WO2013114169A1

WO2013114169A1 - Cardiopulmonary resuscitation device for high quality external chest compressions

Info

Publication number: WO2013114169A1
Application number: PCT/IB2013/000063
Authority: WO
Inventors: Ivor KOVIC
Original assignee: Individual
Current assignee: Individual
Priority date: 2012-01-30
Filing date: 2013-01-21
Publication date: 2013-08-08
Anticipated expiration: 2014-07-30
Also published as: SI23964A

Description

Cardiopulmonary resuscitation device for high quality external chest compressions

Field of the invention

The present invention relates to a device for aiding in the administration of cardiopulmonary resuscitation (CP ). In particular, the present invention relates to the use of a device, which facilitates administration of high quality external chest compressions during CPR.

BACKGROUND ART

Sudden Cardiac Arrest (SCA) is one of the leading causes of death worldwide. In Europe, with 46 countries and with a population of 730 million, the incidence of SCA is estimated at between 0.4 and 1.0 per 1000 inhabitants per year, thus affecting between 350,000 and 700,000 people yearly. Cardiovascular disease, particularly ischemic heart disease, is considered the main cause of SCA, although it can also occur because of electrical shock, the use of illegal drugs, or trauma. Resulting Sudden Cardiac Death (SCD) can often be prevented, if a series of sequential actions called the Chain of Survival is put into motion with minimal delay. One of the most important actions in the Chain of Survival is early CPR, which prevents damage to vital organs such as the brain and heart, and consists of two actions: external chest compressions and artificial ventilation. External chest compressions are performed while the victim is lying on his back on a firm surface, so that the rescuer rhythmically depresses the victim's breastbone (lat. sternum) towards the backbone. This action is also referred to as heart massage, because it enables the blood to flow from the heart and through the body. Since it was first introduced in the late 1950s, the technique of performing heart massage has remained largely unchanged until today. The rescuer performing CPR without any additional equipment performs heart massage with his hands. He or she places the heel of one hand in the centre of the victim's chest, and the heel of the other hand on top of the first. With his elbows straight, the rescuer brings his shoulders up until they are directly over the victim's chest. In this manner, the rescuer forms an assumed triangle with his arms and body representing its sides, while his shoulders and his crossed hands represent the corners of the triangle. Chest compressions are then performed by applying force through rescuer's hands to the victim's breastbone.

For CPR to be most successful, it is crucial to perform it according to international guidelines for CPR, which are based on the most current scientific evidence. International guidelines for CPR have so far been updated every 5 years. The most recent guidelines from the year 2010, recommend that the rate of compressions should be at least 100, but no more than 120 per minute, while the breastbone in an adult victim should be depressed 5 to 6 cm (approximately one-third the depth of the chest in children). It has been shown that such high quality CPR can double or even triple the victim's chances of surviving ah SCA.

However, while performing external chest compressions in a manner previously described, many problems arise, which decrease its effectiveness. It is important to note that the performance of chest compressions is in itself a moderately hard task, which becomes even more tiring for the rescuer as a result of the mentioned unnatural position of the hands, causing pain in the palms, wrists and fingers. As the rescuer becomes tired, and studies have shown that this can happen within the first 2 minutes of CPR, the quality of chest compressions deteriorates and the rescuer is forced to make rest breaks, which have a very negative effect on the victim's chances of survival and good neurological recovery. Furthermore, while performing heart massage without additional devices, the rescuer does not have any insight into his actions and can't be certain whether he is performing CPR according to the international guidelines. Research has shown that CPR knowledge and skills decline quickly after CPR classes and exercises. Rescuers, even the most experienced professionals, are not capable of completely adhering to CPR guidelines as early as several weeks after training on modern CPR mannequins. Moreover, without feedback information regarding depth of compressions, rescuers sometimes tend to compress the breastbone too excessively, which can lead to victim trauma such as breastbone and rib fractures. Trauma can also be induced because of incorrect position of the rescuer's hands, and the fact that all the force transferred to the patient's chest is applied through a small surface of the rescuer's hands. Current research in resuscitation science has demonstrated that delivering chest compressions over a larger surface area results in higher vascular pressures in the patient's vessels. This mainly refers to higher pressure in the coronary arteries, which is related to increased survival and better neurological recovery of the victim. Heart massage can also be inadequate because of rescuer's leaning, which results in incomplete release of the chest between two compressions. This is often seen in rescuers with a bad technique or those who are tired. Leaning on the chest reduces the amount of blood returning to the patient's heart during the release phase, therefore resulting in a smaller volume of blood available to be distributed to vital organs during the next compression.

