How Does a Defibrillator Work?
除颤器是如何工作的？
Defibrillators are instrumental in preventing sudden cardiac arrest (SCA) deaths, but how do they actually work? Though different types of defibrillators have different mechanisms behind them, they all operate on the same basic principle: using controlled electric shocks to prevent cardiac arrest or to restart a heart that no longer beats.
除颤器在防止心脏骤停（SCA）死亡方面发挥着重要作用，但它们实际上是如何工作的？尽管不同类型的除颤器背后有不同的机制，但它们的工作原理都是一样的：使用受控电击来防止心脏骤停或重新启动不再跳动的心脏。
A defibrillator is designed to correct or restore a heartbeat with the use of electric pulses or shocks. In a general sense, it can:
·Correct the kinds of heart arrhythmias (irregular heartbeats) causing cardiac arrest, specifically ventricular fibrillation, and pulseless ventricular tachycardia.
·Restore a normal heartbeat in a cardiac arrest sufferer
A defibrillator first checks for heart arrhythmias. If a shockable arrhythmia is detected, the device triggers a shock to the heart in an effort to restore normal function. A typical defibrillator will deliver 150 to 360 Joules of electricity at a time (less in the case of children). Subsequent shocks may be automatically adjusted with more or less electricity based on the response of the patient.
除颤器旨在通过使用电脉冲或电击来纠正或恢复心跳。在一般意义上，它可以纠正导致心脏骤停的各种心律失常（不规则心跳），特别是心室颤动和无脉室性心动过速。
恢复心脏骤停患者的正常心跳
除颤器首先检查心律失常。如果检测到可电击的心律失常，该设备会触发对心脏的电击，以努力恢复正常功能。一个典型的除颤器每次会提供150至360焦耳的电流（儿童的情况下会更少）。随后的电击可以根据病人的反应自动调整更多或更少的电流。
In the past, defibrillators relied exclusively on monophasic shock delivery, meaning that the electrical current flows in a single direction. In recent years, all device makers have switched to lower-energy biphasic shocks, meaning that the current flow goes in both directions. In the first phase, the current flows from one paddle to the other, and in the second phase it reverses direction. The Philips HeartStart series is one of the first AED lines to standardize biphasic waveform technology.
在过去，除颤器完全依赖单相电击输出，这意味着电流在单一方向流动。近年来，所有设备制造商都转而采用能量较低的双相电击，这意味着电流的流动是双向的。在第一阶段，电流从一个电极片流向另一个电极片，而在第二阶段，电流方向相反。飞利浦HeartStart系列是首批将双相波形技术标准化的AED系列之一。
One key benefit of biphasic delivery is that it allows defibrillators to restore normal heart function with less energy, thereby reducing the risk to the patient and allowing a greater likelihood of success. In fact, studies have shown that 200 J biphasic shocks can be as effective as 360 J monophasic shocks.
双相输送的一个关键好处是，它允许除颤器以较少的能量恢复正常的心脏功能，从而降低了病人的风险，使成功的可能性更大。事实上，研究表明，200焦耳的双相电击可以和360焦耳的单相电击一样有效。
Types of Defibrillators
除颤器的类型
There are three main types of defibrillators:
·Automated external defibrillators (AEDs)
·Wearable cardioverter defibrillators (WCDs)
·Implantable cardioverter-defibrillators (ICD)
除颤器有三种主要类型。
自动体外除颤器（AEDs）
可穿戴式心律转复除颤器（WCDs）
植入式心律转复除颤器（ICD）。
When most people think of defibrillators, they imagine pads or paddles used externally on the chest, but not all defibrillators work this way. An automated external defibrillator (AED) is reserved for cardiac arrest emergencies, but other types of devices are designed for preventive measures.
当大多数人想到除颤器时，他们想象的是在胸部外部使用的电极片或电板，但不是所有的除颤器都以这种方式工作。自动体外除颤器（AED）专门用于心脏骤停的紧急情况，但其他类型的设备是为预防措施设计的。
Automated External Defibrillators (AEDs)
自动体外除颤器(AEDs)
An AED is a small, lightweight, portable defibrillator designed for use on SCA sufferers. Though these defibrillators can vary widely in their cost and complexity, a typical device is equipped with step-by-step voice coaching so that an untrained lay user can save a life in an emergency.
