A professional medical display must support the DICOM PART14 standard, that is to say, it must have the ability to adjust the curve of DICOM standard, so as to ensure the display quality of images.
General size: display size is expressed in diagonal length, generally in inches the main size of the common display is 15 ", 17 ", 19 ";
The common sizes of medical display are 18 ", 20 "and 21", which are basically similar to X film.
Support for gray scale display: gray scale is an important feature of black and white medical imaging, which reflects the layers between black and white images
Gray-level display requires graphics card support, and special medical display should be equipped with special graphics card;
Ordinary display: 8bit- 256 gray level, used to display color images, no gray level requirements, the use of ordinary graphics card;
Medical display: 10bit-1024 gray scale, used to display X-ray gray scale images, related to diagnosis, requirements: 10bit11bit (1024*2048 gray scale). Support BBS function (stable brightness control)
Is the brightness of the display will decay over time, the brightness of the ordinary display because no stable control and calibration, not only attenuated fast, use at ordinary times, also due to the influence of the environment, its brightness cannot long time maintain in a suitable for human naked eye level, and professional medical grayscale display considering this problem, taking the brightness of the stability control technology, calibration of display brightness information feedback by at any time, make it always stay in the standard luminance, in accordance with clinical standard reading.
Brightness and brightness constant requirement
Brightness is how bright an image is on the display. The brighter the image, the larger the dynamic range that can be generated, allowing people to distinguish more tones in the image. This dynamic range must provide a full 8bit grayscale image (that is, 256 different shades).
Ordinary display: 200-300cd/m2 without constant brightness requirements; Medical displays are 600-700 CD /m2 with brightness between 400-500 CD /m2 adjusted; It requires the brightness value to remain the same for 30,000 hours or even 100,000 hours.
Constant brightness is very important for medical display to ensure that the brightness of the display does not change with time. Experimental research has proved that the display brightness and visual sensitivity of the relationship, when the brightness of 500 CD /m2, visual sensitivity of 700, when the brightness of 800 CD /m2, visual sensitivity of 777 (maximum), the ideal brightness of 400~500 CD /m2, so choose the brightness ≥700 CD /m2.
Specification of resolution
The actual number of pixels displayed per unit area, such as 800*600, 1200*1600, etc
Common monitors are: 1024* 768,1280 *1204; Basically landscape, no landscape/portrait conversion required; Medical display: according to the needs of the image, it can convert horizontal/vertical screen.
1024*1280 (portrait) /1280*1024 (landscape),
Known as 1 million pixels (1MP), it is commonly displayed on horizontal screen, and is mostly applicable to CT, MRI and digital gastrointestinal machine.
1200*1600 (portrait) /1600*1200 (landscape);
It is called 2 million pixels (2MP), or 1K for short. It is usually displayed on vertical screen, and is mostly applicable to CR, DSA, digital gastrointestinal machine, and PACS film reading workstation.
1536*2048 (portrait) /2048*1536 (landscape); It is called 3 megapixels (3MP), referred to as 1.5k. It is usually displayed in vertical screen, which is suitable for ccd-dr and PACS diagnosis stations.
2048*2560 (portrait) /2560*2048 (landscape);
It is called 5 million pixels (5MP), referred to as 2k. It is usually displayed on vertical screen, and it is more suitable for flat DR, breast machine and PACS diagnostic workstation.
The resolution of medical display is proportional to the price and positively correlated with the resolution of radiological equipment, and the corresponding equipment shall be matched with the display of corresponding resolution. The response time
Response time refers to the response rate of the LCD to the input signal, that is, the reaction time of the liquid crystal from dark to bright or from bright to dark. It is usually measured in milliseconds (ms). By response time, we mean the sum of two parts -- Rising and Falling. Remnants of human existence "visual" phenomenon, namely motion images in the brain can form a brief impression, people can accept the picture display speed is commonly with 24 per second, which is the origin of the movie played 24 frames per second speed, if display speed is lower than the standard, the person will clearly feel the picture pause and discomfort. According to this standard, the display time of each screen should be less than 40ms. According to the actual use of liquid crystal, the response time should be 30ms (1/0.03=33.3 sadg/s), and the tail can still be dragged, which is not suitable for real-time playback of dynamic medical images. The response time below 25ms (1/0.025=40 sadg/s) can satisfy the real-time playback of clinical cardiovascular DSA.
In the selection of medical display, CR and DR still images have no high requirement for response time. However, in the system configuration of playing dynamic images, such as cardiovascular machines and digital gastrointestinal machines, medical displays with response time below 25ms should be preferred.