Medical monitors are high-end display devices with high definition and high brightness in the display field.
PACS technology is becoming more mature and popular, as well as a variety of digital imaging equipment, rapid development of medical monitors, is the doctor to achieve a "soft readout" of the patient's observation and diagnosis of the terminal image presenter, and used to display black-and-white, color images or text of the ordinary monitors have different differences.
The LCD monitor, for example, from the technical parameters, functions, safety certification of the three aspects of comparison.
1, technical parameters
①Size: diagonal length to calculate, generally in inches.
Medical: basically similar to the X-film, common size: 18 ", 20", 21"
General: common size: 19", 22", 24 ", 27";
② resolution: the actual number of pixels displayed per unit area. 1MP = 1 megapixel
Medical: 1MP (1024×1280) 2MP (1200×1600) 3MP (1536×2048) 5MP (2048×2560) 10MP (4096×2560)
Common: 800×600, 1024×768, 1280×1204
③ Brightness: Brightness is how bright the display image on the monitor, the unit (cd/m2) Candela per square meter
Medical: 600-700 cd/m2 standard calibration set the brightness between 400-500 cd/m2; 30,000 hours, or even 100,000 hours of brightness value remains unchanged.
Ordinary: 200-300 cd/m2 No special requirements
④Contrast ratio: describes the difference between black and white of the display, expresses the ratio of the brightest value of the display and the darkest value of the display, contrast ratio is also called dynamic range.
Medical: 600:1--1000:1 Ordinary: 300:1---400:1
5 Gray scale: reflecting the levels between black and white images, it is a very important feature of black and white medical images. Grayscale display requires a dedicated graphics card
Medical: 10 bit - 1024 grayscale, 10bit or 12bit (1024 - 2048 grayscale)
Ordinary: 6bit-64, 8bit- 256 grayscale
6 Viewing Angle
Medical: Up and down/left and right can reach 178 ° wide viewing angle
Adjustable for the most demanding applications. p>
Ordinary: up and down the viewing angle of about 140 °, left and right viewing angle of about 160 °
⑦Response time: refers to the LCD display of the image of the input signal response speed, that is, the liquid crystal from dark to bright or from bright to dark response time. Usually calculated in milliseconds (ms)
Medical: for some dynamic high-definition images, generally about a few milliseconds, for static images do not require high
Common: 16 - 5ms or so
2, function
① DICOM PART14 standard: dicom curve is one of the most important parameters in the characteristics of the monitor, it directly reflects the performance of the monitor! The dicom curve is one of the most important parameters of the display characteristics, which directly reflects the performance of the display
Because of the characteristics of the electronic components, the input and output of the display is not an ideal linear relationship. Input and output characteristics of both ends of the curve, the input changes caused by the output changes are not obvious enough, assuming that the range of input and output are 0-99, in the beginning, the input is 3, perhaps its output is only 1, if this situation is directly applied to medical imaging, it will be found that the monitor can not correctly identify some of the subtle changes in the density of the soft tissues (as Figure 2). In order to assign a specification to the performance of medical displays, the World Medical Organization has developed the dicom standard, which is designed to widen the difference between each gray scale, i.e., to make the output also 3 if the input is 3.
Medical: With the ability to adjust the curve of the DICOM standard to match that of the DICOM standard, so as to ensure that the quality of the image display is guaranteed.
Ordinary: no
② SBC function: constant brightness adjustment function
Monitor brightness will decay with the use of time (Figure 3), in order to comply with the clinical reading standards, the stability of the image-by-image, consistency and wholeness (refers to the same image displayed on the workstations in different locations within the hospital, the brightness, gray scale, contrast, etc. is identical). So that doctors in different locations to see the same image; print out the image and display the image on the monitor is also the same), it is necessary to carry out a monitoring of the brightness at any time to calibrate the adjustments to control, so that it is stable in the 400 ~ 500 cd/m2 standard between, and not less than 30,000 hours of brightness to maintain the value.
Medical: the back of the optical sensor interface, you can access the optical sensor for calibration, to ensure the consistency of the system display and overall.
Ordinary: no brightness monitoring and control of kinetic energy, brightness decay is fast enough
③Display modes: diagnostic workstations and other needs of two or more monitors
Medical: horizontal/vertical screen conversion, 10bit - 12bit gray scale output; combined with graphics card functions, complete independent display, extended display, copy display, color - black and white conversion, main and secondary display interchangeable. Black and white conversion, main and secondary display interchangeable, one card, two displays and other functions.
Ordinary: regular mode
3, certification
①Medical certification
Medical: FDA510(k), ISO13485
Ordinary: no
②Safety certificates
Medical: CE, UL, CCC
Ordinary: CCC, and other basic standards
Ordinary: CCC and other basic standards
Other: due to the teaching of the teaching of the first two. >
Another: due to the requirements of teaching and the habits of doctors, doctors at home and abroad are accustomed to use a pen to point on the film or display to express the views of the specific details of the image, the LCD screen material is a fragile material, in order to adapt to the medical environment, the display manufacturer will be responsible for the production of the LCD screen installed on the protective plate.