Satoshi Iwai

Environmental neutron measurements around nuclear facilities with moderated-type neutron detector.

A cylindrical BF3 counter with cylindrical polyethylene moderators of 1-, 3-, 6- and 10-cm wall thickness were developed for neutron spectrometry, having response functions calculated by the time-dependent multi-group Monte Carlo code, TMMCR, and evaluated by a time-of-flight experiment in the energy region from epithermal to about 50 keV. This system of neutron detectors was used to measure the environmental neutron spectrum and dose equivalent around a 252Cf fission neutron source, a fast neutron source reactor, a cyclotron and an electron synchrotron. The neutron spectrum and dose obtained by this detector system showed very good agreement with those measured by a commercially available neutron rem counter and calculated by our MMCR Monte Carlo code. As a result of these comparisons, this detector system has been established as a standard spectrometer and dosimeter for environmental measurements around nuclear facilities.

Impact of a New Medical Record System for Emergency Departments Designed to Accelerate Clinical Documentation: A Crossover Study.

AbstractRecording information in emergency departments (EDs) constitutes a major obstacle to efficient treatment. A new electronic medical records (EMR) system focusing on clinical documentation was developed to accelerate patient flow. The aim of this study was to examine the impact of a new EMR system on ED length of stay and physician satisfaction.We integrated a new EMR system at a hospital already using a standard system. A crossover design was adopted whereby residents were randomized into 2 groups. Group A used the existing EMR system first, followed by the newly developed system, for 2 weeks each. Group B followed the opposite sequence. The time required to provide overall medical care, length of stay in ED, and degree of physician satisfaction were compared between the 2 EMR systems.The study involved 6 residents and 526 patients (277 assessed using the standard system and 249 assessed with the new system). Mean time for clinical documentation decreased from 133.7 ± 5.1 minutes to 107.5 ± 5.4 minutes with the new EMR system (P < 0.001). The time for overall medical care was significantly reduced in all patient groups except triage level 5 (nonurgent). The new EMR system significantly reduced the length of stay in ED for triage level 2 (emergency) patients (145.4 ± 13.6 minutes vs 184.3 ± 13.6 minutes for standard system; P = 0.047). As for the degree of physician satisfaction, there was a high degree of satisfaction in terms of the physical findings support system and the ability to capture images and enter negative findings.The new EMR system shortened the time for overall medical care and was associated with a high degree of resident satisfaction.

Embedded-structure template for electronic records affects patient note quality and management for emergency head injury patients: An observational pre and post comparison quality improvement study

AbstractAlong with article-based checklists, structured template recording systems have been reported as useful to create more accurate clinical recording, but their contributions to the improvement of the quality of patient care have been controversial. An emergency department (ED) must manage many patients in a short time. Therefore, such a template might be especially useful, but few ED-based studies have examined such systems.A structured template produced according to widely used head injury guidelines was used by ED residents for head injury patients. The study was conducted by comparing each 6-month period before and after launching the system. The quality of the patient notes and factors recorded in the patient notes to support the head computed tomography (CT) performance were evaluated by medical students blinded to patient information.The subject patients were 188 and 177 in respective periods. The numbers of patient notes categorized as “CT indication cannot be determined” were significantly lower in the postintervention term (18% → 9.0%), which represents the patient note quality improvement. No difference was found in the rates of CT performance or CT skip without clearly recorded CT indication in the patient notes.The structured template functioned as a checklist to support residents in writing more appropriately recorded patient notes in the ED head injury patients. Such a template customized to each clinical condition can facilitate standardized patient management and can improve patient safety in the ED.

Interface design dividing physical findings into medical and trauma findings facilitates clinical document entry in the emergency department: A prospective observational study

PURPOSE The interface design and its effect on workflow are key determinants of the usability of electronic medical records (EMRs) in the emergency department (ED). However, whether the overall clinical care can be improved by dividing the interface design of physical findings into medical and trauma findings is unknown. We previously developed an EMR system in which the checkpoints were separated into different sections according to the body part. Herein, we modified this EMR system by remaking the interface design specifically for trauma patients, and evaluated its performance. METHODS This study was undertaken in a single-center ED between October 2014 and September 2015. In the modified EMR system, all trauma findings are displayed together on the screen, according to the Japan Advanced Trauma Evaluation and Care. We compared the time to final documentation entry and the length of ED stay between the previous (used in the first 6 months) and current systems (used in the latter 6 months). Furthermore, we stratified the patients by triage levels. RESULTS The study involved 2141 patients (934 and 1207 assessed using the previous and modified EMR systems, respectively). The modified EMR in trauma patients significantly decreased the time to final documentation entry from 131.5 [interquartile range, 86.8-207.3] to 115 [78.8-161] min (p = 0.049). When stratifying trauma patients by triage level, significantly shorter clinical documentation times were observed with the modified EMR system in levels 2 (emergency) and 3 (urgent). CONCLUSIONS Using different interfaces for trauma findings shortened the time for clinical documentation for trauma patients.

