What I am concerned is that if I am going to use spaces, CR and NL
The problem with any delimiter, when you are sending binary data, is that the delimiter can naturally be part of the data stream. So, seeing a 10 in the data stream does not necessarily mean that a CR was intended.
If can be assured that no data will ever be lost, then simply assume that 12 bytes are all the data for one sensor, and interpret the 12 bytes as 6 ints.
You can't, of course, assume that no data will ever be lost.
It'd be very troublesome if it is not wireless.
How is the wearer of the device supposed to see the output? Is the wearer supposed to cart a laptop around?
If the device is intended to be applied and the output studied in a clinical setting, wired is not necessarily out of the question.
Surprisingly, even though it is cheap, it is very reliable, as reviewed by many users and tested by myself.
It is only as good as the error detection and correction is applies. That is none. That is not what bluetooth is intended for.
XBees, on the other hand, do perform error detection and correction, and packet the data in a way that start and end markers (where a packet starts and ends) are present, so one can be assured that a packet does contain exactly 12 bytes in the correct order.
Of course, you can't get two XBees, a shield, and a USB explorer for $6, but you can't expect to get something for nothing. TANSTAAFL.