Designing an Automatic CPR Machine

[Isos]

Hello everyone,

I am a member of a student team of engineers designing an automatic, portable CPR machine. This device could be positioned in public areas (similar to AEDs) and could be attached to patients, freeing medical personell to simultaneously move patients or tend other injuries.

We really need to prioritize design characteristics (portability, adjustability, etc.), but without field medical experience, we're a bit in the dark!

Would you be able to give us a hand by ranking the following CPR machine characteristics (in terms of importance) on a scale of 1-10?

Thank you so much! If you have any other thoughts, we'd love to hear those as well!

Form/Enclosure:

1. Size -
   
2. Weight -
   
3. Appearance -
   
4. Few components -
   
5. Comfort (for patient and operator) -
   
6. Adjustability to different body types -
   

Operation:

1. How fast it can by moved/applied -
   
2. Simplicity of use -
   
3. Ability to move patient while in use -
   
4. Ability to monitor patient condition -
   
5. Ability to automatically adjust to patient status -
   

User Interface:

1. Communication of instructions -
   
2. Ability to manually adjust rate/force of chest compression, etc. -
   
3. Ability to interface with ambulances, other medical equipment -
   

Other:

1. Weather resistance -
   
2. Theft deterrence -
   
3. Low maintenance required -
   
4. Battery life -
   

[BEorP]

Are you trying to design something to do compressions specifically? If so, how will your device be different from the existing Autopulse or LUCAS?

[Arctickat]

Form/Enclosure:

1. Size - 10: It must be able to fit on the cot, about 18 inches wide, yet fit obese patients.
   
   
2. Weight - 6: Two people could apply it, but only one can adjust it.
   
   
3. Appearance - 1: I don't care what it looks like, I care about functionality
   
   
4. Few components - 8: The less mucking around I have to do the better.
   
   
5. Comfort (for patient and operator) - 3: The patient will never know it's being used. As the operator it shouldn't be relevant.
   
   
6. Adjustability to different body types - 8: No matter how you try, there will be some people that you just can't fit. Aim for the majority of the population.
   

Operation:

1. How fast it can by moved/applied - 10: The fewest interruptions to CPR the better the outcome for the patient. Perfection would be to apply the device without stopping manual compressions
   
   
2. Simplicity of use - 7: Simplicity = speed.
   
   
3. Ability to move patient while in use - This is a two edged sword: From floor to cot - 10, current devices are usually applied once the patient is on the cot or on a long board. Being public access the cot isn't available, so it would be applied before EMS arrives While on the cot - 10. We have to be able to move into and out of the ambulance,
   
4. Ability to monitor patient condition - 1: Unless you're integrating a complete mechanical and electrical monitoring system it wouldn't be feasible. Someone has to check if that pulse on the monitor translates to a pulse in the artery.
   
   
5. Ability to automatically adjust to patient status - 3: CPR needs to continue even if the patient has a detectable pulse. It's pretty much a gut call on the practitioner to determine when to adjust CPR. Unless the patient wakes up (which is extremely rare) there is no need to stop or adjust the machine before the ambulance arrives.
   

User Interface:

1. Communication of instructions - 10: If These devices are for public use they will need to be very clear, with voice instruction.
   
   
2. Ability to manually adjust rate/force of chest compression, etc. - 0 and I mean zero. If this is for the untrained lay person they shouldn't be messing with that stuff. Besides there is a standard compression speed of 100/minute, it shouldn't change.
   
   
3. Ability to interface with ambulances, other medical equipment - 2: There are so many different brands of equipment that it would be difficult to incorporate all of them and keep your machine cost effective.
   

Other:

1. Weather resistance - 5: unless they're being stored outside or carried by mountain climbers weather resistance isn't a huge factor. Occasional rain drops may occur, but it won't be under water. The storage case should be weather resistant though.
   
   
2. Theft deterrence - 3: Provided these are stored similar to Public Access Defibrillators, I don't see theft as a big problem.
   
   
3. Low maintenance required - 7: routine checks to ensure functionality and a user test to check systems should suffice.
   
   
4. Battery life - 10: At least 30 minutes would be good. Also, the optional ability to plug into a 110 volt power source would be useful too.
   

[Isos]

Are you trying to design something to do compressions specifically? If so, how will your device be different from the existing Autopulse or LUCAS?

Yes, it is intended to perform the compressions. We'd like to design a device which could be contained in public locations (like AEDs). Ultimately though, we want to improve on the shortcomings of existing devices. Hence, we really appreciate any input from the forums given our very limited medical experience!

