WO2010066014A2

WO2010066014A2 - Automated external defibrillator and its method of operation

Info

Publication number: WO2010066014A2
Application number: PCT/BR2009/000407
Authority: WO
Inventors: Rubem Dutra Ribeiro Fagundes; Denis Xavier Barbieri; Diogo Scolari; Luís Vitório CARGININI; Martin Antonio Behrens
Original assignee: Instramed - Indústria Médico Hospitalar Ltda; União Brasileira De Educação E Assistência - Mantenedora Da Pucrs
Priority date: 2008-12-11
Filing date: 2009-12-11
Publication date: 2010-06-17
Also published as: BRPI0806147A2; BRPI0806147A8; WO2010066014A3

Abstract

The present invention comprises an automated external defibrillator and its method of operation. In particular, the defibrillator is portable and easy to operate. It automatically performs the analysis of the cardiac rhythm and guides the operator by voice and/or visual signals with respect to the several steps until the use of the electric shock to recuperate the patient. In particular, the use of this equipment does not require that the operator is a physician.

Description

Patent Specification

AUTOMATED EXTERNAL DEFIBRILLATOR AND ITS METHOD OF OPERATION.

Field of the Invention The present invention comprises of an automated external defibrillator and its method of operation. In particular, the defibrillator is portable and easy to operate. It automatically performs the analysis of the cardiac rhythm and guides the operator by voice and/or visual signals with respect to the several steps until the use of the electric shock to recover the patient. In particular, the use of this equipment does not require specialized physician. The present invention is located principally in the field of medicine.

Background of the Invention

Automated External Defibrillator Automated external defibrillator (AED) is a portable electronic device that automatically diagnoses cardiac arrhythmias such as the ventricular fibrillation and tachycardia of the patient. It has the capability of treating them using defibrillation, or rather, the application of electrical therapy (shock) that reverses the arrhythmia, allowing the heart to re-establish its normal rhythm. An AED is classified as being external when the operator applies the electrodes (or pads) on the thorax of the patient, unlike internal defibrillators, where the electrodes are applied directly onto the heart of the patient. The term "automated" refers to the capability of the unit to analyze autonomously the condition of the patient. Some of the units have voice commands or displays to view the information. Some AEDs instruct the user to connect /the ejectrodes (pads) tά the patient. Nobody should touch the patient with the pads connected, in order to avoid false heart beat readings by the AED. The pads allow the AED to collect the electric signals from the heart and determine if the patient has an altered cardiac rhythm. If the device determines that a shock is necessary, it will use the energy from its battery to charge an internal capacitor that stores the energy necessary for the application of the shock. Depending on the model of the AED, after the shock it will analyze the cardiac signals of the patient and issue instructions. The first commercial models of AEDs applied shocks or monophasic discharges, with a maximum energy in the range from 360 J to 400 J. These models were discontinued and, currently, the devices tend to be of the biphasic type, with a maximum energy in the range from 200 J to 240 J, reducing the risk of burns and damage to the myocardium of the patient.

The AED of the present invention presents certain particular characteristics, described herein. During the operation of the AED, the cardiac signals, obtained from the patient and used for the diagnosis of his condition, are stored in an internal memory device, for subsequent consultation by medical staff. The AED also has an internal microphone and is capable of recording sound from the entire environment where it is being used, from the first moment it enters into operation. All the information, both the clinical data of the patient, including the acquired signals and the issued diagnosis, and the sound recordings of its use, is stored in a non-volatile internal memory. It is available for subsequent consultation via the USB port of the equipment and the specific application program for its reading and recuperation ("download").

It is also highlighted that the AED of the present invention has a critical mission system that monitors all the functions and internal and external operations of the equipment, in order that all the functions and procedures are executed simultaneously when necessary. The most common failures during the emergency procedures to the patient (for example: disconnection of the device's pads during the operation) are detected, indicated and, in some cases, corrected. During the entire time in which the AED of the present invention is in operation, the equipment guides the user/operator (the user that is supplying the assistance and operating the AED), by means of sound and visual signals and voice commands, in each step of the procedures necessary for the correct assistance to the patient including, if necessary, the application of an electric shock. In the patent area, some documents describe automated external defibrillators and their use.

