Case of monitor maintenance

With the rapid development of medical technology, the function of monitor is more and more, and its application in clinic is more and more extensive. Medical monitor can monitor many physiological parameters of human body, which can be generally divided into basic measurement parameters and optional measurement parameters. The basic parameters included electrocardiogram (ECG), blood oxygen saturation (SpO2), noninvasive blood pressure (NIBP), heart rate (HR), and respiration (RESP). The optional parameters included invasive blood pressure (IBP), respiratory end carbon dioxide (ETCO2), body temperature (Temp), cardiac output (co), blood analysis, etc. It can be said that the monitor is an essential tool for clinical monitoring of patients. With the increase of service life and frequency of use, the number of malfunctioning instruments is increasing and there are more kinds of faults. Some of the phenomena and solutions encountered in the maintenance process are introduced to you Monitor manufacturers.

Fault case:

1 noninvasive blood pressure measurement part

Noninvasive blood pressure measurement part of the frequent failures are: no gas pump out; gas pump out, but pump gas is weak, and no measurement results; measurement data is not accurate. Generally, the following three steps can be used to find the fault:

(1) check the sleeve. First check the sleeve of the above fault, because there is a gas pump but not the result of the result is basically gas leak point, because the sleeve bag repeatedly inflated, easy to air leakage with the part of the pipe joint, and again, it is more convenient to check the sleeve, and do not need to open the machine, and the simplest and feasible inspection. The method of sleeve bag is to replace a same kind of sleeves directly. Failure to exclude the original sleeve bag has air leakage, if the failure still does not exclude that the internal gas path of the instrument has leakage, can be further opened to the machine for internal inspection.

(2) check the inflatable pump and the internal gas path. After the leak of the sleeve bag is removed, the machine should be turned on to check the inflatable pump and the internal gas path. After opening the machine, we should look at two listens and three senses. One is to observe whether the gas path of the inflatable pump is broken or not, causing the gas leakage; two listening is the sound of the working sound of the pump, and the three sense is the feeling of vibration or not. After pulling out the sleeve joint of the blood pressure, it feels like there is no air pump. According to the condition of inspection, the gas pump is refixed or replaced by the gas pump. Through this step, the gas pump and the pump gas can be eliminated.

(3) check the sensor. The inaccuracy of the measurement data is most likely due to the failure of the sensor. When measuring blood pressure with the kolkie sound, the sound sensor may not measure the fluctuation of the blood vessel due to dust or other reasons, or the measurement is inaccurate. At this time, the sensor needs to be cleaned and the sensor needs to be replaced when necessary. It needs to be pointed out that in order to ensure the accuracy of the measurement, it is necessary to use special testing and correction tools for metrological verification after maintenance.

2 ECG waveform measurement part

The electrocardiogram machine and the printed ECG can be used for diagnosis, so it requires higher machine environment, such as grounding wire. The ECG waveform displayed by the ordinary monitor can only be used for monitoring because of low sampling rate, which can not be used directly for diagnosis, so it has a little low requirement for the use of the environment, and the internal frequency interference circuit is also designed in the interior of the instrument, so the measured waveform has less interference.

When the monitoring of the ECG wave form of the monitor can not be detected or displayed very seriously, it is generally considered that the external conductance line or cable fault of the instrument can be considered, and it may also be caused by the decrease of the electrical conductivity of the electrocardiogram electrode. The electrical conductivity of the electrocardiogram electrode can be detected by a multimeter, and the cardiac conductance line and cable fault can be judged by the comparison method, that is to change the same type of cardiac conductance line or cable, see if the fault is excluded, the fault disappears to indicate the original line has problems, and the failure need to be further opened to the machine. Check.

3 measurement part of blood oxygen saturation

The principle of measurement of blood oxygen saturation is based on the different absorption spectrum characteristics of oxygenated hemoglobin (I-IbO2) and reduced hemoglobin in red and infrared light regions. Using the Lambert - Beer rule, the absorption of light intensity I is calculated, and then a series of calculations have been made to obtain the saturation of oxygen. In actual measurement, the central frequency is 660nm and 940nm respectively, and the two luminous tubes start alternately in a certain order at 80 Hz frequency.

Blood oxygen saturation measurement is partly damaged by blood oxygen saturation sensor (finger or finger type). The above mentioned comparison method can be used to determine whether the sensor problem is preliminary. The sensor fault is usually caused by the internal cable fracture. It can be carefully reconnected after the incision and can also be replaced directly. It is necessary to point out that the general joints of the different types of machines are different and some of the joints are the same, but because the connection methods used by different manufacturers are different, although the external joint is the same but the internal structure is different, the matching can not be matched.
Use.
The above is only a simple way to deal with the surface fault. In fact, there are many failures in the machine. We need to accumulate experience in the ordinary work. The structure of the internal line includes the composition of the circuit board, and the measurement principle of the parameters of each unit can solve the problem quickly.