WO2018001413A1

WO2018001413A1 - Lung simulator

Info

Publication number: WO2018001413A1
Application number: PCT/DE2017/100525
Authority: WO
Inventors: Peter Schaller
Original assignee: Peter Schaller
Priority date: 2016-07-01
Filing date: 2017-06-21
Publication date: 2018-01-04
Also published as: CN109478380A; EP3479369A1; DE102016112073A1

Abstract

The invention relates to a lung simulator which can be used both as an intubation simulator and a respiratory simulator. It simulates the respiratory mechanics of a real two-compartment system, wherein it is particularly suitable for dual lumen intubation and one-sided respiration.

Description

lung simulator

The invention relates to a device for simulating a z. B. human lung and is particularly applicable in the field of educational tools in medicine.

The lungs serve the gas exchange, ie the supply of oxygen to the blood and the removal of C02 produced by the metabolism.

The lung is divided symmetrically into two lung halves. Each lung has its own bronchial tree and alveolar area. The inhaled respiratory gas flows through the trachea across the two main bronchi into both halves of the lung.

The bronchi represent a flow resistance called resistance, and the alveolar region in combination with the respiratory musculature has elastic properties described by the term compliance. In addition, stretching forces are exerted on the alveoli by the respiratory muscles. This force is called the respiratory drive.

These resistive, elastic and physical properties of the lung are summarized under the term respiratory mechanics.

A model of respiratory mechanics in the simplest case assumes that both halves of the lung are grouped into a compartment characterized by a single resistance, a single compliance, and a single respiratory drive. Such a model is called a one-compartment lung model.

A two-compartment lung model applies this model to each lung. Thus, the actual behavior of the respiratory mechanical properties of the lung is much better describable.

The mechanical ventilation of respiratory-deficient patients can lead to significant damage to the ventilated patient if the ventilators are improperly adjusted. For this reason, physicians need to know how to operate and properly tune the ventilators to a lung simulator before they ventilate a patient. Such a lung simulator is the physical realization of a lung model.

However, it is not only the correct setting of the ventilators, but also the intubation of the patient, i. H. the introduction of the ventilation tube in the

Trachea, which requires practical experience.

DE 10 2010 027 436 B3 describes a lung simulator that realizes a single-compartment lung model. Respiratory tube and airway resistance are realized as pneumatic resistances. The compliance and the respiratory drive are generated by a piston-cylinder system in conjunction with a linear drive in that the linear drive on the piston exerts such a position-dependent counterforce that leads to the desired elastic behavior.

In PL 183237 B1 a system is described which is based on the fact that in a piston-cylinder system by measuring the pressure in the cylinder and the knowledge of the volume flow at the output via an electropneumatic analogy resistance and compliance of the patient are modeled. Such a solution does not require a physical realization of these parameters.

A similar solution for the simulation of multi-compartment systems is also described in WO 97/12351 A1. Here too, it is claimed, based on a piston-cylinder system, that the behavior of resistances and compli- cations can only be simulated by mathematical modeling of multi-compartment lung models.

A model in which the resistance and compliance are also generated by simulation is shown in WO 2012/155283 A1. In contrast to the other simulators, this system uses a bellows system whereby two bellows are moved by a single linear drive. DE 30 49 583 C2 discloses a two-compartment lung model with two breathing bellows which are driven by a piston drive.

The last three solutions are all very voluminous, heavy and can not be transported as hand luggage in the aircraft.

Other lung simulators in which the pulmonary halves are physically modeled separately are described in US 6 874 501 B1, which shows a transparent thoracic teaching and visual model, and US 6 296 490 B1, which includes a lung training manikin for measuring the lung introduced respiratory gas flow shows, known.

All of the aforementioned systems representing the prior art have an additional computer, either as a laptop or as a PC, which allows very complex analyzes and evaluations of the intrapulmonary connections via its screen. They all use a single drive that either moves a piston inside a cylinder or a bellows.

Thus, known from the prior art compliance breathing drive system consist of either a piston-cylinder system or a bellows system, wherein either the piston or the movable end plate of the bellows are moved by a linear drive.

The bellows solution has the advantage of absolute leak-free, but the disadvantage that as a result of the deflection of the folds, the compliance is not as well defined as in a piston-cylinder system.

