EP3114450A1

EP3114450A1 - Sensor block, pipe, and production method

Info

Publication number: EP3114450A1
Application number: EP15707379.2A
Authority: EP
Inventors: Martin Baecke
Original assignee: Seleon GmbH
Current assignee: Seleon GmbH
Priority date: 2014-03-04
Filing date: 2015-03-03
Publication date: 2017-01-11
Also published as: US20170074695A1; EP2916120A1; JP2017508577A; WO2015132239A1

Abstract

The invention relates to a sensor block (1) for measuring fluid flow or pressure in a pipe (22). The sensor block (1) comprises a sensor (4, 24) and a housing. The housing has an elastic clamp part (11, 12), which is shaped in such a way that the clamp part can be placed onto the pipe in a radial direction and, while placed, surrounds part of the pipe. The invention further relates to a pipe (72), which is produced by means of MID technology. The pipe (72) comprises conducting tracks (77) and a sensor (24, 84), which is rigidly connected to the pipe (72). The invention further relates to a pipe (2; 22) having an opening (49, 36, 46, 56, 66) in the pipe wall, which opening is closed by means of a sterile filter (28, 38, 48). The pipe (2; 22) also has two elongate grooves (15) for detachably fastening a sensor block (1). The invention further relates to a pipe (72), which has a double pitot tube (6). The invention further relates to a pipe (72), which has an orifice plate (86) made of porous material. Before and after the orifice plate (86), one opening (79, 89) is formed in the pipe wall in each case. Both openings (79, 89) are closed by means of a sterile filters. The invention further relates to a production method, in which both a sensor block (1) according to the invention and a pipe (2; 22; 72) according to the invention are produced by means of the same set of masks, the same injection mold, and/or the same control program part.

Description

Sensor block, tube and manufacturing process

The field of the invention are ventilators, in particular sensor components for this purpose.

The invention relates to sensor blocks according to the preamble of patent claim 1, 5, a pipe with a sensor, tubes according to the preambles of claims 12 to 14 and a manufacturing method.

According to Wikipedia, a microsystem is a miniaturized device, assembly, or component whose components are micron-sized and cooperate as a system. Usually, a microsystem consists of one or more sensors, actuators and control electronics on a substrate or chip. Microsystems technology is the study of the development of microsystems and the techniques for their realization.

The abbreviations MEMS and MOEMS are common in the English language for micro-15 electro-mechanical systems and micro-opto-electro-mechanical systems.

In Asian, primarily Japanese, publications, however, there is also the extended name micromachines. The use of microsystems is conceivable and useful wherever sensors, actuators and electronics work together. Medical devices as well as products from the fields of safety technology, sports, life sciences and logistics can become more versatile, simpler, smarter, smaller and more efficient with the help of microsystems.

The production of both pressure and flow sensors by microsystem technology is well known. Exemplary are the

25 differential pressure sensors called SDP1 108 and SDP2108 from SENSIRON AG. Since these sensors have a thermal sensor element, they are actually flow sensors that measure the low gas flow through a capillary. Within the scope of this application, as differential pressure sensors according to the data sheet of SDP1 108 and SDP2108, flow sensors are also to be used.

30 are understood in particular thermal mass flow sensors, which measure the pressure drop across a capillary. As Molded Interconnect Devices (English for: injection molded circuit carriers), short MID, electronic components are referred to, in which metallic conductors are applied to injection-molded plastic carrier. Essential fields of application for the MID technology are automotive engineering, industrial automation, medical technology, the household appliance industry, telecommunications technology, measurement and analysis technology, and aerospace.

The improved design freedom and the integration of electrical and mechanical functions in an injection molded part can lead to a miniaturization of the assembly. Rationalization potential lies in the reduction of the number of parts through material savings and the shortening of the process chains. Furthermore, the reliability can be increased by reducing the assembly steps.

