Custom insoles depend on three traditionally manual steps: measuring the foot, designing the correction and manufacturing it. Davol Feet has replaced the plaster mould with a 3D scanner, option-based design software and sintered polypropylene manufacturing. In episode 80 of Toque de Ingenio, David Avilés explains how a custom medical device is made while the podiatrist retains control over diagnosis, against the backdrop of the debate between barefoot footwear and insoles.
Guest: David Avilés, who was introduced in the episode as a podologist and biomechanics specialist, is part of Davol Feet. Interview published: June 9, 2026. Episode: 80. Duration: 1 h 28 min.
In this episode:
- Why an insole should provide correction only where the body needs it.
- What does 3D scanning of the foot offer compared to traditional plaster molds and phenolic foam?
- How a custom insole is designed, manufactured and sold using this system.
The conversation was recorded at i-mas facilities at the beginning of June, approximately eight months after Davol Feet began selling its system. David brought a printed scan of a foot and several manufactured insoles, allowing them to follow the process with real-world examples.
Podología del pie: abordar la causa y no solo los síntomas.
David describes the feeling as a pulling sensation at the ankle, extending up to the knee, hip, and lower back. He explains that an open step or a flattening of the foot can manifest as lower back strain, which is why his assessment focuses upwards.
In his view, the negative reputation of braces stems from an old practice: a one-size-fits-all approach, which is rigid and lacks a precise diagnosis. He argues against this model, advocating instead for functional braces, which restrict movement only where the body requires it, and compensate where it needs to be compensated.
Regarding barefoot walking, David acknowledges that walking barefoot is a beneficial form of neuro-sensory stimulation and recommends it at home. He notes that its effectiveness diminishes when there’s an imbalance the body can’t correct on its own. In such cases, he describes the technique as a way to incorporate the treatment into daily life, without relying on a specialist.
This approach explains the demand placed on the product. Adding more thickness than is necessary can restrict the ankle and negate the desired effect. Precision was a clinical requirement.
From plaster molds to 3D scanners: what went wrong with the manual system.
“Up until now,” David explained, “the podologist would take the shape of the foot using plaster, a phenolic foam that was stepped on, or a footprint cushion. Afterwards, he would adapt the foot using vacuum machines and hand polishing, or send it to a workshop.”
He identifies four limitations in that process. A handmade insole cannot be reproduced exactly when the patient needs another one. The finish depends on the practitioner’s skill. The correction does not achieve the desired precision. And the materials suffer fatigue, deform or cannot accommodate small adjustments.
Before developing their own system, the team tested existing solutions. David explains that the insoles did not fit the foot well and that the materials could not be adjusted or would break. He also notes a regulatory trend towards having the podiatrist sign the diagnosis and refer manufacturing to laboratories.
From this arises the objective that David summarizes: that the specialist’s diagnosis continues to be the priority, and that the design and manufacture precisely match what is requested, without any deviations or approximations.
Measuring the foot: 3D scanning in a standing and neutral position.
The process begins just as it always does: a patient history and examination, whether standing, walking, or running depending on their activity. David insists that the podologist’s diagnosis remains crucial.
Following the diagnosis, the foot is scanned in a standing position. The professional positions the foot in a neutral position, with the femur and tibia aligned, and at 90 degrees, and obtains an STL file showing all the curves: the metatarsals, toes, and arch. The software checks that the foot is properly neutralised before allowing the design to proceed.
Measuring download performance came at a cost. David explains that it took two years of clinical development to ensure the system incorporates foot expansion during loading. This effectively combines a faithful representation of the arch and the reality of walking. The system also allows scanning a foam or mold, although this then reinterprets the dorsal part.
Selecting the scanner proved to be equally challenging. They tested several units, including the mobile LiDAR, and ruled out those that only captured the plant or filled in gaps using artificial intelligence. The scanner included in their package captures the entire foot and, according to David, maintains a precision of 0.1 millimeters up to the manufacturing stage.
“If we don’t achieve that level of precision and actively pursue that clinical success, what makes you different from the rest”.
David Avilés 68:56.
Designing without being an engineer: software offering options, not drawing tools.
