WO2014102391A1

WO2014102391A1 - System for monitoring independent respiratory protection

Info

Publication number: WO2014102391A1
Application number: PCT/EP2013/078168
Authority: WO
Inventors: Mattias DETOBEL
Original assignee: Detobel Mattias
Priority date: 2012-12-31
Filing date: 2013-12-31
Publication date: 2014-07-03
Also published as: BE1022452B1

Abstract

The invention relates to a system, suitable for monitoring open-circuit independent respiratory protection of a user of a pressurized container, com-prising : (1) an open-circuit independent respiratory protection, (2) at least two communication units suitable for exchanging between them on the one hand information concerning at least the immediate gas pressure in the pressurized container and on the other hand information concerning the course of intervention; (3) a computer, suitable for executing a computer-implemented monitoring pro-gram (4), that is not carried by the carrier of the independent respiratory protection; and (4) a computer-implemented monitoring program.

Description

SYSTEM FOR MONITORING INDEPENDENT RESPIRATORY

PROTECTION

Introduction

This invention relates to a system for monitoring open-circuit independent respiratory protection, to a computer-implemented monitoring program that is used in combination with said system and to a method for monitoring respiratory protection, in particular for use by fire fighters. Background of the invention

Often, fire fighters have to deal with situations that require carrying an open-circuit independent respiratory protection (also called open-circuit breathing system). We refer, among other things to:

(a) an increasing number of fires that require a so-called in-house fire- fighting. In this respect, homes that are increasingly better insulated, play a major role : namely, when a fire starts in such a home, it will develop much more slowly than before, because a growing focus on prevention and adjusted construction methods strongly reduces the probability of development of such an in- house fire. Where once a house would be consumed by a roaring fire even be- fore the arrival of the fire fighters, fire fighters today must increasingly enter the building in order to extinguish the fire and/or to execute rescues.

(b) an increasing amount of incidents involving dangerous substances, wherein hazardous (toxic, corrosive, biologic, mutagenic) gasses or vapours may invade the body through breathing. Not only the exponentially increasing use of dangerous substances in the industry, but also a more frequent occurrence of dangerous transports on public roads, contributes to this.

(c) the growing awareness, within the fire service, concerning the extremely harmful effects of fumes on health, either acute or chronically.

In short, fire fighters need to protect themselves more and more against the risks they are exposed to. Carrying an open-circuit independent respiratory protection, especially carrying a compressed air container (i.e. a pressurized container) on the back in combination with, for example, a full-face mask on the face is an absolute priority. With container is meant any device of holding compressed air, such as a cylinder, a bottle, a tank and the like. The open-circuit independent respiratory protection generally comprises (a) a harness comprising straps for carrying a pressurized container; (b) a pressurized container that is preferably suitable for compressed air and that, for example for use by fire fighters, is customarily filled to about 300 bar (i.e. is brought to an initial pressure that is 300 times higher than the atmospheric ambient pressure), or that, for use by divers, is customarily filled to about 200 bar (i.e. brought to an initial pressure that is 200 times higher than the atmospheric ambient pressure), (c) a means for the administration of air, for example a full- face mask, a mouthpiece and/or pressure suit, connected to the pressurized container by means of one or more air tubes and a pressure regulator, such that the means for administration of air can be provided with air at the moment the compressed air carrier requires air, in particular on inhalation by the compressed air carrier, and (d) a pressure sensor, in particular a manometer, in particular a readable manometer, on which the compressed air carrier can read and monitor the gas pressure in the pressurized container.

When fire fighters proceed to the use of open-circuit independent respiratory protection, this is done in the following manner, being taught in the context of the mandatory firefighter training, which meets the Belgian federal standards. Deployment is always made by a team of three firemen, wherein two firemen of said team (the compressed air carriers), are provided with open-circuit independent respiratory protection, enter the location (i.e. property, factory, apartment, house, barn, container, etc.) to extinguish a fire, where a rescue or another action needs to be executed with the aid of open-circuit independent respiratory protection, and wherein the third fireman of said team (the guardian) is in radio contact, i.e. through a wireless oral radio connection, from outside of the field of action, for example a property, casualty area, industrial area, etc. that is entered by the two compressed air carriers, with said two compressed air carriers and wherein information between the two compressed air carriers and the third fireman can be exchanged orally, for example concerning the (remaining, immediate) pressure in the pressurized container, the total residence time of the two compressed air carriers on the location of deployment, etc. The guardian can determine how long the two compressed air carriers still have till empty pressurized container (danger for lack of air). Said information can be calculated by the guardian, based on the known initial air pressure in the pressurized con- tainer, the immediate air pressure in the pressurized container for each of the two compressed air carriers, which can be transmitted by each of the two compressed air carriers through periodical radiophonic transmission to the third fireman during deployment, and the time elapsed in between. To the extent that this calculation is already happening, this calculation is currently done by hand by the third fireman and is a pretty rough estimate.

Background prior art

WO2004/091725 A1 (Aust, 28 October 2004) discloses a method for mon- itoring at least two people carrying out a time-limited activity using an external respiratory air supply, such as firemen. Said method does not calculate the time-to-return in a dynamic manner, nor distinguishes between different situations (such as described later in this application) or determines the way out from a deployment area, i.e. from data stored during the way in, nor produces an Af- ter-Action report.

GB 231 1015 (Elis Bernard Cohen, 17 September 1997) discloses a respiratory monitor for breathing apparatus.

GB 2368705 (Elis Bernard Cohen, 08 May 2002) discloses an apparatus for monitoring and control of persons using breathing apparatus.