By using the MID technology, the conventional material mix of a combination of printed circuit board and mechanical component, which usually consists of many materials, can be replaced by a metallized plastic part (MID). MIDs are made from recyclable thermoplastics and are less critical to disposal than conventional printed circuit boards. The base material for a printed circuit board, however, is generally a difficult to dispose of and not recyclable thermoset.

Also known are devices for carrying out CPAP (continuous positive airway pressure) therapy, cf. WO 2004/045693 A2 with further evidence. A CPAP device applies by means of a compressor, preferably via a humidifier, via a hose and a nasal mask a positive overpressure up to about 30 mbar in the respiratory tract of the patient. This overpressure is intended to ensure that the upper airways remain fully open during sleep during the entire night and thus no obstructive respiratory disorders (apnea) occur (DE 198 49 571 A1).

Furthermore, sterile filters are commercially available. They consist for example of a porous plastic body made of polypropylene or Teflon (PTFE, polytetrafluoroethylene) to intercept microorganisms. Typical bacteria can be from 0.2 to 4 μιη large. Viruses are smaller than 0.3 μιη and bacteriophages can even be up to 0.01 μιη small.

US 7,814,907 B2 describes a system for applying gases for ventilators. A blower pushes air through a humidification chamber and a breathing duct to a patient. At about one quarter of the length of the breathing duct from the humidifying chamber, the breathing duct is interrupted by, for example, a T-shaped tube having a connection for a sensor housing. The sensor in the sensor housing can measure air humidity, temperature and / or flow. Between the interior of the breathing duct, in particular the interior of the tube, and the sensor, a filter, for example a SYMPATEX® film, is provided. The filter should keep dust, steam, bacteria and viruses away from the sensor. The filter can be glued to the tube. The connection between the tube and sensor housing can be made by a thread, a snap fastener, a bayonet mount or a silicone gasket. The sensor housing itself can be located in the tube and itself consist of a tube whose ends are closed by filters.

It is an object of the invention to provide an improved sensor block, an improved tube and an improved manufacturing method.

This object is achieved by the teaching of the independent claims. Preferred embodiments of the invention are subject of the dependent claims.

Advantageously, on a sensor block having a housing with a resilient clip portion shaped to be slidably mounted on a tube in the radial direction and plugged into a portion of the tube, the sensor block can be easily mounted on the tube. This is when mounting z. B. of CPAP devices advantageous. Furthermore, it allows the use of tubes as disposable while reusing the relatively expensive sensor block. To avoid contamination of the sensor, the openings of the tube are usefully closed with sterile filters. Elongated projections on the staple parts that extend parallel to the axis of the tube and / or corresponding grooves in the tube allow for reproducible positioning of the sensor block on the tube.

The use of a differential pressure sensor advantageously allows the use of pitot tubes or orifices for the correct-sign measurement of the gas flow in the pipe.

A double pitot tube, in contrast to a simple pitot tube or a Prandtl pitot tube, also allows the correct measurement of the gas flow regardless of the direction of flow in the tube. A connection for a hose advantageously makes it possible to supply additional gases, in particular oxygen, or to draw samples from the respiratory air.

A differential pressure sensor, which measures the pressure difference between the port of the hose and the interior of the pipe or the environment of the pipe, advantageously enables a flow measurement of the gas supplied or withdrawn via the port. This flow measurement becomes more accurate when the port is connected to the interior of the pipe via a capillary port.

The flow measurement in the tube may be more accurate when measuring the differential pressure at a diaphragm (86) of porous material than when using a double pitot tube. The reason for this is the flow-dependent flow profile in the pipe.

A sensor block and a tube can be designed in an advantageous manner so that both can be produced with a single mask set in MID technology, at least partially the same injection molding tools and at least partially the same control program parts. Hereinafter, preferred embodiments of the invention will be explained in more detail with reference to the accompanying drawings. Showing:

1 shows an inventive flow tube of a CPAP device.

