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dgeba7040

Wireless CCTV in a hospital - RFI?

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Hi, had a couple basic(ish) questions regarding a possible wireless cctv security installation. The site would be a hospital, and the system would be mobile; place the camera in current trouble spots and set up the dvr/receiver nearby in a secure room. A camera was purchased and tested prior to my involvement in this, operating around 900MHz with a 100mw output. It's not providing the range at this power level, so I've been asked to investigate options. Now for the questions. Does anybody have knowledge regarding RFI and common hospital/patient care equipment? I'm assuming 2.4Ghz is out of the question due to the large number of wireless access points utilized. If 900MHz has been used successfully, is there a recommended limit to the output power to go with it? My gut feeling tells me to consult bio-medical engineering and go over equipment, and test if necessary. However, the people who purchased the camera equipment didn't expect these questions to come up and didn't want many people to have knowledge about it, so I guess I really want to know whether or not to pull the plug on the project. The bottom line is that I'm not going to be held accountable for interference problems with patient care equipment. I've heard about other hospitals using wireless cctv, but all I can find is FCC regulations regarding wireless medical telemetry operating at 608-614, 1395-1400, & 1429-1432 MHz. I know 902-928, 2400-2500, & 5725-5875 MHz are ISM frequencies, but I'm unaware of the RFI possibilities in this setting, and I don't want to find out the hard way.

 

Thanks for any help/ideas,

Dave

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I would be extremely careful, whilst some hospitals are using wifi-networks, and their may be no problem, it is best that all departments who need to know are informed and consulted.

 

Hospitals use not just off the shelf stuff, but often use custom built appliances, even if today they are not using anything that is affected by what you choose, there is no guarentee that next year someone wont install something that is affected, unless they are aware of what has been installed.

 

If these people dont want the hospital techies to know what new equipment is radiating signals around the hospital, then not only are they probably incompetent and insane, they are putting peoples lives at risk.

 

Any equipment used in a hospital needs to be not only top-notch, it will also need to be safety tested before use (so the techies will almost certainly need to be involved) and documentation needs to be available for any one who needs to check to ensure devices are not going to be interfered with etc.

 

Sounds like these people want to keep it under wraps, I would not only walk away, I would be scared to get treatment in a hospital ran like that.

 

Patient confidentiality would also be an issue, as you dont know where the system will be recording, it could record patient movements etc, and wireless is not usually (if ever) secure.

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I would NOT use wireless in a hospital. Not only will you most likely encounter interference from hospital equipment, but you might also cause problems on the equipment once you turn on the wireless equipment.

 

Lets also not forget that wireless is for all practical purposes: Microwave. I would't want to be responsible for possibly causing problems with pacemakers.

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One of my larger clients is a hospital.

 

I've tried to use a number of different wireless devices there with little success.

 

There is commonly to much interference for a monitored panic button to transmit more than 50 feet when it should be giving me more like 1000 feet.

 

I would never even try to go wireless with a camera feed unless we were talking licensed bands up in the 23. Ghz range. And then, good luck getting their MIS guys to approve the frequency...

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There was concern some time ago (1990's) about television HD broadcasts interferring with hospital equipment. If I recall, the federal government required all hospitals to move their equipment from these frequencies. There are many types of hospital equipment that operate on digital frequencies. You will not want to use a digital frequency to broadcast a camera.

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A lot of it has to do with frequencies present at the location and what you can safely operate with. Typically if you did a survey with a spectrum analyzer (I'd rent one, they are expensive) and found out what other frequencies are present, you'd have the first hard part done. You would have to go through the entire sweep of where your signal(s) must travel. Next you would have to make sure that you don't use anything in the 2GHz range, as hospitals are places where pacemakers are present all the time and just like microwave ovens (most of which use ~2.5GHz to cook food) you would have a liability for making someone have a lot of problems.

 

I would check to see if 900MHz was clean in the facility (it probably won't be) and use that to try and penetrate walls. If you can't use that, then the 400MHz band is available but data throughput would probably be limiting for video transmission.

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I have to agree with all the above respondents. We do a lot of work for a hosiptal and they are adding all types of wireless gadgets almost on a monthly basis. Nurse calls, mobile paging, baby monitors that will alarm if someone trys to take an infant from the peds department etc. We also fine we have many dead spots due to the construction of the building. So you often have to make a lot of difficult wire runs to setup access points.

 

My main objection is what happens if some other wireless device stops working when "your equipment" is installed. It could get very interesting trying to point to the right problem.

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