There are intubation simulators that simulate a trachea in which the physician, endoscopically assisted, learns to insert a breathing tube into the trachea. This is especially important when it comes to the intubation of double-lumen tubes, the ends of which must be inserted into each main bronchus. Such intubation, which is difficult to perform, is needed for frequently used single-sided ventilation. Some of these intubation simulators have one quite simple lung simulation, but not about the comfortable analysis possibilities by a computer.

A disadvantage of the prior art is that intubation simulator and lung simulator are usually designed as two different devices. In addition, the prior art does not allow true two-compartment simulation, which is a requirement for double-lumen intubation and single-face ventilation.

The object of the invention is to provide a lung simulator which permits both intubation simulation with double-lumen tubes and lung simulation on the basis of a true physical two-compartment lung model and which offers complex analysis possibilities via an external or internal computer should. In addition, the lung simulator should be light, easy to transport and, if possible, still approved as carry-on luggage in the aircraft.

This object of the invention is achieved according to claim 1.

Essential to the invention is that a two-compartment model of the lung is achieved by the lung model has a trachea tube, which branches at its output into two narrower bronchial tubes. From each bronchial tube there is a pneumatic connection to one resistance-compliance respiratory drive system each. The entrance of the tachometer tube is pneumatically connected to an intubation port (i.e., the intubation port) through which the ventilator tube is inserted.

It is particularly favorable if the trachea tube with the two bronchial tubes mechanically simulates a real physical trachea with the two main bronchi. This is easily possible via 3D printing of CAD data of a real trachea. This has the advantage that the intubation usually performed with endoscopic support can be practiced under largely real circumstances. Likewise, the trachea tube and the bronchial tubes may also be formed by simple tubes or tubes. Resistance compliance breathing drive systems each consist of a pneumatic resistance element and a compliance breathing drive system. They are preferably structurally identical for both compartments, but may also be designed differently.

The resistance is formed by a pneumatic resistance element, which is variable in its value.

One way of doing this is to provide a plurality of different flow resistances, which are selectable by a pneumatic switch. In this case, it is known to the person skilled in the art that combinations of flow resistances similar to a binary staggering can also be selected by the changeover switch.

Preferably, however, the resistance is formed by a variable pneumatic resistance element whose hydraulic diameter can be changed either manually or via a drive.

A solution consists in a pneumatic resistance element, which is constructed as follows:

A conical inner body is arranged axially aligned in a conical tube. Both parts have the same conicity and the inner body is axially displaceable relative to the tube. Both parts form an annular gap to each other, whose size, and thus also its hydraulic diameter, is dependent on the axial position of the inner cone to the tube. The flow resistance is a function of annular gap width and annular gap length.

The axial displacement of the inner cone to the tube can be done manually, but preferably electric motor, z. B. by means of a small linear drive, which can be adjusted by a path control loop for the position of the inner cone to the pipe a defined distance, which results in a defined Resistance. Another variant for a variable in value pneumatic resistance element is that a system of gaps is formed by thin plates, each plate to the other at the lateral periphery by an elastic material is kept at a distance. As a result, the free gap surface can be flowed through. If one exerts a force on the outer plates, the plate spacing and, in turn, the hydraulic diameter of this gap system is reduced, which leads to a change in the flow resistance. The change in the gap distance can be done either manually or by motor gear.

The first pneumatic resistance element is pneumatically connected to the outlet of the first bronchial tube and the second pneumatic resistance element is pneumatically connected to the outlet of the second bronchial tube.

The compliance-breathing drive system can be formed in a known manner either by a piston-cylinder system or a bellows system, on which a force is applied via a linear drive. In the case of the piston-cylinder system, the linear drive acts on the piston and in the case of the bellows system on the movable end plate of the bellows.

This is under linear drive either

• an electrodynamic drive in the form of a voice coil motor, or

• a rotary actuator whose rotary motion is converted into a linear motion by a spindle, or

• a linear motor

Roger that.

The inlet of the first compliance breathing system is pneumatically connected to the outlet of the first pneumatic resistance element and the inlet of the second compliance breathing system is connected to the outlet of the second pneumatic resistance element. The drive units of the compliance breathing drive systems and, if driven by an electric motor, the flow resistances require a power supply and one motor drive each. Furthermore, the lung simulator comprises a central control, which coordinates the interaction of all units.

