defibrillator

Field of the invention

The present invention concerns an automatic external cardiac defibrillator (AECD) comprising extractable electrodes that can be used by the patient himself or by a first-aider.

Prior art

Defibrillation electrodes generally consist of a non-conductive layer produced from a flexible material, a conductive metal layer serving as an electrode and an adhesive gel, also conductive, for holding the electrode on the patient.

In order to limit phenomena of desiccation of the adhesive gel and to protect the electrode, it is usual to use an easily peelable protective film covering the adhesive gel. This is generally the case when disposable electrodes are used.

This type of electrode does however have the disadvantage of requiring numerous manipulations before being able to be applied to the patient, which may prove to be critical in the case of urgent intervention.

In order to overcome these drawbacks, electrodes with a different structure have been developed, thus simplifying use thereof. There is known through the application WO 97/26 350 a disposable electrode system for a defibrillator that is easily usable and reliable, which consists of an electrode mounted on a flexible support and held on the housing by a holding means. The electrodes are folded so that, when they are extracted, the protective film automatically detaches .

Electrodes in the form of a unitary ribbon making it possible to be positioned quickly while being simple in use are also known through US 5 191 886.

The electrodes known from the prior art are easier to use since they limit the number of steps necessary for the correct placing of the electrodes and the application of the conductive gel while preserving the integrity of the electrodes when they are not being used. However, they do not have any interaction with the AECD.

AECD devices combining several functions, which increases the chances of survival of the patient, are also known. An AECD may for example integrate audio or video communication means for obtaining assistance remotely. An AECD may also comprise location means, in particular by GPS.

Among these complementary functions, some AECDs may integrate functions facilitating cardiac resuscitation. For example, the housing of the AECD may be used advantageously as a support for cardiac resuscitation. EP 2 228 097 describes the integration of cardiopulmonary resuscitation (CPR) in the AECD housing. The dimensions and form of the AECD are adapted so that it can be placed on the chest of the patient, thus simplifying the use of the apparatus and thus enabling the first-aider to concentrate on the patient himself. The reduced dimensions of this AECD do however have the disadvantage of making its correct positioning on the sternum of the patient and its use difficult, in particular when the first-aider is inexperienced. Thus the apparatus described in EP 2 228 097 has the drawback of not being able to be kept in a stable position when the first-aider is performing CPR.

WO 2001/056 652 and US 2003/0 055 477 combine the functions of AECD and CPR, in a device that integrates the electrodes of the AECD. The use of this type of device would make it possible to obtain better stability during cardiac massage. This device, in the form of a semi-rigid mat intended to be placed on the chest of the patient in order to facilitate CPR, the mat also comprising the electrodes of the AECD. The position of the electrodes on the mat also avoids the risks of faulty placement of the electrodes. However, the electrodes must be electrically connected to an external apparatus comprising the electronic circuits necessary to the functioning of the systems situated at a distance from the mat containing the electrodes.

These systems are in fact difficult to transport and have been designed so as to be manipulated by an experienced first-aider rather than by the patient himself, who cannot use the device, which is not fully automated .

There therefore exists a need for a compact and practical device combining the functions of portable AECD and CPR which is easily and rapidly usable by the patient or by a first-aider.

Description of the invention

The inventors have developed a device for solving the problem disclosed above by judicially integrating in: - a rigid or semi-rigid housing, suitable for serving as a support for cardiopulmonary resuscitation and suitable for receiving a compression force coming from a user,

- a pair of electrodes comprising an adhesive layer .

The electrodes stored in the housing being extractable at a variable distance making it possible to obtain a total separation between the electrodes, that is to say the distance between the parts of the electrodes intended to deliver an electric shock, lying between approximately 30 and approximately 45 cm, the separation between the electrodes being maintained by locking means, preferably mechanical means generating a resistance requiring applying a traction force on the electrodes in order to extract them further. These locking means thus make it possible to ensure the correct positioning and holding of the AECD on the patient .

Brief description of the figures

These aspects, as well as other aspects of the invention, will be clarified in the detailed description of particular embodiments of the invention, reference being made to the drawings in the figures, in which:

Figure 1 is a perspective view of the defibrillation apparatus before use.

Figure 2 is a perspective view of the defibrillator on the partial extraction of the electrodes .

Figure 3 is a perspective view of the defibrillator on complete extraction of the electrodes. Figure 4 is longitudinal section of the defibrillator according to the invention.

Figure 5 is a view illustrating the use of the defibrillator during cardiopulmonary resuscitation.

Figure 6 shows the bottom face of the housing presenting a cruciform contact surface in contact with the patient.

Detailed description of particular embodiments

It will appear obvious to a person skilled in the art that the present invention is not limited to the examples illustrated and described above. The invention comprises each of the novel features as well as the combination thereof. The presence of reference numbers cannot be considered to be limitative. The use of the term "comprises" may in no way exclude the presence of other elements other than those mentioned. The use of the definitive article "a" to introduce an element does not exclude the presence of a plurality of such elements. The present invention has been described in relation to specific embodiments, which have a purely illustrative value and must not be considered to be limitative .

