Biosensor Biofouling & Signal Drift: 2D Diffusion-Path Simulator

Implant Conditions

Time speed 2.0 d/s

Biofouling rate k 0.35 /day

True blood level 4.0 mg/L

Dosing pulses off

Live Readout

Days implanted

0.0 d

Fouling layer

0.0 µm

Sensitivity

100 %

Reported error

0.0 %

True vs reported concentration

4.00 vs 4.00 mg/L

How it works

This is the 2D companion to the 3D biosensor biofouling simulator, computed independently rather than a flattened render of the 3D scene. It keeps the same real diffusion-path physics — Fick's first law, with the electrode's effective diffusion path lengthening as a protein/fibrous-capsule shell closes in over days:

J = D · A · (C_blood − C_surface) / L(t)
L(t) = L0 + Lmax · (1 − e^(−k·t))
S(t) / S0 = L0 / L(t)

What's genuinely different here is a live true-vs-reported concentration strip chart — a 2D-native diagnostic the 3D version has no room for — plus a realistic first-order dosing pulse model (absorption/elimination, not a flat baseline) so drift and dosing kinetics can be watched fighting each other on the same axis:

C_true(t) = baseline · [0.4 + 1.6 · shape(phase)/peak(shape)]
shape(φ) = e^(−ke·φ) − e^(−ka·φ),  φ = t mod period

Time speed — simulated days per real second.
Biofouling rate k — how aggressively the tissue reacts to the implant; higher k saturates the fouling shell sooner.
True blood level — the actual analyte concentration the sensor is trying to measure.
Dosing pulses — switches the true level from a flat baseline to a first-order absorption/elimination sawtooth, like a real drug dosing schedule.
Recalibrate — a two-point calibration against a reference reading zeroes the current offset, exactly like the clinical workflow — but it cannot undo the underlying sensitivity loss, so the reported curve keeps drifting away again immediately afterward.
Replace sensor — the only fix that resets L(t) to zero: a fresh electrode with no fouling, and clears the strip-chart history.
Drag the map to pan, scroll/pinch to zoom in on the fouling shell.

This is why continuous therapeutic-drug and glucose monitors specify a finite wear time (typically 7–14 days) rather than running indefinitely on one electrode.

Drag to pan · scroll to zoom

Analyte molecule Fouling protein Electrode