The determination of the volume flow V on the route from the exit of the first bronchial tube to the first compliance breathing drive system and the output of the second bronchial tube to the second compliance breathing drive system can be carried out in a known manner by measurement by means of volume flow sensor at the appropriate place in this track will be installed. Another possibility is the volume flow by evaluating the piston movement in the respective

Compliance breathing drive system acc. the equation v ^y = ^ - to determine.

dt

In this known solution, however, the influence of the compressible volume, which is no longer negligible, especially in the case of large cylinder or bellows volumes, is not taken into account.

For this reason, according to the invention, the above equation is modified according to _v , ₌ dVz _| Vz ^ dpz

dt pO dt

Here, Vz is the cylinder volume, pz the cylinder pressure in the respective piston-cylinder system and pO the atmospheric air pressure.

The pressures within the lung simulator are determined by pressure sensors. In this case, at least two pressure sensors are needed, the

• as representative of the alveolar pressure 1 the pressure at the inlet or inside the first cylinder or bellows and

• as representative of the alveolar pressure 2, the pressure at the inlet or inside the second cylinder or bellows

determine.

Advantageously, two further pressure sensors are provided which

• the pressure on the Y-piece of the ventilator as well • the pressure at the end of the trachea tube just before the branching into the two bronchial tubes

determine.

The outputs of the pressure sensors are electrically connected to the inputs of the central controller.

The entire intelligence of the device is programmatically in a computer, z. B. a PC / laptop, which allows communication with the operator via a graphical user interface (GUI). The computer also takes over the control of the central controller and evaluates its output signals by means of complex algorithms and displays the results in numerical and graphic form.

The linear drive of the respective compliance breathing drive system is controlled by a drive control. This drive control receives the control signals from the central controller. At the same time the drive control supplies signals, position, speed, power to the central control.

The housing of the lung simulator is divided according to the invention into a front part and a back part.

The front part can, for. B. by means of hinges, be connected at the lower end to the back so that it can be opened against the back, with preferably the Aufklappwinkel is limited to 90 °.

In the front part of the trachea tube is arranged with the two bronchial tubes. The pneumatic connection between the entrance of the trachea tube and the intubation opening can be done in different ways:

As a preferably curved pipe section;

• a physical replica of the larynx and another tube; or • a physical replica of the larynx and a physical replica of the oral cavity, including the mouth, preferably as a three-dimensional replica of a human face with the mouth open (hereafter called the facial model).

Due to the possibility of unfolding, the trachea tube and its different connection options lie horizontal to the intubation opening in the position in which the physician intubates. The piston-cylinder system, however, is arranged vertically, whereby a disturbing friction between the piston and cylinder is largely reduced.

If it is less about the intubation, but about the simulation of the respiratory mechanics, the front part does not need to be unfolded. In order to still be able to make a connection to the ventilator via a tube, can be introduced into the front part of an opening to which a second input of the trachea tube is pneumatically connected. The doctor can use this opening to insert a breathing tube into the two bronchial tubes just before the branching.

According to the invention, a tubular linear motor is used as a linear drive, which exerts the force directly on the piston of the piston-cylinder system or the bellows, without further gearbox.

In this tubular linear motor, a rotor bar moves within a stator. For example, when the rotor bar pulls the piston outwardly with its first end, the second end of the rotor bar moves away from the stator. The result of this is that in this type of tubular linear motor requires a large amount of space, which increases the housing unnecessarily.

For this reason, in the housing in the area where the rotor bar emerges, a telescopic tube may be provided, whose extension length is variable, and which can be pulled out during operation of the device and pushed together in the other case. Alternatively, removable sleeves may be provided, which can be used prior to operation of the device on z. B. closable openings of the housing, from which the rotor bars emerge during operation, are plugged.

Since the lung simulator according to the invention represents a two-compartment lung model, two such telescopic tubes or sleeves are needed. In the case of the telescopic tubes, these can be connected to the, the linear motor remote end portion by a crossbar, which also serves as a carrying handle. The telescopic tubes are z. B. locked in a known manner by laterally projecting bolts, which is possible both for the pulled out and the pushed-in state.

This solution has the advantage that the housing can be kept small for transport, but in operation by pulling out of the telescopic tubes or attaching the sleeves of the required space for the movement of the rotor bar is given. At the same time, the device has an extendable carrying handle.

The weight of the lung simulator is not insignificant. In order to transport it better, at the back of the housing z. B. be mounted two rollers. In conjunction with the pull-out handle, the device thus resembles a trolley from its transport capability. This is a very cheap, weight and cost saving solution.

So that when driving on uneven ground no impermissible vibrations are exerted on vibration-sensitive parts of the lung simulator, these parts are preferably arranged vibration-damped within the housing.