On the market, a telemetric system is known by Drager (Drager Safety

Belgium S.A., Wemmel, Belgium), named DragerMan PSS® Merlin, to be used by firemen, in combination with an electronic manometer (for example Bodyguard by Drager) wherein information about, amongst others, immediate gas pressure in the pressurized container of a fireman, equipped with an open- circuit independent respiratory protection, the air consumption, temperature at the height of his wireless transceiver and a predicted "time to spare pressure" is calculated by the electronic manometer and is periodically (e.g. every 20 seconds) wirelessly transmitted to and displayed on an information board that is placed visibly outside of the location of deployment. Such an information board can simultaneously present the deployment of 12 firemen. Furthermore, said system from the prior art can also display an audible and/or visual alarm signal, provided by the fireman when he would be in trouble, and can, with the aid of the system, give a signal to the fireman to retreat from the location of deployment. The prior art system is provided to be able to read out the information that is displayed on the information board on a separate information carrier (such as for example a laptop, desktop computer, ...) by means of separately obtainable software. However, this readout does not contain information that was transmit- ted to the guardian by the carriers themselves (for example by means of the oral radio communication).

The system of the prior art has the disadvantage that it does not indicate actual "time-to-return", but merely a time to the moment on which the lack of gas in the pressurized container, carried by the fireman, is imminent. However, at that moment, in practice, a return is often already too late. Therefore, the system of the state of the art does not in any way take into account where the fireman is located at that point in time, how he got there, how long it took to get there, and can therefore not actively ensure the safety of the entire action in its entirety.

The system of the prior art further has the disadvantage that the information that is processed and displayed by such as system, is limited. Moreover, the acquisition cost of the system is so high that, in practice, it is only available for larger (and wealthy) fire departments. Finally, the system is quite bulky and thus requires a lot of storage room in the fire wagon, storage room that is often not available. Also, carrying the wireless transceiver that is connected to the system means an extra carrying load for the deployed fireman (which already carries a communication system such as portable radio), which might compromise his mobility and therefore also his safety. Finally, such a system can only be used in combination with an electronic manometer, and not with the much cheaper manometer with a dial because the calculation of, amongst others, the time-to-'spare pressure' (= which is named in the DragerMan PSS® Merlin as the 'time-to-whistle' [remaining 50 bar]) is not done by the information board, i.e. outside the location of deployment. Detailed description of the invention

It is the goal of the invention to provide a simple, multi-deployable, versatile and cheap system for monitoring open-circuit independent respiratory protection, in particular to firemen, thereby making their deployment easier and at least ensuring their safety and preferably raising it, with respect to the current practice.

In general, the disclosed invention can be used to safeguard all persons using open-circuit breathing apparatus, such as firemen and divers.

The system for monitoring open-circuit independent respiratory protection according to the invention calculates in a dynamic fashion the time-to-return, thereby making a safer deployment of, in particular, firemen possible, and this for each specific situation in the most relevant manner.

With the aid of the system for monitoring open-circuit independent respiratory protection according to the invention, all semi-automatic aspects will be monitored that safeguard, or just may jeopardize, the wellbeing of in particular firemen during a course of intervention. The system for monitoring open-circuit independent respiratory protection according to the invention calculates each output completely automatically. In one embodiment, the system requires the manual input of information, obtained from radiophonic oral communication be- tween a first and a second person, in particular a fireman. In another embodiment, the system requires the wireless input of information, obtained from the wireless communication between the pressure sensor, carried by the compressed air carrier and the computer, connected to or equipped with a receiver for receiving the wireless information obtained from the pressure sensor.

For this purpose, the system for monitoring open-circuit independent respiratory protection of a user of a pressurized container according to the invention comprises the following components:

(1 ) an open-circuit independent respiratory protection, comprising at least a harness, a pressurized container, a pressure regulator, one or more pressure tubes, a means for the administration of air, and a pressure sensor.

(2) at least two communication units, suitable for exchanging between them on the one hand information concerning at least the immediate gas pressure in the pressurized container and on the other hand information concerning the course of intervention, such as the path followed and deployment activities.

(3) a computer, suitable for executing a computer-implemented monitoring program (4), that is not carried by the carrier of the open-circuit independent respiratory protection; and

(4) a computer-implemented monitoring program that is provided with information about at least the filling pressure and the physical volume of the pres- surized container, the immediate gas pressure in the pressurized container and the time-lapse, and that at least calculates the time-to-return in a dynamic manner.

The operation of the system will now be described in detail with reference to the use of compressed air as gas in the pressurized container, and by firemen. However, one has to note that the deployment of open-circuit independent respiratory protection is not limited to firemen, but may also be used in other situations than a fire, for example, by divers under water and carriers of a protective suit, or gastight suit, or splash suit, carrying open-circuit breathing appa- ratus, for example in industrial environments such as spray booths, with the maintenance and cleaning of chemical storage tanks, or in spaces with limited amount of air, an excess of dust, harmful chemical substances, and the like. The scope of protection for this invention is therefore not limited to the use by firemen, but also concerns everyone who uses said open-circuit independent respiratory protection for a particular application.

1 . Independent respiratory protection

The open-circuit independent respiratory protection comprises at least a harness, a pressurized container, a pressure regulator, one or more pressure tubes, a means for the administration of air, and a pressure sensor.

Carrying a compressed air apparatus is also called carrying of open-circuit independent respiratory protection because the respiration of the compressed air carrier remains completely separated from the atmospheric air that surrounds him. In the prefilled pressurized container there is, after all, a limited amount of compressed air, which the carrier both systematically and independently uses as he breaths.

A compressed air apparatus, such as the one that is used by the fire department, is at least composed of the following components:

• A harness comprising a carrying frame with straps;

· A pressurized container with valve, filled with breathable air;

• A pressure regulator with pressure relief valve (reduces the high pressure to medium pressure);

• A flexible medium pressure tube with a respirator;

• An additional flexible pressure tube with a quick-connect coupling; • A high pressure tube with pressure sensor comprising an alarm device;

• A means for the administration of air, i.e. a full-face mask.

The harness, the pressure regulator, the tubes with pressure sensor and lung machine can be considered as an integrated whole, that can be used with a separate full face mask. The manufacturer has designed such assembly as one whole according to the NBN-EN 137. The assembly is therefore also tested as one whole for the type validation.

