Human trials proceed
December 20th, 2008
I’ve just finished the second week of human trials, and I’ve already learned a lot about device usability and some weaknesses which I want to incorporate into a newer version of the chest strap. The data is quite fun to go through, and it looks better than I expected for an ambulatory device. Here’s an excerpt from one of our subjects..
Hi Reza,
I am interested in how you did the circuit for the tetrapolar leads for the bioimpedance part of your device.
Please send me an email so we can discuss.
Keep up the great work,
Ray
There are a number of papers that discuss the configuration. What exactly are you interested in?
reza
I am interested in the VCCS configuration. Are you willing to give a circuit out or lead me in the right direction?
The actual schematic – but I guess thats asking too much
Or a similar circuit for the front-end.
I mean just the front-end VCCS part. The part that the AD5933 connects to .. Can you please email me to discuss?
Hi,
My name is ANDY.I’m studying at the university in china.I’m very interested in the circuit of SPO2. Now, I am trying to make one. Could you send me your PCB design or give me some advices?
Any help is appreciated.
Thanks!
my email address: wsliutong@126.com
yours sincerely,
Andy
I can’t give you my design, but I can give you a basic overview. You’ll need an h-bridge to determine which LED illuminates, a way to control the current precisely, and two stage amp. first stage is a transimpedance amp, second stage is a differential amp with gain that subtracts out an offset to maintain it’s output from saturating (you’ll supply this from a DAC). then you read the signals.
Hello Reza, I’m very ashamed for my rude action to ask fou your PCB design! Please forgive me!
According to your advice, I work very hard to design my own sch and PCB!
But it is very difficult for a newer!
Frankly speaking, I can’t understand how to select the best frequency of a DAC and Whether I need an analog Multiplexer/Demultiplexer to separate the DC component and AC component or any better choice. Could you give me some advices?
Any help is appreciated.
Thanks a lot!
yours sincerely,
Andy