A particularly favorable embodiment of the invention provides that the front part and the rear part of the housing are connected to each other via a zipper.

The invention will be explained below by way of examples.

The show FIG. 1 shows a schematic representation of the functional interaction of all components of the lung simulator,

FIG. 2 shows a schematic representation of the most important pneumatic components of the lung model,

Figure 3 is a schematic representation of the compliance-breath drive system and

FIG. 4 shows a schematic representation of the housing with facial model.

The explanation of the embodiment will be made with reference to the individual figures.

FIG. 1 shows that the ventilation tube 16 is introduced into the trachea tube 1 via the intubation opening 1 .1. The input of the ventilation tube 16 is connected to the Y-piece 15 of the ventilator. The trachea tube 1 branches into the bronchial tube 1 .2 and the bronchial tube 1.3.

From the bronchial tube 1 .2 is a pneumatic connection to the pneumatic resistance element 2, which is variable in its value. The output of the pneumatic resistance element 2 is connected to the input of the compliance breathing system 4. This consists of a cylinder 4.1 and a piston 4.2, which is mechanically connected via a rotor bar 4.4 with the linear drive 4.3.

The control of the linear drive 4.3 is performed by the drive control 9, which in turn is connected to the central controller 8 via a CAN bus in combination. The central controller 8 is connected to an external computer 1 1 via a data connection 12. The power supply for the entire system is provided by a power supply 7.

The pneumatic resistance element 2 gives its information about its switching position via a data line to the central controller 8. A pressure sensor 6.1 determines the pressure at the inlet of the compliance breathing drive system 4. The second pressure sensor 6.2 determines the pressure at the input of the compliance breathing system 5. The third pressure sensor 6.3 determines the pressure at the end of the trachea tube 1 and the fourth Pressure sensor 6.4 determines the pressure on the Y-piece 15.

The function of the other lung half, represented by the pneumatic resistance element 3, the compliance breathing drive system 5 and the drive control 10, is identical to that of the first lung half and therefore will not be further described.

Figure 2 shows the pneumatic scheme for both lung halves, which are symmetrical. In the following, only one lung half will be described. The output of the bronchial tube 1 .2 is connected to the input of the pneumatic resistance element 2. This includes the resistance switch 2.1, which is manually changed via the knob 2.4. Four, in their value different pneumatic resistors 2.2 open into the collection block 2.3. A hose 2.5 establishes the pneumatic connection to the cylinder 4.1 of the compliance respiratory drive system 4.

FIG. 3 shows the compliance breathing drive system 4, which is identical to the compliance breathing drive system 5. The linear drive 4.3 is mechanically connected to the piston 4.2 via its rotor rod 4.4. This moves inside the cylinder 4.1. It can be seen how the rotor bar 4.4 extends upwards out of the stator of the linear drive 4.3.

Figure 4 shows the housing 13, consisting of the front part 13.1 and the rear part 13.2, in which all components are structurally housed. On the unfolded front part 13.1, the face model 14 is arranged, the mouth opening with the

Tracheairohr 1 is pneumatically connected. From the rear part 13.2 protrude both telescopic tubes 17.1 and 17.2 out, which are connected at their end by a carrying handle 17.3. The transverse pins required for the locking of the telescopic tubes 17.1 and 17.2 are not shown. The power supply 7, central control 8 and the drive controls 9 and 10 are arranged within the rear part 13.2.

The rear part 13.2 contains at its lower end on both sides each a roller 18th

List of reference numbers

1 Trachea I röhr

1 .1 intubation opening

1 .2 first bronchial tube

1 .3 second bronchial tube

2 first pneumatic resistance element

2.1 Resistance switch

2.2 pneumatic resistors

2.3 collection block

2.4 knob

2.5 Connecting hose

3 second pneumatic resistance element

4 First Compliance Breathing Drive System

4.1 cylinder

4.2 piston

4.3 Linear drive

4.4 Piston rod

5 Second Compliance Breathing Drive System

5.1 cylinder

5.2 Piston

5.3 Linear drive

6 pressure sensors

6.1 Pressure sensor for alveolar pressure 1

6.1 Pressure sensor for alveolar pressure 2

6.1 Pressure sensor for pressure in trachea

6.1 Pressure sensor for pressure on the Y-piece

7 power supply

8 Central control

9 first drive control

10 second drive control

1 1 calculator

12 data connection

13 housing front part

rear part

Face model Y-piece

Ventilation tube Carrying system First telescopic tube Second telescopic tube Carrying handle

castors

Claims

claims

1 . Lung simulator, having

A trachea tube (1) having at least one pneumatic input connected to an intubation opening (1.1) and a branching into two laterally exiting bronchial tubes (1.2, 1 .3) as pneumatic outputs,

