Application areas with ordinary monitors are different, the technical requirements of the parameter requirements are different, the following comparison based on the main parameters: a professional medical monitor must support the DICOM PART14 standard, that is to say, it must have the ability to adjust the DICOM standard curve, so that it and the DICOM standard match, so as to ensure that the image of the display quality.
Conventional size: monitor size is expressed in diagonal length, generally in inches for the unit of the mainstream size of ordinary monitors for 15 ", 17", 19";
Medical monitors are commonly found in sizes of 18 ", 20 ", 21", the size is basically similar to the X-ray film.
Support for grayscale display: grayscale is a very important feature of black and white medical images, which reflects the level between black and white images
Grayscale display requires graphics card support, medical monitors should be equipped with a dedicated graphics card;
Common monitors have: 8bit- 256 grayscale, for the display of color images, no grayscale requirements, the use of ordinary graphics cards;
Medical monitors have: 8bit- 256 grayscale, for the display of color images, no grayscale requirements, the use of ordinary graphics cards;
Medical monitors have: 10 bit-1024 grayscale, used to display X-ray grayscale images, related to diagnosis, requirements: 10bit11bit (1024 * 2048 grayscale). Support BBS function (stable brightness control)The brightness of the monitor will decay over time, ordinary monitors due to the lack of stable brightness control and calibration, not only decay faster, usually use, but also due to the influence of the environment, its brightness can not be maintained for a long time in a suitable level for the human eye, and professional medical grayscale monitors taking into account the problem. Taking into account this problem, the professional medical gray scale monitor adopts a stable brightness control technology to calibrate the information fed back from the display brightness at any time, so that it always stays on top of the standard brightness, which is in line with the clinical standard of reading films. Brightness is how brightly the image is displayed on the monitor, and the brighter the display, the greater the dynamic range that can be produced in the image, allowing more tones to be discerned in the image, which must provide a full 8-bit grayscale image (i.e., 256 different tones).
Ordinary monitors have: 200-300 cd/m2 no brightness constant requirements; medical monitors have: 600-700 cd/m2 calibrated to set the brightness of the 400-500 cd/m2; the requirement of 30,000 hours or even 100,000 hours of the brightness value remains unchanged.
Brightness constancy is important for medical monitors to ensure that the monitor brightness does not change over time. Experimental studies have proved that the relationship between monitor brightness and naked eye sensitivity, when the brightness of 500 cd/m2, the naked eye sensitivity of 700, when the brightness of 800 cd/m2, the naked eye sensitivity of 777 (maximum), the ideal brightness of 400 ~ 500 cd/m2, so the choice of brightness ≥ 700 cd/m2 can be. The number of actual display pixels per unit area, such as 800*600, 1200*1600, etc.
Ordinary monitors have: 1024*768, 1280*1204; basically a horizontal display, no need for horizontal/vertical conversion; medical monitors have: according to the needs of the image, can be horizontal/vertical conversion,
1024*1280 (vertical screen)
1024*1280 (vertical screen)/1280*1024 (horizontal screen),
known as 1 megapixel (1MP), commonly used in horizontal display, mostly for CT, MRI, digital gastrointestinal machine;
1200*1600 (vertical screen)/1600*1200 (horizontal screen);
known as 2 megapixel (2MP), referred to as 1K, commonly used in vertical display, mostly used in CR, DSA, digital gastrointestinal machine. CR, DSA, digital gastrointestinal machine, PACS reading workstations;
1536*2048 (vertical)/2048*1536 (horizontal); known as 3 megapixels (3MP), referred to as 1.5 K, commonly used in the vertical display, mostly for CCD-DR, PACS diagnostic workstations;
2048*2560 (vertical)/2560*2048 (horizontal). 2560*2048 (horizontal);
known as 5 megapixels (5MP), referred to as 2 K, commonly used in vertical screen display, mostly applicable to flat-panel DR, mammography, PACS diagnostic workstations;
Medical monitor resolution and price are directly proportional to the resolution of radiological equipment is positively correlated with the corresponding equipment should be accompanied by the corresponding resolution of the monitor. Response time
Response time refers to the LCD's response speed to the input signal, that is, the response time of the liquid crystal from dark to light or from light to dark. It is usually calculated in milliseconds (ms). Response time is generally said to be divided into two parts - Rising (Rising time) and Falling (Falling time), and what we call response time refers to the sum of the two. The human eye has the phenomenon of "visual residual", that is, the movement of the picture in the human brain will form a short-lived impression, people can accept the picture display speed is generally 24 pictures / second, which is also the origin of the movie playback speed of 24 frames per second, if the display speed is lower than this standard, the person will obviously feel the picture of the stagnation and discomfort. Calculated in accordance with this standard, each screen display time needs to be less than 40ms, according to the actual use of liquid crystal, response time: 30ms (1/0.03 = 33.3 jin / sec), or there will be a trailing phenomenon, is not suitable for real-time playback of dynamic medical images. Response time below 25ms (1/0.025=40 zhen/sec) can meet the clinical cardiovascular DSA real-time playback.