In connection to the special circumstances in which the fire fighters have to work, EN 137 dictates a number of requirements to the compressed air de- vice, including:

• The device should have an alarm device, that indicates with the use of an alarm signal that the reserve pressure has been reached. The alarm device may be executed as an acoustic signal (flute), or as breathing resistance signal. In the fire brigade the devices are usually fitted with a flute;

· The device has to be provided with a pressure sensor, for example a manometer, that is always easy to read for the carrier; the pressure sensor may be an analogue (with a dial) or digital version.

• The load of a deployable device, with full face mask and full pressurized container, may be 18 kg at most;

· When using a full face mask, an overpressure of 300 l/min has to be present at inhalation.

• When exhaling, the excess pressure may be maximum 10 mbar. In practice an excess pressure of 3.5 mbar is optimal;

• The valve of the pressurized container has to be positioned in such a way that the carrier of the device can operate it independently.

The operating principle of the compressed air device is as follows: the pressurized container of the device consists out of composite material and is usually filled at the fire station to a pressure of about 300 bar (thus, a pressurized container with a volume of 6.8 litres, that is filled to a pressure of 300 bar, contains approximately 2040 litres of air). This is done prior to its use and with the help of a compressor. The pressurized container has a valve and is attached to the harness by means of a screw connection. The screw connection connects the pressurized container and the harness via a so-called pressure regulator. This is meant to reduce the filling pressure of 300 bar (high pressure) for further distribution to a so-called medium pressure of 6 to 9 bar. A pressure relief valve ensures that the air is vented, in case an error would occur during the reduction and the air under a pressure of more than 9 bar is at risk of being passed to the medium pressure tube (and therefore to the user). Just before the pressure re- duction, a high pressure tube leads a part of the compressed air away to the pressure sensor, for example a manometer. On the latter it is then possible to always read how much pressure still prevails in the pressurized container, or in other words, how much air pressure the container still contains.

Once reduced to a pressure of 6 to 9 bar, a medium pressure tube distrib- utes the compressed air to the lung machine. The lung machine reduces the medium pressure in turn to a pressure of 1 .005 to 1.010 bar. When, for example, a full face mask is attached to the lung machine, the compressed air carrier is assured of a overpressure of 5 to 10 mbar in the full face mask. This assures him that, in case the full face mask would leak, only air can escape from within the full face mask to the outside, and excludes the possibility that (potentially harmful) ambient air could penetrate the full face mask.

The lung machine is equipped with a calibrated spring on the inside, which ensures with a counter pressure of 5 to 10 mbar that air is only released when the compressed air carrier inhales. Then, the spring is moved out if its zero posi- tion, due to the underpressure, created by inhaling. Using a compressed air device, only air from the pressurized container is consumed when the compressed air carrier inhales. The exhaled air is expelled from the mask at each exhale through a so called exhalation valve (one way valve), and is therefore not recuperated.

Examples of suitable open-circuit independent respiratory protection according to the invention are Drager PA 94 and Drager PSS 7000 (Drager Safety Belgium S.A., Wemmel, Belgium).

It should be noted that the system is not limited to the use of air (compressed air), but that also other gas mixtures can be used. When in this applica- tion reference is made to a compressed air carrier, in general also reference is made to a carrier of a pressurized container, in so far as this pressurized container contains a compressed gas. 2. Communication units

The open-circuit independent respiratory protection comprises at least two communication units, suitable for exchanging between them on the one hand information concerning at least the immediate gas pressure in the pressurized container and on the other hand information concerning the course of intervention, such as the path followed and deployment activities.

Emergency and security services have to be able to communicate with each other at any time, and this in a reliable and secure manner. In Belgium, the digital radio network ASTRID is made available for this purpose that is especial- ly tailored to the needs of everyone that is involved in public safety.

Digital radio communication through the ASTRID network is fast, reliable and has an optimum sound quality. Moreover, ASTRID provides radio coverage throughout Belgium.

ASTRID stands for All-round Semi-cellular Trunking Radio system with Integrated Dispatching.

With All-round is meant that the offered radio communication is multifunctional and has national coverage.

Semi-Cellular means that each base station provides radio coverage to a particular geographical area (cell).

For its data transmission, the radio communication utilizes the Trunking- technique: radio users are allocated capacity when they request it. Frequencies are therefore never restricted to one particular user. ASTRID makes use of the frequency band 380 MHz - 400 MHz that is specifically reserved in Europe for emergency and security services.

The Integrated Dispatching finally stands for the supporting function of the emergency room. However, this matter is beyond the scope of the actual radio communication itself.

The radio network is based on the TETRA standard. This is an European open standard for portable digital telecommunications for emergency and secu- rity services. It is developed and maintained by the European Telecommunications Standard Institute (ETSI) and is implemented in technologies such as offered by radio manufacturers such as Motorola, Siemens, EADS, ...

ASTRID radio communication operates within previously programmed dialogue groups. In this way, an organisation has access, so to speak, to its own network within the common, national network. When transmitting voice and data, the user can count on maximum confidentiality, due to digital, encrypted communication. However, at the same time, there exists the possibility to form mixed dialogue groups with other services. Each user can therefore, in accord- ance with their responsibilities, be part of different dialogue groups within their own organisation or with other services.

When powering on an ASTRID-radio, the user must therefore be aware of the dialogue group to which the radio is set to at that point in time. In the usual operating mode, only communication with other radios is possible, provided the- se are set to the same dialogue group.

The frequency over which the data is sent, as cited above, is variable and is managed by the network.

Changing the selected dialogue group is done by going through the menu of the radio, and does not require more than a few button presses.

Technically-chronologically seen, the radio communication between different ASTRID-radios (on the same dialogue groups) goes as follows:

1 - Person A choses a dialogue group (he can only chose from the dialogue groups for which the network administrator has granted him membership).

2- Person A presses the send button (also known as PTT or 'Push to Talk').

3- The radio of person A sends a request to the nearest base station (over the so-called control channel, which is automatically - so without his intervention or knowledge - determined by the network administrator).

4- The base station receives the request signal and passes it on to a pro- vincial data switch (by wire).