A first pneumatic resistance element (2) and a second pneumatic resistance element (3),

o wherein the first bronchial tube (1.2) with the input of the first pneumatic resistance element (2) and

o the second bronchial tube (1 .3) are connected to the inlet of the second pneumatic resistance element (3),

A first and a second compliance-breathing drive system (4, 5), which is moved by a respective linear drive (4.3, 5.3), wherein

the output of the first pneumatic resistance element (2) is connected to the input of the first compliance breathing drive system (4) and o the output of the second pneumatic resistance element (3) is connected to the input of the second compliance breathing drive system (5),

• means for determining the volume flow through the first pneumatic resistance element (2) and the second pneumatic resistance element

(3)

• at least two pressure sensors (6.1, 6.2, 6.3, 6.4), where

o a first pressure sensor (6.1) via a hose with the input o- the interior of the first compliance-breathing drive system (4), and

a second pressure sensor (6.2) is connected via a hose to the inlet or the interior of the second compliance breathing drive system (5),

• at least one power supply (7) and a central controller (8) for data exchange with the drive controls (9, 10) of the linear drives (4.3, 5.3) and for communication with the pressure sensors (6.1, 6.2, 6.3, 6.4) and the means for Determination of the volume flow, • an integrated in the device or an external computer (1 1), which is coupled to the central controller (8) via a data connection (12), wherein the computer (1 1) is adapted to establish the communication of a user with the lung simulator and to simulate the respiratory mechanics of a patient, and

• A housing (13) enclosing a front part (13.1) and a rear part (13.2), largely enclosing the lung simulator for transporting the same.

2. lung simulator according to claim 1, characterized in that the

Tracheal tube (1) and the bronchial tubes (1.2, 1 .3) in shape and size corresponding to a human trachea with the two main bronchi are modeled.

3. lung simulator according to the preceding claims, characterized in that the two pneumatic resistance elements (2, 3) are each variable in their value.

4. lung simulator according to any one of the preceding claims, characterized in that the compliance-Atemantriebs system (4, 5) consists of a respective piston-cylinder system, wherein each within a cylinder (4.1, 5.1) movably arranged piston (4.2 , 5.2) is moved by a respective linear drive (4.3, 5.3).

5. lung simulator according to one of claims 1 to 3, characterized in that the compliance breathing drive system (4, 5) consists of a bellows each system in which the movable end plate of each bellows by a respective linear drive (4.3, 5.3) is moved.

6. lung simulator according to one of the preceding claims, characterized in that the means for determining the flow rate through the respective pneumatic resistance element (2, 3) is determined by

• that in each case a volumetric flow sensor is arranged in both routes, and / or • that the determination of the volume flow in the respective route is calculated according to the equation V '= ^ - + - *,

dt pO dt

with the cylinder or bellows volume Vz, the cylinder or bellows pressure pz in the respective piston-cylinder or bellows system, as well as the atmospheric pressure pO.

7. lung simulator according to one of the preceding claims, characterized in that the housing (13) comprises a front part (13.1) and a rear part (13.2), wherein the front part (13.1) at the lower end with the rear part (13.2) is connected, and the front part (13.1) opposite the rear part (13.2) can be opened by 90 °, wherein on the inside of the front part (13.1) the trachea tube (1) is arranged.

8. Lung simulator according to one of the preceding claims, characterized in that the trachea tube (1) has two pneumatic inputs, wherein the second input (1 .4) is connected to a on the front of the front part (13.1) arranged opening.

9. lung simulator according to one of the preceding claims, characterized in that the linear drives (4.3, 5.3) are tubular linear motors with rotor bar, wherein at the rear part (13.2) of the housing (13) at the positions where the rotor bars from the stators Exiting linear motors (4.3, 5.3) extendable telescopic tubes (17.1, 17.2) are arranged, which are connected at their ends by a handle bar (17.3), whereby a support system (17) is formed.

10. Pulmonary simulator according to one of the preceding claims, characterized in that the rear part (13.2) of the housing is provided on its underside with two rollers.

- For this four sheet drawing -