Development of the triple ring body surface laplacian sensor and its experimental study.

The Laplacian of the body surface potentials (Laplacian ECG--LECG) is a new approach to resolve spatially distributed bioelectric sources. LECG is a weak signal so an LECG sensor needs a good signal-to-noise ratio (SNR) and high common mode rejection ratio (CMRR). In this paper, we discuss a LECG sensor, which integrated tripolar concentric ring electrodes and signal conditioning circuit on a printed circuit board. The experimental results are in agreement with the theoretical calculations suggesting the feasibility of measuring the surface Laplacian. This lays the foundation for using such a device to assist in heart disease diagnoses.

Memory-assessing methods which help the clinical diagnosis of early Alzheimer's disease / 中国医学科学院学报

<p><b>OBJECTIVE</b>To evaluate distribution and influence factors of logic memory (LM) modified in assessing and scoring method in normal population and Alzheimer's disease (AD) patients, and definite the cut-off point of the modified scale.</p><p><b>METHODS</b>Totally 183 AD patients, including 118 mild and 65 moderate in degree, 1,417 controls, including 1,283 normal individuals and 134 individuals suffered from other diseases, were recruited in this study. Modified LM was conducted.</p><p><b>RESULTS</b>Educational level (F=354.36, STB=0.46, P=0.0001) was the most obvious factor in demographic data to influence total score in normal control group by a fitting of multiple regression models. The total score increased with the rising of educational level in normal controls (P=0.0001) and other diseases controls (P=0.0001), but not in AD cases (P=0.1365). The total scores were significantly different among normal controls (20.2 +/- 0.2), other diseases controls (17.5 +/- 0.5), mild AD patients (9.6 +/- 0.5) and moderate AD patients (7.1 +/- 0.7) (P=0.0001, P=0.0059), after adjusted educational level, age, sex and rural/urban status by multiple analysis covariance. The sensitivity of cut-off points using modified methods to diagnose AD reasonably increased to 71.98%, while the specificity was 94.11%. According to the sum of long-delayed recall and long-delayed recognition, the sensitivity increased with the rising of educational levels. For education levels at illiteracy, elementary school, junior middle school, senior middle school and above senior middle school, the cut-off points for total score of modified method were 6.5, 9.5, 10.8, 13 and 15.8, respectively, and for sum of long-delayed recall and long-delayed recognition the cut-off points were 5, 6, 8, 9, 10.</p><p><b>CONCLUSIONS</b>When modified LM used as a neuropsychological assessment, it is with high specificity, high accuracy and reasonable sensitivity. It is suitable for the diagnosis of AD in early stages, especially for individuals with high educational levels.</p>

Clinical analysis of hemianopic anosognosia / 中国康复理论与实践

@#ObjectiveTo investigate the clinical features, mechanism and cerebral functional correlation of hemianopic anosognosia.Methods16 patients with homonymous visual field defects due to ischemic infarcts were examined on visual field and MMSE. The neuropsychological tests were administered such as hemianopic awareness and visual neglect. The facts were analyzed with the location of ischemic infarct documented by MRI or CT. Results10 of 16 patients with hemianopia had anosognosia of their visual deficit. 8 of 13 right side lesion patients had hemianopic anosognosia. 2 of 3 left side lesion patients had hemianopia anosognosia. 3 of 6 awareness hemianopia patients had visual hemineglect. 7 of 10 hemianopic anosognosia patients had larger infarction of middle cerebral artery. 3 else had smaller infarction in the occipital lobe or in the connective area between the occipital and temporal lobes.ConclusionsThere is no specific cortical area for conscious visual perception. Visual awareness is processed by a distributed network including multiple cortices and subcortices. Both hemispheres are involved in visual processing and conscious awareness.