Besides basic life support, consisting of heart massage and artificial ventilation, CPR also includes the use of defibrillator, a device which terminates irregular heart rhythm called ventricular fibrillation (VF) by means of an electric shock. After rhythm analysis and determination that defibrillation is necessary, the defibrillator is charged, and the electric shock through the patient's heart is delivered, via paddles or pads placed on the patient's bare chest. During defibrillator charging and especially during shock delivery, rescuers must not touch the patient because of electrocution risk. Even when defibrillators are used by a team of well trained professional rescuers, the pause in chest compressions, as a result of defibrillator charging and shock delivery, lasts at least 30 seconds. During this period, due to no chest compressions being performed, patient's blood flow stops.

Some of the mentioned problems of CPR performance are relatively well solved by mechanical devices for chest compressions. However, the known devices of this kind are too large and too heavy, which limits their use to specialized medical institutions. Their high prices are another barrier to their widespread use. Nevertheless, such devices still do not solve all the CPR problems described above. To determine if defibrillation is necessary, it is crucial to continuously record an electrocardiogram (ECG) of the patient's heart during CPR. ECG is recorded using electrodes or pads which are placed on the patient's bare skin. However, during chest compressions, regardless if they are performed by the rescuer or a mechanical device, ECG does not show the actual recording of the heart's electrical activity, but the artefacts produced by the movement of the chest. In order for an automated external defibrillator or the rescuer to analyse the heart rhythm, which is done every 2 minutes during CPR, chest compressions must be paused, resulting in complete termination of blood flow to the patient's vital organs. After each pause, it takes significant time of good quality chest compressions in order to build up the blood flow to the levels achieved before the pause.

The use of various resuscitation devices is known in the prior art. U.S. Pat. No. 5,295,481 describes a CPR assist device composed of a column, pair of handles and a suction cup. The aim of this device is to make chest compressions easier and to allow for active chest expansion as the cup is pulled away from the chest. This invention does not include a system for detection of CPR quality (depth, rate and force of compressions), nor can such systems be added to it. It also does not include electrodes for continuous ECG recording. Position of the rescuer's hands while using this device is similar to that of riding a bicycle. This leads to faster tiring and poor control of the device position on the patient's chest. Furthermore, this device is large and therefore inappropriate for field work. Also, during performance of artificial ventilation, this device cannot remain standing on its own on the patient's chest. The device described in patent application EP 0 623 334 Al uses a similar design to that described above. It also features a suction pump, which adheres to the patient's chest, and a handle. Its handle is shaped like a disc, which is grasped at the opposite sides by the rescuer. Rescuer's palms are facing each other, but are very close so that the rescuer still forms an assumed triangle with his arms and body. In the middle of the disc of the mentioned invention there is a pressure measuring device, which helps limit excessive force applied to the patient. However, pressure information is of limited value and does not provide accurate information regarding the depth and rate of compressions. There are also no ECG recording electrodes. Some of the other CPR devices include those described in: U.S. Pat. No. 5,634,886; U.S. Pat. Appl. No. 2009/0234255 Al; U.S. Pat. No. 4,019,501; U.S. Pat. No. 5,738,637 and U.S. Pat. No. 4,664,098.

The primary technical problem which is solved with this invention is how to perform high quality CPR, while delivering external chest compressions with the appropriate surface for applying force to the patient's breastbone, utilizing a natural and ergonomic hands position, because of which the rescuer performs better CPR while getting less tired and feeling less pain.

The second technical problem solved with this invention is how to reduce the risk of patient trauma such as breastbone and rib fractures or rupture of internal organs, while achieving higher vascular perfusion pressures in coronary arteries of the patient's heart.

The third technical problem solved with the invention is how to continuously perform chest compressions during charging of the defibrillator and shock delivery without the risk of rescuer electrocution, and how to continuously perform chest compressions during heart rhythm analysis, with continuous ECG recording without chest compression artefacts.