FIG. 2 is an exploded view of the flow tube shown in FIG. 1; FIG. 3 shows an exploded view of a sensor block according to the invention shown in FIGS. 1 and 2;

4 shows a cross section through a second embodiment of a sensor block according to the invention and a flow tube according to the invention;

5 shows a longitudinal section through a third embodiment of a sensor block according to the invention and a flow tube according to the invention;

Fig. 6 shows a cross section through the third embodiment of a sensor block according to the invention and a device according to the invention

Flow tube along the line A-A in Fig. 5;

Fig. 7 shows a cross section through a fourth embodiment of a flow tube according to the invention;

Fig. 8 shows a longitudinal section through a fifth embodiment of a flow tube according to the invention;

9 shows a cross section through a sixth embodiment of a flow tube according to the invention; and

10 shows a cross section through a seventh embodiment of a flow tube according to the invention. Fig. 1 shows an inventive flow tube 2 for a CPAP device. The front, diffused end of the flow tube 2 is fixed in a wall of the CPAP device. There is also the breathing tube connection 3, which remains accessible from the outside after assembly of the CPAP device. On top of the flow tube 2 sits a sensor block 1. The sensor block 1 may include sensors for flow and / or pressure measurement in the flow tube 2.

Fig. 2 shows the removed sensor block 1. Fig. 3 shows the detail of Fig. 2 with the sensor block 1. The sensor block 1 is C-shaped. The two ends are referred to as clip parts 1 1 and 12. The sensor block 1 with its two clamp parts 11 and 12 comprises slightly more than half or, with In other words, a little more than 180 ° of the flow tube 2. For a more reliable hold each staple part 1 1, 12 at its end an elongated projection 13 and 14, respectively. Each elongate projection 13 and 14 engages in a groove 15 on the flow tube 2 a. In FIGS. 1 and 2, only the groove 15 is shown on the side of the flow tube 2 facing the observer.

Below projects out of the sensor block a pitot tube 6 out. When the sensor block 1, as shown in Fig. 1, is attached to the flow tube 2, the pitot tube 6 protrudes through the opening 8 into the interior of the flow tube 2 into it. The construction of the pitot tube 6 is similar to the construction of the pitot tube 26 shown in FIG. 5 with two openings, wherein an opening in the flow direction 9 and an opening opposite to the flow direction 9 is directed. In the case of the flow tube 2, the flow direction 9 is directed towards the breathing tube connection 3.

In so-called single-tube ventilators, such as those exemplified by CPAP devices, a defined leak is provided in or near the respiratory mask, through which the exhaled carbon dioxide is washed out. Averaged over a breath so results in a net flow from the ventilator to the respiratory mask out in the direction of the flow direction 9. Nevertheless, when exhaling air to the CPAP device against the flow direction 9 are pushed back. The flow tube 2 and / or the sensor block 1 are made of an elastic material, so that the sensor block 1 can be plugged onto the flow tube 2 several times and removed again. The sensor block 1 is implemented in MID technology. On a plastic body conductor tracks 7, for example, copper and electronic components are attached to the conductor tracks. By way of example, the components for a preamplifier 51 and a further electrical component 52 are shown in FIG. The attachment takes place for example by soldering, in particular wave soldering (English: flow soldering) or gluing, for example, with silver conductive adhesive. This type of attachment is not only mechanical in nature, but also ensures electrical contact between the electronic components and the tracks 7.

In particular, a differential pressure sensor 4 and a cover 5 is mounted on the sensor block 1. As mentioned above, in the context of this document as differential pressure sensors and flow sensors, in particular thermal mass flow sensors, understood that measure the pressure drop across a capillary such as the sensors SDP1 108 and SDP2108.