Figure 1 shows the defibrillation apparatus before use thereof, that is to say when the electrodes 3 are not yet extracted from the defibrillator. The housing 1 preferably has a length of between 15 and 20 cm and a width preferentially between 7 and 11 cm, comprises in its bottom part non-traumatic rims 2 having a rounded form. The bottom face of the housing in contact with the patient may comprise a complementary surface 8 intended to be in contact with the patient. This surface 8 concentrates the cardiac massage force on the sternum (figure 6) . The opposite face of the housing 1 is suitable for a first-aider to be able to place his hands when he is performing CPR (figure 5) . The surface 8 in contact with the patient is produced from an elastomer material such as rubber. According to another embodiment, the surface 8 in contact with the patient is cruciform, as shown in figure 8, thus affording better location of the force exerted by the first-aider.

The apparatus comprises two electrodes 3 wound around an axis 4 and integrated inside the housing 1 in order to facilitate extraction thereof and extension in the case of emergency because of the absence of a cable and connections, reducing the risks of tangling and faulty connection (figure 4) . Moreover, locking means generating mechanical resistance maintain the distance between the electrodes 3 during use of the AECD. The electrodes 3 have the dimensions of a ribbon with a width of around 5 to 10 cm, which also affords better positioning and holding of the housing 1 during use thereof .

The electrodes 3 comprise a substrate made from material of a polymer type covered with an adhesive layer and peelable protective film. The adhesive coating makes it possible to position and hold the electrodes 3 in position on the patient. The electrodes 3 and the housing 1 being integral, the housing 1 of the apparatus is thus directly at the level of the sternum of the patient in an ideal position for performing cardiac massage . The separation between the electrodes 3 may advantageously be adapted according to the patient. The electrodes 3 may be in a partially extracted position, that is to say with a separation between the electrodes 3 of approximately 30 cm or completed extracted, that is to say approximately 45 cm (figures 2 and 3) . An additional force is then necessary to extract the electrodes 3 beyond a separation between the electrodes 3 of approximately 30 cm. The transition between these two positions is indicated by a visual mark for distinguishing the "partial" and "total" extraction positions of the electrodes 3, indicated by hatched areas in figure 3. The change in position is also marked by an additional mechanical resistance for which an additional force will be necessary to extract the electrodes 3 further. When the electrodes 3 of the AECD are in their first position, that is to say when the electrodes 3 are partially extracted and distant from each other by approximately 30 cm, the AECD can then be utilised on patients aged more than 3 years and/or weighing less than 20 kg. When the electrodes 3 are completely extracted, that is to say separated by approximately 45 cm, the AEDC can be used on patients of more than 8 years and/or weighing more than 20 kg.

Depending on the partial or total extraction of the electrodes 3, an adapted charge is delivered; for example, in the partially extracted position, the apparatus can be used on a child of more than 3 years and/or less than 20 kg, an energy of between 60 and 80 joules two-phase, preferably around 70 joules two- phase, will be delivered. When the electrodes 3 are totally extracted, an energy of between 180 and 220 joules two-phase and preferably around 200 joules two-phase will be delivered.

The embodiment illustrated in figures 2, 3 and 4 shows, when the electrodes 3 are extracted, the automatic and simultaneous peeling of the protective film from the electrodes 3, revealing the adhesive layer and thus facilitating the rapid positioning of the electrodes 3 and the AECD.

The mechanism of extraction by unwinding is preferably synchronised and comprises a double reel, allowing the simultaneous extraction of the electrodes 3 without disturbing the positioning of the housing of the apparatus .

The external defibrillator is preferably entirely automatic and is powered up as soon as the electrodes 3 are extracted from the housing 1 and delivers an energy of approximately 70 joules two-phase. When the electrodes 3 are completely extracted, they then deliver approximately 200 joules two-phase.

Once extracted from the housing 1 and positioned on the patient through their adhesive part, the electrodes 3 make it possible to immobilise and hold the housing 1 on the apparatus on the sternum in a stable fashion. The form and position of the housing 1 facilitate any cardiac massage.

In order to be available at any time, a battery is generally chosen so that it is functional for a minimum period of one year and provides at a minimum 15 shocks with energy of 200 joules two-phase, and a continuous analysis life of at least one 1 hour. The device may be able to provide automated assistance during the resuscitation procedure and may comprise audible 5 or visual 6 means, as well as data transfer means 7 facilitating the use of the apparatus. The audible means 5 such as a loudspeaker make it possible to use a voice guide, multifunction visual means 6 such as an indicator lamp, which may for example be green when put in service, red to alert on the electric shock or any problem and orange to indicate the end of life of the battery. The device may also comprise data transfer means 7, preferably a USB and/or WiFi port for the recovery of history data.

Optionally, this equipment will be provided for single use.