WO2007084058A1

WO2007084058A1 - System for controlled supply of laughing gas

Info

Publication number: WO2007084058A1
Application number: PCT/SE2007/000046
Authority: WO
Original assignee: DROBIN DAN
Current assignee: DROBIN DAN
Priority date: 2006-01-20
Filing date: 2007-01-18
Publication date: 2007-07-26
Anticipated expiration: 2008-07-20
Also published as: EP1979031A1; SE0600945L; SE529147C2

Abstract

The present invention relates to a system (2) for collecting laughing gas and that makes decreased consumption of laughing gas possible during childbirth, where the mother inhales mixtures of laughing gas through a face mask (14) . The system comprises an apparatus (12) that controls different mixtures of laughing gas (4) , oxygen (6) and air (8) and provides this mixture to the mother (10) simultaneously as the apparatus (12) at the end of a labour pain switches over the mixture to a non- laughing gas supply to the mother (10) . Control of the gas mixture via the apparatus (12) is carried out by a sensor (16) for recording of labour pains, or by a timer (18) , or an air flow meter arranged in the face mask (14) for measuring of the air flow that flows through the face mask (14) as a response to labour pains, or a combination of at least two of said controls of the gas mixture.

Description

System for controlled supply of laughing gas.

Technical field

The present invention relates to a system for collection of laughing gas and that makes decreased consumption of laughing gas possible, that is used as alleviation of pain during childbirth.

Background

Destruction of laughing gas is done for environmental reasons. One kilogram of laughing gas has the same effect as greenhouse gas as 200 kilogram carbon dioxide. For that reason, Stockholm county council has a programme where new installation of laughing gas catalysers are set up at the hospitals. However, the problem is that only a fractional part, about 20-30 % of the used laughing gas, is collected. Approximately 80 % of the laughing gas utilization at the hospitals is carried out in connection to childbirth. When the child delivering woman has a labour pain, she breathe in a mask and will then receive up to 70 % of laughing gas with a residual amount of oxygen. When the labour pain has passed, she is recommended to take away the mask. Then she exhales the already inhaled laughing gas freely in the room. Out of the room the gas may only be eliminated via the ventilation of the room, and through windows and doors.

Labour pains appears in intervals each twentieth second up to intervals of several minutes. The laughing gas only needs to be inhaled during the start of the labour pain and can be ended already just before a labour pain has disappeared since the remaining gas provides alleviation of pain during the time it takes for it to eliminate. The child delivering woman feels when a labour pain starts and begins usually by herself her treatment with laughing gas. But since the mother does not have the same ability to feel in due time when it is suitable to stop breathing laughing gas, when the labour pain starts to decrease, the mother often will breathe an unnecessarily long time, whereby a surplus is accumulated in the body. When the labour pain is ended, the mother takes away the mask and breathe air from the room again, and then all the gas that has been accumulated will be exhaled in the room, and thus the gas becomes hard to collect for destruction.

Description of the Invention

One object with the present invention is to provide an apparatus or a system that at least in part eliminates those drawbacks that are associated with apparatuses according to the state of the art. One object is further to achieve a system that decreases free discharge of laughing gas that is used as alleviation of pain during childbirth. Yet an object is to provide a system that decreases the consumption of laughing gas that is used as alleviation of pain during childbirth and that suitably may collect the inhaled amount of laughing gas from the mother, such that the mother does not exhale it freely in the air, for the purpose of destroying the laughing gas. These objects are achieved with a system for collecting laughing gas and that makes decreased consumption of laughing gas possible during childbirth, where the mother inhales mixtures of laughing gas simultaneously as a free exhalation of laughing gas from the mother is prevented, according to the present invention as defined in claim 1, which system comprises an apparatus that controls different mixtures of laughing gas, oxygen and air and provides this mixture to the mother simultaneously as the apparatus at the end of a labour pain switches over the mixture to a non-laughing gas supply to the mother. The control of the gas mixture via the apparatus is carried out either by a sensor connected to the apparatus for recording of labour pains, or that the gas mixture is controllable and adjustable by a timer connected to the apparatus, or that an air flow meter is arranged in the face mask and connected to the apparatus for measuring of the air flow that flows through the mask as a response to labour pains, or a combination of at least two of said controls of the gas mixture.

The system according to the present invention can be used without the mother taking part or noticing anything of the process. By having a system, in accordance with the present invention, that switches off the laughing gas automatically or by manually setting of the apparatus, the risk for unnecessary laughing gas accumulation is minimised and owing to that, the consumption of laughing gas may be decreased. Since the mother cannot judge that she can stop breathe laughing gas, the gas mixture can be changed by an automatic mechanism to only oxygen or air/oxygen, such that the mother continues to breathe in the mask for a while, but without supply of laughing gas, which results in that accumulated laughing gas in the mother is exhaled in the mask and not in the room. When the gas is exhaled in the mask, it is completely accessible for the systems of the hospitals for collection and destruction of laughing gas.