5- The provincial switch verifies which other radios are set on the same dialogue group, and which base station they are part of.

6- The provincial switch checks which frequency channel is available for the voice transmission.

7- The provincial switch directs the base station to the free frequency channel to be assigned to the radio of person A.

8- A few milliseconds after the person A presses the send button, the indicator light of the radio turns green. Person A can now send his message.

9- The base station distributes the message both locally (to the radios that are located within its coverage area and that are located within the same dialogue group) as well as to the provincial switch (which distributes the message to other base stations, and therefore also to all other radios in that dialogue group).

10- All persons whose radio is set to the same dialogue group (as that of person A) receive the message.

The communication with an ASTRID radio is executed in a simplex way. During the time that the transmitter transmits, the receiver is only able to receive. Only after the transmitter has finished transmitting, the receiver is able to answer by, in turn, pressing the send button.

Preferably, the two communication units between which information is exchanged, are incorporated in the ASTRID network.

However, the invention is not limited to the communication units between which information is exchanged, which are included in the ASTRID network. The information can also be exchanged through walky-talky's, mobile phones, satellite phones, and the like.

(3) Computer

A computer, suitable for executing a computer-implemented monitoring program according to the invention, is preferably a portable computer, laptop, notebook, ultrabook, PDA, smartphone, Blackberry or any other computer that is suitable for this purpose. The computer is not carried by the carrier of the open- circuit independent respiratory protection, but remains outside of the action area and is, for example, operated by the aforementioned third fireman. In particular, the computer is a computer that is suitable for fire brigade applications for use in the field, for example a computer available under the name Emerec (Rosenbau- er International AG, Austria). A fire brigade that is deployed, often already has access to the suitable computer in the fire brigade equipment, for example for consulting a database with dangerous substances. It is an advantage of the present invention that no further electronic device, especially computer equipment, is required for the system for the monitoring of the open-circuit independent respiratory protection than the already present computer equipment in a standard fire brigade equipment.

According to one embodiment, the computer-implemented monitoring pro- gram is present on said computer, for example a hard disk, a memory stick, a removable medium such as a DVD or CD-ROM, and the like.

According to another embodiment, the computer-implemented monitoring program is not present on said computer, but said computer is in connection to a second computer that is provided with said computer-implemented monitoring program, for example wireless or by cable, for example over the internet. Preferably, second said computer is a server, incorporated in the internet.

4. Computer-implemented monitoring program

The computer-implemented monitoring program that is provided with information concerning at least the immediate pressure in the pressurized container and the time-lapse (i.e. the time that has passed during the deployment, or during the carrying of the pressurized container), and that at least calculates the time-to-return in a dynamic manner, guards the safety of each carrier of a pressurized container, in particular each compressed air carrier, in the following ways:

Managing the lapsed deployment time, to calculate immediately and dynamically the average air consumption of the compressed air carrier.

Determining the remaining (safe) deployment time, based on the average air consumption.

Indicating a remaining 'time-to-return' or 'time-to-empty pressurized container' based on the above data.

Providing assessment to which extent the physical exertion of the compressed air carrier may or may not compromise his safety, based on the aver- age air consumption.

Combining the time recorded memo-input (by the guardian), together with each output generated by the program, in an After-Action-Report. In this context, the term "guardian" refers to the aforementioned third fireman.

Generating both in the run-time as in the After-Action-Report, a graphical representation of the compressed air consumption (decrease of pressure in the container in the course of time), and the associated consumption rate in the course of the time (for example in litres per minute).

Generating a visual representation of the residual fill level of the container (for example on the basis of a progress bar), which refreshes its status every time the guardian enters a residual pressure value, but thereafter also automatically (so without requiring an action from the user of the system) and periodically in the course of time (for example every second).

Keeping track of the travelled way by using reference points, in order from this, on the moment of return, immediately generate the route of return to be taken.

For each calculation the system checks the difference between the filling pressure (pressure in the container at the start of the deployment) of the pressurized container and the immediate (remaining) pressure in the pressurized container, in order to calculate the already consumed amount of air based on the ideal gas law (the product of the pressure in the pressurized container and the physical volume of the pressurized container is in fact a measure for the amount of compressed gas, in this case air, present in the pressurized container). The system divides this consumed amount of air by the already passed de- ployment time (wherein this amount of air was thus consumed), and calculates in this manner immediately the average consumption of the compressed air carriers up until that moment.

Based on this, the system simulates for how long the compressed air carrier can continue his deployment while making use of open-circuit independent respiratory protection.

The way the system calculates and/or displays its output, is always as a function of the specific situation of that moment (is the compressed air carrier still on his way up, or is he already on his way back, or is he entering into a stationary action for some time, etc.) in this way, all the intervention factors are taken into account to watch over the safety of the deployed personnel.

Hereby, every influence as a result of heating up and cooling down of the compressed air, at respectively the filling (compression) and consumption (expanse) of the pressurized container, is taken into account by the inclusion of a correction factor, also known as 'filling coefficient' and which is known to the skilled person from tables. Note that the filling coefficient in reality is always dependent on the immediate pressure. As the filling coefficient has a range of 0.970 to 1 .100, one should always be aware of the margin of error between -3% and +10%, compared to the true content value when one would not take this filling coefficient in account, which should always be the case when a "rough" calculation is done by the third fireman, if done anyway.

Based on the filling pressure in the pressurized container at the start of the deployment, the physical volume of this pressurized container, the immediate (still remaining) pressure in the pressurized container and the already passed deployment time, the system, in particular the computer-implemented monitoring program calculates the average consumption of the compressed air carrier, and generates, based on the latter, immediately and dynamically, how long the compressed air carrier can still continue with the deployment. With dynamic is meant that the output is frequently or continuously adjusted (updated) based on each new piece of data, available during the deployment, such as pressure in the compressed air container.

To connect the calculation of this remaining deployment time as effectively as possible to the nature of his activity, the computer-implemented program distinguishes between three possible situations:

1 - The fireman is on his way to extinguish a fire or to find a victim.

