WO1996003174A1 - Checking the operation of breathing equipment - Google Patents

Checking the operation of breathing equipment Download PDF

Info

Publication number
WO1996003174A1
WO1996003174A1 PCT/SE1995/000784 SE9500784W WO9603174A1 WO 1996003174 A1 WO1996003174 A1 WO 1996003174A1 SE 9500784 W SE9500784 W SE 9500784W WO 9603174 A1 WO9603174 A1 WO 9603174A1
Authority
WO
WIPO (PCT)
Prior art keywords
pressure
value
closure valve
indicating
pressure regulator
Prior art date
Application number
PCT/SE1995/000784
Other languages
French (fr)
Inventor
Mats Lundberg
Original Assignee
Comasec International S.A.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Comasec International S.A. filed Critical Comasec International S.A.
Priority to CA002196094A priority Critical patent/CA2196094C/en
Priority to EP95926556A priority patent/EP0956065B1/en
Priority to DE69523960T priority patent/DE69523960T2/en
Priority to JP50568796A priority patent/JP3782823B2/en
Priority to AU30889/95A priority patent/AU707011B2/en
Publication of WO1996003174A1 publication Critical patent/WO1996003174A1/en

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63C—LAUNCHING, HAULING-OUT, OR DRY-DOCKING OF VESSELS; LIFE-SAVING IN WATER; EQUIPMENT FOR DWELLING OR WORKING UNDER WATER; MEANS FOR SALVAGING OR SEARCHING FOR UNDERWATER OBJECTS
    • B63C11/00—Equipment for dwelling or working underwater; Means for searching for underwater objects
    • B63C11/02—Divers' equipment
    • B63C11/18—Air supply
    • B63C11/22—Air supply carried by diver
    • A—HUMAN NECESSITIES
    • A62—LIFE-SAVING; FIRE-FIGHTING
    • A62B—DEVICES, APPARATUS OR METHODS FOR LIFE-SAVING
    • A62B27/00—Methods or devices for testing respiratory or breathing apparatus for high altitudes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63C—LAUNCHING, HAULING-OUT, OR DRY-DOCKING OF VESSELS; LIFE-SAVING IN WATER; EQUIPMENT FOR DWELLING OR WORKING UNDER WATER; MEANS FOR SALVAGING OR SEARCHING FOR UNDERWATER OBJECTS
    • B63C11/00—Equipment for dwelling or working underwater; Means for searching for underwater objects
    • B63C11/02—Divers' equipment
    • B63C11/18—Air supply

