Masafumi Okada

Polynomial design of the nonlinear dynamics for the brain-like information processing of whole body motion

For the development of an intelligent robot with many degrees-of-freedom, the reduction of the whole body motion and the implementation of the brain-like information system is necessary. We propose a reduction method of the whole body motion based on singular value decomposition and a design method of the brain-like information processing system using a nonlinear dynamics network with polynomial configuration. By using the proposed method, we design the humanoid whole body motion that is caused by the input sensor signals.

Design of programmable passive compliance shoulder mechanism

Design of mechanical compliance would be one of the most important technical foci in making humanoid robots really interactive with the humans. For safety insurance mechanical compliance should be developed for humanoid robots. The introduction of the passive compliance to humanoid robots has large possibility for achieving human skill by using the dynamical energy stored in the compliant members. Programmable passive compliance plays an important role in coping with the changing environments and task execution. We evaluate the effectiveness of the passive compliance for the realization of human skill and design a programmable passive compliance mechanism PPC cybernetic shoulder which is a four degree of freedom shoulder mechanism for humanoid robots using a closed kinematic chain. The programmability of the PPC cybernetic shoulder is evaluated by experiments.

First Report on 30-day and Operative Mortality in Risk Model of Isolated Coronary Artery Bypass Grafting in Japan

BACKGROUNDnRisk models of coronary artery bypass grafting (CABG) using a large database are useful for improving surgical quality. To obtain accurate, high-quality assessments of the surgical outcomes, each country should maintain its own database. This study was conducted to collect Japanese data and prepare a risk stratification of isolated CABG procedures using the Japan Adult Cardiovascular Surgery Database (JACVSD).nnnMETHODSnWe analyzed 7133 CABG-only records from 97 participating sites throughout Japan using a data entry form with 255 variables that was sent to the JACVSD office by our Web-based data collection system. The statistical model was constructed by multiple logistic regression. Model discrimination was tested using the area under the receiver operating characteristic curve (C index). Model calibration was tested by the Hosmer-Lemeshow test.nnnRESULTSnOf 7133 operations, 47.2% had diabetes mellitus, 14.0% were urgent, and 15.6% involved peripheral vascular disease. The observed 30-day and operative mortality rates were 2.02% and 2.72%, respectively. Significant variables with high odds ratios included emergency or salvage status (3.71), preoperative creatinine value exceeding 3.0 mg/dL (3.59), aortic valve stenosis (3.01), and moderate to severe chronic lung disease (2.86). Hosmer-Lemeshow test and C-index values for 30-day mortality were satisfactory at 0.96 and 0.85, respectively.nnnCONCLUSIONSnThe results obtained in Japan were at least as good as those reported elsewhere. The performance of our risk model also matched those of the Society of Thoracic Surgeons National Adult Cardiac Database and the European Society Database.

Bronchioloalveolar carcinoma (lepidic growth) component is a more useful prognostic factor than lymph node metastasis.

Introduction: Although many factors predictive of patient survival have been reported for lung cancer, no comparative studies have attempted to determine those that are most significant for practical medicine. Methods: We conducted a retrospective review of 139 patients who underwent complete resection of adenocarcinomas less than 2 cm in diameter between 1993 and 2000 at the National Cancer Center Hospital (Tokyo, Japan). The MIB-1 labeling index (LI), immunohistochemical staining for carcinoembryonic antigen (CEA), p53, p27, epidermal growth factor receptor (EGFR), phosphorylated-EGFR (pEGFR), Cox-2, neuronatin, &ggr;H2AX, and thyroid transcription factor-1 (TTF-1), the prevalence of a micropapillary pattern, and the ratio of the bronchioloalveolar cell carcinoma (BAC) or lepidic growth (LG) component were determined, and their significance as prognostic factors for lung adenocarcinoma was compared. Results: Univariate analysis showed that lymph node metastasis (p-N status), BAC/LG component, vascular invasion (p-V status), MIB-1 LI, pEGFR, and CEA were prognostically significant (p-N status: p < 0.0001, BAC/LG: p = 0.0005, p-V status: 0.002, MIB-1 LI: p = 0.005, pEGFR: p = 0.024, and CEA: p = 0.049). Multivariate analysis showed that only p-N status (p = 0.013) was of prognostic significance. However, BAC/LG component (p = 0.051) was a more reliable prognostic factor than p-N status in mixed adenocarcinoma with a BAC/LG component. Conclusion: In comparison with other immunohistochemical and histopathologic factors, BAC/LG component is independently and reliably prognostic for small adenocarcinoma of the lung, and, in particular, for the major histologic subtype (adenocarcinoma mixed subtype with BAC/LG), BAC/LG component is more reliably prognostic than lymph node metastasis.

Small Occupancy Robotic Mechanisms for Endoscopic Surgery

To make the endoscopic surgery more precise and more accessible, computer-enhanced surgical robot systems are introduced and accepted in the surgical community. Present surgical robot systems unfortunately occupy a significant amount of space in operating rooms. It sometimes prohibits surgeons from emergency access to the patient. In this paper, we propose a design of small occupancy robots for endoscopic surgery. The design concept consists of three components. Namely, the Active Forceps, the Active Trocar, and the passive positioner. The detailed design of the Active Forceps and the Active Trocar presented, and the performance of prototypes are also reported.