2- The fireman remains stationary on a location where he will execute a certain action for a certain period of time, without progressing further.

3- The fireman is on his way back, after executing and/or halting his mission.

In yet another embodiment according to the invention, it is possible to register the oral communication between the two communication units, for example by typing this into a program, or to record it as a voice-logging, on tape, or in any other way, known to those skilled in the art.

In contrast to the state of the art, the system is further characterized in that all the inputted and system-generated data are stored in a log-file ("history") which is adapted to be consulted by the user at any time, which, for example, is displayed in run-time in the form of a summary table.

The system stores information in the log-file, at any moment when :

- a calculation on the remaining deployment time is executed (i.e. a pressure value is entered for an intermediate calculation, return or setting or updating an action point) ;

- a reference point (an object), a direction and/or a change of direction is being entered ;

- a no-response-alarm is started ; - a no-response-alarm is cancelled.

With input data are particularly meant :

- the radiophonically obtained value of the immediate air pressure in the compressed air container of the compressed air carrier.

- the information that the compressed air carrier returns, and whether or not he is carrying a victim.

- the information that the compressed air carrier on its way in is not progressing further, but halts at a stationary point to perform an action ( called action point).

- the launch of a no-response-alarm.

- the cancellation of a no-response-alarm.

With the data generated by the system are particularly meant :

- each point in time at which an above-described calculation as to the remaining deployment time was carried out (i.e. at which a pressure value has been entered).

- the pressure value entered by the user for that calculation.

- the consumption of the compressed air carrier (and, optionally victim) in litres per minute at that time.

- the time remaining to retreat at that time.

- the time remaining to empty pressurized container at that time.

- a visual representation of the residual fill level of the container (for example on the basis of a progress bar), which refreshes its status every time the guardian enters a residual pressure value, but thereafter also automatically (so without requiring an action from the user of the system) and periodically in the course of time (for example every second).

- the information that a compressed air carrier at a specific point in time with a specific residual pressure in the container begins his retreat, and whether or not he is carrying a victim with him.

- the information that a compressed air carrier at a specific time, with a certain residual pressure in the container, performs a stationary action without further progressing (action point).

- the information that on a specific point in time a no-response-alarm has been initiated. - the information that on a specific point in time a no-response-alarm has been cancelled.

The history and all information contained therein, like many other operating data, are also fully included in the generated After-Action report.

The computer-implemented monitoring program according to the invention is further adapted to automatically determine the way back (or way out) from the area of deployment from data stored during the way into the deployment area.

According to procedures within the fire department, a deployment team selects, when entering a building or property always one side.

If this side is "left", the deployment team at all times, and during the whole way in, contacts the left wall with the left hand.

If this side is "right", the deployment team at all times, and during the whole way in, contacts the right wall with the right hand.

The task of the second member of the deployment team is to memorize the way in, based on each direction and change of direction, and on as much as possible reference point, encountered on the way in. The moment the team turns back, the team members turn 180°, and keep contact with the same wall as contacted during the way in, but now with the other hand. The second member of the team will reconstruct the way back, based on the memorized way in and this according to the following logic :

1 . Two degrees of freedom are subject to reversal (way in versus way out)

- "Right" on the way in means "Left" on the way out

- "Left" on the way in means "Right" on the way out

- "Stairs up" on the way in means "Stairs down" on the way out

- "Stairs down" on the way in means "Stairs up" on the way out

The degrees of freedom 'left-right' and 'up-down" should be inverted for the way out, compared to the way in, at least if one would like to find the exit via the same route.

2. One degree of freedom is not subject to reversal (way in versus way out)

- "Straight ahead" on the way in remains "straight ahead" on the way out.

The degree of freedom "forwards-backwards' should not be inverted for reconstruction of the way out. 3. Reference points

- Encountering a refrigerator (or any other possible reference point) on the way in means that one should encounter the same refrigerator on the same location on the way out. Hence, also the reference points do no change on the way out (compared to the way in). In the system according to the invention, the route followed can be registered on the basis of the radio phonically transmitted directions, change of direction and reference points.

The system according to the invention, in particular the computer program includes a well-defined logic, which at the time of return of the team verifies which information entered on the way in concern a degree of freedom of the first type, a degree of freedom of the second type or a reference point. Depending thereon, the logic will respectively, invert or non-invert the information entered.

Finally, the logic provides that the data entered (optionally after inversion) appear in reverse order [First in - Last out ]. The first direction, change of direc- tion or reference point as recorded on the way in, will be shown last on the way out, and vice versa.

On the basis of all this, the safety of the deployment team (i.e. the ability to correctly find the exit on time) by use of the system according to the invention described is no longer dependent on the ability to memorize of a team member, and operates flawless. Also, the user of the system, in particular the guardian, will remain always aware of the route followed, he may consult the route at any time, and may guide a retreating deployment team on which way to follow, for example, in this case, they have forgotten the sequence of directions, change of directions and/or reference points. This feature is novel compared the prior art. A local GPS-based method is not an alternative as the signal transmission is unreliable, inaccurate on very short distances (less than 1 meter) and does not include reference points.

After-Action Report

The computer-implemented method is further able to provide an After-Action Report.

The After-Action Report is a document, generated by the computer- implemented method after every use, which collects, summarizes and presents the whole course of the intervention performed under open-circuit breathing ap- paratus by summarizing all significant data, inserted and/or generated by the system, in a well-ordered and easy-view manner.

In one form, the After-Action Report is a printable pdf-document, but it can also exist in any other form (digital or on paper) that makes it possible to reread the course of intervention and all significant data input and/or data output afterwards.

