HMB in DRAM-less NVMe SSDs: Their usage and effects on performance.

Solid-state drives (SSDs) that do not have internal dynamic random-access memory (DRAM) are being widely spread for client SSD and embedded SSD markets in recent years because they are cheap and consume less power. Obviously, their performance is lower than conventional SSDs because they cannot exploit advantages of DRAM in the controller. However, this problem can be alleviated by using host memory buffer (HMB) feature of Non-Volatile Memory Express (NVMe), which allows SSDs to utilize the DRAM of host. In this paper, we show that commercial DRAM-less SSDs clearly exhibit worse I/O performance than SSDs with internal DRAM, but this can be improved by using the HMB feature. We also present methods that reveal how the host memory buffer is used in commercial DRAM-less SSDs to improve I/O performance. Through extensive experiments, we conclude that DRAM-less SSDs evaluated in this study mainly exploit the host memory buffer as an address mapping table cache rather than a read cache or write buffer to improve I/O performance.

Taming Performance Variability of Healthcare Data Service Frameworks with Proactive and Coarse-Grained Memory Cleaning.

This article explores the performance optimizations of an embedded database memory management system to ensure high responsiveness of real-time healthcare data frameworks. SQLite is a popular embedded database engine extensively used in medical and healthcare data storage systems. However, SQLite is essentially built around lightweight applications in mobile devices, and it significantly deteriorates when a large transaction is issued such as high resolution medical images or massive health dataset, which is unlikely to occur in embedded systems but is quite common in other systems. Such transactions do not fit in the in-memory buffer of SQLite, and SQLite enforces memory reclamation as they are processed. The problem is that the current SQLite buffer management scheme does not effectively manage these cases, and the naïve reclamation scheme used significantly increases the user-perceived latency. Motivated by this limitation, this paper identifies the causes of high latency during processing of a large transaction, and overcomes the limitation via proactive and coarse-grained memory cleaning in SQLite.The proposed memory reclamation scheme was implemented in SQLite 3.29, and measurement studies with a prototype implementation demonstrated that the SQLite operation latency decreases by 13% on an average and up to 17.3% with our memory reclamation scheme as compared to that of the original version.

USB drives for communication of medical information in a pediatric dialysis unit.

We evaluated the feasibility of using universal serial bus (USB) drives for communicating medical information between parents of children receiving dialysis and medical personnel during clinical encounters. When surveyed, parents and pediatric resident physicians supported the use of USB drives and were willing to use the devices. The utilization rate of USB drives was 57%.

Multi personal computer storage system: solution of sea capacity PACS storage.

OBJECTIVE: According to the characteristics of digital medicine and the demands of digitalized management in hospitals, we established a storage system that is affordable, highly expandable, and reliable. METHODS: The multi personal computer storage system (MPCSS) was constructed using hardware and software. The image data were archived from major servers to storage personal computers (PCs) by using Neusoft-picture archiving and communication system (PACS) and backed up on storage PCs. We simulated data loss on storage PCs and then restored the data. We also expanded the storage system to enlarge its capacity. RESULTS: The average transfer rate from MPCSS was 27.7 MB/s, and the average cost for this system was yen 74/GB. In the testing stage, only 6 of 187 instances of data retrieval (from 100 patients) failed. CONCLUSION: The MPCSS is much less expensive than other high capacity systems or devices. It is feasible and suitable for digital image storage.

Audit of populations in general practice: the creation of a national resource for the study of morbidity in Scottish general practice.

STUDY OBJECTIVE: To create a national data resource for studying morbidity in Scottish general practice, complementary to existing information systems and available for management and research purposes at national and local levels. DESIGN: The Department of General Practice, University of Aberdeen has worked since 1988 to collect and analyse computerised information at practice, regional, and national levels by distribution of a floppy disk-based software program, which extracts a predetermined dataset from each general practice computer system. SETTING: Almost 100% of patients in Scotland are registered with a general practitioner. Scotland has a national computer system, General Practice Administration System for Scotland (GPASS), used by over 75% of all Scottish practices. Escalating costs of health care and demographic changes in the national population emphasise the monetary value of the gatekeeper role of general medical practice. General practitioners' increasing involvement in the provision and purchasing of care has raised the importance of the management of populations as well as the care of individual patients. PATIENTS: Collection of major morbidity and prescribing data from up to 2.4 million patients, approximately half the population of Scotland, takes place biannually. A subset of practices (population 282,700 patients; 52 practices) are continuously collecting doctor/patient contact information (symptoms or diagnoses). MAIN RESULTS: The data collected provide information at the level of the individual patient. Morbidity, prescribing, screening, and administrative data can be linked by patient, date or postcode. The sample population studied is representative by age, sex, deprivation, and sparsity (using the postcode) of the national population. Large sub-populations of patients satisfying a selected criteria can be extracted for further study of needs assessment or of epidemiological research. CONCLUSIONS: The gatekeeping role of Scottish general practice and the predominance of GPASS favours standardisation of methods of data capture and the construction of large regional, national, and Continuous Morbidity databases. Analysis by geographical, demographic, and temporal distributions allows the changing patterns of illness and provision of health care to be studied in substantial detail to the benefit of patients, doctors, and the national health service.

