WO2014111536A1

WO2014111536A1 - Device and method for monitoring the positioning of a respiration tube

Info

Publication number: WO2014111536A1
Application number: PCT/EP2014/050931
Authority: WO
Inventors: Michael CZAPLIK; Mark ULBRICH; Robert Pikkemaat; Steffen Leonhardt
Original assignee: Rwth Aachen
Priority date: 2013-01-18
Filing date: 2014-01-17
Publication date: 2014-07-24
Also published as: DE102013200712A1

Abstract

The invention relates to a device for monitoring the positioning of a respiration tube. The device has at least four electrodes (E_1, E₂, E₃, E₄), each two electrodes (E₁, E₂; E₃, E₄) being assigned to one measurement channel (S_L, S_R). Furthermore, the device has an AC signal-generating unit (WE), which is set up by means of at least two further electrodes (E₅, E₆) to transmit an AC signal to a body (K). The device determines a measurement value that is representative of the ventilation of one lung from each measurement channel (S_L, S_R) or the combination of the two, and the device determines a further measurement value (S_M) that is representative of an intubation of the oesophagus with consecutive ventilation of the stomach from the signal between two electrodes (E₁, E₂, E₃, E₄) of different measurement channels (S_L, S_R). Furthermore, the invention also relates to a corresponding method for monitoring the positioning of a respiration tube.

Description

Device and method for controlling the placement of a ventilation tube

RWTH Aachen, Germany

The invention relates to a device and a method for controlling the placement of a ventilation tube.

Background of the invention

In many medical situations, it is necessary to support or ensure the breathing of a patient by external means. For this purpose, a connection between the patient's lungs and an external oxygen supply is established by means of a respiratory tube. For this purpose, the respiratory tube must first be introduced. The placement of the ventilator tube, also known as intubating, can lead to errors, so only one lung rather than both lungs or the stomach is ventilated via the esophagus rather than the lungs.

It can also be stated again and again that an initially correctly placed respiratory tube is dislocated. Such a dislocation may e.g. occur during transport or rearrangement of a patient. Irrespective of the cause of the dislocation, misplacement can lead to a significant deterioration of the condition of the patient.

In the past, the C0 ₂ content of exhaled air was usually checked to ensure correct placement of a ventilator. If no CO ₂ content corresponding to normal respiratory activity was detected, this was signaled accordingly.

Although this monitoring of the C0 ₂ content allows a global statement as to whether any lung is ventilated at all, it is not possible to determine whether both are ventilated or which lung is currently not ventilated. That is, a sufficient oxygen supply is not necessarily ensured even when measuring the C0 ₂ content alone. Based on this situation, it is an object of the invention to provide a novel device and a novel method for controlling the placement of a ventilation tube, which make it possible to safely decide whether the ventilation tube is correctly placed.

The object is achieved by a device for controlling the placement of a ventilation tube. In this case, the device has at least four electrodes, wherein each two electrodes are assigned to a measuring channel, and an alternating current signal generating unit which is set up via at least two further electrodes in order to transmit an alternating current signal to a body.

The device determines from each measurement channel or the combination of both measurement channels a measurement which is representative of the ventilation of a lung, wherein the device determines from the signal between two electrodes of different measurement channels a further measurement which is representative of an intubation of the esophagus with consecutive ventilation of the stomach is.

This makes it possible that both a statement can be made whether both lungs, or whether only the right lung, or whether only the left lung, or the stomach is ventilated.

In an advantageous development of the invention, the device has a wireless interface in order to transmit the measured values to a visualization and / or evaluation device.

This is of particular advantage, since now the cabling effort is minimized and also an evaluation can begin faster. In addition, faulty wiring is avoided by a common wireless interface and the device can be used immediately after a patient transport.

According to yet another embodiment of the invention, the wireless interface of the measuring device on a ZigBee, Bluetooth, infrared or wireless LAN interface.

In this way, it can be achieved that the evaluations of measured values can be made on a multiplicity of already existing devices, which are therefore available at low cost. According to yet another embodiment of the device according to the invention, the alternating current generation unit generates an alternating current signal with a current of up to 10 mA, preferably up to 5 mA. This ensures that the current as a rule has no pathophysiological effect on a human body within the meaning of IED 60479-1 / VDE V 0140-479-1.

According to yet another embodiment of the device according to the invention, the alternating current generation unit generates an alternating current signal with a frequency of up to 1 MHz, preferably up to 50 kHz.

This ensures that the current as a rule has no pathophysiological effect on a human body within the meaning of IED 60479-1 / VDE V 0140-479-1. In a further advantageous embodiment of the invention, the device is integrated into a further monitoring device, in particular a respirator.

As a result, spatially integrated patient monitoring devices can be provided which can be integrated into mobile devices or rescue vehicles without requiring much space and / or requiring large amounts of weight.

