FR3000893A1 - Respiratory assistance apparatus i.e. ventilator for use in emergency vehicle to assist e.g. male nurse, to practice cardiac massage on patient during e.g. traffic accident, has display unit displaying frequency of cardiac massage - Google Patents

Abstract

The apparatus i.e. ventilator (1), has a turbine (4) delivering gas into a ventilatory circuit (2) connected to a patient (20). A measurement unit (6) measures a parameter e.g. gas pressure, insufflated gas output, gas output expired by the patient, turbine speed, representative of the flow and delivers a signal representative of the flow. A signal processing unit (5) analyzes signal representative of a parameter representative of gas flow, and deduces cardiac massage on the patient from the signal and to determine frequency of the massage. A display unit (7) displays the frequency.

Description

The invention relates to artificial ventilation devices, also called respiratory or ventilatory assistance devices. More particularly, the invention relates to assistance that the device can provide to a rescuer, such as a doctor of the SAMU, a firefighter, a nurse or the like, when it performs a cardiac massage on a ventilated patient. Some ventilators or respiratory assistance equip first aid vehicles which intervene in particular on road accidents or vital emergencies. These emergencies often require the combination of mechanical ventilation and cardiac massage. Numerous studies reveal that the frequency of cardiac massages is a determining factor of its effectiveness.

At present, there is a consensus to set the minimum frequency of cardiac massage at 100 compressions per minute. This recommendation is, for example, described by the American Heart Association in its Guidelines for Cardiopulmonary Resuscitation (CPR) and Emergency Cardiovascular Care (ECC); 2010. However, the observations made among practitioners show a certain tendency to slow heart massage, as evidenced by the document "Chest Compression Rates During Cardiopulmonary Resuscitation Are Suboptimal: A Prospective Study During In-Hospital Cardiac Arrest"; American Heart Association; Abella and Al, 2005 Therefore, it seems interesting to give the rescuer a way to guarantee the frequency of the cardiac massage he performs. Such devices exist, indicating to the rescuer the frequency with which he performs his massage. Thus, US-A-5496257 discloses a device to be placed on the patient's chest during the cardiac massage, which device is capable of measuring the frequency of the compressions and to give information relating to this frequency to the rescuer. Similarly, US-A-6390996 discloses a device, placed around the wrist of the rescuer, capable of giving information relating to the frequency of the massage.

The major disadvantage of such devices is to add to all the equipment needed by the rescuer, thus slowing down the implementation of the cardiac massage, also determining in the survival of the patient. Furthermore, the first device cited makes the maneuvering more complex because it must be positioned in the hands of the rescuer and the thorax of the patient, while the second device cited does not allow two rescuers to relay themselves easily during the massage, unless each is provided with a device. It would therefore be very useful to be able to provide such indications of frequency of chest compressions to the rescuer without the need to resort to an additional device so as not to complicate the task of the rescuer. In addition, other studies, such as "Hyperventilation-Induced Hypotension During Cardiopulmonary Resuscitation"; Aufderheide and Al; 2004, suggest the need to reduce the volumes injected to the patient during the cardiac massage in order to limit the intrathoracic pressure and thus not to impede the blood circulation.

Finally, another disadvantage posed by the cardiac massage concerns the disturbances caused by the massage on the regulation of the ventilator delivering the assistance gas to the patient during said massage. Indeed, the chest compressions force the exsufflation of the patient. The fan may end up alarming excessively and ventilating inefficiently and, in extreme cases, it may incorrectly detect that it is down.

The problem is therefore to propose a medical device to solve all or part of the aforementioned problems and disadvantages, in particular a medical device not only to assist the rescuer to tell him if the massage he is trying to achieve is adapted or not but also to deliver a correct volume of gas to the patient despite the cardiac massage he undergoes and without engaging an alarm inadvertent or consider himself out of order or malfunction. The solution is then a respiratory assistance device comprising at least one gas source, in particular a turbine, capable of delivering a flow of gas in a ventilatory circuit intended to be connected to a patient, and further comprising: - means measuring device capable of measuring at least one parameter representative of the gas flow chosen from the gas pressure, the gas flow rate insufflated, the flow of gas exhaled by the patient and the speed of the turbine, and to deliver at least one representative signal of said at least one parameter representative of the gas flow, signal processing means able to i) analyze said at least one signal representative of said at least one parameter representative of the gas flow, ii) to deduce from said at least one signal, the performing a cardiac massage on said patient and iii) determining the frequency of said cardiac massage, - and display means for displaying the heart massage frequency.