Surveillance of influenza-like illness in France. The example of the 1995/1996 epidemic.

STUDY OBJECTIVES: To discover if continuous computerised collection of morbidity data through a medical practice based sentinel network can be used to monitor influenza-like illness (ILI) epidemics. To obtain rough estimates of influenza vaccine effectiveness. DESIGN: Continuous passive surveillance of ILI through a computerised network of voluntary sentinel general practitioners (SGPs) in France (Sentinelle system). SETTING: Five hundred SGPs practices. PARTICIPANTS: Since 1984, SGPs updated a database with information on eight communicable diseases including ILI, via videotext terminals. Each ILI case is defined by the association of a sudden fever of 39 degrees C or above, respiratory symptoms, and myalgias. An ILI epidemic is detected when the national weekly incidence rate exceeds a seasonal threshold for two successive weeks. MAIN RESULTS: An ILI epidemic was reported from November 1995 to January 1996. In total, 13,951 individual cases were reported by SGPs during the epidemic period. The size of the epidemic (number of patients consulting a GP) was estimated to be 2,370,000 subjects. Maps of the epidemic showed that all regions have reported a high level ILI activity. The attack rate was the highest in school age children (13.5/100) and decreased as the age rose. Nearly 6% of the reported ILI cases among adults and elderly were vaccinated. The flu vaccine effectiveness against ILI was estimated to be 66% (95% CI 73%, 92%), ranging between 83% (95% CI 73%, 92%) among the subjects aged 15 to 24 years old to 16% (95% CI -12%, 44%) among the subjects aged 75 years or older. CONCLUSIONS: The Sentinelle system demonstrated adequate sensitivity and timeliness regarding ILI epidemic. Moreover, results of the monitoring were made available on the internet to increase the dissemination of information. Also, estimates of influenza vaccine effectiveness have been easily obtained. Altogether, they represent key points for the control of crisis situation such as ILI epidemics or pandemics.

Epidemiology of chickenpox in France (1991-1995).

STUDY OBJECTIVES: To decide whether a mass immunisation against chickenpox should be or should not be organised, it is important to have up to date data on the disease and to have baseline data to further assess a mass immunisation strategy, if any. DESIGN: Recent chickenpox epidemiology (age and sex distribution, seasonal dynamic and complications) in France are reviewed. SETTING: The system works with about 500 Sentinelle general practitioners (SGPs) and has provided surveillance of frequent communicable diseases in continental France since 1984. PARTICIPANTS: The data were collected by the computerised Sentinelle system. The Sentinelle system uses a videotex server that allows information exchange, data entry, and synthetic return of information. Chickenpox was defined as a sudden onset of typical skin eruption with pruritus, leaving scabs and associated with moderate fever. For each reported case, the SGP gave information on the age of the patient, sex, prevailing childcare for the children, contacts and complications (skin superinfections, lower and upper respiratory infections, conjunctivitis and corneal infections, nervous system injuries, stomatitis and others). Spectral analysis was used to detect cyclical patterns. MAIN RESULTS: Between 1991 and 1995, 15,817 cases of chickenpox were reported and provided the basis for the analysis. The yearly national incidence was 1.0-1.35 cases per 100 inhabitants. A pronounced annual periodicity of the incidence was observed and confirmed by spectral analysis. Ninety two per cent of chickenpox cases occurred in children under 14 years of age with about 5% being under one. Complications were reported in 2% of the cases. Common complications reported were skin superinfections, lower and upper respiratory tract infections. However, 21 cases out of 318 complications were nervous system injuries including six encephalitis or cerebellar ataxia. All these cases recovered completely. CONCLUSIONS: Chickenpox is usually a benign childhood disease. This study affords up to date observations on the disease in France. A large panel of complications has been reported. This paper provides the first attempt to describe the epidemiology of chickenpox in France.

Compressäo de sinais sem perda com o uso de palavras de tamanho variável / Signals compression without losses whith use of the variable size words

Um novo algoritmo de compressão de dados sem perda de informação, baseado na adequação automática do tamanho da "palavra" usada na amplitude do sinal é apresentado e avaliado para armazenamento de sinais de Tomografia por Ressonância Magnética. Uma comparação com outras implementações de compressores de uso geral é apresentada, demonstrando um desempenho superior tanto na taxa de compressão, quanto no tempo de execução.

Storing radiographs on a PC using a hand scanner: a simple tool to improve the teaching quality of radiographs in medical education.

Using a hand scanner, radiographs were scanned into a personal computer (PC) for storage and viewing. These images were of superior or similar quality to x-ray photographs published in textbooks and journals. This represents a simple and inexpensive way for emergency physicians to store x-ray files electronically for instant access from a desktop or laptop computer. This optimizes emergency medicine teaching when radiographic studies are involved. Identical copies of the image files can be made and distributed for viewing on other PCs. The PC is a new tool that will improve our ability to organize our educational resource materials. Multimedia methods represent a new way to present and distribute audiovisual educational materials at a desktop.