Definitions

  • the present invention relates to a method of checking the working and/or the operational state of breathing equipment prior to its use, and also to breath- ing equipment which includes an arrangement for checking at least one working or state parameter of the equipment.
  • the system gas-supply is completely full and therewith contains the amount of breathing gas that can be expected to be consumed, that the hoses leading to the breathing mask are tightly sealed, i.e. will not leak to the surroundings and therewith reduce the amount of gas available for breathing, that gas is able to flow from the gas res ⁇ ervoir freely and without hinder and will arrive at the breathing mask in sufficient volumes, i.e. that there is practically no resistance to the air flow and that the pressure prevailing in the breathing mask is higher than ambient pressure.
  • the gas reservoir carried by the person concerned will normally have the form of a gas cylinder which contains breathing gas at a pressure of normally 300 bars, when the cylinder is full.
  • the breathing gas is normally air, although under special circumstances may often contain at least 20 percent by volume oxygen and an inert gas, most often nitrogen and perhaps also helium. In some cases, for instance for diving to great depths, the breathing gas contains less than 20 percent oxygen by volume. Since the gas reservoir has a relatively small volume, it is important that the reservoir pressure is sufficiently high to supply the user with an anticipated maximum gas volume.
  • the hoses or lines leading from the gas reservoir are tight and that the flow resistance presented thereby is sufficiently small for the gas reservoir to deliver to the user a quantity of gas which is large enough to satisfy the user's requirements, even in the case of an extreme need, is extreme.
  • Another important safety problem concerns the gas pressure in the mask when the mask is in place. The mask pressure must be greater than the ambient pressure, so that non-breathable atmosphere, particularly toxic atmosphere, is unable to penetrate into the mask.
  • One object of the present invention is to provide a method whereby these functions and/or states can be checked prior to using breathing equipment.
  • Another object of the invention is to provide an arrangement by means of which at least one functional parameter or state parameter of breathing equip ⁇ ment can be checked prior to use.
  • the first of these methods is achieved in accordance with the invention with a method which is characterized by activating a control circuit which meas ⁇ ures at least one functional parameter or state parameter, comparing the meas ⁇ ured parameter value with a control value and indicating acceptable or insuffi ⁇ cient values respectively when the set criterion is fulfilled or when it is not ful ⁇ filled.
  • the second object is achieved with an arrangement which includes breathing equipment, a programmed microprocessor, a sensor which is included in the breathing equipment and connected to the microprocessor, and an indicat ⁇ ing arrangement connected to the microprocessor.
  • the control circuit is activated either by sensing intermittently a functional parameter or a state parameter of the breathing equipment, comparing the sensed parameter value with the latest measured parameter value, and activating the control circuit when there is a significant difference between these values.
  • Another method to activate the control circuit is to intermittently sense a functional parameter or a state parame ⁇ ter of the breathing equipment, to compare the sensed parameter value with a predetermined value, e. g. 10 percent, of the maximum value of said parameter and to activate the control circuit when the sensed parameter is equal to or greater then the predetermined value.
  • the control circuit is acti ⁇ vated manually, by pressing a start button for instance.
  • Fig. 1 is a block schematic illustrating breathing equipment provided with a control circuit for carrying out a functional test
  • Fig. 2 is a diagram which illustrates primary pressure as a function of time when carrying out a functional test.
  • the breathing equipment 16 includes a gas reservoir, which is usually a gas cylinder or gas container 1 containing breathing gas, for instance air or an oxygen-containing gas which includes most frequently at least 20 percent by volume oxygen and an inert gas, for instance nitrogen or helium, at a pressure of normally 300 bars when the container is completely full.
  • the gas container 1 includes an outlet opening in which there is mounted a closure valve 2.
  • the gas container 1 is connected to a primary pressure regulator 4, through the medium of the closure valve 2.
  • a line 3 extends from the primary pressure regulator 4 to a secondary pressure regulator 5 which is located immediately upstream of a breathing mask 6.
  • the pressure regulator 4 is set to reduce the pressure in the gas con ⁇ tainer 1 to typically about 7 bars in the line 3 downstream of the primary pressure regulator, i.e.
  • the first regulator 4, and the second pressure regulator 5 is set to reduce the pressure of the gas passing to the breathing mask 6 still further, to a pressure of about 25 mm water column, i.e. to a pressure suitable for use in the mask 6.
  • the pressure regulator 5 is normally a requirement-controlled regulator which is closed prior to putting on the mask 6 and is opened by the subpressure that is generated when the wearer first inhales.
  • the regulator 5 is opened when the relative pressure in the mask 6 falls beneath a preset value. It is necessary to activate other similar regulators manually, through separate activating means.
  • a pressure sensor 10 is mounted in a space 12 formed between the clo ⁇ sure valve and the primary pressure regulator 4. This sensor 10 measures the pressure in the space 12 and is connected to a microprocessor 7 by means of a line 8. Lines 9 extend from the microprocessor 7 to an indicating arrangement 11 which is preferably, but not necessarily, mounted in the breathing mask 6.
  • the indicating arrangement 11 includes at least one indicating device. Preferably, at least one indicating device is provided for each function included in the functional test.
  • the indicating device is preferably a light-emitting diode (LED).
  • the indicating arrangement 11 provided in the breathing mask 6 is preferably visible to the user, both when the mask 6 is worn and when removed, and will also be visible to people in the vicinity of the user.
  • the breathing mask 6 included in the breathing equipment is preferably also provided with a differential pressure meter 14, which is connected to the microprocessor 7 by means of a line 15.
  • the measured differential pressure is indicated in an indicating device by the indicating arrangement 11.
  • the mask 6 of the illustrated breathing equipment is provided with a differential pressure meter 14 which is connected microprocessor 7 by a line 15.
  • the measured differential pressure is indicated in the indicating arrangement 11 , visible to the user with the mask 6 fitted.
  • the lines 9 and 15 may be replaced with cordless connections between the microprocessor 7 and the indicating ar- rangement 11 and between the microprocessor and the differential pressure meter 14 respectively.
  • the microprocessor 7 is programmed to carry out some or all of the func ⁇ tions described below.
  • the microprocessor senses the pressure in the space 12 intermittently, for instance every second or at some other chosen frequency, through the medium of the sensor 10, and compares the sensed pressure with the pressure that was last sensed.
  • the microprocessor senses the pressure in the space 12 intermittently, for instance every second or at some other chosen frequency, through the medium of the sensor 10, and compares the sensed pressure value with a predetermined pressure value, for example 10 percent of the maximum pressure in the gas container 1.
  • the closure valve 2 before testing the breathing equipment, the closure valve 2 is opened to an extent at which the space 12 is under the same pressure as the container 1 , whereafter the valve 2 is closed.
  • the pressure in the space 12 increases as gas from the container 1 flows into the space.
  • the sensor 10 will deliver a much higher pressure value to the microprocessor 7.
  • the microprocessor 7 receives the start signal required to carry out the functional diagnosis and state diagnosis in accordance with the in- vention in conjunction with the pressure comparison that automatically takes place.
  • the microprocessor is fitted with a start button which replaces the start signal obtained when a marked pressure in ⁇ crease is obtained after each alternate sensed pressure value when the closure valve 2 is opened. It is also necessary in this case to open the closure valve to an extent in which the pressure in the space 12 will at least substantially equal the gas pressure in the container 1 , whereafter the valve is closed.
  • the primary pressure valve 4 In order for the test to provide the information required, it is necessary for the primary pressure valve 4 to be set so that a suitable pressure will be ob- tained in the line 3. Furthermore, the secondary pressure regulator 5 must be closed prior to opening the valve 2.
  • Figure 2 illustrates the gas pressure in the proximity of the sensor 10 as a function of the time at which the test was carried out. None of the axes is graduated. Position 0 shows the relative pressure at the sensor 10 prior to starting the test.
  • the closure valve 2 When the closure valve 2 is opened, the pressure in the space 12 will rise to the pressure of the gas reservoir, as illustrated at position 1 , and there is obtained in the line 3 a pressure which is contingent on the setting of the regulator 4, this pressure being 7 bars in the illustrated case.
  • the valve 2 is then closed.
  • the pressure that now prevails in the line 3 is not shown in Figure 2.
  • the microprocessor 7 senses the pressure prevailing in the space 12 after a maximum pressure has been reached, i.e. after position 1 , for instance at posi ⁇ tion 2.
  • the microprocessor will understand this to mean that the gas supply does not fulfil the necessary pressure criterion and indicate in the indicating arrangement 11 an insufficiency value, said arrangement preferably being mounted in the mask 6.
  • the indicating arrangement 11 indicates an acceptable value, when the pressure exceeds or is equal to the control value.
  • the present functional test also includes ensuring that the line leading to the mask 6, i.e. the second pressure regulator 5, is tight and will not leak gas to the surroundings.
  • the sensor 10 measures the pressure after a pre- determined time period, for instance 3-20 seconds, from the time at which pres ⁇ sure was measured in position 2 in Figure 2. The duration of this time lapse will depend on the level of accuracy desired.
  • This pressure is measured before po ⁇ sition 3.
  • the indicating arrangement 11 will indicate an insufficiency value.
  • the in ⁇ dicating arrangement will indicate that the value is acceptable.
  • the regulator 5 is opened with the mask 6 removed, so that the gas present between the closure valve 2 and the regulator 5 is able to flow freely to atmo ⁇ sphere, the valve 2 still being closed, and the pressure decrease in the space 12 is measured as a function of time, with the aid of the sensor 10.
  • One criterion of acceptable outflow or function is found in the time taken for the pressure to fall to a% of the original pressure, for instance the pressure that prevailed prior to opening the second regulator, from (b-a)%, where b is a value greater than a. and equal or less than 100, for example 50, and a may be 10 for instance.
  • this time duration is equal to or smaller than a third control value, the indicating arrangement 11 will indicate an acceptable value; in other cases, an unacceptable value will be indicated.
  • Position 3 indicates that the second regulator 5 is open so that the gas content of the equipment downstream of the closure valve is able to flow freely from the system.
  • Position 4 indicates that the pressure has fallen to a value of (100 -a)% of the pressure prevailing at position 3.
  • Position 5 indicates that the pressure has fallen to a%.
  • Another criterion for acceptable gas outflow, or function is one in which the pressure that prevails after opening the second regulator 5 is measured after a predetermined time interval. If, when measured, it is found that the pressure has fallen to the same value as a predetermined highest value or to a lower value, during this time period, the microprocessor 7 will indicate, via the indicat ⁇ ing arrangement 11 , that the supply of gas to the mask 6 is acceptable. Other ⁇ wise, the indicating arrangement 11 will indicate that the equipment is faulty.
  • This second criterion is also shown in Figure 2.
  • the pressure is measured from the time of opening the second regulator 5, i.e. at position 3, and is compared with a fourth control value, for instance at position 5 for the sake of simplicity. If the pressure at time point t5 exceeds a predetermined pres ⁇ sure, P5, the ordinate at position 5, the indicating arrangement 11 will indicate a malfunction.
  • the pressure decrease as a function of time can be measured in other ways.
  • the derivative of the pressure curve can be measured as a function of time at the curve inflection point.
  • the derivative i.e. the directional coefficient of the curve, is then a measurement of the outflow rate.
  • the face mask 6 fits tightly to the user's face and that when breathing with the closure valve 2 open a relative overpres ⁇ sure with regard to ambient atmosphere is maintained in the space between the mask 6 and the wearer's face. Accordingly, the closure valve 2 is opened after carrying out the aforedescribed tests, and a check is optionally made to ensure that the primary pressure regulator 4 is set to the correct setting. After having put on the mask 6, the regulator will open automatically as the user breathes in, or is opened manually if the regulator should be closed or switched-off.
  • the breathing mask 6 includes a sensor 14 which measures the differ ⁇ ence between the pressures that prevail inside and outside the mask 6. Should the pressure between the mask 6 and the face of the wearer be greater than the pressure prevailing outside the mask during at least one breathing cycle, the indicating arrangement 11 will indicate a positive pressure, i.e. a fully acceptable function. Otherwise, the indicating arrangement will indicate a non-acceptable function.
  • serviceable equipment is indicat ⁇ ed when all tests have shown an acceptable result.
  • the use of the equipment is prevented when one or more tests show an unacceptable result.
  • the equipment can be used when the gas reservoir has been filled to a higher pressure than a predetermined lowest pressure, wherein the indicating arrangement 11 will indicate that the reservoir pressure is lower than the lowest recommended value for a full gas reservoir.
  • use of the equipment is prevented, or blocked, when the pressure in the gas reservoir is lower than a lowest predetermined pressure value, for instance 20 percent of maximum pressure.
  • the microprocessor is powered by a small source of electric current, for instance by one or more batteries.
  • the indicating arrangement will also preferably indicate the remaining operational time or useful life of the current source. If the remaining operational time is lower than a predetermined operational time, this is indicated in the indicating arrangement.
  • the equipment includes a registering device which is associated with the control circuit. This device registers each activation of the control circuit and the results of the tests and functional checks carried out after each activation.
  • An active or a passive memory unit connected to the microprocessor is one ex- ample of such registering devices. This registration enables subsequent checks to be made to ascertain the number of times the equipment has been tested and the results obtained in conjunction therewith.