In order to load the printed conductors 7 and the electronic components as little as possible mechanically in the central part of the sensor block 1, the central part of the sensor block 1 is stiffer than the clamp parts 11 and 12. This can be achieved by making the central part thicker and / or thicker. or of a stiffer material than the staple parts 1 1, 12 consists. If the clamp members 11, 12 comprise more than 180 ° of the flow tube 2, the grooves 15 and the projections 13, 14 are not

10 required. The correct positioning of the sensor block 1 with respect to the flow tube 2 can also be ensured by the pitot tube 6 and the opening 8 in this case. If the projections 14 and 15 and the grooves 15 are present, the sensor block may also include less than 180 ° of the flow tube 2. When the projections 13 and 14 a hook-shaped cross-section

15, and the grooves 15 are formed accordingly, it is sufficient if the sensor block 1 only a small angular range, ie 60 °, 30 ° or less of the flow tube 2 comprises.

4 shows a cross section through a second embodiment of a sensor block 101 according to the invention and a flow tube according to the invention

20 102 with preamplifier 51 and electrical component 52. The flow direction 9 extends into the plane of the drawing. The sensor block 101 has on the outside ribs 115 and 16 which facilitate the removal and attachment of the sensor block 101 to the flow tube 102. In this embodiment, the clamp members 1 1 1 and 1 12 have no projections and the flow tube 102 also

25 no grooves on. The sensor block 101 includes about 240 ° of the flow tube 102.

The sensor block 101 comprises a hose connection 141 for a hose 142. The flow in the hose 142 is measured by means of a flow sensor. How the flow measurement is carried out will be explained with reference to the sections shown in FIGS. 9 and 10. The tube 142 may be for supplying oxygen or

30 other gases or gas mixtures can be used for diagnostic or therapeutic purposes. The tube 142 may also be used to draw samples, in particular from exhaled gas. In the flow tube 102, an opening 149 is attached below the hose connection 141, the pneumatically connected to the hose connector 141. Sealing ring 124 prevents a pneumatic connection to the environment. For illustration, the components for a preamplifier 51 and another electronic component 52 are shown in FIG. 4 again. The sensor block 101 shown in FIG. 4 can be expanded by a second differential pressure sensor 4 and a pitot tube 6, similar to that shown in FIG. 5. Conversely, the sensor block 1 can also be supplemented by a second differential pressure sensor and a hose connection 141, similar to that shown in FIG. 5. 5 shows a longitudinal section through a third embodiment of a sensor block according to the invention with an MID component 21 and a cover 25 as well as a flow tube 22 according to the invention. FIG. 5 essentially represents a combination of those shown in FIGS. 1-3 as well as in FIG. 4 In contrast to such a combination, the gas space in the flow tube 22 through the sterile filter 28, 38 and 48 separated from the gas space in the sensor block 1.

When the flow tube 22 shown in FIG. 5 is used near a respiratory mask, both inspired and exhaled air flows through the flow tube 22. The flow direction 9 is thus arbitrarily selectable parallel to the axis of the flow tube 22 and regardless of the choice come positive and negative gas flows, ie gas flows in the flow direction 9 or against the flow direction 9 before. In terms of amount, the positive and negative gas flows are about the same size.

In order to be able to measure gas flows in and against the flow direction 9, the double pitot tube 26 is symmetrical to a plane perpendicular to the flow direction 9. In particular, an opening 46 in the flow direction and an opening 36 against the flow direction. Via a channel 56 and an opening 39, the pressure at the opening 36 is supplied to an input of the differential pressure sensor 24. The channel 56 is pneumatically connected via a sterile filter 38 to the opening 39, wherein the sealing ring 37 causes the seal against the environment. Similarly, the pressure in port 46 is supplied via port 66 through port 29 to the other input of differential pressure sensor 24. As a sterile filter for small air molecules such as N ₂ , O ₂ and H ₂ O represents a certain flow resistance, the channels 56 and 66 extend directly below the sterile filter 28 and 38, whose area is made as large as possible. As a result, the flow resistance is kept low by the sterile filter. The channel 66 is pneumatically connected via a sterile filter 28 to the opening 29 and sealed by a sealing ring 27 against the environment. It is known to those skilled in the art that based on the Bernoulli equation, the flow velocity can be calculated from the signal provided by the differential pressure sensor 24. In doing so, the Bernoulli equation is parameterized, ie adapted to the specific case of measurement. The sign of the gas flow results from the sign of the signal supplied by the differential pressure sensor 24.