The fourth technical problem solved with this invention is how to allow for simpler, easier, safer and better use of available devices for CPR, including devices with accelerometer or other systems for movement tracking, electrocardiographs, or automated external defibrillators, which can be permanently or temporarily incorporated into the invention. With such devices the invention provides continuous insight into accuracy of external chest compressions, utilizing feedback information regarding depth and rate of compressions, as well as detection of incomplete release of the chest.

DESCRIPTION OF THE INVENTION

The main purpose of the presented invention is to enhance the rescuer's performance of cardiopulmonary resuscitation (CPR). The presented invention primarily allows the rescuer to become tired less quickly during performance of chest compressions by holding his hands in a natural position. The rescuer grasps the device by the handles 2, which allow for rotation of the rescuer's hands, so his palms can be rotated towards his body, away from his body, or towards each other (Figure 2). During performance of chest compressions, the rescuer can change the position of his hands, without the need to pause chest compressions. Because of the size of the device and the distance between the two handles 2, the rescuer forms an assumed rectangle with his arms and body, rather than an assumed triangle, as is the case when chest compressions are performed with hands alone (Figure 1). Performing high quality chest compressions in such a manner requires less energy, so the rescuer gets tired less quickly. Ergonomic design of the handles 2 also contributes to easier performance of chest compressions, since it reduces pain in the fingers, palms and wrists. Because of these benefits, the rescuer can perform high quality chest compressions for a prolonged period of time, which is extremely important since CPR sometimes yields success after more than 60 minutes.

While using the presented invention, the rescuer does not come into direct contact with the victim, but depresses his breastbone with the device, which does not conduct electricity. Because of this, the rescuer can keep performing chest compressions during defibrillator charging and delivery of shock, since he is protected from electrocution. The lower surface 6 of the device, which is placed on the patient's chest, can be made in various shapes and sizes. In case the device is used on an adult, the area of the lower surface 6 is at least that of the average human palm, but preferably larger in order to reduce the risk of patient trauma and increase vascular pressures in the heart.

Embedding an electrocardiograph and ECG electrodes 7 into the lower surface 6 of the device allows for continuous recording of the electrical activity of the patient's heart, without recording the artefacts produced by chest compressions. In such a way, the rescuer does not need to stop chest compressions in order to analyse the patient's heart rhythm and the necessity of defibrillation. The very position and size of the electrodes 7, as well as the proper manner of performing chest compressions with the device, can eliminate the need to filter the recorded ECG, since it already shows a high quality recording of the patient's heart rhythm. The device includes a convenient drawer 8 for storage of self adhesive defibrillator pads, protective gloves, face shield for rescue breathing, face mask for rescue breathing, and other small equipment which is commonly used during CPR.

The device according to this invention allows for temporary or permanent installing of other devices into it. Therefore, it can serve as a carrier for electronic devices which include an accelerometer, inclinometer, laser, infrared sensors, electromagnetic transmitter and receiver, or other system for tracking movement during performance of chest compressions, artificial ventilation or spontaneous breathing of the patient. Electronic device with built-in accelerometer or other above mentioned movement tracking system, such as a mobile phone, watch, remote control or a standalone CPR device, can track movement during performance of chest compressions and provide feedback information regarding the correctness of the performed task. Using accelerometer or other systems, such devices can determine the rate and depth of compressions. By additionally adding a pressure- measuring device, force applied to the patient's chest can also be measured, which can provide feedback information regarding the completeness of release of the chest between two subsequent compressions. All the information gathered by the CPR devices, can be continuous and relayed to the rescuer in real-time with visual, audio and tactile feedback. The screen of electronic devices can show visual information about the rescuer's actions, as well as the reference guides. Audio prompts and voice commands can be used to further instruct and alert the rescuer. Such feedback information allows the rescuer to adjust his actions according to the international guidelines for CPR, which are very important to follow, since they are based on the most recent scientific evidence ensuring the best survival and good recovery rates. Additional benefit of using such devices in combination with the presented invention is the reduced risk of patient trauma. When performing chest compressions without CPR feedback, rescuers are sometimes prone to push on the chest with too much force, which often leads to patient trauma including sternal and rib fracture or rupture of internal organs. Using the presented invention in itself reduces such risk, because the downward force applied to the chest is distributed over a much larger surface area of the device. The lower surface 6 of the device is designed without sharp edges and can additionally be covered with a layer of softer material which can adjust its shape to the individual patient's chest. Adding a CPR feedback device into the invention furthermore reduces the risk of applying excessive force, and therefore injuring the patient.

