An implantable device manufacturer evaluating a new engineering partner asks two questions: can they work at the micron scale, and can they deliver hardware that holds up in a clinical setting? These two projects are our answer.
2013 – 2015
Keeping the patient in view
During surgery, an anesthesiologist moves around the room while the patient's vital signs stay on a fixed monitor. With a team from Sopnus and Universidad EAFIT, I worked on a real-time assistant that moves those signals to a head-up display, so they follow the clinician instead.
The display color-codes each vital sign: in range (left) and out of range (right).
A second mode used augmented reality: the software recognizes markers placed in the room and shows each patient's data where the clinician is looking.
Vital signs anchored to a printed marker that represents the patient.
We tested the system with anesthesiologists at a medical simulation center, and then in a working operating room during surgery. The hardware ran without interfering with the room's monitors or the clinical staff, and the patient's vital signs were recorded correctly.
The lesson carries over to any implant: a medical device has to work where it is used, without disrupting the people around it, and with documented evidence that it does. That is the discipline behind design verification and validation.
The implementation test in the operating room (left) and the assistant's hardware installed behind the vital-signs monitor (right).
Software registered with Colombia's National Copyright Directorate, record 13-81-6 (2020). Figures from the project's final report (2015).
2019
Focusing light below the micron
For my MSc in Applied Physics at Universidad EAFIT, I studied how to design diffractive optical elements for direct-write lithography, where the goal is a focal spot as small and clean as possible. I wrote a simulation suite in MATLAB that designs Fresnel zone plates and photon sieves and propagates light through them with the angular spectrum method.
This is the physics behind laser-processed implants. Many implantable devices are laser-cut or laser-machined from thin-walled tubing or sheet, with features often under 100 µm wide, so kerf width, edge quality and heat-affected zone depend on how the laser beam is shaped and focused. Understanding how a spot forms, and what makes it grow or blur, is the starting point for tuning a cutting process.
Transverse slices of the field behind a Fresnel zone plate. The spot tightens as the light approaches focus.
340 nmFull width at half maximum of the focal spot for a 76-zone Fresnel zone plate, from the simulated radial profile above.
A 75-zone photon sieve (λ = 355 nm, f = 50.9 µm), simulated from a design published in the literature to compare it with the zone plate.
%% SUDOE: simulation and design of diffractive optical elements
TypeOfdesign = input('Fresnel zone plate (1) or photon sieve (2)? ');
focal_length = input('Focal length [50-200 um]: ');
wavelength = input('Wavelength [0.300-0.650 um]: ');
optimal_n = secant(1, 11, 0.9, 10, wavelength, focal_length);
Excerpt from the suite's entry point. Thesis: Optimal conditions and sensitivity analysis for the design of a diffractive optical element for direct-write lithography (Universidad EAFIT, 2019).
The thesis was a sensitivity analysis: how far each design parameter can drift before the focal spot degrades. In production terms, that is the question behind defining a process window and validating it.
Today
What this means for implantable device manufacturing
We don’t present ourselves as an implant manufacturer. We are a small engineering team in Rionegro, Colombia, that brings the physics behind laser processing and optical measurement, and the habit of documenting every result. Where that helps an implantable device line:
Laser-cutting process developmentParameter studies on focus, spot size and pulse settings to find a stable process window for feature geometry and edge quality.
Optical and dimensional inspectionMeasurement methods for feature width, wall thickness and surface defects, with documented repeatability.
Process validation supportProtocols and reports for IQ/OQ/PQ, written to your quality system (ISO 13485 / 21 CFR 820).
Prototype runs and test documentationShort runs of precision components and test reports to your protocol, with root cause analysis for any deviation.
The work starts with a technical review under NDA, so we can tell you early what we can take on and what we can’t.