The MID component 21 furthermore has a hose connection 41 for a hose 42. For example, oxygen can be forced from the tube 42 into the flow tube 22 via another sterile filter 48 and a capillary opening 49. Another differential pressure sensor 44 is provided to measure the pressure differential across the capillary port 49. The first pressure port of the differential pressure sensor is pneumatically connected via the opening 69 to the interior of the hose connection 41 and sealed by the sealing ring 47 from the environment. Since the second pressure port of the differential pressure sensor 44 is connected via the opening 59 to the environment and not to the interior of the flow tube 22, the differential pressure sensor 44 does not measure the differential pressure at the capillary opening 49. Normally, however, the pressure in the flow tube 22 only deviates by a few tens mbar from the ambient pressure. When the pressure difference measured by the differential pressure sensor 44 is large compared to some 10 mbar, the pressure difference between the ambient pressure and the pressure in the flow pipe 22 can be neglected. In most cases, however, the differential pressure between the interior of the flow tube 22 and the environment is known, so that the pressure measured by the differential pressure sensor 44 can be corrected by this pressure difference. The capillary opening 49 may be expanded similar to the channels 56 and 66 below the sterile filter 48. This may be particularly advantageous when drawing gas samples through the tube 42. When oxygen is supplied via the hose 42, the oxygen is usually under sufficient high pressure, so that despite differential pressure at the capillary 49 and the sterile filter 48, the oxygen flow is sufficient. Under this condition, a high differential pressure is more advantageous because a high differential pressure can be more accurately measured by the differential pressure sensor 44. Therefore, no widening of the capillary opening 49 below the sterile filter 48 is shown in FIG. 5.

In another embodiment, a further opening in the flow tube 22 may be provided below the opening 59. Both openings are pneumatically connected in this embodiment via a sealing ring.

Instead of the sealing rings 27, 37 and 47, it is also possible to use a single seal 10, for example consisting of soft material, which for the application in FIG. 5 would have to have three openings separated by sealing material.

The MID component 21 is manufactured in MID technology. For example, therefore, the solder joints 34 and the conductors 33 of the electrical line 32 15 are shown, via which the differential pressure sensors 24 and 44 are supplied with electrical energy and read out. A cover 25 protects the components on the MID component 21.

6 shows a cross section along the line A-A in FIG. 5 with the MID component 21, the flow tube 22, the double pitot tube 26, the sterile filter 20, the differential pressure sensor 24, preamplifier 51 and an electronic component 52.

FIG. 7 shows a flow tube 72 manufactured in MID technology and comprising the double pitot tube 76. The MID component 21 shown in FIGS. 5 and 6 is part of the embodiment shown in FIG

25 flow tube 72. On top of the flow tube 72 are again preamplifier 51, differential pressure sensor 24 and an electronic component 52, conductors 77, solder joints 74 and an electrical connection 73 shown. The advantage of the embodiment illustrated in FIG. 7 is that the dimensions of the flow tube 72 at least in the upper region are equal to the MID component 21

30, so that the same mask set, one or more same injection molds and / or the same in one or more parts Control program for the production of the MI D component 21 as can be used for the production of the flow tube 72. Mask set and injection molds can be summarized under the generic term tool set.