Nuclear Grading of Primary Pulmonary Adenocarcinomas: Correlation Between Nuclear Size and Prognosis

According to the World Health Organization Classification of Tumors, the prognostic value of morphometric cytologic atypia has not been assessed in pulmonary adenocarcinoma.

Expression profiling of genes related to asthma exacerbations

Background Asthma is a chronic airway inflammatory disease; however, the molecular mechanisms that underlie asthma exacerbation are only partially understood.

Geographical distribution for malignant neoplasm of the pancreas in relation to selected climatic factors in Japan

BackgroundMalignant neoplasm of the pancreas has become one of the leading causes of death from malignant neoplasm in Japan (the 5th in 2003). Although smoking is believed to be a risk factor, other risk factors remain unclear. Mortality from malignant neoplasm of the pancreas tends to be higher in northern Japan and in northern European countries. A recent study reported that standardized mortality ratios (SMRs) for malignant neoplasm of the pancreas were negatively correlated to global solar radiation level. People residing in regions with lower solar radiation and lower temperatures may be at higher risk of development of malignant neoplasm of the pancreas. Therefore, this study aimed to examine the relationship between SMRs for malignant neoplasm of the pancreas and climatic factors, such as the amount of global solar radiation and the daily maximum temperature in Japan.ResultsThe study used multiple linear regression models. Number of deaths and demographic data from 1998 to 2002 were used for the calculation of SMR. We employed mesh climatic data for Japan published in 2006 by the Japan Meteorological Agency. Regression coefficients for the amount of global solar radiation and the daily maximum temperature in males were -4.35 (p = 0.00034) and -2.81 (p < 0.0001) respectively, and those in females were -5.02 (p < 0.0001) and -1.87 (p < 0.0001) respectively. Increased amount of global solar radiation or daily maximum temperature was significantly related to the decreased SMRs for malignant neoplasm of the pancreas in both males and females.ConclusionThis study suggested that low solar radiation and low temperature might relate to the increasing risk of malignant neoplasm of the pancreas. Use of group data has a limitation in the case of evaluating environmental factors affecting health, since the impact of climatic factors on the human body varies according to individual lifestyles and occupations. Use of geographical mesh climatic data, however, proved useful as an index of risk or beneficial factors in a small study area. Further research using individual data is necessary to elucidate the relationship between climatic factors and the development of malignant neoplasm of the pancreas.

Development of the cybernetic shoulder-a three DOF mechanism that imitates biological shoulder-motion

Discusses the integration of mechanical softness into the humanoid robot mechanisms design. The mechanical softness includes such requirements as human-like high mobility and human-like sensitive compliance. We focus on the shoulder mechanism, and propose a parallel mechanism to integrate the two requirements. The mechanism is called the cybernetic shoulder and possesses three degrees-of-freedom. The nature of motion curves of the human shoulder, and the design and development of the cybernetic shoulder are described with the computation issue of kinematics. The integration of compliance into the parallel mechanism is also discussed, and its experimental evaluation is made.

Measurement of health-related quality of life in patients with chronic kidney disease in Japan with EuroQol (EQ-5D)

BackgroundChronic kidney disease (CKD) is a health-related quality-of-life (HRQOL) deteriorating disease which is not only a public health but also a socioeconomic problem. Interest in developing cost-effective interventions to control CKD has increased. The aim of this study was to measure HRQOL in terms of quality-adjustment weights for cost-effectiveness analysis using EQ-5D in patients with CKD. The relationships between the measured HRQOL and clinical indices/complications were also analyzed.MethodsEQ-5D, a generic preference-based instrument, was administered to 569 CKD outpatients at Tsukuba University Hospital between November and December 2008. The response rate was 94.4% (537/569). Data on sex, age, creatinine, hemoglobin, serum albumin and eGFR were obtained from the patients’ records. Data on the presence of complications such as hypertension, diabetes, and history of cardiovascular disease (CVD) were also retrieved.ResultsMeasured quality-adjustment weights by the CKD stage were 0.940 (95% CI 0.915–0.965), 0.918 (0.896–0.940), 0.883 (0.857–0.909), 0.839 (0.794–0.884), and 0.798 (0.757–0.839) for stages 1–5, respectively. The decrease in weight was significant by ANOVA (Pxa0<xa00.0001), and the weight for all stages was 0.885 (0.871–0.898). There was a positive relationship between hemoglobin/serum albumin and the weight. The presence of hypertension lowered the weight from 0.910 (0.885–0.936) to 0.874 (0.858–0.891), diabetes from 0.901 (0.886–0.917) to 0.840 (0.811–0.869), and CVD from 0.892 (0.878–0.906) to 0.783 (0.718–0.848).ConclusionsHRQOL decreases with progression of CKD stage and/or presence of anemia, undernutrition, hypertension, diabetes, or history of CVD.