SPIROERGOMETRY APPARATUS

Abstract

A spiroergometry apparatus for detecting parameters of a respiratory gas. The spiroergometry apparatus has a main body, a measuring device, a computing unit and an energy store. The measuring device includes a sensor, which is provided on the main body, whereby it becomes possible to detect parameters directly in the respiratory gas flow, so that an in-situ detection of the parameters of the respiratory gas is made possible.

Claims

1. An apparatus for detecting the parameters of a respiratory gas, comprising a main body which is a respiratory mask or a mouthpiece and has a respiratory gas guide section, a measuring device for detecting parameters of the respiratory gas, a computing unit for processing the detected parameters of the respiratory gas, and an energy store for supplying energy at least to the measuring device and the computing unit, wherein the measuring device is provided on the main body for detecting the parameters directly in a respiratory gas flow which is guided through the main body, so that in-situ detection of the parameters of the respiratory gas is made possible.

2. The apparatus according to claim 1, wherein the evaluation and/or analysis of the detected parameters of the measuring device can be carried out via the computing unit.

3. The apparatus according to claim 1, wherein the measuring device comprises a sensor which has at least one laser, the parameters of the respiratory gas being determined by laser spectroscopy.

4. The apparatus according to claim 3, wherein the sensor comprises two lasers having different wavelengths.

5. The apparatus according to claim 1, wherein the measuring device comprises an optical sensor.

6. The apparatus according to claim 3, wherein the pressure and the temperature of the respiratory gas are determined via the spectral evaluation of the line profile of absorption lines of the respiratory gas and wherein the spectral evaluation is carried out by the computing unit.

7. The apparatus according to claim 1, wherein the respiratory gas guide section is tubular and a first laser and a second laser illuminate the respiratory gas guide section and at least one detector for measuring the absorption is provided in the region of the respiratory gas guide section.

8. The apparatus according to claim 7, wherein the first laser, the second laser and/or the detector are flexibly provided at the periphery of the respiratory gas guide section so that the position is variable relative to the respiratory gas guide section.

9. The apparatus according to claim 1, wherein the measuring device detects as parameters at least one of the following parameters: the CO.sub.2 concentration of the respiratory gas, the O.sub.2 concentration of the respiratory gas, the volume flow of the respiratory gas, the respiratory gas humidity, the ambient temperature, and the respiratory gas pressure.

10. The apparatus according to claim 1, wherein the main body can be fixed to a test person via fixing elements and the computing unit, measuring device and energy store are accommodated on the main body, the main body having the respiratory gas guide section for guiding the respiratory gas flow with a test person-side respiratory gas inlet and a respiratory gas outlet and the sensor being provided in the respiratory gas guide section.

11. The apparatus according to claim 1, wherein the apparatus obtains the energy required for the operation exclusively via the energy store.

12. The apparatus according to claim 1, wherein the measuring device comprises a non-dispersive infrared sensor and/or a zirconium dioxide sensor.

13. The apparatus according to claim 1, wherein a generator for carrying out energy harvesting is provided so as to allow energy recovery from shock pulses and/or respiratory gas heat and/or ambient lighting.

14. The apparatus according to claim 1, wherein an orifice plate is provided for determining the volume flow of the respiratory gas via a differential pressure in the respiratory gas guide section, the orifice plate being provided between a first laser and a second laser.

15. The apparatus according to claim 1, wherein the apparatus is a mobile spiroergometry apparatus.

Description

FIGURES

[0044] FIG. 1: shows a schematic structure of a respiratory gas mask with a measuring device for detecting parameters of the respiratory gas;

[0045] FIG. 2: shows a schematic representation of the respiratory gas guide section and the lasers and detectors arranged thereon for determining the CO.sub.2, O.sub.2 and H.sub.2O concentrations as well as the temperature, pressure and final volume flow;

[0046] FIG. 3: shows a respiratory mask with the respiratory gas inlet and outlet;

[0047] FIG. 4a: shows an embodiment of the present invention with two detectors and two lasers;

[0048] FIG. 4b: shows an embodiment of the present invention with one detector and two lasers;

[0049] FIG. 5: shows a spiroergometry apparatus according to the present invention with an energy harvesting apparatus; and

[0050] FIG. 6: shows a diagram for the multiparameter determination.

[0051] In the following, various examples of the present invention are described in detail and with reference to the drawings. The same or equal elements are designated by the same reference signs. However, the present invention is not limited to the features described, but also includes modifications of features of various examples within the scope of the independent claims.

