Yes, it seems likely that using a car battery would be feasible. The AED devices that I have seen typically use a large capacitor to build up the charge necessary for the defibrillation shock and either run off of "wall power" or a rechargeable battery. In this way, the shock doesn't come directly from the power source. There is a caveat though, I believe car batteries are typically rated at 12 volts and can deliver considerably more peak current then one would need to charge a defib cap (on the order of hundreds of amps I would think). Unfortunately, the cigarette lighter outlet is likely fused (maybe around 10 amps), so although a device might work well for lower joule discharges - you might be up against the rails for 200+ joules. You could use the cigarette lighter to charge a battery which then charges the cap, etc. This adds to cost, bulk, etc. "Secondly, why is the current generation of AED's so expensive? Two to three thousand dollars seems to be the norm - is there anyway to reduce the cost?" I think that the actual hardware is probably a good deal less than the $2k mean, depending on the volume of product produced, but add in research & development costs, marketing, clinical trials, etc - I imagine costs start to rise. Perhaps when the next design cycle goes through products at a lower price point will appear. Medical devices mfg's seem to have longer cycle times than other electronic mfg's. I assume it is because of the trials and regulatory structure. The design of defibrillators are made to be portable devices. Hospitals use them on 'crash carts' to be used in code blue situations. These particular devices are constantly being kept at charge through a charging system plugged into an AC outlet. It's not the AC source that supplies the joules (watt Seconds) that are used to defibrillate the heart. A bank of capacitors are used for that purpose. I'm sure you have heard the whine that ensues when the device is charging the capacitor bank for a new attempt at defibrillation. The battery packs are actually, usually, 12 volt batteries, and the whine you hear is a voltage converter converting the voltage upwards to, as I recall, about 350 volts. I'm a bit fuzzy on this as it's been some time since I've worked in medical devices. Anyhow, the large weight that is associated with these devices isn't the battery pack, but rather the bank of capacitors that stores the charge, joules, to accomplish defibrillation. A good technician in a hospital will check the capacitor bank, and batteries, periodically by discharging the device's paddles across a box containing a load resistor, to emulate the patient, and comparing the reading on the box's meter with the set point established by the dial on the defibrillator. Okay, that said, capacitors have evolved considerably since the first portable units showed up in the mid- 70's. It's this advance that has allowed Phillips to build an 'affordable' home unit. Pricing on anything that is used as a medical device is inflated in disproportion to the components and knowledge needed to build a device. The companies always claim that it's because of the regulations that they must adhere to. In a small way, this is true, but the cost far exceeds these factors. Now, as you likely are aware, a monitor of the patients PQRS complex must be monitored to prevent the heart from either stopping completely or going into a circus arrhythmia; fluttering, kind of. It's is of the utmost importance that this monitoring circuitry be accurate. Most 'LifePak' type devices provide a scope and paper strip type read out. This isn't truly necessary for the synchronization to occur, but rather is provided as feedback for immediate activity structure of the complex, and a record for a cardiologist to examine after the event has occurred. What I'm saying is that the operator of the defibrillator doesn't attempt to follow the indicated waveform and guess when to press the buttons on the paddles. The device must be intelligent enough to identify the point in which to emit the discharge to the patient. Although the buttons are activated, there may well be a delay before the discharge of the capacitor bank occurs. Of course, if there is a flat line condition, the device must be intelligent enough to realize that factor. The operator of the device must also apply intelligence in determining the amount of charge to apply to the patient. Factors such as patient size, age, skin resistance (usually related to age), if there are any alternative current paths (such as a catheter or IV point(s), open wounds, etc; must be taken into consideration. I recall being called into the ER because the patient didn't 'jump' high enough. In the Black Humor of the hospital, we suggested that perhaps we should forego the calibration box, previously mentioned, and just make lines on the wall to indicate how high the patient jumped. I am digressing simply to point out the fact that the human factor, i.e. operator of the device, remains a factor. The shortcomings of weight and patient skin resistance have probably been overcome somewhat by smarter circuitry to measure skin resistance, but I'm not instantly aware of a method to factor in the patient weight and size. In summation, there is NO HUMANE REASON that a device that you suggest couldn't be built. There is no reason why this device or the home unit that Phillips makes, couldn't be made much more inexpensive for ordinary people to have in the home, car or anywhere. I would like to see all Police vehicles and shopping areas have ready access to the devices. The amount of training to use the devices is minimal. I would think that a waiver of some sort could be attached to your driver&Acircs license, like organ donors, absolving the operator of such units of any liability. The aforementioned alternate path issues are a potential problem, I believe that it only takes 10 micro amps to fibrillate a catheterized patient. That's why all hospital equipment has JCAH stickers affixed to them by the local hospitals bio-medical technicians; to display the leakage current of the electrical device(s).

Not directly, no. Battery voltage is too low. You need a device that takes the energy of the battery and steps the voltage up and has some way of preventing dangerously high voltage or current. So, a battery can be used to power one, but can not be used as one.

Just call 911 first, okay? Then you can play Mr. Wizard with someone who's got five minutes to live.

Maybe you could use the spark plug wires when the engine is running, but then the engine wouldn't run if it were missing too many plug wires and the poor fool would have to lean over the engine... haha... Try CPR after calling 911..!!!!