Adaptive linear filter for real time noise reduction in surface plasmon resonance systems

1. A method for linear filtering of noise in a sensorgram generated from a surface plasmon resonance apparatus, the method comprising:

providing a linear filter of variable length to filter an output signal in the sensorgram; and

determining an optimal length of the linear filter based on a slope of the signal in the sensorgram and a plurality of timing of occurrences of events during measurement of refractive index in the apparatus to reduce noise in the sensorgram.

2. The method of claim 1 , wherein the linear filter provided comprises a symmetric finite impulse response filter.

3. The method of claim 1 , wherein the linear filter provided comprises a variable-length symmetric moving average filter.

4. The method of claim 1 , wherein the filter length varies dynamically for ensuring the signal in the sensorgram to preserve characteristics indicative of a critical biochemical process.

5. The method of claim 1 , further determining a longer filter length when variations in the signal decreases.

6. The method of claim 1 , further determining a shorter filter length when variations in the signal increases.

7. The method of claim 1 , wherein the events are an indicative of a start of association and dissociation of reactants in a biochemical process.

8. The method of claim 7 , wherein the events comprise opening and closing of a plurality of valves in the surface plasmon resonance apparatus.

9. The method of claim 8 , wherein the events comprise a plurality of distances between the valves in the apparatus.

10. The method of claim 1 , wherein the events comprise a plurality of distances between a plurality of transducers in the apparatus.

11. The method of claim 1 , wherein the events comprise flow rates in the apparatus.

12. A method for linear filtering of noise in a sensorgram generated from a surface plasmon resonance apparatus, the method comprising:

providing a linear filter of variable length to filter an output signal in the sensorgram;

determining a first filter length based on a plurality of timings of occurrences of events during measurement of surface plasmon resonance in the apparatus;

determining a second filter length based on a slope of the signal between the plurality of events;

comparing the first filter length and the second filter length; and

selecting a shorter length between the first filter length and the second filter length.

13. The method of claim 12 , further providing the first filter length based on determining a plurality of event times and estimating significance of the events.

14. The method of claim 12 , further providing the second filter length based on an instantaneous slope of the signal.

15. The method of claim 12 , further providing a filtering algorithm based on real-time characteristics wherein an output is delayed by a specified amount.

16. A linear filtering system for filtering noise in a surface plasmon resonance sensorgram, the system comprising:

a SPR measurement apparatus for generating a sensorgram;

a processor for receiving the sensorgram, which processor is configured to:

provide a linear filter of variable length to filter an output signal in the sensorgram;

determine a first filter length based on a plurality of timings of occurrences of events during measurement of refractive index in the apparatus;

determine a second filter length based on a slope of a signal between the plurality of events;

compare the first filter length and the second filter length; and

select a shorter length between the first filter length and the second filter length.

17. The system of claim 16 , wherein the SPR measurement apparatus comprises an optical source, an optical detection unit, a SPR transducer, an output device, a metal film and a flow channel system.

18. The system of claim 16 , wherein the optical source generates a light beam.

19. The system of claim 16 , wherein the SPR transducer further comprising a prism, a glass slide with a thin optically reflective backing, and a binding layer.

20. The system of claim 16 , wherein the optical detection unit intercepts optical signals reflected from the SPR transducer and provides the surface plasmon resonance sensorgram.