Abstract

The invention relates to a method of checking the working and/or the state of breathing equipment prior to its use, and also to an arrangement for carrying out the method. The breathing equipment includes a control circuit which, in turn, includes a programmed microprocessor (7), a sensor (10) mounted in the breathing equipment and connected to the microprocessor, and an indicating arrangement (11) connected to the microprocessor (7). The inventive method is characterized by activating the control circuit and therewith measuring or determining at least one functional or state parameter, comparing the measured parameter value with a control value, and indicating an acceptable or unacceptable value in the indicating arrangement (11).

Description

CHECKING THE OPERATION OF BREATHING EQUIPMENT
The present invention relates to a method of checking the working and/or the operational state of breathing equipment prior to its use, and also to breath- ing equipment which includes an arrangement for checking at least one working or state parameter of the equipment.
It is absolutely necessary to ensure that the breathing equipment used by a diver or a fireman, for instance, is fully serviceable and faultless prior to enter¬ ing non-breathable atmospheres, for instance when diving or when working in smoke-filled or toxic environment for instance.
Among other things, it is necessary to check that the system gas-supply is completely full and therewith contains the amount of breathing gas that can be expected to be consumed, that the hoses leading to the breathing mask are tightly sealed, i.e. will not leak to the surroundings and therewith reduce the amount of gas available for breathing, that gas is able to flow from the gas res¬ ervoir freely and without hinder and will arrive at the breathing mask in sufficient volumes, i.e. that there is practically no resistance to the air flow and that the pressure prevailing in the breathing mask is higher than ambient pressure.
The gas reservoir carried by the person concerned will normally have the form of a gas cylinder which contains breathing gas at a pressure of normally 300 bars, when the cylinder is full. The breathing gas is normally air, although under special circumstances may often contain at least 20 percent by volume oxygen and an inert gas, most often nitrogen and perhaps also helium. In some cases, for instance for diving to great depths, the breathing gas contains less than 20 percent oxygen by volume. Since the gas reservoir has a relatively small volume, it is important that the reservoir pressure is sufficiently high to supply the user with an anticipated maximum gas volume.
It is also important that the hoses or lines leading from the gas reservoir are tight and that the flow resistance presented thereby is sufficiently small for the gas reservoir to deliver to the user a quantity of gas which is large enough to satisfy the user's requirements, even in the case of an extreme need, is extreme. Another important safety problem concerns the gas pressure in the mask when the mask is in place. The mask pressure must be greater than the ambient pressure, so that non-breathable atmosphere, particularly toxic atmosphere, is unable to penetrate into the mask.
One object of the present invention is to provide a method whereby these functions and/or states can be checked prior to using breathing equipment. Another object of the invention is to provide an arrangement by means of which at least one functional parameter or state parameter of breathing equip¬ ment can be checked prior to use.
The first of these methods is achieved in accordance with the invention with a method which is characterized by activating a control circuit which meas¬ ures at least one functional parameter or state parameter, comparing the meas¬ ured parameter value with a control value and indicating acceptable or insuffi¬ cient values respectively when the set criterion is fulfilled or when it is not ful¬ filled. The second object is achieved with an arrangement which includes breathing equipment, a programmed microprocessor, a sensor which is included in the breathing equipment and connected to the microprocessor, and an indicat¬ ing arrangement connected to the microprocessor.
Advantageous embodiments of the present invention are set forth in the dependent Claims.
According to the present invention, the control circuit is activated either by sensing intermittently a functional parameter or a state parameter of the breathing equipment, comparing the sensed parameter value with the latest measured parameter value, and activating the control circuit when there is a significant difference between these values. Another method to activate the control circuit is to intermittently sense a functional parameter or a state parame¬ ter of the breathing equipment, to compare the sensed parameter value with a predetermined value, e. g. 10 percent, of the maximum value of said parameter and to activate the control circuit when the sensed parameter is equal to or greater then the predetermined value. Alternatively, the control circuit is acti¬ vated manually, by pressing a start button for instance.
The present invention will now be described in more detail with reference to the accompanying drawing, in which
Fig. 1 is a block schematic illustrating breathing equipment provided with a control circuit for carrying out a functional test; and
Fig. 2 is a diagram which illustrates primary pressure as a function of time when carrying out a functional test.
The breathing equipment 16 includes a gas reservoir, which is usually a gas cylinder or gas container 1 containing breathing gas, for instance air or an oxygen-containing gas which includes most frequently at least 20 percent by volume oxygen and an inert gas, for instance nitrogen or helium, at a pressure of normally 300 bars when the container is completely full. The gas container 1 includes an outlet opening in which there is mounted a closure valve 2. The gas container 1 is connected to a primary pressure regulator 4, through the medium of the closure valve 2. A line 3 extends from the primary pressure regulator 4 to a secondary pressure regulator 5 which is located immediately upstream of a breathing mask 6. The pressure regulator 4 is set to reduce the pressure in the gas con¬ tainer 1 to typically about 7 bars in the line 3 downstream of the primary pressure regulator, i.e. the first regulator 4, and the second pressure regulator 5 is set to reduce the pressure of the gas passing to the breathing mask 6 still further, to a pressure of about 25 mm water column, i.e. to a pressure suitable for use in the mask 6. As the wearer breathes, the pressure in the mask will oscillate around this value during a breathing phase, therewith constantly maintaining an overpressure. The pressure regulator 5 is normally a requirement-controlled regulator which is closed prior to putting on the mask 6 and is opened by the subpressure that is generated when the wearer first inhales. The regulator 5 is opened when the relative pressure in the mask 6 falls beneath a preset value. It is necessary to activate other similar regulators manually, through separate activating means.
A pressure sensor 10 is mounted in a space 12 formed between the clo¬ sure valve and the primary pressure regulator 4. This sensor 10 measures the pressure in the space 12 and is connected to a microprocessor 7 by means of a line 8. Lines 9 extend from the microprocessor 7 to an indicating arrangement 11 which is preferably, but not necessarily, mounted in the breathing mask 6. The indicating arrangement 11 includes at least one indicating device. Preferably, at least one indicating device is provided for each function included in the functional test. The indicating device is preferably a light-emitting diode (LED). The indicating arrangement 11 provided in the breathing mask 6 is preferably visible to the user, both when the mask 6 is worn and when removed, and will also be visible to people in the vicinity of the user.
The breathing mask 6 included in the breathing equipment is preferably also provided with a differential pressure meter 14, which is connected to the microprocessor 7 by means of a line 15. The measured differential pressure is indicated in an indicating device by the indicating arrangement 11. Accordingly, the mask 6 of the illustrated breathing equipment is provided with a differential pressure meter 14 which is connected microprocessor 7 by a line 15. The measured differential pressure is indicated in the indicating arrangement 11 , visible to the user with the mask 6 fitted.
According to the present invention, the lines 9 and 15 may be replaced with cordless connections between the microprocessor 7 and the indicating ar- rangement 11 and between the microprocessor and the differential pressure meter 14 respectively.
The microprocessor 7 is programmed to carry out some or all of the func¬ tions described below. According to a third embodiment, the microprocessor senses the pressure in the space 12 intermittently, for instance every second or at some other chosen frequency, through the medium of the sensor 10, and compares the sensed pressure with the pressure that was last sensed. Alterna¬ tively, the microprocessor senses the pressure in the space 12 intermittently, for instance every second or at some other chosen frequency, through the medium of the sensor 10, and compares the sensed pressure value with a predetermined pressure value, for example 10 percent of the maximum pressure in the gas container 1.