It is particularly advantageous if the device is furthermore able to provide data relating to the respiratory rate, heart rate and / or ECG from the measured values determined.

As a result, not only spatially integrated patient monitoring devices can be provided, but a novel patient monitoring device, which also provides a linkage of different data. Furthermore, the object is also achieved by a method according to the invention. The method comprises a step of generating an alternating current signal by means of an alternating current signal generating unit and transmitting the alternating current signal to a body via at least two electrodes. Furthermore, in the method, a first measuring channel is measured by means of a first pair of electrodes, the pair of electrodes having a first and a second electrode, and a second measuring channel by means of a second pair of electrodes, wherein the pair of electrodes has a first and a second electrode. Furthermore, in the method of measured values of the first and second Measurement channel determines whether a lung is ventilated, and from the signal between a first electrode of the first measurement channel and a first electrode of the second measurement channel is determined whether the esophagus is intubated and consecutively ventilated the stomach. This makes it possible that both a statement can be made whether both lungs, or whether only the right lung, or whether only the left lung, or the stomach is ventilated.

In one embodiment of the method, the first electrode of a measurement channel and the second electrode of a measurement channel are arranged approximately on different lines, in particular selected from a group medioclavicular line, parasternal line, front axiliar line, middle axillary line, rear axilar line.

This makes it possible that the measured values are particularly meaningful and thus a particularly simple signal processing is possible.

According to yet another embodiment of the method, a first electrode for transmitting the AC signal is arranged on the left side of the body and a second electrode for transmitting the AC signal on the right side of the body.

According to yet another embodiment of the invention, a first electrode for transmitting the AC signal on the left side of the body and a second electrode for transmitting the AC signal on the right side of the body are arranged, wherein the first and second electrodes in approximately the same lines, in particular selected from a group Medioclavicular line, parasternal line, anterior axiliar line, medial axillary line, posterior axilar line.

The invention will be explained in more detail below with reference to the figures and the table. In these shows:

1 shows an exemplary arrangement of electrodes with respect to a first and second measuring channel according to an embodiment of the invention,

2 shows an exemplary arrangement of electrodes with respect to a further measured value according to an embodiment of the invention, and Tab. 1 an exemplary assignment of measurement signals to states.

In FIG. 1 and FIG. 2, an exemplary device for controlling the placement of a ventilation tube is shown. Although a human body K is shown by way of example, the invention is not limited to humans, but can be used in a similar manner in other mammals.

This device has at least four electrodes Ei, E ₂ , E ₃ , E ₄ , wherein more electrodes can be used. In this case, commercially available electrodes, as are known from the medical field, eg ECG electrodes can be used.

Two electrodes each form a measuring channel. In the example of FIGS. 1 and 2, the electrodes Ei, E _{2 form} a first measuring channel S _R and the electrodes E ₃ , E _{4 form} a second measuring channel S _L.

Furthermore, the device according to the invention has an alternating current signal generating unit WE which is set up via at least two further electrodes E ₅ , E _{6 in} order to transmit an alternating current signal to the body K. In this case, commercially available electrodes, as are known from the medical field, eg ECG electrodes can be used.

The device now determines from each measuring channel S _L , S _R or the combination of both measuring channels a measured value which is representative of the ventilation of a lung. Corresponding lungs are shown in Figures 1 and 2 as a dark shadow RLF, LLF within the body K, the right and left assignment used in medical use being also used here, so that the right lung RLF is depicted on the left side. Furthermore, the device determines from the signal between two electrodes Ei, E ₂ , E ₃ , E _{4 of} different measuring channels S _L , S _R a further measured value S _M , which is representative of an intubation of the esophagus with consecutive ventilation of the stomach. For example, it is shown in FIG. 2 that the further measured value S _{M is} determined from the electrode E _{2 of} the first measuring channel S _R and the electrode E _{3 of} the second measuring channel S _L. Of course, the electrode E 1 and / or the electrode E _{4 may} alternatively be used here without limiting the generality. In addition, it would also be possible with suitable wiring, the electrodes of the first measuring channel S _R and the electrodes of the second measuring channel S _L together as an enlarged measuring electrode for the determination of the further measured value S _M to use.

This makes it possible that both a statement can be made whether both lungs, or whether only the right lung, or whether only the left lung, or the stomach esophagus is ventilated.

By way of example, this will now be explained in more detail with reference to Table 1, wherein the waveforms shown are merely exemplary. Here, it is assumed that the AC signal generating unit WE transmits a sinusoidal AC signal to the body K. In this case, the invention makes use of the fact that the ventilation of the lungs or of the stomach leads to an impedance change.