FIG. 8 shows a longitudinal section through a fifth embodiment of a flow tube 72 according to the invention. In this embodiment, a pressure difference at a porous diaphragm 86 is generated in a known manner by a gas flow in a flow tube 72. The flow direction 9 is determined from left to right. The pressure difference is supplied via two openings 79 and 10 89 to the two terminals of a differential pressure sensor 24. In this embodiment, the flow tube 72 is implemented in MID technology. However, those skilled in the art will appreciate that the double pitot tube 26 may also be replaced by a porous shield 86 in the embodiment shown in FIG.

FIGS. 9 and 10 show alternative embodiments for the left part of the flow tube 22 shown in FIG. 5 along the line B-B. In both cases, the flow tube 72 is designed as in FIGS. 7 and 8 in MID technology. In Fig. 9, no hose is attached to the hose connector 81. One terminal of the differential pressure sensor 84 is above the

20 Hose connection 81 pneumatically connected to the environment. The other terminal of the differential pressure sensor 84 is connected to the interior of the flow tube 72 via the opening 99. The differential pressure sensor 84 thus measures the pressure difference between the interior of the flow tube 72 and the environment.

In contrast to this, in FIG. 10, a hose 82 is plugged onto the hose connection 81 and a capillary opening 109 is provided as a bypass to the differential pressure sensor 84. It is thus possible via the tube 82 to supply additional gases, in particular oxygen, to the flow tube 72 or to draw gas samples from the flow tube 72. By way of the differential pressure at the capillary opening 109, the gas flow from the hose 82 into the flow pipe 72 and vice versa can be determined.

The flow tubes 72 shown in FIGS. 9 and 10 can be produced with very similar injection molding tools, which can only be replaced by a single injection molding tool different stamp different. The stamp for producing the flow tube 72 shown in FIG. 9 is somewhat shorter, because the cavity in the hose connection 81 is also somewhat shorter. Conversely, the punch for making the flow tube 72 shown in Fig. 10 is slightly longer to make the capillary opening 109 as well.

If the differential pressure sensor 84 in FIG. 9 has a thermal sensor element, that is strictly speaking a flow sensor, a hose 82 can also be plugged onto the hose connection 81 in the embodiment shown in FIG. 9, so that either gases are supplied to the interior of the flow pipe 72 can be drawn or gas samples from the interior of the flow tube 72 can be pulled.

Although the invention has heretofore been described in the context of gas, it is clear to those skilled in the art that the flow measurement also works with liquids and therefore that the term gas can be replaced by the generic term fluid. The invention has been explained in detail above with reference to preferred embodiments. However, it will be apparent to those skilled in the art that various modifications and changes can be made without departing from the spirit of the invention. Therefore, the scope of protection is defined by the following claims and their equivalents.

Claims

claims

A sensor block (1) for measuring fluid flow or pressure in a pipe (2; 22;

102) comprising: a sensor (4, 24); and a housing, characterized in that the housing has an elastic clamp part (11, 12) which is shaped such that it can be plugged onto the tube (2; 22; 102) in the radial direction and attached a part of the tube (11; 2, 22, 102).

2. Sensor block according to claim 1, characterized in that the clamp part (11, 12) has two elongated projections (13, 14) which extend parallel to the axis of the tube (2; 22; 102) when the sensor block (1) is attached to the tube (2; 22; 102).

3. Sensor block according to one of the above claims, characterized in that the sensor is a differential pressure sensor (24) and in the sensor block (1) on the tube (2; 22; 102) facing side two openings (29, 39), wherein each port is pneumatically connected to a pneumatic port of a differential pressure sensor (24).

4. Sensor block according to one of claims 1 or 2, characterized in that the housing has a double pitot tube (6), the two openings

(36, 46) in opposite directions and two channels (56, 66), the sensor being a differential pressure sensor (4), each channel (56, 66) defining an opening of the double pitot tube with the corresponding port of the differential pressure sensor (4). pneumatically connecting, the double pitot tube (6) protruding into the tube (2, 102) when the sensor block (1) is fitted onto the tube (2, 102).