According to the invention, before testing the breathing equipment, the closure valve 2 is opened to an extent at which the space 12 is under the same pressure as the container 1 , whereafter the valve 2 is closed. The pressure in the space 12 increases as gas from the container 1 flows into the space. As the valve 2 is opened, the sensor 10 will deliver a much higher pressure value to the microprocessor 7. The microprocessor 7 receives the start signal required to carry out the functional diagnosis and state diagnosis in accordance with the in- vention in conjunction with the pressure comparison that automatically takes place.
According to another embodiment, the microprocessor is fitted with a start button which replaces the start signal obtained when a marked pressure in¬ crease is obtained after each alternate sensed pressure value when the closure valve 2 is opened. It is also necessary in this case to open the closure valve to an extent in which the pressure in the space 12 will at least substantially equal the gas pressure in the container 1 , whereafter the valve is closed.
In order for the test to provide the information required, it is necessary for the primary pressure valve 4 to be set so that a suitable pressure will be ob- tained in the line 3. Furthermore, the secondary pressure regulator 5 must be closed prior to opening the valve 2.
Figure 2 illustrates the gas pressure in the proximity of the sensor 10 as a function of the time at which the test was carried out. None of the axes is graduated. Position 0 shows the relative pressure at the sensor 10 prior to starting the test. When the closure valve 2 is opened, the pressure in the space 12 will rise to the pressure of the gas reservoir, as illustrated at position 1 , and there is obtained in the line 3 a pressure which is contingent on the setting of the regulator 4, this pressure being 7 bars in the illustrated case. The valve 2 is then closed. The pressure that now prevails in the line 3 is not shown in Figure 2. The microprocessor 7 senses the pressure prevailing in the space 12 after a maximum pressure has been reached, i.e. after position 1 , for instance at posi¬ tion 2. If the pressure is below a first control value, for instance a value within the range of 97 to 80 percent, particularly a value in the vicinity of 90%, for instance a value in the range of 95% to 85%, particularly about 90% of the full pressure in the gas reservoir 1 , the microprocessor will understand this to mean that the gas supply does not fulfil the necessary pressure criterion and indicate in the indicating arrangement 11 an insufficiency value, said arrangement preferably being mounted in the mask 6. The indicating arrangement 11 indicates an acceptable value, when the pressure exceeds or is equal to the control value.
The present functional test also includes ensuring that the line leading to the mask 6, i.e. the second pressure regulator 5, is tight and will not leak gas to the surroundings. To this end, the sensor 10 measures the pressure after a pre- determined time period, for instance 3-20 seconds, from the time at which pres¬ sure was measured in position 2 in Figure 2. The duration of this time lapse will depend on the level of accuracy desired. This pressure is measured before po¬ sition 3. When the pressure difference between the pressure measured at posi¬ tion 2 and the pressure measured before position 3 is greater than a second control value, the indicating arrangement 11 will indicate an insufficiency value. When the pressure difference is lower than or equal to the control value, the in¬ dicating arrangement will indicate that the value is acceptable.
After testing the equipment for tightness, i.e. leakage, a check is made to ensure that the line 3 to the mask 6 is not blocked or that the supply of gas to the mask 6 through the regulator 5 is not hindered in some other way. To this end, the regulator 5 is opened with the mask 6 removed, so that the gas present between the closure valve 2 and the regulator 5 is able to flow freely to atmo¬ sphere, the valve 2 still being closed, and the pressure decrease in the space 12 is measured as a function of time, with the aid of the sensor 10. One criterion of acceptable outflow or function is found in the time taken for the pressure to fall to a% of the original pressure, for instance the pressure that prevailed prior to opening the second regulator, from (b-a)%, where b is a value greater than a. and equal or less than 100, for example 50, and a may be 10 for instance. When this time duration is equal to or smaller than a third control value, the indicating arrangement 11 will indicate an acceptable value; in other cases, an unacceptable value will be indicated.
This is shown in Figure 2, where position 3 indicates that the second regulator 5 is open so that the gas content of the equipment downstream of the closure valve is able to flow freely from the system. Position 4 indicates that the pressure has fallen to a value of (100 -a)% of the pressure prevailing at position 3. Position 5 indicates that the pressure has fallen to a%. When the time, t5-t4, is shorter than or equal to the third control value, the function of the equipment with regard to gas supply is considered to be fully acceptable.
Another criterion for acceptable gas outflow, or function, is one in which the pressure that prevails after opening the second regulator 5 is measured after a predetermined time interval. If, when measured, it is found that the pressure has fallen to the same value as a predetermined highest value or to a lower value, during this time period, the microprocessor 7 will indicate, via the indicat¬ ing arrangement 11 , that the supply of gas to the mask 6 is acceptable. Other¬ wise, the indicating arrangement 11 will indicate that the equipment is faulty.
This second criterion is also shown in Figure 2. In this case, the pressure is measured from the time of opening the second regulator 5, i.e. at position 3, and is compared with a fourth control value, for instance at position 5 for the sake of simplicity. If the pressure at time point t5 exceeds a predetermined pres¬ sure, P5, the ordinate at position 5, the indicating arrangement 11 will indicate a malfunction.
Naturally, the pressure decrease as a function of time can be measured in other ways. For instance, the derivative of the pressure curve can be measured as a function of time at the curve inflection point. The derivative, i.e. the directional coefficient of the curve, is then a measurement of the outflow rate.
Another important function of the equipment resides in checking that the control circuit (10, 7, 8, 9, 11 ) works satisfactorily. Accordingly, the indicating ar- rangement 11 will indicate the functional state of the control circuit (10, 7, 8, 9,
11) when measuring the pressure after having changed the pressure in the re¬ gion where the sensor 10 acts. A malfunction is indicated if this does not take place.
Another important function is that the face mask 6 fits tightly to the user's face and that when breathing with the closure valve 2 open a relative overpres¬ sure with regard to ambient atmosphere is maintained in the space between the mask 6 and the wearer's face. Accordingly, the closure valve 2 is opened after carrying out the aforedescribed tests, and a check is optionally made to ensure that the primary pressure regulator 4 is set to the correct setting. After having put on the mask 6, the regulator will open automatically as the user breathes in, or is opened manually if the regulator should be closed or switched-off.
The breathing mask 6 includes a sensor 14 which measures the differ¬ ence between the pressures that prevail inside and outside the mask 6. Should the pressure between the mask 6 and the face of the wearer be greater than the pressure prevailing outside the mask during at least one breathing cycle, the indicating arrangement 11 will indicate a positive pressure, i.e. a fully acceptable function. Otherwise, the indicating arrangement will indicate a non-acceptable function.
According to one preferred embodiment, serviceable equipment is indicat¬ ed when all tests have shown an acceptable result. The use of the equipment is prevented when one or more tests show an unacceptable result. However, according to one preferred embodiment, the equipment can be used when the gas reservoir has been filled to a higher pressure than a predetermined lowest pressure, wherein the indicating arrangement 11 will indicate that the reservoir pressure is lower than the lowest recommended value for a full gas reservoir. However, use of the equipment is prevented, or blocked, when the pressure in the gas reservoir is lower than a lowest predetermined pressure value, for instance 20 percent of maximum pressure.
The microprocessor is powered by a small source of electric current, for instance by one or more batteries. The indicating arrangement will also preferably indicate the remaining operational time or useful life of the current source. If the remaining operational time is lower than a predetermined operational time, this is indicated in the indicating arrangement. According to another preferred em¬ bodiment, the equipment includes a registering device which is associated with the control circuit. This device registers each activation of the control circuit and the results of the tests and functional checks carried out after each activation. An active or a passive memory unit connected to the microprocessor is one ex- ample of such registering devices. This registration enables subsequent checks to be made to ascertain the number of times the equipment has been tested and the results obtained in conjunction therewith.