This automatic mechanism will not really influence the alleviation of pain for the mother, if the automatic mechanism is correctly set, since it switches off the laughing gas in a stage when the labour pain decreases. The remaining gas will be eliminated within 1-2 minutes and then the pain has already ended. However, the alleviation of pain may be slightly higher than what is the case according to the present technique during childbirth, but the system according to the present invention results instead in that the mother does not feel unnecessarily influenced between the labour pains, whereby the net result will be to the advantage of the mother.

By the term "free exhalation" is meant that inhaled laughing gas that is accumulated in the body is exhaled freely in the room, that is without exhalation taking place in the face mask. Thus, as is intended in this respect in the description and the claims, free exhalation shall be avoided, which implies that the mother and the staff are instructed that the face mask, to the outmost possible extent, should be used by the mother without substantially any interruption under at least inhalation and exhalation of laughing gas during childbirth, in accordance with the purpose of the invention for decreasing the consumption of laughing gas and a suitable collection of the exhaled laughing gas for destruction. According to a preferred embodiment, the timer is adjustable by a computer program or manually. The timer may be arranged to control or adjust the gas mixture, with respect to lockout time for how long time the laughing gas should be provided during each cycle, as well as how long time that shall pass between the cycles. The face mask may comprise an exhaust valve for exhaled gas and air. According to a preferred embodiment, a conveying pipe can be arranged to the face mask for removal and collection of exhaled laughing gas from the mother, for further conveyance to destruction. Said sensor may measure electronic activity from the uterus and/or uterine muscular contraction as a pressure. Further advantages and features according to embodiments of the invention are evident from the claims, and also in the following description of the embodiments.

Description of the drawings

The present invention will now be described in embodiments in greater detail, with reference to the accompanying drawing, without limiting the interpretation of the invention thereto, where the drawing schematically shows a system according to an embodiment of the present invention.

Detailed description of embodiments

In fig. 1 is shown a system 2 according to an embodiment of the present invention, to which reference is made in connection with the following detailed description.

Different ways exist, to both receive signals for control of the system, as well as different ways to adjust the flows. Some possible ways for measuring is to (i) measure the uterine contraction by a usual pressure gauge

(tocometry) , or (ii) to measure by electronic recording

(electromyography) , or (iii) to measure the breathing pattern by a flow meter at the mask. The adjustment of the gas mixture may be controlled by the different input sensors, and with a timer the lockout-times may be set for how fast a new cycle of laughing gas can be initiated. Setting of lockout-times may also be done for how long time a cycle of laughing gas may last. The gas mixture is a mixture of air / laughing gas / oxygen, where the levels for these may be 0-100%, except for laughing gas that at most can be 70%. Since the mother can not decide by herself exactly when she may stop breathe laughing gas, the apparatus controls this by an automatic mechanism or by a manual setting.

The system 2 is intended to minimise the consumption of laughing gas during childbirth when the laughing gas is used as inhalation analgesic. In addition, the system contributes to that the mother inhales and exhales in the mask after the laughing gas not is supplied, but only inhale and exhale air/oxygen, such that the laughing gas that leaves the mother after each labour pain can be collected for destruction. This can be carried out without the mother participating or noticing anything of the process. Different mixtures of laughing gas 4, oxygen 6 and air 8, can be provided to a mother 10. The system 2 comprises an apparatus 12 that controls the different mixtures of the laughing gas 4, oxygen 6 and air 8, and supplies this mixture to the mother through a face mask 14, simultaneously as the apparatus 12 at the end of a labour pain switches over the mixture to a non-laughing gas supply to the mother. The control of the gas mixture via the apparatus may, as evident from the embodiment according to fig. 1, be carried out by way of a sensor 16 that is connected to the apparatus for recording of labour pains. The sensor 16 may, according to the shown embodiment, measure electronic activity from the uterus and/or uterine muscular contraction as a pressure.

The gas mixture may alternatively, or as a complement to the sensor recording of a labour pain as mentioned above, be controllable and adjustable by a timer 18, connected to the apparatus. Furthermore, yet an alternative or complement to the sensor recording or timer controlling/adjustment, can be that an air flow meter (not shown) is arranged in the face mask 14 connected to the apparatus for measuring of the air flow that flows through the mask as a response to labour pains. The apparatus 12 can be connected to a computer 20. The timer 18 can be adjustable by a computer program and/or manually. Said time is arranged to control or adjust the gas mixture with respect to lockout time for how long time laughing gas shall be provided at each cycle, as well as how long time that shall pass between the cycles.