Depending on the case, the respiratory assistance apparatus of the invention may comprise one or more of the following technical characteristics: the signal processing means comprise a microprocessor and at least one algorithm. the measuring means make it possible to measure at least one parameter representative of the flow of gas within said ventilatory circuit. the signal processing means are able to compare said at least one representative signal of said at least one representative parameter of the gas flow with at least one threshold value representative of the realization of a cardiac massage. the display means comprise a display screen. - The measuring means comprise at least one pressure sensor, a flow sensor or a rotational speed sensor of the turbine. - It further comprises means for measuring duration able to determine the duration during which the cardiac massage is performed. it furthermore comprises means for measuring duration including a chronometer integrated into a processor. - The display means are adapted to further display the heart massage time. - It further comprises ventilatory mode changing means adapted to and designed to move from a first ventilatory mode to a second ventilatory mode in response to detection by the signal processing means, the realization of a cardiac massage on the patient. - The ventilatory mode changing means are adapted to and designed to move from a first ventilatory mode selected from volumetric modes (VAC particular), barometric (VPC, VSAI, CPAP, Duo-Levels ...), intermittent (VACI , PVACI ...) to a second ventilatory mode chosen from the same list, and in particular the barometric modes (VPC, VSAI, CPAP, Duo-Levels ...). In fact, the ventilation is adapted to the current ventilatory mode, pressure values, flow rate, volume delivered, the nature of the gas delivered, synchronization mechanisms, alarm management .... - it comprises further provided volume changing means adapted and adapted to change from a first delivered volume, typically between 10 and 2000 mL, to a second delivered volume, typically in the same range and usually less than the first volume, in response detection by the signal processing means of performing a cardiac massage on the patient. it furthermore comprises means for changing the nature of the delivered gas adapted to and designed to pass from a first gas or gas mixture delivered, typically a mixture of air and oxygen to a certain first oxygen ratio; a second gas or mixture of gases, typically a mixture of air and oxygen at a certain second ratio of oxygen, for example higher than said first ratio, in response to detection by the signal processing means, performing a cardiac massage on the patient. it furthermore comprises means for changing the "patient-machine" synchronization algorithms, typically based on the analysis of the measured pressure and / or flow signals, sometimes also on signals derived from gaseous concentration or pulse measurements neurons, adapted and adapted to move from a first algorithm to a second algorithm, in response to detection by the signal processing means, of performing a cardiac massage on the patient. it furthermore comprises adjustment means, such as a push button, an activation key, a slider or the like, enabling the nursing staff to indicate to the ventilator the performance of a cardiac massage or to confirm to the ventilator the detection which was made of performing a cardiac massage. - It further comprises sound signal generating means adapted to and designed to emit a periodic sound signal. the means for generating a sound signal comprise a loudspeaker. - The sound signal generating means are controlled by said microprocessor so as to deliver said sound signal periodically, at a rate between 20 and 200 strokes per minute, for example of the order of 100 strokes per minute. - It further comprises time adjustment means adapted to and designed to set a desired period of time, said sound signal generating means being controlled by said microprocessor so as to output a sound signal to said desired period of time. the time adjustment means are adapted to and designed to set or adjust the duration of each sound signal so that the rescuer can follow on said signal to apply the cardiac massage with a ratio of compression time / release time adapted. The present invention will now be described in more detail with reference to the accompanying figures in which: - Figure 1 shows an embodiment of a breathing apparatus according to the present invention; and - Figure 2a is a record of the pressure setting of a respirator during a cardiac massage; and - Figure 2b is a record of the breath rate parameter of a respirator during the same cardiac massage.

Figure 1 shows schematically an embodiment of a ventilatory assistance apparatus or ventilator 1 according to the present invention. The fan 1 comprises a turbine 4 delivering a flow of respiratory assistance gas, typically a stream of air or air enriched with oxygen, in a ventilatory circuit 2, also called a patient circuit, comprising one or more passages or lines of gas, fluidly connecting the ventilator 1 to the airways of a patient 20, via a patient interface 3, such as a breathing mask or an intubation probe. According to another embodiment, the turbine 4 may be replaced by another gas source such as a valve connected to a gas pipe, in particular a gas pipe ending in a wall outlet arranged on a wall of a hospital building and supplied with a respiratory gas, such as air or oxygen, at a pressure of a few absolute bars, typically of the order of about 4 bar abs.