Claims

Claims
1. A method of checking the function and/or state of breathing equipment (16) prior to its use, characterized by activating a control circuit (7-11 , 14, 15) which measures or determines at least one functional or state parameter of the equipment, comparing the measured parameter value with a control value, and indicating an acceptable or unacceptable value.
2. A method according to Claim 1 , characterized by registering each acti- . vation of the control circuit and the result derived thereby.
3. A method according to Claim 1 or 2, characterized by sensing intermit- tently a functional parameter or state parameter of the breathing equipment (16), comparing the sensed value with a latest measured value, and activating the control circuit (7-11 , 14, 15) when a significant difference exists between the values.
4. A method according to Claim 1 or 2, characterized by sensing intermit- tently a functional parameter or state parameter of the breathing equipment (16), comparing the sensed value with a predetermined value, and activating the con¬ trol circuit (7-11 , 14, 15) when a significant difference exists between the values.
5. A method according to Claim 3 or 4, wherein the breathing equipment (16) includes a gas reservoir (1 ) provided with an outlet opening, a closure valve (2) mounted in the reservoir outlet opening, a line (3) in which there is included sequentially, as seen from the closure valve (2), a primary pressure regulator (4), a second regulator (5) and a breathing mask (6), characterized by measuring the pressure between the closure valve (2) and the first pressure regulator (4) as a first functional or state parameter.
6. A method according to Claim 5, wherein the second pressure regulator (5) is closed and the closure valve (2) is then opened and then closed, character¬ ized by measuring the pressure between the closure valve (2) and the first pressure regulator (4) over a predetermined time interval, determining the pres¬ sure decrease during said time interval, and indicating an acceptable value when the pressure decrease is smaller than a first control value or an unacceptable value when the pressure decrease is equal to or greater than a first control value respectively.
7. A method according to Claim 5, wherein the second pressure regulator (5) is closed and the closure valve (2) is thereafter opened and then closed, characterized by opening the second pressure regulator (5) after closing the closure valve (2) so as to empty the space (12) between the closure valve (2) and the first pressure regulator (4) of gas, measuring the pressure in the space (12) as a function of time, and indicating an acceptable or an unacceptable value when, after a predetermined time period, the pressure decrease (negative slope) is greater than a second control value and equal to or smaller than a second control value, respectively.
8. A method according to Claim 5, wherein the second pressure regulator (5) is closed and the closure valve (2) is thereafter opened and then closed, characterized by opening the second pressure regulator (5) after closing the closure valve (2) so as to empty the space (12) between the closure valve (2) and the first pressure regulator (4) of gas, measuring the pressure in the space (12) a second predetermined time period after opening the second pressure regulator (5), and indicating an acceptable or an unacceptable value when the pressure value less than a third control value and equal to or smaller than a third control value, respectively.
9. A method according to one or more of Claims 1 -8, characterized by indicating functioning of the control circuit (7-11 , 14, 15) when said circuit is activated in response to opening the closure valve (2).
10. A method according to one or more Claims 1-9, characterized by indi¬ cating an acceptable result when all tests have resulted in fully acceptable values, or by indicating an unacceptable result when at least one test has shown an unacceptable value.
11. A method according to Claim 5, characterized by indicating a fully acceptable result when the pressure is equal to or higher than a predetermined pressure value within the range of 97 to 80 percent of maximum pressure, pref¬ erably within the range of 95 to 85 percent of maximum pressure.
12. An arrangement for checking at least one functional parameter or state parameter of breathing equipment (16), characterized by a programmed microprocessor (7), a sensor (10) which is included in the breathing equipment (16) and connected to the microprocessor (7), and an indicating arrangement (11) connected to the microprocessor (7).
13. An arrangement according to Claim 12, characterized in that the arrangement also includes a registering device which registers each activation of the control circuit and the results that derive from checks carried out in response to this activation.
14. An arrangement according to Claim 12 or 13, in which the breathing equipment (16) includes a gas reservoir (1) having an outlet opening, a closure valve (2) mounted in the reservoir outlet opening, a line (3) which includes sequentially, as seen from the closure valve (2), a first or a primary pressure regulator (4), a second pressure regulator (5), and a breathing mask (6), char- acterized in that the sensor (10) is mounted in the space (12) between the closure valve (2) and the primary pressure regulator (4).
15. An arrangement according to Claim 12, 13 or 14, characterized in that the indicating arrangement (11 ) is mounted in the breathing mask (6) and is visible to the user and also to people in the vicinity of the user; and in that the indicating arrangement (11) includes at least one light-emitting diode (LED).
16. An arrangement according to one or more of Claims 12-15, character¬ ized in that the breathing equipment (16) includes a second pressure sensor (14) which measures the difference in pressure between the pressures prevailing inside and outside the mask (6); and in that the second sensor (14) is connected to the indicating arrangement (1 1 ) through the microprocessor (7).
PCT/SE1995/000784 1994-07-28 1995-06-26 Checking the operation of breathing equipment WO1996003174A1 (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
CA002196094A CA2196094C (en) 1994-07-28 1995-06-26 Checking the operation of breathing equipment
EP95926556A EP0956065B1 (en) 1994-07-28 1995-06-26 Checking the operation of breathing equipment
DE69523960T DE69523960T2 (en) 1994-07-28 1995-06-26 FUNCTIONAL CONTROL OF BREATHING DEVICES
JP50568796A JP3782823B2 (en) 1994-07-28 1995-06-26 Method for examining the action of a respiratory device
AU30889/95A AU707011B2 (en) 1994-07-28 1995-06-26 Checking the operation of breathing equipment