Edgar raised the obvious objection: the podologist doesn’t know how to design in 3D. The response was software where the professional selects options, and the system generates: heel height, correction degree, pronation, and material. The only thing drawn by hand is the width, to adapt it to footwear or to overcorrect the heel.
According to David, the design is structured around four or five screens and offers over 500 phonological variables. Each change is visualized in real-time on a virtual foot, in 3D. When the professional is satisfied, they press “validate” and proceed to manufacture.
“We’ve made it intuitive, easy to use, and so that you don’t need to be an engineer to create a design”.
David Avilés 48:26.
Artificial intelligence is an optional aid. Based on a clinical questionnaire, it proposes a treatment, supported by a database of cases compiled by the team, but the podologist can choose to ignore it and work with their own method.
This approach connects with User experience design In technical products: the tool speaks the language of the professional and hides the complexity of the modeling process.
Creating a bespoke medical product: polypropylene and traceability.
The mold is produced using sintering in polypropylene. David points out that most of the industry prints using PA12, and that polypropylene is more flexible, can be polished, and can be heated if the podiatrist wants to make a correction. Typical thicknesses range from 1 to 2 millimeters, and can sometimes reach 4 millimeters.
That base incorporates the geometries previously added through subsequent sanding, such as heel relief for heel pain or fasciitis. It is then combined with a soft section for athletes or patients who need it to stay in place. There is also a short version for narrow or high-heeled shoes.
Each insole has a code, is shipped in an envelope and is manufactured at the company’s facilities, with traceability through the app. It reaches the clinic in around five days, with its width and length tailored to the patient; at most, the podiatrist trims the length.
David puts the saving at one or two hours of work per insole previously spent on fitting, sanding and testing, as well as materials and potential errors. This is an example of how prototyping and additive manufacturing They transform a traditional process when the measurement is accurate.
A model designed for the clinic to test.
At the time of the interview, the scanner, software and service package cost €2,500 as a one-off payment that could be split into instalments, with no monthly subscription. The only recurring charge was for manufacturing each insole. David explains that if the clinic is not satisfied within a month, the amount is refunded minus the cost of refurbishing the scanner.
For the patient, the implant costs between €150 and €450, according to the clinic, with an average that David estimates to be between €250 and €300. They began selling in October of the previous year, following two years of development, and by June, they were working with four clinics in addition to their own. He acknowledges that the pace of adoption is slower than initially anticipated due to resistance to change within the sector.
The funding combined private funds, a bank loan for the machinery, a €9,000 grant, and a collaboration with engineers, who agreed to take part in the development in exchange for a percentage on sales. One bank rejected the project, deeming it too innovative and lacking a proven track record.
From his experience, he extracts three key pieces of advice: to verify that the market is buying, to set a financial limit, and to surround yourself with knowledgeable people who are working towards the same goals. He cites a key mistake as being to blindly trust, in an area where he lacked expertise, without exploring different development options.
What can another development team learn?
The Davol Feet case offers four key lessons for anyone developing a bespoke product based on clinical or technical evidence:
- Establishing the level of accuracy required for its use. The scanner was chosen for its clinical reliability, although the software could function with other devices.
- Translate the modeling to user-friendly language. The professional selects options they understand, and the system handles the geometry.
- Choosing the material based on the entire process. Polypropylene was chosen for its elasticity and ease of post-treatment, not just because it was printable.
- Design the customer entrance. A one-time payment, without subscriptions and with a money-back guarantee – this reduces the risk of trying it out in a conservative market.
At the time of the interview, Davol Feet offered its system to podology clinics in Spain, Andorra, and Portugal. The prices, terms, and figures in this document correspond to what was explained in June 2026.
At i-mas, we develop products that combine measurement, software, materials, and manufacturing. If your project needs to convert a measurement into customized product Capable of being manufactured with precision. Tell us about your project..
To continue reading: How is a medical device with electronics developed?.
Source of article: Interview with Edgar Guerrero and David Avilés on Toque de Ingenio. The excerpts cited link to the minute of the conversation. The recommendations for other projects are a summarised editorial from i-mas.
