Friday, February 21, 2014

Someone Needs to Make This: Wireless IV alarm system.

A relative of mine had to have emergency surgery this week and I had to listen to beeping. 

There is a real shortage of nursing staff in the US, they are overworked and do the best they can so this is not to be critical of the profession. My relative was in a lot of pain and they had him hooked to a IV machine to provide fluids and pain medications on demand. The problem is when the machine would beep loudly when it needed attention of some kind. The patient is supposed to hit the call button when it beeps the member of staff comes in and reads the screen and then fixes the problem. If the patient is too sick or can not hear the beeping the issue will go on until a staff member hears the beeping and fixes the problem. In this case an IV bag needed to be replaced so the staff member hand to come to the room, read the display, and then go back and get a new bag of IV solution. 

Safety and Regulation.
I am sure that these are super regulated and that will cause some delay in something like this into service and no one wants to make things any less safe than they are now. Hacking could also be an issue but there are ways to prevent hacking.

The Fast, Quick, Cheap, and Dirty Solution.
The simplest solution is to build a device that goes into the room and listens for the beeping, once it detects the beeping it sends a message over wifi to the nursing staffs smartphones or PDAs. The member of staff would know exactly what room to go to. The hardware costs would be under $30 for the device. A digital signal processor chip or even a simple MCU like the Texas Instruments MPS430 could listen for the beeps. In fact they have this example of doing something just like that on their website. To interface to the wifi Texas Instruments offers the CC3000 SimpleLink chip. The MPS430 cost between $.50 and $3.00 while the CC3000 costs around $12.00 each. Add in the cost of a keyboard and lcd and the bill of materials would cost about $25.00 so as a product it should cost no more than say $50. This device should take minimum medical certification since it is not attached to any medical device and should work with all the current IV machines that beep. It is also safe as far as someone "hacking it". The worse that could happen is the staff would get false alerts. If that happened they just turn off the app. The machines will still beep and the patients will still hit their call buttons.


  • Cheap.
  • Secure.
  • Works with existing equipment.
  • Should require a minimum of certification.
  • fails safe.
  • Staff does not know what the problem is until they get to the room and read the display.
The Smarter Version.
A smart version of this device would use the same hardware but instead of listening for the beep it would interface to the IV machine or be built in. The best solution would be for the makers of the IV machines to come up with a standard for the data and all of them use it. The key to this device is to use a one way serial interface for safety. A traditional serial interface uses a minimum of 3 connections a transmit, receive, and ground, this device would only use a ground and the transmit of the IV machine controller would be attached to the receive of MCU the IV controller can only talk and not listen.  No matter what data gets sent to over the wifi to the IV machine it can not effect the machine in anyway. One thing you do not want is for someone besides the staff to change the settings. What this version would add is the information on the screen would be transmitted to staff. They would know what is wrong before they got to the room. If they needed to get a new IV bag because it was out they could grab it on the way to the room instead of having to make an extra trip to get it. You could also have the IV machine only start beeping five minutes after it sends the message. That way the patient may never have to hear the beeping. Of course this solution will only work for new IV machines and would require more certification since it is part of the machine. I would hope that by using a hardware air gap that the certification would be simple matter. 

Why do this?
These devices will not save any lives but they could make the patient more comfortable and save the staff time. 

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