Causes and Repairs of Abnormal Image in Medical Electronic Endoscope

With the development of the level of non-invasive medical diagnosis and treatment, medical electronic endoscopes have increasingly become one of the indispensable medical equipment in the medical professional field.In order to ensure the safety and accuracy of the endoscope in use, operators and engineers should be familiar with the principle of the endoscope, strengthen daily maintenance, do a good job of quality control, and have fault judgment and processing capabilities to ensure the smooth progress of clinical diagnosis and treatment.

Analysis and treatment of the causes of abnormal images

The causes of abnormal images can be divided into two categories. One is that the image is abnormal due to the failure of the electronic endoscope body, and the other is due to the failure of the cold light source, the host, and the wrong settings.

1.Image display color cast

Fault analysis: The image has a color cast, and the color of the tissue cannot be truly displayed, which is not convenient for diagnosis and treatment.First of all, observe the monitor image: if it is a color cast in the whole area, the signal format set by the image monitor and the host is mostly inconsistent; if it is only a color cast in the image area, first confirm whether the special light mode is enabled, and then follow the principle of imaging step by step troubleshooting.

Treatment method：

• Enter the setting menu of either the host or the monitor to switch the signal format and observe the image color.
• Connect the RGB video cable correctly, and use the color bar function to determine whether the connection of the monitor cable is normal.
• Perform standardized white balance operations, while ensuring that the reference object is standard white.
• The host’s color emphasis is set improperly, so reset it.
• Turn on the host and the light source, hold the front end of the insertion part and shake it quickly, and check the RGB grating of the light source. If there is a red, green and blue color deficiency, it is determined that the grating of the light source has fallen off and the light source needs to be repaired.
• The color is cast, and the endoscope is tested for water leakage. It may be damage to the CCD caused by water leakage, and the endoscope needs to be repaired.

2.The image is dark

Fault analysis: The image is too dark to view the tissue normally. Since the human body is completely dark, the brightness is provided by a cold light source. The reason is checked separately from the light source to the endoscope through the sequence of light, and it is not ruled out that abnormalities in the system settings cause the image to be dark.

Treatment method：

• Correctly adjust the brightness level of the panel light source and the brightness and contrast values of the monitor.
• Check the instructions on the panel. If the xenon lamp is running for more than 500 hours, or the spare halogen lamp is enabled, replace the cold light source xenon lamp.
• Choose the correct metering mode.If it is peak metering, the image may be dimmed.
• Dust removal of the light source grating and lens assembly.
• If the image is dimmed by the endoscope itself, check the light transmittance of the endoscope to determine whether the optical fiber is broken.For the endoscope leakage test, the image may be darkened due to damaged cover glass, or CCD damage, and the endoscope needs to be repaired.

Image stripe interference

Fault analysis: If there are stripes or interference in the image, environmental factors must first be eliminated, and then troubleshooting must be carried out. The image display of the endoscope is transmitted, processed and displayed after imaging through endoscope CCD. If this fault is troubleshooting, it must be eliminated one by one from simple to difficult.

Treatment method：

• Stay away from electromagnetic wave equipment, avoid interference, and use power outlets separately from high-frequency electrical equipment.
• The correct and effective connection between the endoscope and the image processing host.If the endoscope cable is broken, it will be replaced, and the electronic contacts will be slightly polished with rust spots to ensure good contact.
• If there is obvious interference when bending the endoscope or angling, the CCD cable fails and the CCD as a whole is replaced.
• If the endoscope leaks and the test leaks, it is very likely that the CCD will fail due to water entering the endoscope.