Tool 04 / Balloon calculator
Balloon catheter inflation & deflation
Simulates the full cycle of a balloon (inflation to nominal diameter, deflation to the withdrawal profile). Automatic Hagen-Poiseuille / Darcy-Weisbach switching for the inflation lumen, P-V model calibrated on the manufacturer datasheet. Feasibility verdict hand syringe vs indeflator.
✓
Verdict
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P(t) and V(t) profile
—
Compliance curve D vs V
Model calibrated on provided points
Physical model
Transient cycle — main equation
P_piston = ΔP_lumen(Q) + P_balloon(V)
dV/dt = Q · sgn(phase)
Inflation lumen
Laminar: ΔP = 32·η·L·v / Dh²
Turbulent: ΔP = f·(L/Dh)·(ρ·v²/2) ; f = 0.316·Re⁻⁰·²⁵
Cylindrical: Dh = ID · Annular: Dh = D_l − D_w · Custom: Dh = 4·A/P
Balloon pressure (derived model)
V ≤ V_nom: P_b = P_nom · (V/V_nom)^2.5
V > V_nom: P_b = P_nom + (RBP−P_nom)·(V−V_nom)/(V_burst−V_nom)
Explicit integration dt = 20 ms. Flat-balloon withdrawal criterion:
D_target = 0.85 · OD_sheath, mapped to V_target via the compliance curve.
Sources and references
Friction coefficients: Blasius (smooth turbulent), Hagen-Poiseuille (laminar).
Hydraulic diameter for non-circular sections: Schlichting, Boundary Layer Theory.
Typical thumb-on-plunger push forces: 25–35 N per medical-ergonomics literature.
Compliance curve: derived P-V model with power 2.5 (compliant phase) +
linear (rigid phase), calibrated on provided (V, D) points.
Educational tool — indicative information only.
The model assumes an incompressible Newtonian fluid, a straight and smooth lumen,
and an ideal inflation device (no play, no leak). It does not cover initial
balloon wrap-up (first deployment at very low pressure), shaft elasticity,
minor losses (connectors, valves), or fatigue/hysteresis under repeated cycles.
Typical thumb-piston forces are averages — actual capability depends on the
operator.
Rapid balloon prototyping
Protobrix produces custom balloons (PET, Nylon, Pebax) — from prototype to pilot batch in under 4 weeks.
Protobrix · R&D Tools · Balloon calculator v0.1 — Transient P-V model + Hagen-Poiseuille / Darcy-Weisbach
Tool 04 / Balloon calculator
Balloon catheter inflation & deflation
Simulates the full cycle of a balloon (inflation to nominal diameter, deflation to the withdrawal profile). Automatic Hagen-Poiseuille / Darcy-Weisbach switching for the inflation lumen, P-V model calibrated on the manufacturer datasheet. Feasibility verdict hand syringe vs indeflator.
✓
Verdict
—
—
P(t) and V(t) profile
—
Compliance curve D vs V
Model calibrated on provided points
Physical model
Transient cycle — main equation
P_piston = ΔP_lumen(Q) + P_balloon(V)
dV/dt = Q · sgn(phase)
Inflation lumen
Laminar: ΔP = 32·η·L·v / Dh²
Turbulent: ΔP = f·(L/Dh)·(ρ·v²/2) ; f = 0.316·Re⁻⁰·²⁵
Cylindrical: Dh = ID · Annular: Dh = D_l − D_w · Custom: Dh = 4·A/P
Balloon pressure (derived model)
V ≤ V_nom: P_b = P_nom · (V/V_nom)^2.5
V > V_nom: P_b = P_nom + (RBP−P_nom)·(V−V_nom)/(V_burst−V_nom)
Explicit integration dt = 20 ms. Flat-balloon withdrawal criterion:
D_target = 0.85 · OD_sheath, mapped to V_target via the compliance curve.
Sources and references
Friction coefficients: Blasius (smooth turbulent), Hagen-Poiseuille (laminar).
Hydraulic diameter for non-circular sections: Schlichting, Boundary Layer Theory.
Typical thumb-on-plunger push forces: 25–35 N per medical-ergonomics literature.
Compliance curve: derived P-V model with power 2.5 (compliant phase) +
linear (rigid phase), calibrated on provided (V, D) points.
Educational tool — indicative information only.
The model assumes an incompressible Newtonian fluid, a straight and smooth lumen,
and an ideal inflation device (no play, no leak). It does not cover initial
balloon wrap-up (first deployment at very low pressure), shaft elasticity,
minor losses (connectors, valves), or fatigue/hysteresis under repeated cycles.
Typical thumb-piston forces are averages — actual capability depends on the
operator.
Rapid balloon prototyping
Protobrix produces custom balloons (PET, Nylon, Pebax) — from prototype to pilot batch in under 4 weeks.
Protobrix · R&D Tools · Balloon calculator v0.1 — Transient P-V model + Hagen-Poiseuille / Darcy-Weisbach