An AED is equipped with pads and a battery, both of which come with an expiration date. The pads are equipped with a special gel that adheres to a patient’s bare skin, and built-in sensors allow the defibrillator to analyze the heart for a shockable rhythm. Most devices will only allow shock delivery after determining that such an intervention is safe and advisable.
自动除颤器是一种小型、轻便、便携式的除颤器，专门用于SCA患者。尽管这些除颤器在成本和复杂程度上差别很大，但一个典型的设备配备了逐步的语音指导，以便未经训练的非专业用户能够在紧急情况下拯救生命。
AED配备有电极片和电池，两者都有一个有效期。电极片上装有一种特殊的凝胶，可以粘附在病人的裸露皮肤上，内置的传感器允许除颤器分析心脏的可冲击节奏。大多数设备只有在确定这种干预是安全和可取的情况下才允许电击。
The ‘Automated’ in ‘Automated External Defibrillator’ means that these devices are designed to read the heart rhythm and make a shock/no-shock decision automatically, as opposed to hospital or EMS-grade defibrillators which allow the operator to read the EKG rhythm and make their own decision as to whether to shock, and at what energy level. AEDs use a built-in algorithm to make the determination whether a shock is needed. How that shock is delivered is what makes an AED either Fully Automated or Semi Automated.
自动体外除颤器中的 “自动 ”是指这些设备被设计用来读取心律并自动做出电击/不电击的决定，而医院或EMS级除颤器则允许操作者读取EKG心律并自行决定是否电击，以及以何种能量水平电击。自动体外除颤器使用一个内置的算法来决定是否需要电击。如何进行电击是使AED成为全自动或半自动的原因。
·Semi-automatic shock delivery is standard with most AEDs. After the device determines that a shock is warranted, it instructs the user to press a “Shock” button on the device. The shock button is only activated once the AED determines a shockable rhythm, which removes the risk of accidentally shocking someone inappropriately. Devices available in semi-automatic mode include the Philips OnSite and FRx, the Heartsine 350P and 450P, and the Defibtech VIEW.
半自动电击输出是大多数AED的标准配置。在设备确定需要电击后，它会指示用户按下设备上的一个 "电击 "按钮。只有当AED确定了可电击的心律后，电击按钮才会被激活，这就消除了意外地不适当地电击某人的风险。半自动模式的设备包括飞利浦OnSite和FRx、Heartsine 350P和450P，以及Defibtech VIEW。
·Fully automatic shock delivery requires no intervention from the user once the pads are placed on the patient, other than ensuring everyone stands clear. As soon as the device determines that a shock is warranted, it sounds verbal warnings to let all responders know to stand clear due to an imminent shock, then delivers that shock automatically. This feature is becoming popular in a growing number of defibrillators and is sometimes available as an upgrade. AEDs with this option include the Cardiac Science Powerheart AED G3 Plus and the Cardiac Science Powerheart G5. Several AED models can be purchased as either semi- or fully automated, such as the ZOLL AED Plus, and the Defibtech Lifeline.
完全自动的电击输出不需要用户的干预，一旦电极片放在病人身上，除了确保每个人都站开之外。一旦设备确定需要电击，它就会发出口头警告，让所有响应者知道由于即将发生电击而要站开，然后自动进行电击。这一功能在越来越多的除颤器中变得流行，有时可作为一种升级。具有这一选项的AED包括Cardiac Science Powerheart AED G3 Plus和Cardiac Science Powerheart G5。有几个AED型号可以买到半自动或全自动的，如ZOLL AED Plus和Defibtech Lifeline。
In addition, a typical external defibrillator will include features like CPR coaching, automatic daily self-tests, child-friendliness settings, and—in many cases—bilingual functionality.
此外，典型的体外除颤器将包括心肺复苏辅导、每日自动自检、儿童友好型设置等功能，在许多情况下还包括双语功能。
Unlike with other types of defibrillators, anyone can own an AED. In fact, these devices have become popular—and are often even required—in places like hotels, offices, gyms, and schools, because sudden cardiac arrest can strike at any time.
