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排序方式: 共有833条查询结果,搜索用时 15 毫秒
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Rohini Srivastava Sonali Ray Meenakshi Sharma Nitin Sahai Ravi P. Tewari Basant Kumar 《Journal of medical engineering & technology》2020,44(7):423-430
Abstract This paper presents the hardware implementation of low delay, power-efficient, rate-adaptive dual-chamber pacemaker (RDPM) using a piezoelectric sensor. Rate adaptive pacemaker has the ability to sense the patient’s activity by means of some special sensors and it controls the pacing rate according to the patient’s activity. Ideally, there should be no delay between sensing and the subsequent pacing operation performed by the pacemaker. However, delay in the responses of various components in the circuitry produces an accumulative delay effect in any practical circuit. Physical activity and the physiological needs of the patient can be easily adapted by the rate-responsive pacemakers using a wide range of sensor information. The piezo-electric sensor recognises the pressure on human muscles because of physical activity and converts it to an electrical signal, which is received by the pulse generator of the pacemaker. When the patient is in the rest mode, the heart rate is the only parameter that is to be detected by the pacemaker. Thus, the heart rate and the physical activity both are the inevitable parameters for the design of RDPM. Performance analysis of the proposed RDPM shows a significant reduction in the delay between sensing and pacing. Device utility analysis shows that the proposed design not only requires lesser memory but also reduces the number of components on the chip. Therefore, it becomes very clear that the proposed pacemaker design will consume much lesser power. 相似文献
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Andrew S Artz Daniel A Pollyea Masha Kocherginsky Wendy Stock Elizabeth Rich Olatoyosi Odenike Todd Zimmerman Sonali Smith Lucy Godley Michael Thirman Christopher Daugherty Martine Extermann Richard Larson Koen van Besien 《Biology of blood and marrow transplantation》2006,12(9):954-964
Comorbidity measurements have recently been used to improve estimation of tolerance to allogeneic hematopoietic cell transplantation (HCT). We sought to determine the independent effect of comorbidity and performance status on HCT outcome and to devise a simple risk classification system for transplant-related mortality. We analyzed 105 consecutively enrolled patients who underwent HCT and received reduced intensity conditioning with fludarabine, melphalan, and alemtuzumab. Comorbid conditions were tabulated using 2 scales, the Charlson Comorbidity Index (CCI) and the Kaplan-Feinstein Scale (KFS). Comorbid conditions were found in 47% of patients by the KFS and in 27% by the CCI (P < .001). Using the Eastern Cooperative Oncology Group Performance Status (PS) scale, 34% had a PS score >0 (range, 0-2). A simple scale combining the KFS and PS enabled separation of high- from low-risk patients, with 6-month cumulative incidences 50% and 15%, respectively for transplant-related mortality (P = .001) and enhanced prognostic power over the CCI alone (P = .018). Prospective studies evaluating more comprehensive functional and comorbidity measurements are warranted. 相似文献
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Raji MA Tang RA Heyn PC Kuo YF Owen SV Singh S Ottenbacher KJ 《Journal of the National Medical Association》2005,97(6):808-814
PURPOSE: We conducted a cross-sectional study examining potentially modifiable factors associated with cognitive impairments (mild or severe) in older whites, African Americans and Hispanics attending an outpatient eye clinic. METHODS: In-clinic interviews and physical examinations assessed social, demographic and health information from 100 consecutive Hispanic, African-American and white adults aged > or = 55. Our primary outcome was presence of any cognitive impairment (mild or severe) using the St. Louis University Mental Status Examination (SLUMS) scale. RESULTS: Of the 100 subjects, 65 screened positive for cognitive impairments on the SLUMS cognitive instrument: 46 with mild cognitive impairment and 19 with severe impairment (possible dementia). African-American and Hispanic adults (nonwhites) were significantly more likely to have cognitive impairment compared to white adults (OR 2.80: 95% CI = 1.05-7.44), independent of age, years of education and systolic blood pressure. Subjects with diabetes also had increased odds of cognitive impairments (OR 3.28, 95% CI = 1.21-8.90) even after adjusting for relevant confounders. There was a nonsignificant trend between visual acuity impairment and cognitive impairment (p = 0.059). CONCLUSIONS: Sixty-five percent of adults aged > or = 55 attending the eye clinic screened positive for cognitive impairments, with higher rates among nonwhites and adults living with diabetes. 相似文献
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J M Enoch V Lakshminarayanan A Itzhaki B M Khamar K Landau T Lowe T Surendran J Comerford 《Optometry and vision science》1991,68(10):807-812
Three visual manifestations of Gilles de la Tourette syndrome (TS), a neuropsychiatric disorder, have been previously reported. In this paper we report anomalies in the measured kinetic paracentral visual field of TS patients and their family members. We found that 96% of TS patients exhibited paracentral kinetic visual field defects (nasal and temporal steps, enlargement, "ringing," and/or baring of the blind spot). Ninety-three percent of fathers of TS children and, surprisingly, about 80% of mothers exhibit these characteristic visual field anomalies. Sample data and examples of family studies are reported. 相似文献
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J M Enoch R D Hamer V Lakshminarayanan T Yasuma D G Birch S Yamade 《Vision research》1987,27(4):507-510
Contrary to previously published studies, monocular light exclusion did not alter the shape of the Stiles-Crawford function in a substantial manner in four subjects who were patched in this laboratory for one full week. In order to rule out methodological differences, an experimenter from each of the two sets of experiments (current and prior) patched one eye for 1 week, then tested each other. For one subject, there was little effect of patching. For the other, patching had a measurable effect, but it was different from that originally reported. However, the much larger, symmetrical broadening of the Stiles-Crawford function reported in earlier studies was not replicated. A testable working hypothesis to explain the earlier results is discussed. 相似文献
8.
Mani Lakshminarayanan 《Journal of biopharmaceutical statistics》2013,23(4):944-947
In nondesigned longitudinal observational studies, irregularly spaced measurements are commonly present over a period of follow-up time. We propose a smoothing dynamic model, based on the idea of varying coefficients, to analyze this highly unbalanced longitudinal data. The estimate of model parameters can be obtained by implementing a well-developed B-splines technique. Our method is illustrated with data from a primary care based longitudinal cohort of rheumatoid arthritis patients. The results show that the effects of some risk factors might be underestimated by an intention-to-treat analysis using a last-value-carried-forward method. 相似文献
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Sonali Prabhakar Khadakkar Vivek V. Harkare 《Indian journal of otolaryngology and head and neck surgery》2011,63(1):87-88
Maxillary antral mucocoeles have an incidence of only 3–10%. Mucocoeles are more commonly seen in the frontoethmoidal region. We present one such rare case of a 52-year-old lady who came to us with complaints of pain and swelling of the left cheek of 4 months duration. Clinical examination and investigation revealed a giant maxillary sinus mucocoele which was duly treated surgically. We discuss its classical presentation and management since such large mucocoeles are not often seen in the maxillary sinus. 相似文献