The Standard Operating Procedure for demonstrating the Van de Graaff generator has a number of safety notes including the first one which states:
- Ensure that any person, who may be pregnant, has a heart condition, metal plates, a pacemaker, cochlear implant(s), electronic insulin pump or similar electronic device is not in the vicinity of the Van de Graaff generator.
This is a general safety instruction, as the risk of anyone in these situations being affected by the static electrical discharge is high. The Nuffield Foundation has a good article on Van de Graaff generator safety see: http://practicalphysics.org/van-de-graaff-generator-safety.html
The spark from the Van de Graaff generator causes radio signals, these signals can be picked up by any metal piece resulting in a possible induced electric current. It is this current that could cause damage to any electronic equipment or pump.
In relation to your teacher with an insulin pump who operates the Van de Graaff generator and has not had any issues with the pump. The answer could be a combination of the operating procedure of the pump and some degree of luck.
The insulin pump is probably not active all the time, the majority of the time it may be sitting in standby mode. While a pacemaker has both a sensor and an electrical stimulator, either one or the other is always in operation. An arc or “static discharge” from the generator to any other object may damage it, if the pump was active while operating the Van de Graaff generator. If damage to an insulin pump occurs, it may not be immediately life threatening, unless the fault is not identified quickly enough. Damage to other devices, like a pacemaker, may have a more immediate impact.
We cannot advise on the specifics of types of insulin pumps, or ways of protecting the pump from damage, except to affirm that the Van de Graaff generator should not be operated near electronic devices like these. Users of personal electronic devices should check with the manufacturer of their personal devices about the suitability, or otherwise, of being in close proximity to equipment like the Van de Graaff generator. It may be more appropriate for your teacher to contact the manufacturer/supplier of their insulin pump to ascertain their advice in this situation.
The Science ASSIST recommendation is that any person with sensitive electronic equipment stay at least 1.5m away from an operating VDG.
ASTA, Science ASSIST SOP: Demonstrating the Van de Graaff generator. December 2014 Science ASSIST website, http://assist.asta.edu.au/resource/2570/sop-demonstrating-van-de-graaff-generator?search-id=38575ad
Hayrettin Arisoy, Technical Officer– Electrical Engineering, Deakin University. May 2015. Personal communication