Also, thanks for the info, Arctickat.

[mikeymedic1984]

The machine already exists, and has for some time, as listed above. Your challenge will be to create a smaller version of the machine, that is idiot-proof, while remaining economical. Most public buildings are still not properly equipped with AEDs, which cost less than $2k. To get a business/government to buy both for their building, or choose your machine over an AED, is going to be a tall order. That is if you can afford to meet all of the federal requirements since it is a healthcare device.

I think your time would be better spent creating something that would work in an ambulance/field, as you would have a better audience for such a machine there, if you can create something that is better than what is already on the market. Just my two cents:

Cost is going to be your "10" item, it would have to be cheaper than an AED.

"9" would be it would need a way to monitor the heart like an AED and give voice commands to a layperson with no medical experience. Imagine I have a seizure and I am unconscious, but have a heart beat, but Joe Blow slaps a machine on me that starts doing CPR. Lawsuit for you.

"8" It has to function perfectly on all shapes and sizes of people.

Get through those three, then worry about everything else.

If you still have time to change your topic, design a better ambulance. For years we have been slapping hand built boxes on the back of pick-up truck bodies. Like UPS or the Icecream man, we need a vehicle that is designed for our line of work.

[paramedicmike]

Ultimately though, we want to improve on the shortcomings of existing devices.

What do you view as shortcomings?

[BEorP]

What do you view as shortcomings?

I'm also interested in this... I don't want to put a damper on your enthusiasm, but I don't see how it could get much easier to put on than the LUCAS 2 (though maybe that is why you're the engineering student and I am not!). Even the LUCAS 2 though would be more difficult to use than simply having a lay person push hard and fast in the centre of the chest for a few minutes. I have difficulty imagining a device that would be easier than this simple task of doing compressions manually (again though, not an engineer!).

If I were able to dream of the one thing that would make these devices easier (having only played with them on mannequins), I think that the place where the most improvement could be made in a dream world would be with the actual application to the patient. The fact that something has to wrap all the way around the patient is what is probably the most difficult aspect of application for paramedics and what would be an insurmountable challenge for lay people who are under stress and have never seen one of these devices. If you can design an automatic compression device that does not need to wrap circumferentially around the patient, maybe you'll have something. I just don't quite see how that will be possible, but it would probably be the best improvement you could make in my "dream world" where anything is doable.

I would also suggest that you clarify what your objective is. In your initial post, you mentioned freeing paramedics up to do other things. Now it seems like your focus is more on lay people, so I am a bit confused. Is this something that you are just writing up as a project for school about things you would hypothetically do, or do you actually plan on building this new device?

One last thought (again not wanting to damper your enthusiasm, but wanting to ensure you have all of the important information), there is no evidence that mechanical CPR devices actually improve patient outcomes from cardiac arrest. It seems like a great idea to have these "perfect" compressions done for a while arrest and allow the patient to be moved with CPR ongoing and all of this, but at this point we don't have any reason to believe that these very expensive devices actually do anything good for patients in the end. Just something to keep in mind!

Good luck with your project!

[Arctickat]

Just remember guys, he's not trying to invent and market the machine. He's putting together a school assignment that will likely not go beyond the prof's desk. He doesn't need FDA approval or medical oversight for this.

[Chief1C]

Build one that does the same as the Lucas II, and costs about $200... not $16,000.00 or was it $19,000? I don't remember, I stopped listening to the guy when he said the price.

In fact, I believe I said "HA" out loud. Mostly, the majority of EMS supplies have NEVER changed in 25 years. Yet every year, the price goes up. Even as simple as a 12pc bag of cravats. It's goddamn highway robbery.

Edited September 11, 2012 by 1 C

[Quakefire]

Having used both the LUCAS 1/2 and my service currently uses the auto pulse I'll go over a few things.

Size: Autopulse is a good size as it removes the need for a second piece of equipment namely a spine board

Weight: Autopulse is too damn heavy, LUCAS has it beat there

As for the rest I think the Autopulse has it best, you could integrate an AED into it as you already plug your defib pads into it, and apparently soon you won't need to stop CPR for rhythm checks. User interface should be same as a standard AED, on off and shock. since different manufacturers use different pads and cables most ambulance services would probably just disable the machine and use their own (our service uses zoll products, but also supplies AEDs in our area, but we have to change pads at the hospital because they use life packs)

Big on ease of use and voice instruction, long battery life and low Maintaince