de Boer et al. (2025) — Extracted Parameters for Tier 1 Replication#
Paper: “Wireless mechanical and hybrid thrombus fragmentation of ex vivo endovascular thrombosis model in the iliac artery” Marcus C. J. de Boer et al., Appl. Phys. Rev. 12, 011416 (2025) DOI: 10.1063/5.0233677
Target: Figure 12 — swimming speed vs. time at step-out frequency for 6 UMR configurations.
UMR Geometry#
Parameter |
Value |
Units |
Source |
|---|---|---|---|
Cylinder body diameter |
1.74 |
mm |
§VI.F p.15 |
Conical tip start diameter |
1.74 |
mm |
§VI.F p.15 |
Conical tip end diameter |
0.51 |
mm |
§VI.F p.15 |
Conical tip length |
1.9 |
mm |
§VI.F p.15 |
Total UMR length |
6.0 |
mm |
§VI.F p.15 |
External diameter (body + fins) |
2.84 |
mm |
§VI.F p.15, Table S2 |
Number of fin sets |
2 |
— |
§VI.F p.15 (“Two sets of three propeller fins”) |
Fins per set |
3 |
— |
§VI.F p.15 |
Fin length along UMR |
2.03 |
mm |
§VI.F p.15 |
Fin width |
0.55 |
mm |
§VI.F p.15 |
Fin thickness |
0.15 |
mm |
§VI.F p.15 |
Fin type |
Discontinuous helix |
— |
§II.B p.4, §VI.F p.15 |
Magnetic Properties#
Parameter |
Value |
Units |
Source |
|---|---|---|---|
Magnet material |
NdBFe Grade N45 |
— |
§VI.H p.17 |
Magnet size |
1 × 1 × 1 |
mm³ |
§VI.H p.17 |
Magnets per UMR |
1, 2, or 3 |
— |
Fig. 12 |
Magnetic moment per magnet |
1.07 × 10⁻³ |
A·m² |
§VI.H p.17 |
Moment orientation |
Perpendicular to long axis |
— |
§VI.E p.15 |
RPM permanent magnet |
NdBFe Grade N45, 35mm dia, 20mm height |
— |
§VI.I p.17 |
RPM magnetic moment |
20.67 |
A·m² |
§VI.I p.17 |
RPM-UMR gap |
150 |
mm |
§VI.H p.17 |
Field strength at UMR |
~1.4 (measured), 3 (simulation) |
mT |
§VI.H p.17, Fig. 12 |
Swimming Characterisation#
Parameter |
Value |
Units |
Source |
|---|---|---|---|
Swimming tube ID |
9.5 |
mm |
§VI.I p.17 |
RPM placement |
100mm (1-mag), 150mm (2,3-mag) above tube |
mm |
§VI.I p.17 |
Max RPM frequency |
42 |
Hz |
§VI.I p.17 |
Fluid |
Water |
— |
Fig. 4a-c |
Fluid viscosity (water, 37°C) |
~0.69 |
mPa·s |
Standard |
Figure 12 Data Points (from paper)#
Simulation at 3 mT field strength, Newton’s second law with Euler’s method.
Diameter (mm) |
Magnets |
Step-out freq (Hz) |
Peak speed (m/s) |
|---|---|---|---|
2.8 |
1 |
128 |
~0.4 |
2.8 |
2 |
181 |
~0.7 |
2.8 |
3 |
222 |
~0.85 |
2.1 |
1 |
144 |
~0.5 |
2.1 |
2 |
204 |
~0.8 |
2.1 |
3 |
250 |
~1.1 |
Note: 2.1mm UMR is described as “75% of baseline size” (p.16).
Swimming Model (Eq. 1)#
$$ U \propto R_{\text{cyl}} \omega \varepsilon_{\text{cyl}}^2 f(De, \beta) $$
where:
R_cyl = average UMR radius
ε_cyl = helical amplitude normalised by R_cyl
De = τω = Deborah number (τ = fluid relaxation timescale)
β = η_s / η = serum viscosity / total viscosity
f(De, β) = unspecified function of viscoelastic parameters
Critical note: The paper does NOT tabulate drag coefficients. Eq. 1 is a scaling relation, not a closed-form drag model. The actual simulation uses “Newton’s second law with Euler’s method” (§VI.E p.16), which implies a full force-balance ODE with the specific drag model embedded in the code but not published as explicit coefficients. See ADD-1 in UMR_REPLICATION_PLAN.md.
Drag Torque Comparison (Fig. 4d)#
OpenFOAM CFD simulation comparing continuous vs. discontinuous helix:
Discontinuous helix has lower drag torque than continuous
The difference increases with actuation frequency
At 200 Hz: continuous ~4×10⁻⁴ N·m, discontinuous ~3×10⁻⁴ N·m
“Our frequency range” marked on figure: ~100-300 Hz
Rheological Data#
Property |
Blood |
Blood Clot |
Source |
|---|---|---|---|
Deborah number (De) |
2 |
3 |
§VI.C p.15 |
Relaxation timescale (τ) |
20 s |
30 s |
§VI.C p.15 |
Viscosity at 0.1 s⁻¹ |
34 Pa·s |
— |
Fig. 4f |
Viscosity at 100 s⁻¹ |
~60 mPa·s |
— |
Fig. 4f |
G’ at 1 Hz |
68-206 kPa (blood), 205-532 kPa (clot) |
— |
§VI.C p.15 |
Predominantly elastic |
Yes (G’ > G’’) |
Yes |
§VI.C p.15 |
Vessel Dimensions#
Vessel |
Inner Diameter |
Source |
|---|---|---|
Iliac artery |
4.7–9.4 mm |
§VI.F p.16 |
Swimming tube (characterisation) |
9.5 mm |
§VI.I p.17 |
Vessel diameter for flow calc |
8 mm |
§VI.E p.16 |
Wear Model (Reye-Archard-Khrushchov, Eqs. 3-6)#
Parameter |
Value |
Units |
Source |
|---|---|---|---|
K_g (wear coefficient) |
7.1 |
μN·s |
§VI.G p.17 |
W (normal load) |
~U (swimming speed) |
— |
§VI.G p.16 |
L (sliding distance) |
~f (frequency) |
— |
§VI.G p.16 |
H (hardness) |
~G’ (storage modulus) |
— |
§VI.G p.16 |
K_l (lysis rate) |
0.51 |
mm³/min |
§VI.G p.17 |
M (interaction parameter) |
0.7 |
— |
§VI.G p.17 |