As a carrier for other electronic devices, the presented invention brings numerous advantages to their use. In the case of a modern smart phone, which possesses a built-in system for movement tracking, the presented invention allows for its simpler and easier use. While using the invention, the rescuer does not need to hold the smart phone in his hands and additionally make the task of performing chest compressions more difficult and tiring. By placing the smart phone inside the invention, the rescuer sees its screen clearly, and hears the sounds it produces more loudly, since the invention enhances its volume using the specially constructed grooves 4, which direct the sound towards the rescuer's ears. The presented invention also allows for better protection of the devices which are placed into it against the blows, body fluids, and other forces or elements, by attaching them firmly inside the hard shell of the invention.

The invention will be further described using embodiments and figures:

Figure 1: Illustration of the use of the preferred cardiopulmonary resuscitation device.

Figure 2: Illustration of the possible different positions of the rescuer's hands during use of the preferred cardiopulmonary resuscitation device.

Figure 3: A perspective view from above of preferred cardiopulmonary resuscitation device. Figure 4: A perspective view from below of preferred cardiopulmonary resuscitation device.

Embodiment 1

Figure 3 shows the CPR device in a perspective view from above, showing its top and side surfaces. Casing 1 of the device is clearly visible, as well as the handles 2, which are grasped by the rescuer's hands during performance of chest compressions. Economically designed handles 2 allow the performance of chest compressions to be less physically demanding for the rescuer. Handles 2 become narrower towards the front, with slightly convex upper surface, concave lower surface, and rounded edges, allowing them to be gripped by the rescuer's hands in a natural and comfortable manner. The two handles 2 are placed 10 to 20 centimetres apart, which positions the rescuer's shoulders and hands in-line, further reducing his or her fatigue during performance of chest compressions. Final contribution to the ergonomic design of the handles 2 is achieved by the outer layer of soft and foam-like material, which reduces strain and pressure sores to the rescuer's hands during CPR.

Figure 1 illustrates the use of the device with the rescuer kneeling beside the victim. The rescuer holding the device forms an assumed rectangle with his or her arms and body. Her arms are fully extended and her shoulders are in-line with her hands while she is applying force through her palms.

Figure 2 illustrates the different ways the rescuer can grasp the handles 2 of the device in order to apply the force to the victim's chest. The handles 2 allow for rotation of the rescuer hands so his palms can be rotated towards his body or towards each other, while the fingers can grasp the handles 2 or be spread free during performance of chest compressions. The rescuer can interchange between different positions of his hands during performance of chest compressions, without the need to pause.

The presented CPR device is constructed so as to include a cradle 3 for temporary or permanent embedding of electronic devices, which possess an accelerometer or other system for movement tracking, electrocardiograph, or defibrillator. Embedded electronic devices are secured and protected inside the cradle 3, which can also feature an additional cover to offer even more protection from forces, blows, liquids and elements. The presented CPR device can also be constructed to include interchangeable adapters for different electronic devices, including smart phones. The cradle 3 is equipped with specially designed grooves 4, which serve a dual function, directing the sound signals from the electronic device towards the rescuer and allowing for an easier removal of temporarily embedded electronic device, such as a smart phone, from the cradle 3. Because of the design of the grooves 4, the volume of audio CPR feedback and coaching signals from the speakers of the electronic device is elevated. These sound signals direct the rescuer to correct his or her actions, for example instructing to push faster, slower, deeper or shallower. Sound signals also include a metronome playing at a rate of 100 to 120 times a minute, providing the rescuer with the correct rhythm for performing chest compressions.

Figure 4 shows the CPR device in a perspective view from below, with the compression box 5 and its lower surface 6, which is placed on the patient's chest while performing chest compressions. Size of the lower surface 6 is somewhat larger than the average human hand, and is based on the average size of the female body of sternum. Edges of the compression box 5 are rounded, in order to prevent possible injury to the patient. The whole outer layer of the compression box 5 can be additionally enhanced to be even less traumatic to the patient, which is achieved by ergonomic design, and use of pressure-sensitive materials which can adjust quickly to the shape of a body pressing against it.

