You're welcome. It's good to see we're making progress!
A note on DIRPing- I always use contact pads, placed either on the inside of the wrist, over the veins, or near whatever point on the body I'm interested in. I don't use the cylinders. I think it's far too easy to introduce error into the test when using them.
As far as just using the CV, I don't know. My first impression is that would give you a frequency response curve, but wouldn't tell you about peaks, at least not the way the Fscan is currently configured. When connected to a PC, the unit returns a series of values that are interpreted by software into CV and MV. The CV is decided by the range of the value, and the MV by the differentials. I'm going to leave that vague, as Thomas has indicated he considers the inner workings to be proprietary info, and I will respect his right to protect his work. That said, I think that there's a lot of room for improvement. You don't really have access to the CVs when using the unit standalone, for example. Nor can you get at them with the PC software either, really. This is part of what drove me to write w_zap: so I could have the option of using the CV curve to determine the clip levels, and to be able to compare similar DIRP runs.
I should mention that I am in no way affiliated with TB Electronics.
I'd be all for cheaper easier technology. Any ideas? Something that was processor based, but used a DVM for input instead of an ADC? I'm concerned about signal smear, and what happens at or near the Nyquist limit of the ADC when DIRPing.