Measuring means 6 are provided, which are capable of measuring at least one parameter representative of the gas flow chosen from the pressure of the gas, the flow of gas blown by the respirator, the flow of gas exhaled by the patient 20 and the speed rotating the turbine 4 and delivering at least one signal representative of said at least one measured parameter.

For example, the representative parameter of the gas flow is the pressure of the gas in the circuit 2 and the measuring means 6 comprise a pressure sensor whose pressure tap is arranged in said circuit 2. In the embodiment of FIG. 1, the pressure tap 6 is arranged outside the fan. However, depending on the embodiment considered, it may be outside the fan or in the fan. Once the measurement of the parameter (s) representative of the gas flow has been performed, the corresponding signal is analyzed by signal processing means which can then deduce that a cardiac massage is being performed on the said patient. determine the frequency. The signal processing means 5 comprise, for example, a microprocessor 8 programmed in particular with a processing algorithm, as explained hereinafter. More specifically, the signal processing means 5 are adapted to and designed to compare the signal corresponding to the representative parameter of the gas flow with one or more threshold values representative of the realization of a cardiac massage.

These threshold values are stored in a storage memory 12, for example a flash memory. These threshold values can be numerical values, tables of values, curves ... This will allow the fan 1 to assist the rescuer by indicating him a frequency information, for example the numerical value of the frequency, or indications of "too fast", "too slow" ... which will give him very useful information about the effectiveness of the cardiac massage that he is operating. This information can be displayed by means of display 7, such as a screen or a display. Moreover, means for measuring duration, for example a timer integrated in a processor 8, are also provided to determine the duration during which the cardiac massage is performed, and display means 7, such as a screen or a display, to display said heart massage time for the nursing staff, so as to provide him instantly other important information on the cardiac massage which is in progress. The ventilator 1 further comprises ventilatory mode changing means adapted to and designed to pass from a first ventilatory mode to a second ventilatory mode in response to a detection by the signal processing means of performing a massage. 20. More specifically, the ventilatory mode changing means are adapted to and designed to pass a first ventilatory mode selected from volumetric modes (including VAC), barometric (VPC, VSAI, CPAP, Duo-Levels). ...), intermittent (VACI, PVACI ...) to a second ventilatory mode chosen from the same list, and in particular the barometric modes (VPC, VSAI, CPAP, Duo-Levels ...) Alternatively or complementary , the fan 1 may comprise means of volume change delivered adapted to and designed to pass a first delivered volume, typically between 10 and 2000 ml to a second volume delivered, typically in the same range and t ypically lower than the first volume, in response to detection by the signal processing means, of performing a cardiac massage on the patient. Alternatively or additionally, the fan 1 may comprise "patient-machine" synchronization algorithms, typically based on the analysis of the measured pressure and / or flow signals, sometimes also on signals from gas concentration measurements or nerve impulses, adapted and adapted to move from a first algorithm to a second algorithm, in response to detection by the signal processing means, of performing a cardiac massage on the patient. Alternatively or additionally, the fan 1 may comprise means for changing the alarm algorithms, for example alarms intended to monitor the patient's breathing rate or the pressure delivered by the ventilator, or even the proper functioning of the turbine 4 , adapted to and designed to pass from a first algorithm to a second algorithm, in response to detection by the signal processing means, of performing a cardiac massage on the patient, so as not to alarm wrongly, which would unnecessarily disrupt the rescuer. The fan 1 also includes a function of the "metronome" type to assist the health care staff in performing the cardiac massage at a given pace.

To do this, sound signal generation means 9, such as a loudspeaker, are provided which are adapted to and designed to emit a periodic sound signal, that is to say a tempo audible by the nursing staff. For example, sound signals may be at periods typically spaced a few tenths of seconds, for example 6/10 seconds, corresponding to a frequency of one hundred sound signals per minute. The sound signal generation means 9 are advantageously controlled by said microprocessor 8 so as to deliver the sound signal 10 periodically, to the nursing staff practicing the cardiac massage on the patient 20 so that it can be traced on said signal 10 for applying said cardiac massage at the correct rate. The frequency of the sound pulses corresponding to a desired period of time is set or fixed by means of time setting means 11 arranged on the fan 1, for example keys, cursors, selection buttons, a touch screen or any other adjustment device.

Thus, the sound signal generating means 9 can be controlled by the microprocessor so as to deliver a sound signal at said desired period of time. Furthermore, the duration of each sound signal 10 can be set or fixed by means of time adjustment means 11 arranged on the fan 1, so that the rescuer can follow the signal 10 to apply the massage. heart rate with a suitable compression time / release time ratio. The fan 1 further comprises an outer cowl on or in which are arranged all or part of the aforementioned means. The fan 1 is supplied with electric current from one or more batteries, rechargeable or not, the power supply of the emergency vehicle that it equips or the sector, so having a voltage of up to about 230 V. Furthermore, Figures 2a and 2b are simultaneous recordings, respectively of a measured parameter of pressure and a rate parameter as a function of time, during a cardiac massage. This recording was made with a Monnal T60 type device marketed by Air Liquide Medical Systems.

As can be seen in the curves obtained, the pressure measurement is sensitive to cardiac massage since we are witnessing the appearance of peaks that result from the application of the massage to the patient. This shows that it is possible to use pressure measurements to determine the frequency of said cardiac massage and thus to inform the intervention personnel. Thus, in FIG. 2a, the duration 40 separating two such peaks corresponds to the compression period, whereas the duration 30 corresponds to the period between two insufflations delivered by the ventilator. The duration thus measured corresponds, on this recording, to a cardiac massage of frequency equal to about 140 compressions per minute. Similarly, we see in Figure 2b the sensitivity of the flow insufflated cardiac massage and the possibility of determining the duration 40 corresponding to the period between two compressions. Alternatively or additionally, it is also possible to use for the same purpose, other internal direct or indirect measurement means through the servocontrols, such as speed of the turbine, the flow exhaled by the patient ...

In other words, the permanent observation of the pressure or even the flow signals makes it possible, by conventional signal analysis, for example by filtering or pattern recognition, to detect the cardiac massage. Once the massage is detected, the frequency can be calculated by the same usual techniques of signal processing. The duration since the beginning of the massage can also be displayed. Thus, it can be timed by the processor. The respiratory assistance apparatus according to the invention may be of the portable type and provided with a handle or the like of transport. For mobility purposes, said at least one gas source may be a turbine and / or a pressurized gas cylinder, typically provided with a pressure reducer.

Claims (4)

REVENDICATIONS1. Respiratory assistance apparatus (1) comprising at least one gas source, in particular a turbine (4), capable of delivering a flow of gas into a ventilatory circuit (2) intended to be connected to a patient (20), and further comprising: - measuring means (6) capable of measuring at least one parameter representative of the gas flow selected from the gas pressure, the gas flow rate blown, the gas flow exhaled by the patient (20) and the speed of the turbine (4), and to deliver at least one signal representative of said at least one parameter representative of the gas flow, - signal processing means (5) capable of: i) analyzing said at least one signal representative of said at least one representative parameter of the gas flow, ii) deducing from said at least one signal, performing a cardiac massage on said patient and iii) determining the frequency of said cardiac massage, - and display means (7) to display in particular the frequency of massa heart. 2. Apparatus according to the preceding claim, characterized in that the signal processing means (5) comprises a microprocessor (8) and at least one algorithm. 3. Apparatus according to one of the preceding claims, characterized in that the measuring means (6) for measuring at least one parameter representative of the gas flow are disposed within said ventilator circuit (2). 4. Apparatus according to one of the preceding claims, characterized in that the signal processing means (5) are designed to compare said at least one signal representative of said at least one parameter representative of the gas flow with at least one value. threshold representative of the realization of a cardiac massage. . Apparatus according to one of the preceding claims, characterized in that the display means (7) comprise a display screen. 6. Apparatus according to one of the preceding claims, characterized in that the measuring means (6) comprise at least one pressure sensor, a flow sensor or a rotational speed sensor of the turbine (4). 7. Apparatus according to one of the preceding claims, characterized in that it further comprises means for measuring duration able to determine the duration during which the cardiac massage is performed. 8. Apparatus according to one of the preceding claims, characterized in that it further comprises means for measuring duration including a chronometer integrated in a processor. 9. Apparatus according to one of the preceding claims, characterized in that it further comprises ventilatory mode changing means adapted to and adapted to move from a first ventilatory mode to a second ventilatory mode in response to a detection. by the signal processing means, performing a cardiac massage on the patient. 10. Apparatus according to one of the preceding claims, characterized in that it further comprises sound signal generating means (9) adapted and adapted to emit a periodic sound signal (10). 11. Apparatus according to the preceding claim, characterized in that the sound signal generating means (9) comprises a loudspeaker. 3012. Apparatus according to one of the preceding claims, characterized in that it further comprises time adjusting means (11) adapted and adapted to set a desired period of time, said sound signal generating means (9). ) being driven by said microprocessor so as to output a sound signal (10) to said desired period of time.