measuring current output without affecting the circuit

[eurofightertyphoon]

Hello,
I'm a new memeber and if my post does not comply with the format required here, I will change it asap.
I have been working on a current controller for some time and although it's near completion, i have not come up with a clever way to measure the current output without affecting the rest of the circuit or influencing the current output.
My circuit produces a fixed current and desinged to power anyting that requires a steady current of low noise (laser for example)
Hence, the current output has to be measured before it goes into a device and i'd like to come up with a way to do just that without changing the current output or draw power away from the mosfet of the circuit.
Hall probe is one way to go about it but my advisor wants me to come up with a simpler method other than using a low resistor in series.
Any advice ?

Thanks for your help in advance

[pebe]

I would say there is no way, other than using a Hall device, to measure the current without affecting the circuit.

That said, it would depend on your circuit. Could we see it?