5. tube (72) which is produced by MID technology with: printed conductors (77) and a sensor (24, 84) fixedly connected to the tube (72).

Pipe (72) according to claim 5, characterized in that the pipe (72) comprises a double pitot tube (76), the double pitot tube (76) having a first (46) and a second opening (36) and two channels (36). 56, 66), the first opening (46) being directed in the direction of flow (9) in the tube (72) and the second opening (36) being directed counter to the direction of flow (9) in the tube (72), the sensor being a differential pressure sensor ( 24), each channel (56, 66) pneumatically connecting an aperture (29, 39) of the dual pitot tube (76) to the corresponding port of the differential pressure sensor (24), the dual pitot tube (76) fitting into the tube (72). protrudes.

An article according to any of claims 1 or 5, characterized by a port (41; 81) for a hose (42; 82), the sensor being a pressure sensor (24; 84) and being pneumatically connected to the port (41; 81). is connected so that the pressure sensor (24; 84) measures the pressure in the port (41; 81).

An article according to claim 7, characterized in that the pressure sensor is a differential pressure sensor (84) having first and second ports, the first port of which is pneumatically connected to the port (81) of the article and the second port of which is pneumatically connected to the interior of the device Tube (72) is connected.

9. An article according to claim 7, characterized in that the pressure sensor is a differential pressure sensor (24) having a first and a second port, the first port is pneumatically connected to the terminal (41) of the object and the second port pneumatically connected to the environment of Tube (22) is connected.

10. An article according to any one of claims 7 to 9, characterized in that the port (41; 81) is connected to the interior of the tube (22; 72) via a capillary opening (49; 109).

1 1. An article according to any one of claims 1 to 3 or 5, characterized in that the tube (72) has a diaphragm (86) made of porous material, wherein the tube (72) has a first opening (79) in the flow direction (9). in front the diaphragm (86) and a second opening (89) in the flow direction (9) after the diaphragm (86), wherein the sensor is a differential pressure sensor (24) having a first and a second port, wherein the two terminals of the differential pressure sensor (24 ) with one opening (79; 89) of the tube (72) are pneumatically connectable or connected.

A tube (2; 22) comprising: an opening (36, 46, 49, 59, 69) in the tube wall, a sterile filter (28, 38, 48) defining the opening (36, 46, 49, 59, 69 ) for larger particles, but not for molecules, characterized by two elongate grooves (15) extending parallel to the axis of the tube (2; 22) for releasably securing a sensor block (1).

A tube (22) comprising: a first opening in the tube wall, a sterile filter (38) closing the opening for larger particles, but not molecules, characterized in that the tube (22) is a double pitot tube (26). the pitot tube (26) having first and second openings (36, 46), a first channel (56) and a second channel (66), the first channel (56) defining the first opening (36) of the pitot tube (6) with the first opening in the tube wall and the second channel (66) pneumatically connecting the second opening (46) of the pitot tube (6) with a second opening in the tube wall, wherein the second opening in the tube wall by a second sterile filter ( 28) is closed for larger particles, but not for molecules.

14. tube (72) having: a first opening (79) in the tube wall, a stale filter (38) closing the larger particle opening (79) but not molecules, characterized in that the tube (72) has a diaphragm (86) of porous material, the first opening (79) being in the pipe wall in the flow direction in front of the orifice (86) and a second opening (89) in the pipe in the flow direction after the orifice (86) and the second opening (89) in the pipe wall by a second sterile filter (28) for larger particles, not but for molecules, it is closed.

A manufacturing method comprising the steps of: manufacturing a sensor block (1) according to any one of claims 1 to 4 or an article according to claims 7 to 9 as far as they relate to any one of claims 1 to 4 with a mask set, a tool set, a Injection molding tool and / or a control program part; Producing a tube according to claims 5 and 6 or an article according to claims 7 to 9, as far as they relate to any one of claims 5 and 6, with the mask set, the injection molding tool and / or the control program part.