| abstract |
An apparatus for treating a tumor in the body of a subject and facilitating administration of a substance across a blood-brain barrier of the subject's body, said apparatus comprising: an AC voltage generator (44) capable of operating at a first frequency between 50 and 190 kHz and a second frequency between 50 and 500 kHz, the second frequency being different from the first frequency, wherein the AC voltage generator (44) has a control input and is configured to output the first frequency when the control input is in a first state and outputting the second frequency when the control input is in a second state; and a controller (42) programmed to (a) place the control input in the second state so that the AC voltage generator (44) outputs the second frequency, (b) accept a request to change the AC voltage generator (44) to output the first frequency, (c) upon receipt of the request, set the control input to the first state so that the AC voltage generator (44) outputs the first frequency for a time interval, and ( d) after the time interval has elapsed, setting the control input to the second state so that the AC voltage generator (44) outputs the second frequency; characterized in that the time interval is at least 72 hours. |