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE9402594A SE503155C2 (en) 1994-07-28 1994-07-28 Methods and apparatus for functional control of breathing apparatus
SE9402594-7 1994-07-28

Publications (1)

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WO1996003174A1 true WO1996003174A1 (en) 1996-02-08

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EP (1) EP0956065B1 (en)
JP (1) JP3782823B2 (en)
AU (1) AU707011B2 (en)
CA (1) CA2196094C (en)
DE (1) DE69523960T2 (en)
SE (1) SE503155C2 (en)
WO (1) WO1996003174A1 (en)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2000033904A1 (en) * 1998-12-08 2000-06-15 Instrumentarum Corporation Arrangement in connection with feedback control system
WO2000037135A1 (en) * 1998-12-21 2000-06-29 Resmed Limited Determination of mask fitting pressure and correct mask fit
GB2412324A (en) * 2004-03-22 2005-09-28 Clipper Data Ltd Self-contained breathing apparatus with optical display
WO2006036113A1 (en) * 2004-09-28 2006-04-06 Interspiro Ab Pressure indicator for breathing equipment, breathing equipment and method for pressure indication at a breathing equipment
US7040317B2 (en) 1998-11-05 2006-05-09 Resmed Limited Fault diagnosis in CPAP and NIPPV devices
US7343917B2 (en) 2003-09-22 2008-03-18 Resmed Limited Clear cycle for ventilation device
US8302602B2 (en) 2008-09-30 2012-11-06 Nellcor Puritan Bennett Llc Breathing assistance system with multiple pressure sensors
US8322339B2 (en) 2006-09-01 2012-12-04 Nellcor Puritan Bennett Llc Method and system of detecting faults in a breathing assistance device