In the first case, the signal of the further measured value S _M is essentially a strongly attenuated reproduction of the sinusoidal alternating current signal, while the first measuring signal S _R and the second measuring signal S _{L are} less strongly damped. All signals S _M , S _R and S _L have a substantially constant amplitude. In this case, both the left lung LLF and the right lung RLF are ventilated while the stomach is not insufflated.

In the second case, the signal of the further measured value S _M and the second measuring signal S _L is essentially a less strongly damped reproduction of the sinusoidal alternating current signal while the first measuring signal S _{R is} strongly attenuated. All signals S _M , S _R and S _L have a substantially constant amplitude. In this case, only the left lung LLF is ventilated, while the right lung RLF as well as the stomach are not insufflated.

In the third case, the signal of the further measured value S _M and the first measuring signal S _R is essentially a less strongly attenuated reproduction of the sinusoidal alternating current signal, while the second measuring signal S _{L is} strongly attenuated. All signals S _M , S _R and S _L have a substantially constant amplitude. In this case, only the right lung RLF is ventilated while the left lung LLF and the stomach are not insufflated. In the fourth case, the signal of the further measured value SM is strongly attenuated, wherein the amplitude varies, while the first measuring signal S _R and the second measuring signal S _L essentially a very strongly attenuated reproduction of the sinusoidal AC signal are. In this case, neither the right lung RLF nor the left lung LLF is ventilated, while the stomach is insufflated via the esophagus. In the latter case, which in itself can only occur with mask ventilation rather than intubation, both the right lung RLF and the left lung LLF and the stomach are insufflated via the esophagus.

As exemplified can be made by means of the inventive method and the device according to the invention a statement whether both lungs, or whether only the right lung, or whether only the left lung, or the stomach is ventilated.

For example, in FIG. 1 and FIG. 2, the electrode E _{3 of} the second measuring channel SL is arranged approximately on the medioclavicular line, while the electrode E _{4 of} the second measuring channel SL is arranged approximately on the front axial line L ₂ . Although in Figures 1 and 2 the electrodes are shown approximately symmetrically arranged with respect to both horizontal and vertical alignment, this is not a necessary condition for the operation of the invention. This makes it possible that the measured values are particularly meaningful and thus a particularly simple signal processing is possible.

For example, in Fig. 1 and Fig. 2, the electrode E _{5 is} mounted on the right side of the body while the electrode E _{6 is} mounted on the left side of the body. According to yet another embodiment of the invention, a first electrode for transmitting the AC signal on the left side of the body and a second electrode for transmitting the AC signal on the right side of the body are arranged, wherein the first and second electrodes in approximately the same lines, in particular selected from a group Medioclavicular line, parasternal line, anterior axiliar line, medial axillary line, posterior axilar line.

For example, the electrode E ₆ in FIG. 1 and FIG. 2 is arranged on the rear axial line L ₃ . Although in Figures 1 and 2 the electrodes are shown approximately symmetrically arranged with respect to both horizontal and vertical alignment, this is not a necessary condition for the operation of the invention. This makes it possible that the measured values are particularly meaningful and thus a particularly simple signal processing is possible.

Although in FIGS. 1 and 2 the electrodes Ei, E ₂ , E ₃ and E _{4 are arranged} above the electrodes E ₅ and E _{6 of} the alternating current signal generating unit WE, this arrangement is not mandatory. Thus, the electrodes could readily the electrodes E ₅ and E _{6 of} the AC signal generating unit WE also over the electrodes E _; E ₂ , E ₃ and E ₄ or between the electrodes E _; E ₂ , E ₃ and E ₄ are arranged.

In an advantageous development of the invention, the device has a wireless interface in order to transmit the measured values to a visualization and / or evaluation device MON. By way of example, the visualization and / or evaluation device MON can be a PC, a tablet PC, a smartphone, a display or the like, but without being limited thereto.

This is of particular advantage, since now the cabling effort is minimized and also an evaluation can begin faster. Typically, the wiring to an evaluation device MON is faulty, so that connection errors can lead to a distorted reproduction of the measured values. Furthermore, cables are troublesome for medical personnel because they limit the possibilities of movement. Using a wireless interface avoids these disadvantages. In addition, faulty wiring is avoided by a common wireless interface and the device can be used immediately after a patient transport. For example, a patient may remain connected even after reaching a clinic, the device being merely connected to another evaluation device MON. In this way, it can be avoided, in particular, that there is an unnoticed displacement of the respiratory tube during the rearrangement. According to yet another embodiment of the invention, the wireless interface of the measuring device on a ZigBee, Bluetooth, infrared or wireless LAN interface.

In this way, it can be achieved that the evaluations of measured values can be made on a multiplicity of already existing devices, which are therefore available at low cost.

According to yet another embodiment of the device according to the invention, the alternating current generation unit generates an alternating current signal with a current of up to 10 mA, preferably up to 5 mA.