[0052] FIG. 1 shows a schematic design of a spiroergometry apparatus. On a main body 1, which is designed as a respiratory mask in the embodiment shown in FIG. 1, there are various sensors S. A pressure sensor and a temperature sensor can be provided for detecting the pressure and temperature. The sensors S are assigned to the measuring device 4, which is connected to the computing unit 3. The computing unit 3 evaluates the detected measured values of the measuring device 4 for the respective parameters. A battery (energy store 2) is provided for the operation of the computing unit 3. Instead of the various sensors, it is possible to determine the parameters (p, V, T, O.sub.2, CO.sub.2, etc.) using only two lasers with at least one detector, as shown in FIGS. 2, 4a and 4b. The complex evaluation of the various sensor types can thus be greatly simplified since the signals generated by the lasers must now be evaluated.

[0053] In order to allow the test person to breathe, the main body has a respiratory gas outlet opening which is provided opposite the respiratory gas inlet through which the test person's respiratory gas is introduced into the main body. Since the detected measured values can be processed directly in the spiroergometry apparatus, a connection to a base station via cables or tubes is not necessary. It is also not necessary to pump out the respiratory gas via a pump.

[0054] The respiratory gas mask is attached to the test person's head in a sealed manner so that the respiratory gas flow is directed exclusively via the respiratory gas guide section, wherein the mask has sealing agents or sealing surfaces which allow it to be attached to the test person accordingly.

[0055] In a particularly preferred embodiment, the measuring device 4 has two lasers with a total of one (or two) detectors and a turbine wheel. The turbine wheel measures the volume flow of the respiratory air and the two lasers and a detector (and multiplexer) determine the other parameters (p, T, CO.sub.2, O.sub.2, absolute humidity).

[0056] A further simplification is achieved by the design as shown in FIG. 2. In this design, a sensor is provided for the measuring device, which comprises a first laser L1 and a second laser L2, which are arranged at the circumference of the respiratory gas guide section 5. These lasers illuminate the inner portion of the respiratory gas guide section, which at least partially has a reflective surface and comprises a circular reflector, for example. The respiratory gas guide section is preferably of tubular design. Using the first detector D1 and the second detector D2, it is possible to determine the O.sub.2 concentration and CO.sub.2 concentration of the respiratory gas. In particular, the first laser L1 is designed to emit laser radiation with a wavelength different from the wavelength of the second laser L2. By means of laser spectroscopy it is thus possible to determine the O.sub.2 and CO.sub.2 concentration on the basis of the different wavelengths. The first laser L1 emits the radiation at a wavelength of 760 nm and the second laser L2 emits the radiation at a wavelength of preferably 2 m or 4.2 m.

[0057] Due to the advantageous embodiment of the sensor of the measuring device with the first laser and the second laser, improved hygiene is possible since germs are avoided and since the respiratory gas guide section forms a completely closed and smooth surface and the measurement is thus possible without contact.

[0058] The position of the first laser L1 and/or the second laser L2 are adjustable at the circumference of the respiratory gas guide section 5. By changing the position of the lasers or also the detectors, it is possible to change the measuring range of the sensor S by varying the optical path length. Alternatively or additionally, the detector position of the first detector D1 or the second detector D2 can also be changed to influence the measuring range (circulation reflector). By means of an apparatus which includes the measuring device according to the invention, it is possible to reduce the wear since no moving parts or pumps are necessary. The measurement thus takes place in-situ and therefore directly in the respiratory gas mask.

[0059] A diode laser or a light emitting diode in the NIR and MIR range is preferably used for the laser to determine the CO.sub.2 concentration. By using laser sensors to determine the respiratory gas parameters, a long service life of the measuring device can also be achieved since the laser diodes have a long service life. In addition, the condensation problem of the spiroergometry apparatus is reduced so that it is e.g. not necessary to dry off the measuring gas. The design and measurement are therefore simplified.

[0060] The optical path length can be adjusted by varying the detector position, allowing the measuring range of the sensor to be adjusted. In FIG. 2, in which the respiratory gas guide section is shown in cross-section, the inner area of the respiratory gas guide section 5 is illuminated by the laser beam of the laser L1 and the laser L2, as shown schematically by the spoke-like lines inside the respiratory gas guide section 5. In order to generate the reflections, a reflective layer is preferably provided in the section, such as a mirror or the like, although this is not mandatory. The position of the first detector D1 and/or second detector D2 can be varied relative to the respiratory gas guide section 5 so that the optical path length can be extended or shortened. This allows the measuring range to be adjusted.

