Examination of regional pulmonary function offers an important suggestion to diagnosis of some pulmonary disease and indication of lung surgery. For this purpose, bronchospirometry with intrabronchial tube has been usually used. But this method has some technical difficulties and gives patients considerable pain and air way resistance.
In this paper a trial of intrabronchial measurement of air velocity, applying Hot Wire Anemometer (Bronchoanemography) is reported.
Equipments: Hot wire anemometer is based on the convective heat loss in an electrically heated wire (Hot wire) by the flow of gas or fluid. Constant temperature type of it was used in this study.
A new miniature size hot wire probe was made. The probe consists of 5 micron tungsten wire and its span is 0.5mm. This probe is covered with protection basket made of thin steel wire. By this basket the fragile probe is protected from bronchial mucus.
Function lineariser or an analog computer of King's equation, high cut filter and magnetic oscillograph was used for recording the velocity curve.
Test of probe: The probe was tested in an straight tube at several angles under various air velocities by Pitot tube.
The deviation caused by the angulation was 28% at the most. But at the straight position the deviation from the value by Pitot tube was less than 5%.
Measuring: After the surface anesthesia by Xylocain nebulisation the probe and guide tube was inserted transorally under X-ray television. When the probe reached the amed part of the bronchus the basket was opened and measured the velocity. The measurement was tried in 18 patients suffering from lung cancer and large mediasinal tumor, at quiet and forced expiration.
Results: In 11 cases the clear velocity curves were obtained. The ratio of vital capacity of both lungs, and FEVlsec% were calculated by planimetry from these curves. These values were compared with the data of bronchospirometry, and both values in vital capacity were agreed very well.
About FEVlsec% the values from bronchoanemography were closely near to that of total lung spirometry. By this new method measurement of air velocity in the bronchus without any significant artificial air way resistance became possible and it will offer the important data of lung and lobular ventilatory function. At present the probe is still fragile but our new device (solid type probe) will give the solution.

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The authors investigated the possibility of the quantitative evaluation of the regional pulmonary circulation from the chest X-ray film. Theoretically, the density of the chest X-ray film depends upon the pulmonary air content and blood volume in the lung. So, if pulmonary air content was fixed, the X-ray penetration through the chest, i. e. the density of the chest X-ray film should be decided by the pulmonary blood volume. The momentary changes of the pulmonary blood volume were devised to pick up with a mini-computer and to plot on a diagram in four different colors.
Two roentgenograms were taken in a standing position at the terminal moments of systolic and diastolic phase of the heart in the terminal phase of resting inspiration, by means of the breathing-heart beat X-ray synchronizer. Each of the films was developed under the same condition. The synchronizer was controlled by both signals from the thermister mounted in the nose and the photoelectric plethysmograph mounted on a finger tip.
The subtractive density of the two chest X-ray films was measured at each level of all lung fields with a film scanning method—subtractive densitometry, using a small digital computer with a dual channel scanner. Then the signals of this subtractive density were calibrated to the changes of the chest thickness, and displayed by the graphic plotter on a diagram with four different colors according to the difference of the density (red, violet, green and yellow green from maximum to minimum).
In the same patients, macroaggregated albumin labelled with ¹³¹I was injected from the antecubital vein in a sitting position, and the radioactivity in the lung was scanned on a scintilation plot diagram in a supine position. The obtained scintigram was compared with the former data.
For the convenience of comparison, plotted diagrams of the lung fields obtained by both methods were divided into four dimensions: upper and lower fields of bilateral lung. When, in all four quadrants, the results agreed with each other, it was evaluated as good correlation; in three quadrants, as fair; in two or less quadrants, as poor.
Consequently, in 3 out of 4 normal subjects had a good correlation. The other was shown as poor. In the patients of respiratory diseases, 3 out of 10 showed good correlation, 4 fair, and 3 poor.
It was suggested that the present method of semiquantitative evaluation of the regional pulmonary circulation would be usefull for the physiological and clinical study of the lung.

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