Estudo do desempenho de monitores utilizados em radiologia digital / Performance study of LCD in digital radiology

OBJETIVO: O objetivo deste trabalho foi avaliar o desempenho de 24 monitores LCD utilizados nos laudos médicos, segundo testes recomendados pelo AAPM Report 03, de 2005. MATERIAL E MÉ-TODO: Os testes foram realizados de acordo com o AAPM Report 03 de 2005, em parâmetros como: distorção geométrica, reflexão, uniformidade e resposta de luminância, contraste, resolução, ruído e velamento por reflexão interna, com auxílio de fotômetro ou visualmente. RESULTADOS: Apresentaram-se problemas de: ruído (38% das estações de trabalho), resposta de luminância econtraste (33%) e uniformidade da luminância (4%). CONCLUSÃO: Em razão de o modelo MDNC4130 estar configurado para maximizar a vida útil, sua luminância é baixa, fazendo com que ruídos causados por sujeira comprometam a imagem. Em retestes, mostrou-se que a limpeza periódica dosmonitores resolve este problema. Já no caso das não conformidades em luminância e contraste, percebeu-se que a calibração automática com o software do monitor nem sempre corrige as distorções apresentadas.

OBJECTIVE: The purpose of this paper was to investigate the imagequality of 24 display devices and to compare the results of performance. MATERIAL AND METHOD: Tests were executed following AAPM Report 03 on 24 display devices installed in the Instituto de Radiologia do Hospital das Clínicas, São Paulo, SP, Brazil.The evaluation of test pattern considered these parameters:geometric distortions, luminance uniformity and response, contrast,reflections, resolution, and noise. RESULTS: The problems found were: noise (38% of workstations), luminance and contrast (33%) and luminance uniformity (4%). CONCLUSION: The model MDNC4130 was setting to preserve the life of display device, then the luminance is low, making the noise caused by dirt compromising image. The new test showed that regular cleaning of displaydevices solves this problem. In the case of non compliance of luminance and constrast realized that the automatic calibration of the display devices is not always correct the distortions.

Estudo do desempenho de monitores LCD utilizados em radiologia digital / Performance study of LCD in digital radiology

OBJETIVO: O objetivo deste trabalho foi avaliar o desempenho de 24 monitores LCD utilizados noslaudos médicos, segundo testes recomendados pela AAPM Report 03, de 2005. MATERIAL E MÉ-TODO: Os testes foram realizados de acordo com o AAPM Report 03 de 2005 em parâmetros como:distorção geométrica, reflexão, uniformidade e resposta de luminância, contraste, resolução, ruído e velamento por reflexão interna, com auxílio de fotômetro ou visualmente. RESULTADOS: Apresentaram-se problemas de ruído (38% das estações de trabalho), resposta de luminância e contraste (33%) e uniformidade da luminância (4%). CONCLUSÃO: Em razão de o modelo MDNC4130 estarconfigurado para maximizar a vida útil, sua luminância é baixa, fazendo com que ruídos causados por sujeira comprometam a imagem. Em retestes, mostrou-se que a limpeza periódica dos monitores resolve este problema. Já no caso das não conformidades em luminância e contraste, percebeu-se que a calibração automática com o software do monitor nem sempre corrige as distorções apresentadas.

OBJECTIVE: The purpose of this paper was to investigate the imagequality of 24 display devices and to compare the results of performance. MATERIAL AND METHOD: Tests were executed following AAPM Report 03 on 24 display devices installed in Instituto de Radiologia do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP, Brazil. The evaluation of test pattern considered these parameters: geometric distortions, luminance uniformity and response, contrast, reflections, resolution, and noise. RESULTS: The problems found were: noise (38% of workstations), luminance and contrast (33%) and luminance uniformity (4%). CONCLUSION: The model MDNC4130 was setting to preserve the life of display device, then the luminance is low, making the noise caused by dirt compromising image. The new testshowed that regular cleaning of display devices solves this problem.In the case of non compliance of luminance and contrast realized that the automatic calibration of the display devices is not always correct the distortions.

The study of tube voltage selection influencing image quality in digital chest radiography / 中华放射学杂志

Objective To study the relationship between the selection of tube tension in digitalchest radiograph and image quality.Methods When tube current was fixed at 4 mAs, the choice of X-ray tube voltage changed from 60 to 120 kV.CDRAD2.0 contrast details phantom and normal human chest were exposed by X-ray system with 7 kinds of tube voltage (the difference between tube voltage was 10 kV) ,and the X-ray incidental dose of phantom surface was measured.Five radiologists with 3 years working experience evaluated the image quality on monitor and calculated the image quality factor (IQF) and image reading score.Statistics analysis was then performed by using ANOVA test and t test.According to the results, the optimum tube voltage range was determined.Results (1) The incidental dose of phantom surface increased with the higher tube voltage.(2)When the tube voltage was changed from 60 kV to 120 kV, the IQF value observed in CDRAD2.0 phantom image on monitor was 75.0±10.4,57.1±6.4,52.7±2.5,47.9±4.5, 46.0±3.8,46.0±2.8,45.2±3.5 ,there was significant statistical differences between groups(F=19.10, P<0.01).(3)The integrated score of the chest image quality in the tube voltage 90 kV and 120 kV were 12.4±0.9 and 13.0±0.7, respectively, and there was no statistical difference between two groups(t= 1.500,P>0.05).Conclusions (1)With the increase of tube tension,the display capacity of display device gradually strengthened.When the tube tension exceeded 90 kV, the increase of image quality on monitor was not evident.(2) With proper radiation dose, the value of tube tension in digital X-ray chest photograph was about 90 kV.

The portable low power military ECG for triage / 医疗卫生装备

The military portable ECG for triage is a kind of minitype monitoring equipment for life information for the purpose that the ambulanceman carry through first aids in frontline. Life information of the wounded will be acquired exactly and quickly applying with this equipment, then quickening the triage and reducing the casualties. The system is based on C8051F310 single chip microcomputer, applying with high accuracy, low offset drift instrumentation amplifier AD620 and ultra low power LCM LMS019 to display real-time and accurate ECG signal sampled. The equipment is easy to use and inexpensive, suitable for mass requirement of our field army.

The design of the graphic display system of a portable medical equipment / 医疗卫生装备

This paper introduces such information of a LCD graphic display system based on SED1335 as its hardware link with the singlechip computer Atmega128 and the design of system display software. With a simple, compact and stable circuit, this system can be applied to portable medical signal monitoring and controlling equipments.