Document US 6,668,192 describes an AED comprising of an energy supply and circuit to generate the defibrillation pulse. In particular, the defibrillator also maintains information relative to the procedure of the patient's recovery, such as data of the device operation and of the environment close to the patient. The present invention differs from this document by automatically instructing the procedure that the user should perform with the patient, which is a fact that is not cited in the aforesaid document. Document US 6,969,259 describes an AED device that instructs the user by a panel or voice to perform the steps necessary for the operation of the AED. It comprises of the acquisition of patient information, such as ECG signals, identification of use for adult or pediatric patients and the moment to perform the shock. Additionally, the device informs the user if the pads are correctly located on the thorax of the patient. The present invention differs from this document by comprising of an intelligent system of detection and analysis of the electrocardiographic signals of the patient based on Neural Networks, by additionally instructing the user to perform ventilation procedures and by not requiring instruction with respect to the correct positioning of the pads, because the present invention operates correctly, even with the pads inverted.

Document WO 2008/057302 describes an AED with a wireless multiple monitoring system, in which the pads should be applied to the patient in order to measure the cardiac rhythm of the patient and to initiate the charging of the capacitors. The present invention differs from this document by not adopting the solution of wireless monitoring and by additionally automatically instructing the procedure that the user should perform on the patient, which is a fact that is not cited in the aforesaid document.

Document WO 2008/020369 describes an AED and a method to incorporate the analysis of the ECG to determine if the heart should receive the synchronized shock or not, alerting doctors to possible alternative therapies. The present invention differs from this document by using an algorithm of Neural Networks to ascertain the state of health of the patient, which is a fact that is not cited in the aforesaid document.

Document WO 2007/148257 describes a defibrillator comprising of electrodes, a high tension circuit and an interface that receives the data of the patient and controls/performs the production of the shock in accordance with this data. The present invention differs from this document by guiding the user visually and/or by sound about how to proceed in order to deliver the shock, which is a fact that is not cited in the aforesaid document. Furthermore, the operation of the shock is conditioned to the operation of the indicator button on the device.

Therefore, no information was discovered that suggests and/or anticipates the aforesaid document.

Summary of the invention The object of the present invention is an automated external defibrillator comprising of: a) means to detect heart beats and/or the quality of the electrocardiogram of the patient; b) means to identify cardiac arrhythmias of the patient using an intelligent system of Neural Networks; c) means to set the age range of the patient (adult/pediatric); d) means to provide the user, by sound and/or visual signals, of at least one of the following items of information: d1) guidance for the pre-evaluation of the state of health of the patient and the performance of the cardiorespiratory recuperation maneuvers; d2) guidance for the installation of the electrodes (pads) on the thorax of the patient; d3) acquisition procedure of the electrocardiographic signals of the patient; d4) evaluation of the quality of the contact of the electrodes with the patient's skin; d5) warning to avoid the contact of the operator with the patient; d6) emergency service call; d7) guidance to ascertain the state of the patient; d8) guidance to perform the defibrillation procedure of the heart of the patient according to the state of the patient; d9) guidance to perform the evaluation of the patient after the application of the electric shock. e) means to administer information of the patient, of the environment and/or of the device.

An additional object of the present invention is that the method of operation of the automated external defibrillator comprises of the steps of: a) connection of the device to the patient; b) instruction to the user with respect to the cardiac situation of the patient; c) instruction to the user with respect to the next steps to be performed, in accordance with the cardiac conditions of the patient, detected by the device (cardiorespiratory recovery maneuvers); d) acquisition and/or storage of information of the patient, of the environment and/or of the AED device; e) monitoring of all the operation and the internal and external operations of the equipment, using the embedded operational critical mission system.

In a preferential embodiment, the operational critical mission system operates so that all the functions and procedures are performed simultaneously, when necessary, and the most common failures during the emergency procedures to the patient are detected and corrected.

A person skilled in the art will be able to appreciate the present invention in the light of the information described herein and detailed as follows. Description of the Drawings

Figure 1 illustrates the block diagram of the AED, in which some modules are optional and can be opportunely updated (outlined).

Figure 2 indicates the protocol of preferential service.

