosis in the ED. Trained physician reviewers examined the litigation files and the associated medical records to determine whether an adverse outcome because of a missed diagnosis had occurred, what breakdowns were involved in the missed diagnosis, and what factors contributed to it. Main outcome measures were missed diagnoses, process breakdowns, and contributing factors. Results A total of 79 claims (65%) involved missed ED diagnoses that harmed patients. Forty-eight percent of these missed diagnoses were associated with serious harm, and 39% resulted in death. The leading breakdowns in the diagnostic process were failure to order an appropriate diagnostic test (58% of errors), failure to perform an adequate medical history or physical examination (42%), incorrect interpretation of a diagnostic test (37%), and failure to order an appropriate consultation (33%). The leading contributing factors to the missed diagnoses were cognitive factors (96%), patient-related factors (34%), lack of appropriate supervision (30%), inadequate handoffs (24%), and excessive workload (23%). The median numbers of process breakdowns and contributing factors per missed diagnosis were 2 and 3, respectively. Conclusion Missed diagnoses in the ED have a complex cause. They are typically the result of multiple breakdowns in the diagnostic process and several contributing factors.
Optical sensing of biomolecules using microring resonators Yalcin, A.; Popat, K.C.; Aldridge, J.C. ...
IEEE journal of selected topics in quantum electronics,
2006-Jan.-Feb., 2006-01-00, 20060101, Letnik:
12, Številka:
1
Journal Article
Recenzirano
A biosensor application of vertically coupled glass microring resonators with Q/spl sim/12 000 is introduced. Using balanced photodetection, very high signal to noise ratios, and thus high ...sensitivity to refractive index changes (limit of detection of 1.8/spl times/10/sup -5/ refractive index units), are achieved. Ellipsometry and X-ray photoelectron spectroscopy results indicate successful modification of biosensor surfaces. Experimental data obtained separately for a bulk change of refractive index of the medium and for avidin-biotin binding on the ring surface are reported. Excellent repeatability and close-to-complete surface regeneration after binding are experimentally demonstrated.