For every intervention team that has been safeguarded with the system, the After-Action Report contains at least the following elements/data:

The date the intervention took place;

- The point of time at which the intervention team started their action using open circuit breathing apparatus;

The lowest filling pressure of all pressurized containers (of all team members) at that moment;

The physical volume of the pressurized container(s);

- The names (or identities) of the team members of the intervention team;

The nature of their mission (search and rescue, containing the fire source, etc);

The name (or identity) of the user of the system (the guardian);

Every residual pressure value the guardian entered in the system, at which point in time he/she did that, in which context (intervention team on way in, intervention team on way back, intervention team stationary at an action point, secondary compressed air consumption by victim yes/no, ...), and which air consumption rate (e.g. in litres per minute), remaining time till retreat and remaining time till empty pressurized container the system generated at that moment;

The point in time the intervention team started their retreat;

The point in time the intervention team remained stationary at an action point (without progressing further);

a graphical representation (e.g. by chart) of the compressed air consump- tion (decrease of pressure in the container) in the course of the time;

a graphical representation (e.g. by chart) of the associated consumption rate (e.g.. in litres per minute) in the course of the time.

Every object (door, refrigerator, bed, ...) the intervention team encountered on their way in, and at which point in time they did so. Every followed direction or change of direction (90° left, 90° right, stairs up, stairs down, etc.) the intervention team took/made, and at which point in time they did so.

The way to be followed back out (generated by the system on the basis of the way in);

Every additional information about the deployment (occurrence of a bang, the hearing of a victim calling for help, etc.) the user of the system entered as a note, and the point in time he/she did so;

Each point in time at which a no-response-alarm has been started;

- Each point in time at which a no-response-alarm has been cancelled;

A few blank lines to add some extra handwritten remarks on the report, e.g. after printing it out.

The purpose and the benefit of this After-Action Report is that one can reconstruct the whole course of intervention by just reading one single document. For post-incidental research, for example when a fire fighter comes to perish during an action using open-circuit breathing apparatus, this can be very useful to find out all circumstances (and hence even the cause) of the incident.

The invention will now be explained, by way of illustration, with an example.

Herein, reference is made to a computer-implemented monitoring program with the name Flow Control 300® and that is designed by the inventor of this application and wherein the invention has been implemented. It goes without saying that the invention is not limited to this specific computer-implemented monitoring program, but that each variant of the computer-implemented monitor- ing program that meets the characteristics of the invention, falls within the scope of protection of the invention.

EXAMPLES

EXAMPLE 1

In the following example, a full deployment is chronologically described, wherein the computer-implemented monitoring program is used. Friday 24 august 2012 - 18:23h

A fire truck of the fire brigade sets out for what was going to be a house fire, wherein one victim is still present. The fire truck is staffed with six men, wherein each knows by order of procedure what their task will be once the fire truck will be at the location.

Considering the nature of the call, a little later a second fire truck departs, with similar crew, from the fire station.

The fire truck arrives at location around 18:29h. The commander observes a heavy smoke emission with the source of the fire on the second floor. The rescue team (fireman 1 and fireman 2) prepares to enter the property, to look for the victim. From obtained information, the victim is supposed to be at the back of the first floor. Meanwhile, fireman Y has already taken place behind the portable computer in the fire truck. He starts the program Flow Control 300 and logs on for monitoring (to the commander). In the screen 'registration' of Flow Control 300, he notes that a team of 2 persons departs, namely fireman 1 and fire- man 2, with the mission to rescue a missing victim (Figure 1 ).

The rescue team (team 1 ) enters the property. Just before, they radiophonically transmit their current filling pressure of both their compressed air cylinders to the guardian (fireman Y). The guardian enters the lowest of both filling pressures (in this case 303 bar) into the program Flow Control 300. He also enters the physical volume of the compressed air cylinder, which according to current manufacturing standards always amounts to 6.8 litres. He confirms these two data with a few clicks of the mouse, which starts the clock. The deployment is launched. It is 18:30h (Figure 2).

Note that the guardian gets to see a visual representation of the residual fill level of the pressurized container on the basis of a progress bar in the middle of the screen (of which the maximum height represents the filling pressure at start time [303 bar], and the indicated level is determined by the ratio of the [remaining time till 0 bar] to [the remaining time till 0 bar + the elapsed time]). This progress bar will refresh its status every time the guardian enters a residual pressure value, but thereafter also automatically (so without requiring an action from the user of the system) and periodically in the course of time (every second).

Due to the heavy smoke, the rescue team does not see a thing. According to the procedure, the team remains undivided, and the first man goes first, al- ways touching the wall. Every few meters he transmits radiophonically through his full face mask to the guardian which direction changes he makes (90° left, 180°, 90° right, ...) and which recognisable objects he encounters. It is the task of his team member to memorise this information in sequence. After all, when they turn back subsequently, they can correctly reconstruct their way back in this way (wherein the odds of getting lost are minimized).

In the following example of Flow Control 300, the intervention for the rescue team goes as follows:

00:01 :29 - Team 1 (18:31 h)

Radiophonic communication of rescue team to guardian:

"To guardian, here rescue team, we go 90° left, over."

The guardian clicks on '90° left' and radiophonically confirms that he has understood the message well:

"Roger for 90° left." 00:03:00 - Team 1 (18:33h)

Radiophonic communication of rescue team to guardian:

"To guardian, here rescue team, we step through a door, over."

The guardian manually enters 'door' and radiophonically confirms that he hast understood the message well:

"Roger for rescue team, you go through a door."

00:03:31 - Team 1 (18:33h)

Radiophonic communication of rescue team to guardian:

"To guardian, here rescue team, we have 293 bar left and go up a flight of stairs right now."

The guardian enters 293 bar, clicks 'up stairs' and answers radiophonically: "Roger for rescue team, you still have about 58 minutes before starting retreat." (Figure 3)

00:04:36 - Team 1 (18:34h)

Radiophonic communication of rescue team to guardian:

"To guardian, here rescue team, we are on the first floor and hear the victim call for help."

The guardian enters this information as a note, and answers radiophonically:

"That is well understood for rescue team, you hear the victim call for help." (Figures 4 and 5)

The second fire truck arrives on site. An additional team reports as available. The commander decides to immediately deploy the two firemen to fight the fire (in-house firefighting). The guardian initializes the monitoring of a second team, the assault team, in Flow Control 300. In the screen 'registration' of team 2, he enters that fireman 3 and fireman 4 depart, with the mission of locating and containing the source of the fire (an assault) (Figures 6 and 7).

