Tuesday, February 13, 2007

Survivor’s Guide to VNS: Part 9 – Device Settings

You need to know about your device settings before your Dr. turns it on. Not all physicians, nurses, or technicians know their device settings well. In fact, you may be their first patient… Or you may be the 10th patient that they have mis-programed in a row… Errors in device settings could be completely accidental… maybe the doctor forgot to bring his reading glasses that day and confused a 0.2 with a 2 and confused a Signal Frequency with a Signal OFF time.

So understand the settings, and make sure that you check them out before they activate or change settings on the device. Take responsibility for your own device settings. It’s your life. It’s your device. It’s in your body.

What are the settings?
The settings you need to be concerned about are: Output Current, Signal Frequency, Pulse Width, Signal ON Time, and Signal OFF Time. Doesn’t make much sense, right? Here is the layman’s description of what each is:

Output Current
This is one measurement of the amount of electrical energy that is sent to your Vagus nerve. It is measured in milli-Amps (mA). If you think of electricity as waves crashing against a beach, this would measure the height of the wave.

Signal Frequency
This measures how many times per second that those waves of energy are sent to the nerve. The frequency is measured in Hertz (Hz). Imagine again those waves crashing against the beach – how many waves per second is the frequency.

Pulse Width
This measures the width of the electrical signal. It is measured in uSec… which is a number hard to comprehend, but it is another indication of how much electrical energy is sent to your nerve. Just imagine the water waves again and think about how much water comes with each wave. This measures the part that you would have to dive through to get to the other side of the wave.

Signal ON Time
How long the pulse generator sends electrical energy to the nerve. Using the water analogy again, the waves might wash against the beach for 30 seconds and then stop for a while.

Signal OFF Time
This is a measure of how long the VNS waits between sending signals again. No electrical energy is sent during this time.

No comments: