Impulsive pulmonary function (IOS)

Pulse Oscillation Pulmonary Function (IOS) measurement technology is a new instrument that integrates pulse forced oscillation away from computer spectrum analysis technology. The advantage is that the subject can breathe spontaneously without coordination. The test process is more physiological and reproducible. It can better reflect the dynamic characteristics of the patient's respiratory physiology. The clinical application range of pulse oscillating lung function (IOS) is: 1 interstitial pneumonia, fibrosis, pneumoconiosis, granuloma, pulmonary edema. 2 lung occupying lesions, lung tumors, pulmonary cysts and so on. 3 pleural lesions pleurisy, pneumothorax, hemothorax and so on. 4 thoracic lesions scoliosis, spondylitis, thoracic deformity and so on. 5 lung resection. 6 neuromuscular disease, Guillain-Barre syndrome, respiratory muscle fatigue, etc. 7 obstructive pulmonary disease chronic bronchitis, bronchial asthma, emphysema and so on.

Basic Information

Specialist classification: Respiratory examination classification: pulmonary function test

Applicable gender: whether men and women apply fasting: not fasting

Tips: Patients should relax, not nervous, keep their heads natural, level or slightly up, so that the airway can be opened. Normal value

(1) The main parameters of ISO.

1Zrs represents the total respiratory impedance, which is generally less than 0.5 kPa/(L·s).

2R represents the viscous resistance portion of the respiratory impedance. R5 represents the total airway resistance, R20 represents the central airway resistance, and its value should be within 150% of the expected value; healthy people are very close, that is, the surrounding airway resistance is very small, represented by R5-R20.

3X represents the sum of the elastic resistance and the inertial resistance in the respiratory impedance. X5 represents the peripheral elastic resistance, and the difference between the predicted value and the measured value is not more than 0.2 kPa / (L · s) is normal.

4Fres represents the response frequency (ie, the resonance point), which indicates that the elastic resistance is equal to the inertial resistance. It is the most sensitive indicator of bronchial function tests and is twice as sensitive as FEV1. Normal person Fres does not exceed 10Hz.

(2) Spectrum analysis graph The horizontal coordinate of the spectrum analysis graph is the frequency axis, the left side of the ordinate (R) indicates the viscous resistance portion, and the right side of the ordinate (X) indicates the elastic resistance and the inertia resistance portion. The dotted line is the expected value. The normal person R should be around or below the predicted value (dashed line), and X should be around or above the predicted value (dashed line).

(3) Structural parameter map Rc represents the central resistance, from the structural parameter map, not only the viscous resistance, but different from R20; Rp represents the peripheral resistance, also from the structural parameter map, including the surrounding small airway viscous resistance and elastic resistance. Lz represents the inertial resistance of the upper respiratory tract and chest wall; Cm represents the compliance of the oral cavity; Ci represents the compliance of the lung; Cb represents the compliance of the bronchus; Cw represents the compliance of the chest wall; Ru represents the viscous resistance of the upper respiratory tract; Rw represents the chest wall Viscosity resistance; Lu represents the inertial resistance of the upper respiratory tract; Lw represents the inertial resistance of the chest wall; Ers represents the elastic resistance of the lung and chest wall.

(4) The impedance volume map is a graphical representation of the relationship between the total respiratory impedance (at 5 Hz) and the vital capacity. The inflection point at which the impedance (Zrs) rises sharply is the small airway closure point, and the volume at that point is the closed volume.

Normal person (tidal volume) 1Zrs should be less than 0.5kPa / (L · s); 2 exhalation impedance and inspiratory impedance close; 3 respiratory impedance without volume dependence.

Clinical significance

Abnormal result

(1) The meaning of numerical change

The value of 1Zrs increases, indicating that there is respiratory resistance; the larger the negative value of X, the greater the elastic resistance around.

2 In patients with airway obstruction, the R-wide frequency band is uniformly raised; the peripheral airway obstruction patient R5 is obviously elevated, but the high-frequency R20 does not change much.