This ensures that the current as a rule has no pathophysiological effect on a human body within the meaning of IED 60479-1 / VDE V 0140-479-1. According to yet another embodiment of the device according to the invention, the alternating current generation unit generates an alternating current signal with a frequency of up to 1 MHz, preferably up to 50 kHz.

This ensures that the current as a rule has no pathophysiological effect on a human body within the meaning of IED 60479-1 / VDE V 0140-479-1.

However, it should be noted that the values given in animals may be different.

In a further advantageous embodiment of the invention, the device is integrated into a further monitoring device, in particular a respirator. As a result, spatially integrated patient monitoring devices MON can be provided which can be integrated into mobile devices or emergency vehicles without requiring much space and / or requiring large amounts of weight. It is particularly advantageous if the device is furthermore able to provide data relating to the respiratory rate, heart rate and / or ECG from the measured values determined. This can easily be worked out of the signals by appropriate active or passive signal processing by filtering or signal processing. As a result, not only spatially integrated patient monitoring devices MON but a novel patient monitoring device MON, the Also provides a linkage of different data, such as the data on the ventilation of the lung as well as the respiratory rate.

As a result, it can be seen that the presented arrangement according to the invention provides a reliable statement which makes it possible to reliably decide whether the breathing tube is correctly placed.

Claims

claims

Device for controlling the placement of a ventilation tube, comprising:

At least four electrodes (Ei, E ₂ , E ₃ , E ₄ ), each two electrodes (Ei, E ₂ , E ₃ , E ₄ ) being assigned to a measuring channel (S _L , S _R ):

An alternating current signal generating unit (WE) which is set up via at least two further electrodes (E ₅ , E ₆ ) in order to transmit an alternating current signal to a body (K),

characterized in that

The device determines from each measuring channel (S _L , S _R ) or the combination of both a measured value which is representative of the ventilation of a lung, and

Wherein the device determines from the signal between two electrodes (E _; E ₂ , E ₃ , E ₄ ) of different measuring channels (S _L , S _R ) a further measured value (S _M ) which is representative of an intubation of the esophagus with consecutive aeration of the stomach is.

Device according to Claim 1, characterized in that the device has a wireless interface in order to transmit the measured values to a visualization and / or evaluation device (MON).

Apparatus according to claim 2, characterized in that the wireless interface of the measuring device is a ZigBee, Bluetooth, infrared or wireless LAN interface.

Device according to one of the preceding claims, characterized in that the AC generating unit generates an AC signal with a current of up to 10 mA, preferably up to 5 mA.

Device according to one of the preceding claims, characterized in that the AC power generating unit generates an AC signal having a frequency of up to 1 MHz, preferably up to 50 kHz.

Device according to one of the preceding claims, characterized in that the device is integrated into a further monitoring device, in particular a respirator. Device according to one of the preceding claims, characterized in that the device is further able to provide data relating to the respiratory rate, heart rate and / or ECG from the measured values determined.

Method for controlling the placement of a ventilation tube, comprising the steps

Generating an alternating current signal by means of an alternating current signal generating unit (WE) and transmitting the alternating current signal via at least two electrodes to a body (K),

Measuring a first measuring channel (S _R ) by means of a first pair of electrodes (E _1;

E ₂ ), wherein the electrode pair has a first and a second electrode,

Measuring a second measuring channel (S _L ) by means of a second pair of electrodes (E ₃ , E ₄ ), the pair of electrodes having a first and a second electrode, characterized in that the method further comprises the steps

• Determine from measured values of the first and second measuring channels (S _L , S _R ) whether a lung is ventilated, and

Determining from the signal (S _M ) between a first electrode (Ei, E ₂ ) of the first measuring channel (S _R ) and a first electrode (E ₃ , E ₄ ) of the second measuring channel (S _L ), whether the esophagus intubated and Consecutively the stomach is ventilated.

A method according to claim 8, characterized in that the first electrode of a measuring channel and the second electrode of a measuring channel approximately on different lines, in particular selected from a group Medioklavikularer-line (L ^, Parasternal line, front Axiliarlinie (L ₂ ), middle Axillary, rear axillary line (L ₃ ) are arranged.

A method according to claim 8 or 9, characterized in that a first electrode for transmitting the AC signal on the left side of the body and a second electrode for transmitting the AC signal on the right side of the body is arranged.

Method according to one of claims 8 to 10, characterized in that a first electrode for transmitting the AC signal on the left side of the body and a second electrode for transmitting the AC signal on the right side of the body is arranged, wherein the first and second electrodes in approximately the same lines , in particular selected from a group of medioclavicular line, Parasternal line, anterior axiliar line, middle axillary line, posterior axilar line, are arranged.