Prediction of prostate cancer by deep learning with multilayer artificial neural network

INTRODUCTION To predict the rate of prostate cancer detection on prostate biopsy more accurately, the performance of deep learning using a multilayer artificial neural network was investigated. METHODS A total of 334 patients who underwent multiparametric magnetic resonance imaging before ultrasonography guided transrectal 12-core prostate biopsy were enrolled in the analysis. Twenty-two non-selected variables, as well as selected ones by least absolute shrinkage and selection operator (Lasso) regression analysis and by stepwise logistic regression analysis, were input into the constructed multilayer artificial neural network (ANN) programs; 232 patients were used as training cases of ANN programs and the remaining 102 patients were for the test to output the probability of prostate cancer existence, accuracy of prostate cancer prediction, and area under the receiver operating characteristic (ROC) curve with the learned model. RESULTS With any prostate cancer objective variable, Lasso and stepwise regression analyses selected 12 and nine explanatory variables, respectively, from 22. Using trained ANNs with multiple hidden layers, the accuracy of predicting any prostate cancer in test samples was about 5-10% higher compared to that with logistic regression analysis (LR). The area under the curves (AUC) with multilayer ANN were significantly larger on inputting variables that were selected by the stepwise LR compared with the AUC with LR. The ANN had a higher net benefit than LR between prostate cancer probability cutoff values of 0.38 and 0.6. CONCLUSIONS ANN accurately predicted prostate cancer without biopsy marginally better than LR. However, for clinical application, ANN performance may still need improvement.

Current situations and discussions in Japan in relation to the new occupational equivalent dose limit for the lens of the eye

Since the International Commission on Radiological Protection recommended reducing the occupational equivalent dose limit for the lens of the eye in 2011, there have been extensive discussions in various countries. This paper reviews the current situation in radiation protection of the ocular lens and the discussions on the potential impact of the new lens dose limit in Japan. Topics include historical changes to the lens dose limit, the current situation with occupational lens exposures (e.g., in medical workers, nuclear workers, and Fukushima nuclear power plant workers) and measurements, and the current status of biological studies and epidemiological studies on radiation cataracts. Our focus is on the situation in Japan, but we believe such information sharing will be useful in many other countries.

Development of a computer code to calculate the distribution of radionuclides within the human body by the biokinetic models of the ICRP.

This paper describes the Basic Radionuclide vAlue for Internal Dosimetry (BRAID) code, which was developed to calculate the time-dependent activity distribution in each organ and tissue characterised by the biokinetic compartmental models provided by the International Commission on Radiological Protection (ICRP). Translocation from one compartment to the next is taken to be governed by first-order kinetics, which is formulated by the first-order differential equations. In the source program of this code, the conservation equations are solved for the mass balance that describes the transfer of a radionuclide between compartments. This code is applicable to the evaluation of the radioactivity of nuclides in an organ or tissue without modification of the source program. It is also possible to handle easily the cases of the revision of the biokinetic model or the application of a uniquely defined model by a user, because this code is designed so that all information on the biokinetic model structure is imported from an input file. The sample calculations are performed with the ICRP model, and the results are compared with the analytic solutions using simple models. It is suggested that this code provides sufficient result for the dose estimation and interpretation of monitoring data.

Benchmarking of activation reaction distribution in an intermediate energy neutron field

Neutron-induced reaction rate depth profiles inside concrete shield irradiated by intermediate energy neutron were calculated using a Monte-Carlo code and compared with an experiment. An irradiation field of intermediate neutron produced in the forward direction from a thick (stopping length) target bombarded by 400 MeV nucleon(-1) carbon ions was arranged at the heavy ion medical accelerator in Chiba. Ordinary concrete shield of 90 cm thickness was installed 50 cm downstream the iron target. Activation detectors of aluminum, gold and gold covered with cadmium were inserted at various depths. Irradiated samples were extracted after exposure and gamma-ray spectrometry was performed for each sample. Comparison of experimental and calculated shows good agreement for both low- and high-energy neutron-induced reaction except for (27)Al(n,X)(24)Na reaction at the surface.