Anatomy of the chest is highly variable among individual patients, ranging from elevated to depressed breastbones. Adjusting the outer layer of the compression box 5 according to each individual patient would improve the quality of chest compressions, as well as reduce the risk of injuries. Size and shape of the lower surface 6 can be different in different embodiments, according to different sizes of patients (adults and children), as well as future scientific evidence regarding the best practice of performing chest compressions. In one of the embodiments, ECG electrodes 7 are built in the lower surface to allow for continuous recording of the patient's ECG. This, in turn, allows for performing continuous chest compressions without the need to pause for rhythm analysis.

In a further embodiment, the compression box 5 includes a special drawer for storage 8 of self adhesive defibrillator pads, protective gloves, face shield for rescue breathing, face mask for rescue breathing, and other small equipment which is used during CPR.

The above mentioned embodiments can be combined in any combination according to the desired level of complexity of the device and are not mutually exclusive.

Device is made from materials, which are light, but at the same time elastic and solid enough to be able to withstand the forces developed during performance of chest compressions (5-50 kilograms). Furthermore, the device needs to be easy to clean, and resistant to blows, bodily fluids, as well as natural elements.

Claims

CLAI S

1. A cardiopulmonary resuscitation device comprising:

- a casing (1), which includes two handles (2) and an optional cradle for electronic devices (3);

- a compression box (5).

2. A cardiopulmonary resuscitation device as in claim 1, wherein the casing (1) and the

compression box (5) are connected to each other, so that the downward force applied by the rescuer on the handles (2) is transferred via the lower surface (6) of the device to the patient's chest.

3. A cardiopulmonary resuscitation device as in claims 1 and 2, wherein the handles (2) are spaced apart by at least 10 cm to ensure that the rescuer's shoulders and hands are in the same plane and the handles (2) can be gripped by the rescuer's hands in a natural and comfortable manner preferably by becoming narrower towards the front, with slightly convex upper surface, concave lower surface, and rounded edges.

4. A cardiopulmonary resuscitation device as in claims 1 and 2, wherein the cradle for

electronic devices (3) can hold interchangeably or simultaneously one or more of the devices which possess an accelerometer, inclinometer, laser, infrared sensors,

electromagnetic transmitter and receiver, or other system for tracking movement during performance of chest compressions, artificial ventilation or spontaneous breathing of the patient, and are temporarily or permanently embedded into the device.

5. A cardiopulmonary resuscitation device as in claimss 1 - 4, wherein the cradle for electronic devices (3) can hold devices which deliver electrical shock to the patient's heart, and they are temporarily or permanently embedded into the device.

6. A cardiopulmonary resuscitation device as in claims 1 - 4, wherein the cradle for electronic device (3), can hold a mobile phone with its screen fully visible once placed in the device and two grooves (4) for the direction of sound toward the rescuer's ears, and easier removal of a mobile phone after use.

7. A cardiopulmonary resuscitation device as in claims 1 - 4, wherein the cradle for electronic devices (3) can hold devices which measure forces applied via the compression box (5) and its lower surface (6) to the patient's chest during performance of chest compressions.

8. A cardiopulmonary resuscitation device as in claims 1 and 2, wherein the compression box (5) has a shape of a rectangular box with rounded edges, and is constructed from a material which adjusts the shape of its lower surface (6), the size of the average female body of sternum, according to the anatomy of the patient's chest.

9. A cardiopulmonary resuscitation device as in claims 1 and 2, wherein the height of the

compression box (5) is minimally 3 centimetres, whereby the rescuer does not come into direct contact with the patient, while applying the downward force on the handles (2).

10. A cardiopulmonary resuscitation device as in previous claims, wherein the compression box (5) has in its lower surface (6) built-in ECG electrodes (7), which come into contact with the patient's skin while performing chest compressions.

11. A cardiopulmonary resuscitation device as in previous claims, wherein the compression box (5) includes a drawer for storage (8) of self adhesive defibrillator pads, protective gloves, face shield for rescue breathing, face mask for rescue breathing, and other small equipment which is used during CP .