In the selection of medical monitors, CR, DR static images on the response time is not too high requirements. But in the playback of dynamic images of the system configuration, such as cardiovascular and digital gastrointestinal machine, we must prefer the response time of 25ms below the medical display. Ordinary monitors have: environmental protection, electromagnetism related certifications, such as:
Medical monitors have: not only environmental protection, electromagnetism related certifications, and more importantly, the medical industry certification, in order to enter the medical field, is recognized by law.
EU UL certification, China CCC certification. Ordinary monitors have: no LCD protection board, power supply for the built-in way no special requirements.
Medical monitors have: due to the requirements of the teaching and the habits of doctors, specially equipped with LCD screen protection board for the medical environment with a medical power supply. Contrast ratio, also known as dynamic range, contrast rate is to describe the display can show the difference between black and white, express the display of the brightest value and the ratio of the darkest value. Color display is not overly demanding, medical monitor requirements to express the degree of grayscale images between black and white.
Ordinary monitors have: 300:1~400:1;
Medical monitors have: 600:1~1000:1;
Medical monitors have a contrast ratio of up to 1000:1, able to display all the tones need to be larger than the ratio of the general choice of contrast ratio of ≥ 600 is better. Graphics card accuracy directly affects the quality of the output image is good or bad, in the conditions allow should try to choose a high bit graphics card is more ideal.
Ordinary monitors have: memory, speed, 3D indicators, commonly used AGP slot;
Medical monitors have: commonly used PCI slot, the display mode, a card two shows, the main and secondary display interchangeable, color - black and white conversion, 10bit, 12bit grayscale output; horizontal/vertical screen conversion;
(1) the display mode: since the diagnostic workstation needs two or more Diagnostic workstation requires two or more monitors, the graphics card should have a flexible display mode to facilitate the doctor's diagnosis. Medical grayscale series graphics cards, display modes: independent display, extended display, copy display
(2) a card with two displays: when a workstation with two monitors, the graphics card has two output ports.
(3) the primary and secondary displays interchangeable: when the workstation has an ordinary monitor, at the same time, there is one or more medical monitors; set the ordinary display as the primary display, medical for the secondary display, ordinary monitors and medical monitors to display the color and grayscale images, respectively, the color should not be missing, grayscale should not be disconnected, however, the medical card is difficult to get the best of both worlds. Often ordinary monitors for the main display, medical monitors will have grayscale fault phenomenon; medical monitors for the main display, the color display will be missing color, and the program menu to open, always appear in the high-resolution medical monitors on the word is very small, monochrome, it is very inconvenient to use, which is the medical graphics card is a common technical problem, medical grayscale graphics cards, a complete solution to the primary and secondary display settings appear when the Color is not color, grayscale discontinuous problem, whether it is a medical monitor or an ordinary monitor for the main display, color and grayscale are not a problem, to solve the PACS company and hospitals in the problem of the trouble.
