Projects / Influo

Design Team

Influo

Directed flushing system for clogged percutaneous drains

Influo is a catheter add-on designed to reduce clogging in percutaneous drainage procedures. Our team translated clinician interviews, competitive research, concept selection, CAD, prototyping, verification testing, and design master record documentation into a directed flushing mechanism that targets catheter side holes during routine flushing.

View One-Page Poster
My RoleConcept selection, CAD support, prototyping, verification testing, and design documentation
Location / DatesJohns Hopkins Design Team
2023 – 2024
OutputsOne-page poster, final design paper, V&V summary, DMR package, and test data
Skills LearnedClinical interviewing, requirements tracing, CAD iteration, bench testing, risk analysis
1

Project & Problem Background

Influo directed flushing catheter concept
Current surgical drainage catheters are placed percutaneously, with side holes positioned inside the target fluid collection to evacuate fluid.
~4MDrains placed annually in the United States, based on team market sizing.
~30%Approximate clogging burden cited in the project abstract and opportunity framing.
FlushTargeted workflow step: the routine saline flush already used in drain care.
Side holesPrimary clogging region addressed by the directed-flow concept.
Open Project Video PDF
2

Detailed Requirements

  • ✓Fit the existing procedureIntegrates with normal drain flushing behavior instead of asking clinicians to adopt a new procedure.
  • ✓Direct flow toward blocked side holesTargets clogged side holes instead of allowing saline to escape through already-open holes.
  • ✓Maintain a small catheter-compatible profilePreserves compatibility with the geometry and constraints of percutaneous drainage catheters.
  • ✓Advance in controlled incrementsUses a repeatable twisting actuation motion to move the intraluminal tube along the catheter.
  • ✓Protect the patient-facing interfaceImproves the flushing pathway without requiring full catheter replacement during the intervention.
  • ✓Produce measurable evidenceSupports verification through side-hole coverage, flushing order, and directed-flow bench tests.
Influo full solution prototype assembly
Open Design Requirements PDF
3

Prototyping

Solution 1 component breakdown

Exploded-view animation breaking the first solution into its major device components.

Solution 2 assembly and operation videos

Assembly movie for the updated device build.

Operation movie showing the new device actuation.

4

3D Model Explorer

After the prototype videos, the CAD explorer shows the component models used to develop the actuation assembly. GitHub links prioritize GLB files so the models open in GitHub’s interactive 3D viewer.

Open Full GitHub Model Repository
5

Bench Testing Results

Bench testing compared regular flushing against directed flushing across drainage flow rate, clogged-hole configurations, and pigtail stability.

Directed flushing bench-test clip showing fluid routing through the catheter model.

Repeated directed flushing clip used to compare consistency across trials.

Influo catheter movement and stability assessment results
Movement assessment highlighting instability observed in the catheter prototype during bench evaluation.

Additional data collected

Flow-rate comparison
3.74 mL/sMean directed-flushing flow rate from the advanced drainage test data.
2.56 mL/sMean regular-flushing flow rate from the same drainage test set.
p = 0.00006Two-sample t-test result from the drainage testing spreadsheet, below the 0.05 significance threshold.
10/10Directed clog-configuration trials cleared all clogs in the listed test series.
6 configsClog-configuration testing compared regular and directed flushing across six blocked-hole patterns.
<1 degPigtail stability testing kept the pigtail curve within one degree of its original shape across trials.
Open Drain Testing Data
6

Final Package

Influo final poster
One-Page PosterOpen the final poster image.PNG Poster Final Design PaperOpen the complete design paper with mechanism rationale, prototype behavior, and validation evidence.PDF Paper
Verification & Validation SummaryBench and validation evidence package for DHF4.DHF4 PDF Design Master Record TOCIndex for final design record files, CAD files, drawings, and manufacturing documentation.DHF4 DOCX Risk MatrixRisk analysis and controls documented for the final package.DHF4 XLSX Project ManagementGantt chart and planning artifacts from the DHF4 submission.DHF4 XLSX Design Requirements UpdateUpdated design requirements from the DHF4 package.DHF4 DOCX Prototype Design JournalFinal prototype design journal from the DHF4 update set.DHF4 PPTX FDA Pathway MemoRegulatory pathway memo from the DHF4 update set.DHF4 DOCX Final SlidesDHF4 presentation slides for the final package.DHF4 PPTX