Moments later, the assault team reports that they are entering the building, with a starting pressure of 305 bar (the lowest of both filling pressures). It is 18:35h (Figure 8). 00:05:57 - Team 1 (18:35h)

Radiophonic communication of rescue team to the guardian:

"To guardian, here rescue team, we go 90° right, over ."

The guardian clicks on '90° right' and radiophonically confirms that he has un- derstood the message well:

"Roger for rescue team, you go 90° right."

00:01 :16 - Team 2 (18:36h)

Radiophonic communication of assault team to guardian:

"To guardian, here assault team, we go 90° left, over ."

The guardian clicks on '90° left' for team 2 and radiophonically confirms that he has understood the message well:

"Roger for you go 90° left." 00:06:35 - Team 1 (18:36h)

Radiophonic communication of rescue team to the guardian:

"To guardian, here rescue team, momentarily we have a residual pressure of 270 bar, and are now stepping through a sliding door, over."

The guardian enters a pressure of 270 bar, and enters 'sliding door' and an- swers radiophonically:

"Roger for rescue team, sliding door. FYI: you have 30 minutes and 44 seconds before starting retreat." (Figure 9)

00:02:44 - Team 2 (18:37h)

Radiophonic communication of assault team to guardian:

"To guardian, here assault team, we step through a door, over."

"Roger for assault team, you go through a door."

00:03:14 - Team 2 (18:38h)

Radiophonic communication of assault team to guardian:

"To guardian, here assault team, we have 288 bar left and go up a flight of stairs right now." The guardian clicks 'up stairs', enters 288 bar and answers radiophonically: "Roger for assault team, you still have a good 35 minutes before starting retreat." (Figure 10) 00:09:34 - Team 1 (18:39h)

Radiophonic communication of rescue team to the guardian:

"To guardian, here rescue team, momentarily we have a residual pressure of

255 bar, over."

The guardian enters a pressure of 255 bar, and answers radiophonically: "Roger for rescue team, you have 29 minutes and 28 seconds till starting retreat."

00:04:53 - Team 2 (18:39h)

Radiophonic communication of assault team to guardian:

"To guardian, here assault team, we go 90° right, and then back 90° right, over

The guardian clicks twice on '90° right' for team 2 and radiophonically confirms that he has understood the message well:

"Roger for twice 90° right."

00:05:18 - Team 2 (18:40h)

Radiophonic communication of assault team to guardian:

"To guardian, here assault team, go up another flight of stairs, over."

The guardian clicks 'up stairs' and answers radiophonically:

"Roger for assault team, up another flight of stairs."

00:10:21 - Team 1 (18:40h)

Radiophonic communication of rescue team to the guardian:

"To guardian, here rescue team, we have found the victim, over."

The guardian clicks on 'victim', and answers radiophonically:

"Roger for rescue team, you have found the victim."

00:10:40 - Team 1 (18:40h)

Radiophonic communication of rescue team to the guardian: "To guardian, here rescue team, we have provided the victim with a breathing mask and start evacuating on 250 bar residual pressure, over."

The guardian enters 250 bar as return pressure, clicks on 'secondary compressed air consumption', and answers radiophonically:

"Roger for rescue team, you are giving the victim breathable air and return with the victim at 250 bar. FYI: you have about 25 minutes for the retreat, which should be more than enough." (Figures 1 1 , 12 and 13)

In Flow Control 300, one can now see, at a single glance, that the retreat trip has been started well in time (green triangle in graph + green check mark on the timer). The consumption curve, from now on showed by a dotted line, and a compressed air deduplication icon in the monitoring field "-CAC²-" (secondary compressed air consumption) also indicate that the victim is hooked onto the compressed air of the fireman. Based on the conditions of manufacture of the breathing mask, the Flow Control 300 now assumes a continuous flow of 40 l/min additional consumption. A subsequent calculation shall be able to provide a more exact picture of the total consumption (compressed air carrier + continuous flow to the victim).

00:06:11 - Team 2 (18:41 h)

Radiophonic communication of assault team to guardian:

"To guardian, here assault team, we are stepping through a door and have a residual pressure of 247 bar, over."

The guardian manually enters 'door', enters a residual pressure of 247 bar, and answers radiophonically:

"Roger for assault team, you are going through a door with 247 bar residual pressure. FYI: you have about 15 minutes to go till starting the retreat." (Figure 14)

00:07:43 - Team 2 (18:42h)

Radiophonic communication of assault team to guardian:

"To guardian, here assault team, we have found the source of the fire. It is located in the insulation. We will have to remove the wall for some time in order to contain the source of the fire. Residual pressure 242 bar, over."

The guardian clicks on 'found source of fire' and enters a residual pressure of 242 bar. He does this by means of entering an action point. The assault team will not continue on, but will remain stationary. (Figures 15, 16 and 17)

The guardian finally answers radiophonically:

"Roger for assault team, 242 bar and found the source of the fire. FYI: you have a 31 minutes and 38 seconds to go till starting retreat."

For the sake of completeness, the guardian also informatively enters the nature of the source of the fire as a note. 00:12:53 - Team 1 (18:42h)

At approximately the 13^th minute, a sudden loud bang is heard from within the property. The guardian immediately checks if the rescue team is doing ok.

"To rescue team, here guardian, we have just heard a loud bang. Are you doing well, over?"

The guardian gets no response. He tries again. In the meantime he enters the bang as a note... (Figure 18)

"To rescue team, here guardian, come in, over."

The guardian still gets no response and raises alarm. To do this, he clicks 'alarm'. All essential data in Flow Control 300 turn grey. One can no longer enter any manipulations and an alarm tone is stricken. (Figures 19 and 20)

00:13:48 - Team 1 (18:43h)

The guardian hears radiophonically:

"To guardian, here rescue team, we are doing well. I repeat, we are doing well. Residual pressure 214 bar. The bang was a propane tank which exploded due to the heat, but without effects, over."