(4) color - black and white conversion: medical graphics card (grayscale graphics card), with medical monitors, displaying color images, RGB three primary color signals, often using only the G-color representation of grayscale images, so that the color image is displayed as a grayscale image, the loss of the R, B two primary colors of the information.
Medical dedicated grayscale series graphics cards, through the technical processing, the RGB three primary color signals will be displayed on the grayscale monitor complete, without losing any color information.
(5) 10bit grayscale output: ordinary graphics card technology is built on the WINDOWS technology platform, so it is an 8bit output signal, the grayscale should be 256 grayscale, due to the WINDOWS system color palette alone to take up 20 grayscale, the monitor actually displays the grayscale into 236 grayscale, some images will appear obvious grayscale faults, and this is the reason why ordinary graphics cards can not replace the medical graphics card.
Medical graphics cards can be used for a variety of purposes, including
Medical graphics cards take into account the 10bit, 11bit output, but some of the lack of development packages attached to the need for PACS companies to carry out secondary development, not quite suitable for our national conditions.
Medical graphics card series 3MP, 5MP using 10bit technology, display gray scale is 1024, and does not require secondary development, easy to use, good compatibility, is a professional graphics card to use.
(6) Horizontal/vertical screen conversion;
Ordinary graphics cards: horizontal display, such as: 1024 * 768, 1280 * 1024
Medical graphics cards: horizontal/vertical display settings, generally CT, MRI, DSA, breast for the horizontal display, CR, DR chest X-ray for the vertical display;
that is, 1MP: 1024 * 1280 (vertical)/1MP. 1MP: 1024*1280 (vertical screen) / 1280*1024 (horizontal screen) is called 1 megapixel, commonly used in horizontal screen display, mostly applicable to CT, MRI, digital gastrointestinal machine;
2MP: 1200*1600 (vertical screen) / 1600*1200 (horizontal screen) is called 2 megapixel, referred to as 1K, commonly used in vertical screen display, mostly applicable to CR, DSA, digital gastrointestinal machine, PACS reading workstation. PACS reading workstation;
3MP: 1536*2048 (vertical screen) / 2048*1536 (horizontal screen) is called 3 megapixels, referred to as 1.5K, commonly used in vertical screen display, mostly for CCD-DR, PACS diagnostic workstations;
5MP: 2048*2560 (vertical screen) / 2560*2048 (horizontal screen) Known as 5 megapixels, referred to as 2K, commonly used vertical screen display, mostly applied to flat-panel DR, mammography, PACS diagnostic workstations.
Medical monitors are all grayscale, and the graphics cards on the market are generally colorful and cannot accurately express the difference in grayscale. Medical monitors are extremely delicate, and regular performance testing is essential; this performance testing is called calibration.
Medical monitors are more expensive than ordinary monitors because of their high calibration requirements. There are two main ways to calibrate medical monitors: external and internal, and internal is divided into front and rear.
Monitor calibration, strictly speaking, should be through the "display link" on the monitor "display effect" calibration. Its purpose is to maintain the standardization and consistency of the digital image display.
The object of calibration, mainly the brightness value of each pixel on the display (generally ftL, or feet lumens), followed by spatial aberration (such as drawing a straight line results in the display of a curve, drawing a square results in the display of a rectangle or trapezoid). Medical monitors are different from ordinary monitors focus on the calibration of the brightness value.
Luminance value mainly calibrates three values: maximum luminance value, minimum luminance value, linearity.
Parameter performance to meet these requirements above, the production volume is probably less than one millionth of the ordinary display, medical display prices can not be expensive? At present, the purchase of medical monitors configuration has become the focus of attention of hospitals and PACS integrators to understand the medical monitor and ordinary monitors in the technical performance and quality of the difference, according to the unit's specific circumstances, with different types of different grades of monitors, to meet the quality of the image under the premise of saving the hospital funds, reflecting the rationality and economy.
Medical monitors also have a number of different parameters with ordinary monitors, which are not repeated here.