与其他类型的除颤器不同，任何人都可以拥有一台AED。事实上，这些设备已经变得流行，甚至经常被要求在酒店、办公室、健身房和学校等场所使用，因为心脏骤停可能在任何时候发生。
How to Use a Defibrillator
如何使用除颤器
If you have an ICD implanted, you don’t have to do anything. If you’re prescribed a WCD, you need only wear it as advised by your doctor.
An AED is the only type of defibrillator with a learning curve, and even that’s pretty simple on account of the device’s intuitive nature. If you need to use an AED in an emergency, the process is pretty simple:
如果您有植入ICD，您不需要做任何事情。如果您被开具了WCD，您只需要按照医生的建议佩戴它。
AED是唯一一种有学习周期的除颤器，由于该设备的直观性，即使学习周期也很简单。如果你需要在紧急情况下使用AED，过程也很简单。
·Have someone call 911—or do it yourself if nobody is available
·Check to ensure that the patient is experiencing cardiac arrest—no breathing, no heartbeat, unconscious
·Power on the AED (this may be done by pressing a Power button or opening the lid)
·Follow the step-by-step voice instructions
请人拨打120，或者如果没有人的话，就自己打吧
检查以确保病人正在经历心脏骤停--没有呼吸、没有心跳、失去意识
打开AED的电源（这可以通过按下电源按钮或打开盖子来完成）。
遵循逐步的语音指示
The device will guide you through both CPR and defibrillation, prompting you to deliver an electric shock if the intervention is warranted. If a shock is unsuccessful, or if no shockable rhythm is detected, the device will prompt you to continue CPR until emergency services arrive. Remain with the patient until help arrives.
该设备将指导你进行心肺复苏和除颤，如果有必要进行干预，将提示你进行电击。如果电击不成功，或者没有检测到可电击的心律，设备将提示你继续心肺复苏，直到急救服务到达。保持与病人在一起，直到救援到达。
How Effective Is a Defibrillator?
除颤器的效果如何？
When used promptly and properly, an automated external defibrillator can be extremely effective.
如果及时和正确地使用，自动体外除颤器可以非常有效。
Every year, there are approximately 356,000 out-of-hospital cardiac arrests in the U.S., and most are fatal—this high fatality rate is partially due to delayed intervention. When an AED is used, a patient’s prognosis improves significantly.
每年，美国大约有35.6万起院外心脏骤停，而且大多数是致命的--这种高死亡率部分是由于延迟干预。当使用AED时，病人的预后明显改善。
One study examined the data from 13,769 out-of-hospital SCA incidents and found that:
一项研究检查了13,769起院外SCA事件的数据，发现：
·Overall survival to hospital discharge was 7%
·Overall survival with CPR but no AED was 9%
·Overall survival with AED application was 24%
·Overall survival with AED shock delivery was 38%
出院前的总生存率为7%。
使用心肺复苏但不使用AED的总生存率为9%。
使用AED的总生存率为24%。
使用AED电击的总生存率为38%。
In other words, the immediate use of an external defibrillator can increase an SCA patient’s odds of survival by more than five times. Studies into ICDs and WCDs have similarly found these devices to be effective for prolonging the lives of high-risk individuals, even those who have previously suffered a cardiac arrest.
换句话说，立即使用体外除颤器可以将SCA患者的生存几率提高五倍以上。对ICD和WCD的研究同样发现这些设备对延长高危人群的生命是有效的，甚至是那些曾经遭受过心脏骤停的人。
Defibrillators Save Lives
除颤器拯救生命
If you’ve experienced a cardiac arrest or you’re at a heightened risk for SCA, speak to your doctor about whether a wearable or implantable defibrillator is right for you.
如果你经历过心脏骤停或你处于SCA的高风险中，请与你的医生讨论可穿戴或植入式除颤器是否适合你。
If you’re simply looking to protect yourself or others in your home or place of business, consider investing in an automated external defibrillator. Anyone can establish an AED program, and it may just save a life one day.
如果你只是想保护你的家庭或商业场所中的自己或他人，考虑投资一台自动体外除颤器。任何人都可以建立一个自动体外除颤器项目，它可能会在某一天拯救一条生命。
信息来源：CPR1 LLC.
AED急救；自动体外除颤器；心脏除颤；拯救生命；