Detailed Description of the Invention

The examples displayed here have the objective only of exemplifying one of the possible embodiments of the invention, without, therefore, limiting it, in order that similar embodiments are within the scope of the invention. Means to detect the heart beats of the patient

The means to detect the heart beats of the patient comprises of a unit of two pads where internal electrodes of the type used in electrocardiographic equipment are positioned on the chest of the patient, in accordance with the guidance provided by the equipment to the user/operator. If necessary, the electric shock from the defibrillator will be applied through these pads. Means to identify the state of health of the patient

The means to inform the user of the decisions comprises of an intelligent system of Neural Networks that allows recognition of the state of the patient and operates the means to inform the user of the decision to be taken in relation to the health of the patient. The neural network was trained to recognize two types of cardiac arrhythmias: those where the electric shock is not necessary, and in this case the equipment guides the procedure of cardiac massage and cardiopulmonary respiration, and cardiac arrhythmias where the shock should be applied. In the latter case, the equipment clearly guides the operator of the need of defibrillation and awaits the operation of the button corresponding to the release of the shock. The recognizer of the AED was trained to recognize cardiac arrhythmias even when the electrodes are positioned inverted on the chest of the patient, thereby dispensing with additional guidance. Means to inform the user of the decisions The means to inform the user of the decisions comprises of visual and/or sound indications and/or voice commands given by the defibrillator to the user. In particular, these sequential indications inform the steps to be taken until the defibrillation, according to the state of health of the patient. Means to acquire/save patient information

The means to acquire/save patient information comprises of an internal memory device, for subsequent consultation by medical staff. The AED also has an internal microphone and is capable of recording sound from the entire environment where it is being used, from the first moment it enters into operation. All the information, both the clinical data of the patient, including the acquired signals and the issued diagnosis, and the sound recordings of its use, is stored in a non-volatile internal memory. It is available for subsequent consultation via the USB port of the equipment and the specific application program for its reading and recuperation ("download").

Means to monitor continuously the operation of the equipment: The AED has an internal operational critical mission system that continuously monitors the operation of the modules, functions and most important procedures, avoiding errors of operation and assuming alternative operations, if the most common operational failures or damage occur during the use of the equipment.

Example 1. AED

The automated external defibrillator of the present invention, as can be seen in figure 1 , comprises of an easily operated, portable and low cost version that automatically performs the analysis of cardiac rhythm and guides the user as to how to apply the electric shock to recover the patient. Its operation can be performed by any person, not necessarily with medical experience.

The defibrillator of the present invention comprises of a dual-core Soc (RAM+DSP) platform that performs RNA for the recognition of cardiopathies. Furthermore, the present invention is biphasic, allowing an electric shock of up to 360J, with a capacity of 50 shocks without recharging the battery and with a charge time for each shock of less than 10 seconds, with a highly durable rechargeable battery. The present device, as well as not interrupting the monitoring for the performance of internal operations, comprises of an intelligent system of neural networks to recognize the state of health of the patient.

Figures 1 and 2 illustrate the operation of the AED described herein. Figure 1 illustrates the block diagram of the AED, in which some modules are optional and can be opportunely updated (outlined). In accordance with figure 1 , the alpha-numeric symbols correspond to: (a) amplifier/instrumentation; (b) buffer; (c) voltage; (d) current; (e) impedance; (f) ADS8341; (g) 12C; (h) LPC2114; (i) OMAP5912; (j) SPI; (k) 125; (I) 12C; (m) TSC2101 ; (n) MAX1561 ; (o) TFT Display; (p) LCD Display; (1) Electrodes/Defibrillation;(2) ARM7;(3) High voltage control;(4) Storage and locking of energy; (5) ADC; (6) DDR Memory; (7) DSP; (8) ARM; (9) NOR Flash; (10) Audio+Touchscreen Codec; (11) White LED Driver; (12) SD Card; (13) USB Console Pen-Drive; (14) IrDA; (15) Wi-Fi; (16) GPRS; (17) Fuel Gauge; (18) High voltage source; (19) OMAP Regulator; (20) Linear Regulator. Figure 2 indicates the protocol of preferential service. In accordance with figure 2, the alpha-numeric symbols correspond to: (A) Start; (B) Auto-test; (C) Test OK?; (C1) Response if C was negative - Auto-test failure treatment; (D) Response if C was positive - Test if electrodes are connected; (E) "Electrodes connected?"; (E1) Response if E was negative - Follow pre-programmed commands ("Stay calmVCheck if the patient is conscious"/ "Call the emergency service'VOpen the airwaysTCheck if the patient is breathing'7'Ventilate twiceVCheck the pulseTTake the electrodes from the packagingTConnect the electrodes to the equipment; (F) Response if E was positive - "Place the electrodes on the patient";(G) N=O; (G1) FV/TV Recognizer; (H) Measure impedance; (I) "Is there a patient?"; (11) If the response to I was negative, then N=N+1 , proceed to I2;(I2) N<4?, if the response was positive, return to H; (I3) If the response to I2 was negative - "Check if the electrodes are connected correctly"; (J) If the response to I was positive - "Do not touch the patient, analyzing rhythm"; (K) Analyzing rhythm; (L) Shockable?; (L1) If the response was negative, proceed to the RCP Procedure;(M) If the response was positive perform the Treatment - Patient Shockable. Persons skilled in the art will know that this description is not limiting and can be used in several manners, in accordance with the information described herein.