The guardian confirms that he has understood the message well, calls off the alarm by clicking 'end alarm' and enters 214 bar. (Figures 20 and 21 )

He also enters the information about the propane tank as a note.

00:17:13 - Team 1 (18:47h)

Radiophonic communication of rescue team to guardian:

"To guardian, here rescue team, we are currently located at the bottom of the stairs, on the ground floor. We are unsure about which way to go, can you guide us, over?"

The guardian checks the simulated return route, and answers radiophonically: "To rescue team, here guardian, you will find a door at the bottom of the stairs. You have to go through the door, after which you are to turn 90° right to reach the exit of the property (Figure 22). Do you copy, over?"

Radiophonic communication of rescue team to the guardian:

"Roger, that's well understood. Thank you."

00:18:56 - Team 1 (18:48h)

The rescue team and the victim reach the exit of the property. The victim is transferred to medical emergency services.

The guardian clicks on 'end of deployment'. The Flow Control 300 closes the monitoring of team 1 , and displays a generated After-Action Report (Figure 23).

00:27:15 - Team 2 (19:02h)

Assuming that team 2 will require the same amount of time to return as had passed on the outward journey, it has seemingly already exceeded the absolute time of return (timers turns red and an imminent signal tone is heard). However, with the setting of an action point, the guardian can make a well-informed decision to allow the assault team to work somewhat longer. As the assault team remained stationary active after about 7 minutes and 49 seconds, the guardian is allowed to assume that they will also need about 8 minutes to return. The assault team may thus remain stationary active for another good 12 minutes. Only then, their compressed air cylinder will be only 7 minutes and 49 seconds away from being empty (Figure 24).

00:36:44 - Team 2 (19:11 h)

When the time ticks away to less than 5 minutes before absolute return, Flow Control 300 indicates that by flashing it in yellow. In this way, the guardian knows that the assault team better be called back for safety reasons (Figure 25).

Radiophonic communication of guardian to assault team: "To assault team, here guardian, you should return. I repeat, you should return, over."

Radiophonic communication of assault team to guardian: "Roger for guardian, we are returning. FYI: source of the fire has just been contained, over."

The guardian enters as a note that the source of the fire has been contained and answers radiophonically: "Well understood for assault team, source of the fire contained." A few minutes later, the assault team reaches the exit of the property safe and sound.

The guardian clicks on 'end of deployment'. Flow Control 300 closes the monitoring of team 2, and displays a generated After-Action Report (Figure 26).

EXAMPLE 2

Note that, because of the following similarities, a similar example can be given for a diver, for example diving down to a ship wreck in search for something or someone :

- Divers also use independent open-circuit breathing apparatus when going under water (pressurized container filled with air at 200 bar).

- Divers also know the residual pressure left in their container at each moment (they also use a manometer).

- Divers also have no sight when under water (and hence, also have to memorize their way in, in order to afterwards find their way out).

- Divers can also use equipment to communicate information with another person, who is not under water (for example the residual pressure, objects they encounter, etc.). Hereby, this person can guard the diver in the same way as described above, using the defined invention (of which Flow Control 300 is an example).

Claims

A system, suitable for monitoring open-circuit independent respiratory protection of a user of a pressurized container, comprising:

- an open-circuit independent respiratory protection, comprising at least a harness, a pressurized container, a pressure regulator, one or more pressure tubes, a means for administering gas, and a pressure sensor.

- at least two communication units, suitable for exchanging between them on the one hand information concerning at least the immediate gas pressure in the pressurized container and on the other hand information concerning the course of intervention, such as the path followed and deployment activities;

- a computer, suitable for executing a computer-implemented monitoring program (4), that is not carried by the carrier of the open-circuit independent respiratory protection; and

- a computer-implemented monitoring program that is provided with information about at least the filling pressure and the physical volume of the pressurized container, the immediate gas pressure in the pressurized container and the time-lapse, and that at least calculates the time-to-return in a dynamic manner.

System according to claim 1 , wherein the pressurized container is suitable for (compressed) air.

The system according to any one of claim 1 or 2, wherein the means for administering gas is a full face mask, a breathing piece, or a pressure suit.

System according to any one of claim 1 to 3, wherein the communication is radiophonic oral communication.

5. System according to any one of claim 1 to 4, wherein the communication units between which information is exchanged, are incorporated in the ASTRID network.

6. System according to any one of claim 1 to 5, wherein the computer for executing a computer-implemented program is a portable computer.

7. System according to any one of claim 1 to 6, wherein said computer- implemented monitoring program is present on said computer.

8. System according to any one of claim 1 to 7, wherein said computer- implemented monitoring program is present on a server on the internet, that is in connection with said computer.

9. Use of the system according to any one of the claims 1 to 8 by a carrier of an open-circuit independent respiratory protection, such as a fireman, a diver and a carrier of a protective suit.

Use of the system according to any one of the claims 1 to 8 in the case of fire fighting, in underwater situations, and in situations involving hazardous gasses or vapours.

Computer-implemented monitoring program, suitable for monitoring an open-circuit independent respiratory protection, comprising a step of dynamically calculating a time-to-return and/or a time-to-empty pressurized container, based on at least the immediate gas pressure in the pressurized container and the time-lapse. 12. Computer-implemented monitoring program according to claim 1 1 , comprising the step of automatically determining the way out from a deployment area from data stored during the way into the deployment area.

13. A computer-implemented method, comprising a single input of the filling pressure and physical volume of the pressurized container, the continuous receiving of information about the immediate gas pressure in the pressurized container and the time-lapse, and the continuous calculating of the time-to-return and/or the time-to-empty pressurized container of a user of a pressurized container for monitoring open-circuit independent respirato- ry protection.

14. The computer-implemented method according to claim 13, further providing an After-Action Report.

15. A computer comprising a memory and a processor, wherein the processor executes the computer-implemented method according to any one of claims 13 and 14.