Principles of Measurement of Multi-Parameter Monitor and Attention to Its Application

Principles of Measurement of Multi-Parameter Monitor and Attention to Its Application
    Meilun Monitor manufacturers multi-parameter monitor, can monitor the physiological parameters of the human body for a long period of time, and can store, display, analyze and control the detection results, and can send a warning in the event of abnormal situations. Depending on the object of clinical care and the purpose of care, the monitor is mainly used for the following nursing monitoring:
1, intraoperative and post-operative anesthesia monitoring
2, the maternal birth process and pre-and post-natal fetal monitoring
3, ICU patient surveillance
4, convalescent patient custody
5, treatment of patient custody
6, 24 hours dynamic monitoring
The general medical monitor parameters mainly include the following items
1, ECG(ECG) heart electrical excitement spread through the body tissue to the body surface, resulting in a series of potential changes, and was recorded to form an electrocardiogram. The electrocardiogram reflects heart activity.

The general medical monitor parameters mainly include the following items
1, ECG(ECG) heart electrical excitement spread through the body tissue to the body surface, resulting in a series of potential changes, and was recorded to form an electrocardiogram. The electrocardiogram reflects the Bioelectrical changes in the production, transmission, and recovery of heart excitement. It is a comprehensive manifestation of the potential changes that occur in many heart cells in various parts of the heart, not due to the mechanical contraction of the heart.
Electrocardiogram classification
(1) Standard limb lead(bipolar lead): There are I lead, II lead, III lead
(2) Chest leads(unipolar leads): V1, V2, V3, V4, V5, V6
(3) Pressurized unipolar limb leads: AVR, AVL, AVF
Multi-parameter monitor electrocardiogram is mainly divided into three leads and five leads.
Three lead electrode placement position
LA Black(left hand)
RA White(right hand)
LL Red(left foot)
Five lead electrode placement position

Factors affecting ECG signals

1, surgical electrical equipment interference

2, no external ground line

3, the electrocardiogram electrode piece is not properly placed

4, use expired or reuse disposable electrode

5, the placement of electrode parts of the skin is not clean or dandruff, hair caused by poor contact with the electrode

2, blood oxygen saturation(SPO2) The proportion of oxygenated hemoglobin(including oxygenated hemoglobin and reduced hemoglobin) in the blood, reflecting the degree of hemoglobin and oxygen binding and the oxygenated state of the body.

Principles of measurement

Blood oxygen = oxygenated hemoglobin(HbO2) / reduced hemoglobin(Hb) X100 %

Due to the different absorption coefficients of oxygenated hemoglobin(HbO2) and reduced hemoglobin(Hb) in the blood for light of different wavelengths, the absorption coefficient of Hb is greater than that of HbO2 in the red light region with wavelengths of 600 to 700 nm; In the near-infrared light region with a wavelength of 800 to 1000 nm, the absorption coefficient of HbO2 is higher than HB's large. Therefore, SPO2 is calculated by measuring the fluctuation of the peak and valley of the pulse wave when the pulse wave passes through the measured tissue using the 660nm red light and 925nm infrared light.

The blood-oxygen saturation probe is equipped with a light transmitter(light emitting diode) on the side of the probe. The part containing arterial blood vessels is placed between the light emitting diode and the phototube. After entering the light through the tissue, it becomes an outgoing light. The light detector of the probe(phototube) receives the light signal and filters it through the wave. Enlarge, A/D is converted into a digital signal, which is converted from a microcomputer to SPO2 according to Lambert-Bill's law.
Influencing factors of SPO2
1, the probe line should be placed on the back of the hand(nail face) or on the foot of the foot
2, can not monitor the same part for a long period of time.
3, do not and sleeve on the same arm; Use on the extremities of an arterial catheter or internal canal.4, if there is carbon oxyhemoglobin, high-speed hemoglobin or dye dilution chemicals, then there will be deviations in the SPO2 value.5, light interference.6, artificial too frequent movement.Non-invasive blood pressure(NIBP) The side pressure of blood in a blood vessel on the wall of the blood vessel. This pressure is blood pressure. The energy released by the ejection force of the heart and the contraction of the ventricular muscle during the heartbeat cycle becomes part of the kinetic energy that drives the rapid flow of blood, and the other part is converted into potential energy, which is manifested as arterial blood pressure. Non-invasive blood pressure measurement is an indirect method of measuring human blood pressure. There is a certain difference between the blood pressure measured by various non-invasive blood pressure measurement methods and the true blood pressure value of the human body.

There are two methods for measuring non-invasive blood pressure in multi-parameter monitors
(1) Electronic Keshiyinfa
(2) Vibration method(At present, most monitors use this method to measure)Vibration method: When measuring, the monitor automatically inflates the cuff and begins to release gas at a certain pressure(usually 180 ~ 230 mmHg). When the pressure drops to a certain extent, the blood flow can pass through the blood vessels, and the fluctuating pulsating blood flow will produce an oscillating wave. The oscillating wave is transmitted to the pressure sensor of the machine through the trachea. The pressure sensor records the change of the pressure value in the sleeve in real time. Through the computer, a decreasing pressure curve of the oscillating pulse is recorded. According to the curve, the average arterial pressure MP is determined.SP(systolic pressure) = MP/0 .55DP(diastolic pressure) = MP X 0.85NIPP Measurement Note1, choose the appropriate sleeve and mode settings2, Mark φ at the brachial artery3, the measurement site should be maintained level with the heart(right atrium) and spread 45 degrees(0.9 mmgg/cm)Don't wear too thick clothes, especially cotton-wool clothes5, sleeve should be loose and moderate6, do not install armbands on the limbs with intravenous infusion or insertion tube.During the measurement process, the arm must not be squeezed.The patient is moving, shaking, or convulsing, and the measurement will be unreliable or even impossible.Blood pressure should not be measured frequently unless the condition requires it. Frequent measurement will affect the accuracy of the results.10, arrhythmias.11, the patient is connected with an artificial heart andlung machine, will not be able to measure.Normal difference in blood pressure.

Low blood pressure-morning, evening, labor, fullness of food, hot environment

High blood pressure-cold, emotional, nervous, drinking, smoking

Left and right differences-10-20 mmHg

The difference between upper and lower extremities-lower extremity blood pressure is 30-40 mmmHg higher than upper extremity blood pressure

Differences between men and women-slightly higher for men

4, body temperature(TEMP) temperature in the human body is called body temperature. The temperature sensor is used to convert the temperature measurement into a potential amount to measure the temperature and show it.Points to Note for TEMP Measurement1, cylindrical and button-like2, temperature sensor response speed is slow, should be equal to the numerical stability before reading3, one-time temperature probe can only be used once5, breath(RESP) The process of gas exchange between the body and the external environment is called respiration. When the human body breathes, the muscles of the chest wall change and relax, and the thorax is alternately deformed. The electrical impedance of the body's tissues also changes alternately. The amount of change is 0.1 Ω ~ 3 Ω. This impedance is called respiratory impedance. Respiratory impedance has a certain relationship with lung volume.The relatively accurate method of measuring respiration is to measure the amount of tidal gas, while the monitor's breath detection is to use the respiratory impedance method to use the electrocardioelectric electrode to collect the respiratory wave signal.Calculate the respiratory frequency to obtain the respiratory waveform.RESP Measures NoteRespiratory monitoring is not suitable for patients with a high degree of activity because it can lead to false alarms.The liver region and the ventricle should be avoided by connecting them to the respiratory electrode. This will avoid the false difference in the heart cover or pulsating blood flow. This is particularly important for newborns.