I have personally been working with developing an early radio interface for Animas/Lifescan/J&J/Onetuch insuline pump and its control unit, a remote glucose meter. It was around 2002-2005. My design job included work with EMI&ESD to make it pass FCC.
They looked like this:
https://fccid.io/VWT115/Users-Manual/manual-938927Radio system was simple, ISM 916 MHz communication to tell the pump to somewhat increase/decrease insuline depending on measured or manually input data in base unit.
If I remember correct was radio a FSK-modulated CC1101 followed by SAW-filter, impedance tuning and a F-antenna. It is a very classic and well proven design. Both SAW-filter and F-antenna will heavy attenuate any RF-signals below 900 MHz and F-antenna will continue to linear to attenuate signal with lowered frequencies. Shortwave interference that way is not possible even if insulin pump is placed directly at a glowing HAM-antenna in my opinion.
A part of the FCC test includes ESD, electric discharge with 5-15 kV at different location around its enclosure and display window. Main energy in a such discharge is below 30MHz and F-antenna is then a good choice to protect radio from these low frequencies high energy discharges.
Functional design was such that if battery drops in base unit should it not affect pump-units normal function, absolute requirement from FDA.
It was also a pairing function, also required by FDA. Very important as else can pump unit get wrong information at a diabetics meeting with a lot of people at same location.
Assume that 10 base units starts to transmit in same room at 900MHz. All pumps will listen to all signals.
A lost signal is for same reason not a big issue and signal will be retransmitted within 10 minutes from remote unit. If remote unit then still not get any confirmation will it beep av warning.
To interfere with the pump function must HAM-guy transmit correct pairing signal and instruction and that can then result in that normal insulin dose is increased or decreased with something like 10%. Idea is that user easily can adjust insulin level when heavy working or eating more then normal but amount of adjustment relative its base setting is limited on propose.
When this unit was developed did not exist any real smart-phones and Bluetooth was not very common. There was no crypto protection of radio-signal so it was possible to copy an transmit sequence but it would as most just do a minor adjustment of pump-motor speed.
Guess a lot have happen since I did develop first early prototypes but basic principles is the same:
By patient allowed adjustment allows only for a minor adjustment of insulin base setting.
If any communication fails will base setting remain.
If 900 MHz is blocked is no serious situation. If later version of pump electronics have flaws, bad ESD/EMC design, which can make the pump to not deliver expected amount is easily checked be measure amount of insulin added to pump reservoir.
If I should guess a possibility that something could interfere with the pump, is it not by its RF-interface. More likely high magnetic field that directly affects pump drivers, or its voltage regulators that both typically are PWM around 100-200 kHz. Such high magnetic fields are unlikely created by any broadband AM transmitter but something like a faulty inductive cooker or an electric heated blanket can maybe create such fields as they can become much closer to the pump.
"It must be the guy with that big antenna that makes me feeling less good" is same problem as when people becomes sick seeing a cell-tower or any for them unknown technology.
5G must be more dangerous then 4G, then 3G then 2G. It is a never ending story.
I remember when color TV was a new thing. My grandfather was looking at TV sitting behind grandmother because a newspaper had written that color-radiation could harm male reproduction organ and only way to be protected was to have someone in between you and the TV.
For a long period was my grandmother forced to look at a lot of hockey and soccer.
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