3 patients with peripheral airway obstruction, X value is always lower than expected, X5 negative value increased, Fres moved to the high frequency end; patients with mild peripheral airway obstruction, R5 did not significantly increase, but X5 changes very obvious; chest The external airway is obstructed and a platform appears on the X-ray.

4 patients with central airway obstruction, Rc>Rp, the degree of obstruction is mainly determined by R5; in patients with peripheral airway obstruction, Rp>Rc, the degree of obstruction is also determined by R5.

The impedance volume map of 5COPD patients showed A. The expiratory impedance and the inspiratory impedance were separated, showing a mountain-like undulation; B. The gas-trapping phenomenon occurred.

(2) Typical map characteristics of common diseases

1 The proximal airway obstruction spectrum diagram R5, R20 is evenly elevated, X is basically unchanged, reflecting the central airway obstruction and not involving the periphery.

2 The distal airway obstruction spectrum R5 is obviously elevated, while the R20 is not changed much; the X-ray is shifted downward, and the Fres is shifted to the right, reflecting that the obstruction is confined to the peripheral part, affecting the elastic resistance and the total viscosity resistance, and does not affect the center. Viscous resistance of the airway.

3 Restricted ventilatory dysfunction is mainly characterized by peripheral elastic anomaly, and the viscous resistance R is basically normal. It is necessary to further examine the impedance volume map and the flow volume capacity loop, and identify them with atypical peripheral obstructive diseases because they perform very well in R and X. similar.

4 The chest-exclusion spectrum is different in shape depending on the distance and severity of the obstructed part from the El cavity. The main feature is that there is a bulge on R, and there is a platform on the same frequency of X, but this feature may be normal for children before the age of 4.

Need to check the population can be used for all patients with pulmonary function tests, especially for elderly, children and patients with incompatibility.


Inappropriate people: generally no special population.

Requirements for inspection:

(1) Requirements for patients:

1 It is required to sit on an examination chair without a backrest for measurement so that the subject can sit upright and sit upright.

Keep your head 2 natural, level or slightly up, so that the airway can be opened.

3 Be sure to clip the nose clip to avoid the external pressure signal being bypassed.

4 Use both hands to press the ankle to avoid the vibration of the ankle and increase the compliance of the mouth, thus affecting the accuracy of the measurement.

5 Use a tooth to bite the plastic mouthpiece. The tongue should be under the plastic mouthpiece to avoid blocking the breathing passage and increase the resistance. Hold the plastic mouthpiece tightly with the lips, and there is no air leak. Let the patient breathe through the mouth of the plastic mouthpiece. .

6 Avoid over-tight belts, chest straps and clothes.

(2) Requirements for measurement:

1 spontaneous breathing is very important: A. patients should relax, not nervous; B. pay attention to observe whether the patient is in the correct functional residual position, breathing curve balance; C. normal breathing frequency (about 20 times), tidal volume is normal (male :>450ml/min抅, female:>350ml/min); the patient's mouth has no air leaks and even breathing.

2 Recording begins after the breathing is stable: A. Record at least 3 breathing cycles, generally recommended to record 45s; B. Intrabreath analysis requires at least 30s; C. Epidemiological studies must record at least 3 spontaneous respiratory waves.

3 Stop recording before the patient releases the plastic mouthpiece.

(3) Requirements for quality control: Observe whether the respiratory wave curve is stable, whether there is up and down drift, whether the tidal volume is normal, whether the breathing is uniform or not, whether the parameters are normal, and whether the health search of each map is abnormal. In particular, it is necessary to avoid the fake movements of the mouth and throat, such as swallowing water, leaking gas, holding breath, dead space ventilation and the like.

Inspection process

The pulse-oscillation lung function (impulseoscillometry, IOS) measurement technology is a new type of instrument that integrates the principle of pulse forced oscillation and advanced computer spectrum analysis technology. It has no contraindications and has a wide range of applications. It can reflect the dynamics of patient's respiratory physiology more comprehensively. feature.

Not suitable for the crowd

No taboos.

Adverse reactions and risks

Generally no complications and harm.