Claims

ClaimsAUTOMATED EXTERNAL DEFIBRILLATOR AND ITS METHOD OF OPERATION.

1. Automated external defibrillator characterized by comprising of: a) means to detect heart beats and/or the quality of the delineated electrocardiogram of the patient; b) means to identify cardiac arrhythmias of the patient using an intelligent system of Neural Networks; c) means to set the age range of the patient (adult/pediatric); d) means to provide the user, by sound and/or visual signals, of at least one of the following items of information: d1) guidance for the pre-evaluation of the state of health of the patient and the performance of the cardiorespiratory recovery maneuvers; d2) guidance for the installation of the electrodes (pads) on the thorax of the patient; d3) acquisition procedure of the electrocardiographic signals of the patient; d4) evaluation of the quality of the contact of the electrodes with the patient's skin; d5) warning to avoid the contact of the operator with the patient; d6) emergency service call; d7) guidance to ascertain the state of the patient; d8) guidance to perform the defibrillation procedure of the heart of the patient according to the state of the patient; d9) guidance to perform the evaluation of the patient after the application of the electric shock. e) means to administer information of the patient, of the environment and/or of the device.

2. Defibrillator, in accordance with claim 1 , characterized by the system of neural networks recognizing different types of cardiac arrhythmias and guiding the user as to how to proceed in each one of them.

3. Defibrillator, in accordance with claim 2, characterized by the cardiac arrhythmias comprising of those where the electric shock is not necessary. The user is guided by the equipment with respect to the procedure of cardiac massage and cardiopulmonary respiration.

4. Defibrillator, in accordance with claim 2, characterized by the cardiac arrhythmias comprising of those where the electric shock should be applied. The user is guided by the equipment with respect to the necessity of defibrillation and awaits the operation of the equipment for the release of the shock.

5. Defibrillator, in accordance with claim 2, characterized by the recognition of the cardiac arrhythmias even when the electrodes are positioned inverted on the chest of the patient.

6. Method of operation of the automated external defibrillator characterized by comprising of the stages of: a) connection of the device to the patient; b) instruction to the user with respect to the cardiac situation of the patient in accordance with the decision of the System of Neural Networks; c) instruction to the user with respect to the next steps to be performed, in accordance with the cardiac conditions of the patient, detected by the device, such as cardiorespiratory recovery maneuvers or defibrillation; d) acquisition and/or storage of information of the patient, of the environment and/or of the AED device; e) monitoring of all the operation and the internal and external operations of the equipment, using the embedded operational critical mission system.

7. Method, in accordance with claim 6, characterized by the system of neural networks recognizing different types of cardiac arrhythmias and guiding the user as to how to proceed in each one of them.

8. Method, in accordance with claim 7, characterized by the cardiac arrhythmias comprising of those where the electric shock is not necessary. The user is guided by the equipment with respect to the procedure of cardiac massage and cardiopulmonary respiration.

9. Method, in accordance with claim 7, characterized by the cardiac arrhythmias comprising of those where the electric shock should be applied.

The user is guided by the equipment with respect to the necessity of defibrillation and awaits the operation of the equipment for the release of the shock.

10. Method, in accordance with claim 6, characterized by the recognition of the cardiac arrhythmias even when the electrodes are positioned inverted on the chest of the patient.

11. Method, in accordance with claim 6, characterized by the operational mission critical system operating so that all the functions and procedures are performed simultaneously, when necessary, and the most common failures during the emergency procedures to the patient are detected and corrected.