Families Citing this family (63)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE503155C2 (en) * 1994-07-28 1996-04-01 Comasec International Sa Methods and apparatus for functional control of breathing apparatus
US5878745A (en) 1996-03-01 1999-03-09 Brain; Archibald I.J. Gastro-laryngeal mask
US6119686A (en) * 1996-03-29 2000-09-19 Datex-Ohmeda, Inc. Apnea detection for medical ventilator
GB9727367D0 (en) * 1997-12-24 1998-02-25 Brain Archibald Ian Jeremy Improvements in laryngeal mask airway devices
US7331346B2 (en) * 1997-12-24 2008-02-19 Indian Ocean Medical, Inc. Monitoring and control for a laryngeal mask airway device
GB9821771D0 (en) * 1998-10-06 1998-12-02 Brain Archibald Ian Jeremy Improvements relating to laryngeal mask airway devices
GB9929745D0 (en) * 1999-12-17 2000-02-09 Secr Defence Determining the efficiency of respirators and protective clothing and other improvements
US6817359B2 (en) * 2000-10-31 2004-11-16 Alexander Roger Deas Self-contained underwater re-breathing apparatus
GB2384713B (en) * 2000-10-31 2004-10-27 Deas Alexander Roger Integral life support system
WO2003006310A1 (en) * 2001-07-13 2003-01-23 Tfe Techniques Et Fabrications Electroniques Device for providing acoustic indication to a diver equipped with a diving apparatus concerning breathing mixture pressure in the reservoir and/or hydrostatic pressure
US6820616B1 (en) * 2001-08-01 2004-11-23 Scot Incorporated Combined aircrew systems tester (CAST)
US7089930B2 (en) * 2002-08-20 2006-08-15 Audiopack Technologies, Inc. Wireless heads-up display for a self-contained breathing apparatus
DE10301518B4 (en) * 2003-01-17 2005-11-24 Dräger Safety AG & Co. KGaA Test device for a respiratory protection product
EP1590030B1 (en) * 2003-02-04 2017-05-24 Fisher & Paykel Healthcare Limited Breathing assistance apparatus
GB0303936D0 (en) * 2003-02-21 2003-03-26 Honeywell Normalair Garrett Method of testing
US20040182394A1 (en) * 2003-03-21 2004-09-23 Alvey Jeffrey Arthur Powered air purifying respirator system and self contained breathing apparatus
EP1605999A1 (en) 2003-03-24 2005-12-21 Weinmann Geräte für Medizin GmbH & Co. KG Method and device for detecting leaks in respiratory gas supply systems
WO2005113045A1 (en) * 2004-04-20 2005-12-01 Crutchfield Clifton D Respirator fit-testing apparatus and method
US7353824B1 (en) 2004-08-30 2008-04-08 Forsyth David E Self contained breathing apparatus control system for atmospheric use
GB0510951D0 (en) * 2005-05-27 2005-07-06 Laryngeal Mask Company The Ltd Laryngeal mask airway device
US7587929B2 (en) * 2005-09-09 2009-09-15 Scot Incorporated Joint combined aircrew systems tester
WO2007095266A2 (en) * 2006-02-10 2007-08-23 Ultra Electronic Audiopack, Inc. Communication system for heads-up display
US20090065007A1 (en) 2007-09-06 2009-03-12 Wilkinson William R Oxygen concentrator apparatus and method
JP4281836B2 (en) * 2007-11-21 2009-06-17 ダイキン工業株式会社 Equipment for equipment, management equipment, equipment management system, equipment control method and communication control program between equipment and management equipment
GB0903654D0 (en) 2009-03-03 2009-04-15 Laryngeal Mask Company The Ltd Artificial airway device
US9265904B2 (en) 2009-07-06 2016-02-23 Teleflex Life Sciences Artificial airway
US8281641B1 (en) * 2009-08-03 2012-10-09 The United States Of America As Represented By The Secretary Of The Navy Testing system for self-contained breathing apparatus regulator
WO2011017756A1 (en) 2009-08-13 2011-02-17 Ultimate Medical Pty. Ltd. Pressure indicator
US20120055478A1 (en) * 2010-09-07 2012-03-08 Wilkinson William R Positive pressure therapy systems and methods
US8616207B2 (en) 2010-09-07 2013-12-31 Inova Labs, Inc. Oxygen concentrator heat management system and method
US8603228B2 (en) 2010-09-07 2013-12-10 Inova Labs, Inc. Power management systems and methods for use in an oxygen concentrator
GB201016562D0 (en) 2010-10-01 2010-11-17 Laryngeal Mask Company The Ltd Artificial airway device
CA2814446C (en) 2010-10-15 2018-12-11 The Laryngeal Mask Company Limited Artificial airway device
AU2012212399B2 (en) 2011-02-02 2015-12-03 Berg, John Improved artificial airway
US8910635B2 (en) 2011-05-11 2014-12-16 Carefusion 207, Inc. Lateral gas line configuration
US9022029B2 (en) 2011-05-11 2015-05-05 Carefusion 207, Inc. Carbon-dioxide sampling system for accurately monitoring carbon dioxide in exhaled breath
US8695602B2 (en) * 2011-05-11 2014-04-15 Carefusion 207, Inc. Corrugated flexible seal of a ventilation mask
US8944059B2 (en) 2011-05-11 2015-02-03 Carefusion 207, Inc. Non-invasive ventilation exhaust gas venting
US9616194B2 (en) 2011-06-22 2017-04-11 Breathe Technologies, Inc. Ventilation mask with integrated piloted exhalation valve and method of ventilating a patient using the same
US9038634B2 (en) 2011-06-22 2015-05-26 Breathe Technologies, Inc. Ventilation mask with integrated piloted exhalation valve
US8839791B2 (en) 2011-06-22 2014-09-23 Breathe Technologies, Inc. Ventilation mask with integrated piloted exhalation valve
GB201120628D0 (en) 2011-11-30 2012-01-11 Laryngeal Mask Company The Ltd Endoscopy device
US9399109B2 (en) 2012-03-02 2016-07-26 Breathe Technologies, Inc. Continuous positive airway pressure (CPAP) therapy using measurements of speed and pressure
US10179218B2 (en) 2012-03-02 2019-01-15 Breathe Technologies, Inc. Dual pressure sensor continuous positive airway pressure (CPAP) therapy
US11191914B2 (en) 2012-03-02 2021-12-07 Breathe Techologies, Inc. Dual pressure sensor continuous positive airway pressure (CPAP) therapy
US9993604B2 (en) 2012-04-27 2018-06-12 Covidien Lp Methods and systems for an optimized proportional assist ventilation
US10362967B2 (en) 2012-07-09 2019-07-30 Covidien Lp Systems and methods for missed breath detection and indication
US9027552B2 (en) 2012-07-31 2015-05-12 Covidien Lp Ventilator-initiated prompt or setting regarding detection of asynchrony during ventilation
AU2013328916A1 (en) 2012-10-12 2015-05-14 Inova Labs, Inc. Oxygen concentrator systems and methods
WO2014059405A1 (en) 2012-10-12 2014-04-17 Inova Labs, Inc. Method and systems for the delivery of oxygen enriched gas
WO2014059408A1 (en) 2012-10-12 2014-04-17 Inova Labs, Inc. Dual oxygen concentrator systems and methods
CN103893876B (en) * 2012-12-27 2016-03-02 北京谊安医疗系统股份有限公司 Anesthetic machine airway pressure sensor startup self-detection method
US9440179B2 (en) 2014-02-14 2016-09-13 InovaLabs, LLC Oxygen concentrator pump systems and methods
US9950129B2 (en) 2014-10-27 2018-04-24 Covidien Lp Ventilation triggering using change-point detection
CN104274927B (en) * 2014-11-04 2016-09-28 梅思安(中国)安全设备有限公司 Air respiratorresuscitator detector
US10646732B2 (en) * 2014-12-12 2020-05-12 Honeywell International Inc. Testing a mask seal
US10159815B2 (en) 2014-12-12 2018-12-25 Dynasthetics, Llc System and method for detection of oxygen delivery failure
DE102015216895A1 (en) * 2015-09-03 2017-03-09 Hamilton Medical Ag Ventilation device with error detection for flow sensors
CN108430591A (en) 2015-10-22 2018-08-21 霍尼韦尔国际公司 Intelligent breathing mask module
WO2017192660A1 (en) 2016-05-03 2017-11-09 Inova Labs, Inc. Method and systems for the delivery of oxygen enriched gas
GB2553495B (en) * 2016-07-08 2022-06-22 Design Reality Ltd Fit-checking apparatus
JP2020006017A (en) * 2018-07-11 2020-01-16 株式会社群馬コイケ Medical oxygen supply device
US11324954B2 (en) 2019-06-28 2022-05-10 Covidien Lp Achieving smooth breathing by modified bilateral phrenic nerve pacing

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1988006549A1 (en) * 1987-03-03 1988-09-07 Ernest Comerford A dive parameter indicating assembly
EP0324259A2 (en) * 1988-01-11 1989-07-19 William D Budinger Method for determination and display of critical gas supply information
DE3911154A1 (en) * 1989-04-06 1990-10-11 Interspiro Gmbh Breathing apparatus with a warning device