A conveying pipe 22 can be arranged to the face mask 14 for removal and collection of exhaled laughing gas from the mother for destruction. When the gas is exhaled in the mask, it is completely available for the systems of the hospitals for collection and destruction.

Consequently, in the system according to the present invention, anyone or several of the following apparatuses for control of the gas mixture can be feasible : a) An electric transmitter/sensor 16 is attached to the abdomen and the electrical impulses from the uterus is registered. These impulses are analysed in the apparatus 12 in accordance with a specific program that has been developed for this purpose. The signal will indicate when the laughing gas / oxygen delivering should change to oxygen or change to oxygen /air delivering instead. b) The existing tocometers (pressure gauge that is put on the abdomen or in the uterus, that measures labour) for registration of labour pains may also be used as sensor/transmitter 16. These exists substantially always during childbirth in Sweden today and their recordings may also be utilised. c) An air flow meter, that is arranged in the face mask 14, can be connected to the apparatus 12 in the system, for measuring of the air flow that flows through the face mask

(14) as a reaction of labour pains. d) The involved apparatus 12 for control of the gas mixture in the system, can comprise a timer 18. The timer is set by one of the staff (nurse or doctor) . The timer may also be set by a computer program in the computer 20. The timer may also be started by breathing of the mother in the face mask 14. The face mask may also have an air flow sensor/meter, as mentioned above, that measures air flows in the face mask 14 during inhalation, and then the timer 18 starts, which switches off the laughing gas within 20-240 seconds. The range is chosen by one of the staff or a computer program. In order to activate a new laughing gas cycle, the user/mother then have to breath without face mask 14 for a while. Also this can be adjusted in the apparatus. In that the sensor not records any flow, a new laughing gas cycle can be started in connection to that flows are again registered by the air flow sensor/meter when the user starts to breathe in the face mask during a new labour pain. The timer 18 can also be controlled manually by the mother or by staff. Measurements with the mentioned methods may instead of automatically controlling the gas mixtures provide an indication in form of a lamp or signal such that one manually may change the flows via control on the timer 18.

Different combinations of the above suggested controls a)-d) of the gas mixture can be used. The time that the mother should be offered laughing gas treatment during each labour pain should thus be controlled on one hand by experienced staff, and on the other, for instance, may measurements on the contraction length of the uterus be used individually such that the alleviation of pain matches the length of the labour pain. An indicator, such as a lamp, may be put on the mask such that the mother or the staff observes when the gas mixture is changed, alternatively may a lamp indicate when the labour pain is over, via the registration of the labour pain, whereby the gas mixture may be changed manually.

The essential issue of the solution is at first hand an increased possibility for collection of laughing gas from the mother and at second hand a decreased consumption of laughing gas owing to that the mother automatically receives air/oxygen at the end of the contractions which implies that inhaled laughing gas can be exhaled and collected via the mask and suitably be further brought to the exhaustion of the hospital where destruction is carried out. The system results in that less laughing gas is consumed and also that more gas can be collected for destruction.

Claims

1. A system (2) for collecting laughing gas and that makes decreased consumption of laughing gas possible during childbirth, where the mother inhales mixtures of laughing gas through a face mask (14) simultaneously as a free exhalation of laughing gas from the mother (10) is prevented, characterised by an apparatus (12) that controls different mixtures of laughing gas (4), oxygen (6) and air (8) and provides this mixture to the mother (10) simultaneously as the apparatus (12) at the end of a labour pain switches over the mixture to a non-laughing gas supply to the mother (10), which control of the gas mixture via the apparatus (12) is carried out either by a sensor (16) connected to the apparatus (12) for recording of labour pains, or that the gas mixture is controllable and adjustable by a timer (18) connected to the apparatus

(12), or that an air flow meter is arranged in the face mask (14) connected to the apparatus (12) for measuring of the air flow that flows through the face mask (14) as a response to labour pains, or a combination of at least two of said controls of the gas mixture.

2. System according to claim 1, characterised in that the timer (18) is adjustable by a computer program or manually.

3. System according to claim 1 or 2, characterised in that a conveying pipe (22) is arranged to the face mask (14) for removal and collection of exhaled laughing gas from the mother (10) .

4. System according to any of the preceding claims, characterised in that said sensor (16) measure electronic activity from the uterus and/or uterine muscular contraction as a pressure.

5. System according to any of the preceding claims, characterised in that said timer (18) is arranged to control or adjust the gas mixture with respect to lockout time, for how long time laughing gas shall be provided at each cycle, as well as how long time that shall pass between the cycles.