[0061] FIG. 3 shows a main body which is designed as a respiratory mask, the measuring device 4 additionally comprising a sensor which contains a driven turbine. Via this turbine driven by the respiratory gas it is possible to carry out a flow measurement and to determine the volume flow of the respiratory gas. The flow of the respiratory gas generated by the inhalation and exhalation of the test person is represented by the arrow, which runs through the main body 1.

[0062] FIGS. 4a and 4b show a particularly advantageous embodiment of the present invention. The spiroergometry apparatus according to FIG. 4a has a first laser L1 and a second laser L2, each of which is assigned to a detector D1 and a second detector D2 (not mandatory). The main body 1 also has a respiratory gas guide section which is guided through the main body and through which the respiratory gas can be guided to the test person and away from the test person. During inhalation, respiratory gas is supplied to the test person through the first opening via the part of the main body facing away from the test person and is discharged through this opening when the test person exhales. However, it is preferred to only provide one detector, as shown in FIG. 4b.

[0063] In order to measure the O.sub.2 concentration and CO.sub.2 concentration, the first laser has a first wavelength and the second laser has a second wavelength, the first wavelength being different from the second wavelength. The radiation emitted by the first laser L1 is guided into the respiratory gas guide section of the main body 1 and reaches the first detector D1. Similarly, the radiation emitted by the second laser is passed through the respiratory gas guide section of the main body 1 to the detector D2. Alternatively or additionally, it is also possible to guide the beam to only one detector, as shown in FIG. 4b.

[0064] The main body 1 has a tubular respiratory gas section, the first laser L1 and the second laser L2 being arranged at a distance from each other in the axial direction along the longitudinal direction of the respiratory gas guide section. An orifice plate B is provided between the first laser L1 and the second laser L2 in the axial direction. In addition, the orifice plate B is arranged between the first detector D1 and the second detector D2. The respective detectors are assigned to the first laser and the second laser. The orifice plate B is located in the respiratory gas guide section 5 and thus extends into the respiratory gas flow which is guided through the respiratory gas guide section 5. The respiratory gas flow is deflected via the orifice plate B. The respiratory gas flow which flows through the detection area of the first sensor (which is formed by the first laser L1 and the first detector D1) is deflected (blocked) by the orifice plate B, so that in the detection area of the second sensor (which is formed by the second laser L2 and the second detector D2) the respiratory gas flow is deflected in such a way that a differential pressure is generated. This differential pressure can be used by using the differential pressure accumulation method for a flow measurement to determine the volume flow of the respiratory gas moving through the respiratory gas guide section. The surface of the respiratory gas guide section 5, through which the respiratory gas passes, can also be coated with a dirt- and water-repellent surface coating such as polytetrafluoroethylene or similar materials. This can further improve hygiene.

[0065] In order to generate the reflection, the inside of the tubular respiratory gas section can be coated with a reflective layer 5s or mirrors can be provided. (In particular, an aluminum oxide layer can be provided.)

[0066] FIG. 5 shows the spiroergometry apparatus as shown in FIG. 4, with an additional radio module 7, an energy harvesting module 6, a battery storage unit 2 and the evaluation electronics 8 being shown as part of the device.

[0067] The energy harvesting module 6 can in particular comprise piezoelectric crystals, which generate electrical voltages when force is applied. Alternatively or additionally, thermoelectric generators and pyroelectric crystals can be provided, which generate electrical energy from the temperature differences between the respiratory gas and the ambient temperature. The energy harvesting module can also include photovoltaic elements to generate energy from ambient lighting. This provides a simplified structure for the spiroergometry system, with which the energy store 2 can be charged directly via the energy harvesting module 6 without the need for complex external charging devices. The apparatus can in particular be charged by inductive charging and thus wirelessly.

[0068] The various modules are also provided directly on the main body 1 in the embodiment of FIG. 5, so that a compact and simple spiroergometry apparatus can be provided.

[0069] The various parameters (O.sub.2, CO.sub.2, T, p, p) are determined by evaluating the spectral data of the laser radiation (spectral lines, absorption lines). For this purpose, a multiparameter determination is carried out. As shown in FIG. 6, the measured intensity I (which was standardized in the figure) changes over the wavelength . The desired parameters for multiparameter determination can be determined by applying laser spectroscopy methods using known spectral models of the gases. For example, a pressure (pressure difference) of the respiratory gas can be calculated by determining the narrowing of the curve. If the orifice plate B is used, the pressure difference can also be used to determine the volume flow.

[0070] The present features, components and specific details can be exchanged and/or combined in order to create further embodiments depending on the required intended use. Any modifications that are within the scope of the knowledge of a person skilled in the art are implicitly disclosed in the present description.