DE2817490A1 - Nose aerodynamic characteristics rhino-rheometer - has sensors to measure total volume breathed and trans-nasal pressure as function of time - Google Patents

Abstract

The rhinorheometer measures and indicates the aerodynamic characteristics of both passages of the nose. During measurement, the patient breathes in through the nose and out through the mouth, and then in through the mouth and out through the nose. The total volume breathed is measured during breathing through the mouth, and the trans-nasal pressure as a function of the time during breathing through the nose. The aerodynamic characteristics are determined by electronic or other signal processing from the total volume breathed and the trans-nasal pressure as a function of the time.

Description

Rhinorheometer

The present invention relates to a rhinorheometer according to the preamble of claim 1.

The measurement of the aerodynamic properties of the nose are important clinical evidence of dysfunction, and it serves as an aid to decision-making and control during operations. The flow in the nose is turbulent, and it persists a quadratic relationship between the transnasal pressure p (t) and the volume flow through the nose # (t) #p (t) = W. # (t) 2. (1) The constant W = ap (t) / V (t) 2 one. the quantity characterizing the flow resistance, which in the following is more quadratic Called resistance. Alternatively, the condition of the nose can be determined by the volume flow Vx can be given for a fixed transnasal pressure # p = x, where.

often x = 1.5 mbar is chosen. From Eq. (1) follows To determine ~ # or Vx, ap (t) and V (t) or V (t) 2 have so far been measured simultaneously with a rhinomanometer. The measured quantities ap (t) and V (t) are then further processed graphically or electronically according to equation (1) or (2), and X and / or Vx is formed. As a rule, one xy recorder or two xt recorders are necessary for this. A device version with direct display of if and / or Vx was described in patent application No. 28 12 093.6. All previously known methods use a breathing mask or a nasal attachment to measure the volume flow through the nose V (t). This creates an air-impermeable connection between one or both nostrils and a flow measuring resistor (e.g. spiroceptor) for measuring V (t). The breathing masks and nasal attachments are very impractical in clinical use, and they often lead to measurement errors due to a leaky fit.

Further systematic errors occur particularly with nasal attachments due to an altered eddy formation and deformation of the nostril.

The present invention is based on the object of specifying a device which are the aerodynamic parameters such as W and / or Vx of the nose without a breathing mask or measure the nose piece to measure the volume flow through the nose V (t) can.

This object is achieved according to the invention by a rhinorheometer with the Features of the characterizing part of claim 1 is solved.

The fact that when inhaling without a breathing mask or nasal attachment through one or two nostrils the nasal pressure a # p (t) preferably in the oral cavity is measured, and when exhaling through the mouth via a flow measuring resistor (e.g. spiroceptor) the total tidal volume V is measured, can be done by a corresponding Signal processing the aerodynamic parameters of the nose when inhaling - such as the square resistance W or the volume flow V at ap = x = 1.5 mbar - calculates the mean will. In order to determine the aerodynamic parameters during exhalation, inhaled through the mouth via the flow meter and exhaled through the nose, the signal acquisition and processing is analogous.

The advantages achieved with the invention are in particular: that measurements of the aerodynamic properties - such as W and / or V with p = x = 1.5 mbar - without breathing masks or nasal attachment to measure the volume flow breathing air is possible.

Developments and advantageous refinements of the rhinorheometer according to the invention are characterized in the subclaims.

In the following, exemplary embodiments of the invention are referred to explained in more detail on the drawings.

They show: FIG. 1: a simplified scheme of a rhinorheometer according to one embodiment of the invention; FIG. 2: a modified one compared to FIG. 1 Form of the acquisition of measured values of the transnasal pressure, whereby the signal processing takes place exactly as in Fig. 1; 3: a simplified scheme of a rhinorheometer according to another embodiment of the invention.

In the simplified scheme of a rhinorheometer according to FIG. 1 means 1, for example, a commercially available Spirozepter, which by means of an additional pressure measuring tube 11 and a movable flap 15 is modified. During the measurement, the spiroceptor put in the mouth 50. First, the study of the aerodynamic properties the nose when inhaling. Here the patient breathes through the nose a, and the movable flap 15 is in the position, not shown, in which it closes the end of the spiroceptor 1 airtight. The patient holds the throat open, so that the static pressure behind the choane also in the oral cavity and in the Spiroceptor prevails. Thus pO-ap (t) acts on the pressure measuring tube 11, where pO is the air pressure and tp (t) is the nasal pressure to be measured. The pressure from the pressure measuring tube 11 is passed through a hose 21 to the manometer 31, which is an electronic Signal A delivers A p (t). During inhalation through the nose there is on the measuring tubes 12 and 13 the same pressure, which is applied via two hoses 22 to the differential manometer 32 is passed, the difference signal being zero. After inhalation, breathes the Patient through the spiroceptor 1, whereby the flap 15 opens in the way drawn. The measuring tube 11 is as shown in Fig. 1 on rear end bent in the axial direction, and the measuring tube measures on exhalation 11 the air pressure po.