Family Cites Families (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2484217A (en) * 1949-10-11 Gas flow apparatus
US3224409A (en) * 1963-11-21 1965-12-21 Fluid Power Inc Low pressure alarm assembly
GB1169908A (en) * 1965-12-23 1969-11-05 Aga Ab Breathing apparatus with Pressure Reduction Warning Device
FR2202677B1 (en) * 1972-10-16 1976-05-21 Minerve Sa
US3957044A (en) * 1974-11-11 1976-05-18 Nasa Self-contained breathing apparatus
US4474175A (en) * 1982-07-16 1984-10-02 Mechanical Service Company Inc. Safety means for administration of anesthetic gas
US4846166A (en) * 1985-11-12 1989-07-11 University Of Cincinnati Non-invasive quantitative method for fit testing respirators and corresponding respirator apparatus
FR2597202A1 (en) * 1986-04-15 1987-10-16 Mms Sa METHOD AND DEVICE FOR SIGNALING INCIDENTS IN THE OPERATION OF A RESPIRATOR
US4674492A (en) * 1986-07-25 1987-06-23 Filcon Corporation Alarm system for respirator apparatus and method of use
US5103815A (en) * 1988-05-13 1992-04-14 Chrislyn Enterprises, Inc. Personal airflow gage for a personal breathing supply of respirable quality air, and related accessories, including a two way communication system, used while working in contaminated air spaces
DE3818052A1 (en) * 1988-05-27 1989-12-07 Geraetebau Gmbh RESPIRATORY MASK
US5033818A (en) * 1989-01-13 1991-07-23 Barr Howard S Electronic diving system and face mask display
US5148802B1 (en) * 1989-09-22 1997-08-12 Respironics Inc Method and apparatus for maintaining airway patency to treat sleep apnea and other disorders
US5097826A (en) * 1989-11-13 1992-03-24 Cairns & Brother, Inc. Pressure monitoring device for self-contained breathing apparatus
US5057822A (en) * 1990-09-07 1991-10-15 Puritan-Bennett Corporation Medical gas alarm system
DE4033292A1 (en) * 1990-10-19 1992-04-23 Uwatec Ag Mobile respirator monitor with pressure gauge - has transmitter with control for spacing of transmission signals, and identification signal generator
US5503145A (en) * 1992-06-19 1996-04-02 Clough; Stuart Computer-controlling life support system and method for mixed-gas diving
US5438320A (en) * 1993-04-09 1995-08-01 Figgie International Inc. Personal alarm system
US5457284A (en) * 1993-05-24 1995-10-10 Dacor Corporation Interactive dive computer
US5570688A (en) * 1993-11-17 1996-11-05 Cochran Consulting, Inc. Advanced dive computer for use with a self-contained underwater breathing apparatus
SE503155C2 (en) * 1994-07-28 1996-04-01 Comasec International Sa Methods and apparatus for functional control of breathing apparatus
US5832916A (en) * 1996-02-20 1998-11-10 Interspiro Ab Method and system for checking the operability of electrical-based components in a breathing equipment

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1988006549A1 (en) * 1987-03-03 1988-09-07 Ernest Comerford A dive parameter indicating assembly
EP0324259A2 (en) * 1988-01-11 1989-07-19 William D Budinger Method for determination and display of critical gas supply information
DE3911154A1 (en) * 1989-04-06 1990-10-11 Interspiro Gmbh Breathing apparatus with a warning device

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7537010B2 (en) 1998-11-05 2009-05-26 Resmed Limited Fault diagnosis in CPAP and NIPPV devices
US9597469B2 (en) 1998-11-05 2017-03-21 Resmed Limited Fault diagnosis in CPAP and NIPPV devices
US8910631B2 (en) 1998-11-05 2014-12-16 Resmed Limited Fault diagnosis in CPAP and NIPPV devices
US8485182B2 (en) 1998-11-05 2013-07-16 Resmed Limited Fault diagnosis in CPAP and NIPPV devices
US8069854B2 (en) 1998-11-05 2011-12-06 Resmed Limited Fault diagnosis in CPAP and NIPPV devices
US7040317B2 (en) 1998-11-05 2006-05-09 Resmed Limited Fault diagnosis in CPAP and NIPPV devices
WO2000033904A1 (en) * 1998-12-08 2000-06-15 Instrumentarum Corporation Arrangement in connection with feedback control system
US7290544B1 (en) 1998-12-08 2007-11-06 Ge Healthcare Finland Oy Arrangement in connection with feedback control system
US6425395B1 (en) 1998-12-21 2002-07-30 Resmed Limited Determination of mask fitting pressure and correct mask fit
US9707361B2 (en) 1998-12-21 2017-07-18 Resmed Limited Determination of mask fitting pressure and correct mask fit
WO2000037135A1 (en) * 1998-12-21 2000-06-29 Resmed Limited Determination of mask fitting pressure and correct mask fit
US7100608B2 (en) 1998-12-21 2006-09-05 Resmed Limited Determination of mask fitting pressure and correct mask fit
US7343917B2 (en) 2003-09-22 2008-03-18 Resmed Limited Clear cycle for ventilation device
GB2412324A (en) * 2004-03-22 2005-09-28 Clipper Data Ltd Self-contained breathing apparatus with optical display
US7571726B2 (en) 2004-03-22 2009-08-11 Clipper Data Limited Self-contained breathing apparatus
GB2412324B (en) * 2004-03-22 2008-09-17 Clipper Data Ltd Self-contained breathing apparatus with optical display
WO2006036113A1 (en) * 2004-09-28 2006-04-06 Interspiro Ab Pressure indicator for breathing equipment, breathing equipment and method for pressure indication at a breathing equipment
US8322339B2 (en) 2006-09-01 2012-12-04 Nellcor Puritan Bennett Llc Method and system of detecting faults in a breathing assistance device
US9649458B2 (en) 2008-09-30 2017-05-16 Covidien Lp Breathing assistance system with multiple pressure sensors
US8302602B2 (en) 2008-09-30 2012-11-06 Nellcor Puritan Bennett Llc Breathing assistance system with multiple pressure sensors

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DE69523960T2 (en) 2002-06-20
US5860418A (en) 1999-01-19
JPH10503675A (en) 1998-04-07
AU3088995A (en) 1996-02-22
US6655383B1 (en) 2003-12-02
SE9402594D0 (en) 1994-07-28
EP0956065A1 (en) 1999-11-17
SE9402594L (en) 1996-01-29
DE69523960D1 (en) 2001-12-20
SE503155C2 (en) 1996-04-01
JP3782823B2 (en) 2006-06-07
EP0956065B1 (en) 2001-11-14
AU707011B2 (en) 1999-07-01
CA2196094A1 (en) 1996-02-08
CA2196094C (en) 2001-04-24

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