The signal zero now arises at the output of the manometer 31.

In contrast, a pressure difference now occurs at the measuring tubes 12 and 13 on, which causes an electronic signal -V (t) at the output of the differential manometer 32.

To understand the electronic signal processing, Eq. (2) reshaped and integrated where the integration time t is in each case an integral multiple of a full breathing cycle. Eq. (3) has compared to Eq. (1) and (2) have the metrological advantage that the exact time course V (t) does not have to be known. It is only necessary to know the total tidal volume V = fV (t) dt. So V (t) and dp (t) no longer need to be measured at the same time.

The electronic signal processing in Fig. 1 will now be based on Eq. (3).

The electronic signal NV (t) from the differential manometer 32 is integrated by the integrating circuit 33 and sent to the dividing circuit 34. From the electronic signal> p (t) from the differential manometer 31, through the root circuit 35 formed, integrated by the integrating circuit 36 and given to the divider 34. After each full breathing period, the output of the divider 34 according to Eq. (3) a signal ## x. At this point in time, the electronic switch 37 is briefly closed, and the electronic signal V is placed in a memory with a display unit 38 x, where V can be read off directly.

x When studying the aerodynamic properties of the nose when exhaling, the patient inhales through the spiroceptor 1 with the valve 15 open. Exhale is through the nose, leaving the pharynx open and the valve 15 is closed. The signs of the signals are reversed, and under consideration the signal processing is analogous to this fact.

If the cross-sectional area of the spiroceptor is large, so that the dynamic pressure can be neglected, it is possible to omit the measuring tube 11 and to connect the hose 21 to the hose 22 from the measuring tube 12 via a T-piece.

A connection to the measuring tube 11 is also possible, provided the signal from the manometer 31 when breathing through the spiroceptor 1 - for example through a not The drawn logic circuit is set to zero.

If some patients are unable to keep the pharynx open while breathing (posterior method), the transnasal pressure #p (t) can also be measured in the contralateral nostril according to FIG. 2 (anterior method). The somewhat longer and thicker pressure measuring tube 11 is now stopped at the contralateral nostril through which one does not breathe with the aid of a nasal attachment piece 19, and Çp (t) is measured with the manometer 31. To compensate for pressure drops at the spiroceptor 1, the manometer 31 can be designed as a differential manometer, the differential pressure at the measuring tubes 11 and 13 being measured. The further signal processing, not shown in FIG. 2, takes place exactly as in FIG. 1. In the posterior method, breathing is carried out through a nostril without a breathing mask or nasal attachment piece. FIG. 3 shows a variant of a rhinorheometer according to the invention. An axially arranged pitot tube 14 with the flap 15 open is used to measure a pressure ~ + V (t) 2 during inhalation or exhalation through the mouth (see patent application no. When the flap 15 is closed, the nasal pressure Ap (t) is measured by the manometer 31. The signals go to the root hold 31, where an electronic signal NV (t) or

is formed. The logic circuit 39 conducts the signal to the integrating circuit 36 and the signal XV (t) to the integrating circuit 33. The further signal processing takes place as described in FIG. The arrangement according to FIG. 3 has the advantage that only one manometer 31 needs to be present, since either ap (t) or V (t) is measured in each case. Analogous to FIGS. 1 and 3, circuits can be set up which, on the memory with display unit 38, show the quadratic resistance W according to Eq. (4) form The signal processing of the rhinorheometer can be integrated into a device for lung function analysis, whereby the measurable variables V (t) and V = (t) dt, which are important for the lung function analysis, are already formed in the rhinorheometer.

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Claims (5)

Claims 1. A rhinorheometer for measuring and displaying the aerodynamic parameters of one or both sides of the nose, d u r c h g e k e It is not noted that during the measurement inhaled through the nose and through the Mouth is exhaled that inhaled through the mouth and exhaled through the nose that when breathing through the mouth, the total tidal volume is measured, that when breathing through the nose the transnasal pressure as a function of the Time is measured that the aerodynamic parameters by an electronic or other signal processing from the total tidal volume and the transnasal Pressure can be formed as a function of time. 2. Rhinorheometer according to claim 1, d a d u r c h g e k e n n z e i c h n e that spirceptors with a flap 15 and / or to measure the tidal volume an additional pressure measuring tube 11 (Fig. 1) can be used. 3. Rhinorheometer according to claim 1, characterized in that it is not e t that to measure the tidal volume pitot tubes 14 (Fig. 3) or other square Pressure pipes measuring the volume flow can be used. 4. Rhinorheometer according to claim 1, characterized g e k e n n z e i without t that in electronic signal processing with at least one measurement signal the root is taken and then both signals are integrated, divided and possibly be squared. 5. Rhinorheometer according to claim 1, d a d u r c h g e k e n n z e i n e t that the rhinorheometer is integrated in a device for lung function analysis will.