From aerospace to healthtech with Fit 4 Start

MDsim, a Luxembourg-based healthtech startup, is transforming spine care through digital twin technology and Luxembourg’s leading startup accelerator Fit 4 Start played a crucial role in its growth. Founded by Roger Assaker and his brothers, MDsim develops software as a medical device that creates patient-specific virtual models of the spine. "It is a tool that helps professionals check the health of the spine, keep it healthy and prevent problems," Mr Assaker explains.

Building a healthtech startup with family expertise

The idea took shape when Mr Assaker, who holds a PhD in aerospace engineering, began discussing surgical challenges with his brother Richard, a neurosurgeon. It was never his plan to enter healthtech, but the overlap between advanced simulation and clinical needs quickly became clear, making the move feel like a natural next step.

Working with family has shaped the company from day one. “We are very close, we do everything together and we know each other’s strengths and weaknesses,” he says. Coming from a culture where family ties are strong, building MDsim with his two brothers feels natural and motivating. There are fewer barriers to discuss medical questions within the family than with an external advisory board, but he stresses the importance of separating family from business when needed.

Navigating medical device regulation with accelerator support

MDsim operates in a highly regulated field, yet Mr Assaker approaches regulation with confidence. “People are afraid of it, but there is a kind of playbook,” he says. This is where their third brother, Dany, stepped in, leading quality and regulatory affairs to ensure every product meets medical device standards and is certified for commercialisation.

With support from consultants and the knowledge gained during Fit 4 Start, Luxembourg’s leading startup accelerator, the team built a clear regulatory roadmap. They will submit their first product for both FDA and CE marking in May, a major milestone supported by recent team hires and a structured quality approach.

The team has now grown to almost 20 people. Together they have reached significant milestones: ISO 13485 certification, a € 1 million pre-seed round followed by a € 2.3 million seed round, receiving financial aid for an R&D project from the Luxembourg government and their first revenue. The company also opened an office in Barcelona to access specialised engineering and quality talent.

Why experienced founders still benefit from Fit 4 Start

Although he already had decades of entrepreneurial experience, Fit 4 Start played a crucial role for MDsim. At first, Mr Assaker questioned whether an accelerator was necessary, but moving to a completely new field became the main motivator. “When you get to something new and are open minded, you never know what you do not know,” he reflects.

The programme helped him fact check the business plan, practise pitching, learn about regulatory pathways, develop his network and access investors. The € 150,000 support accelerated early hiring and validated the roadmap. “Even if you take only 10% of what you learn, it still adds value,” he says, noting that the experience is valuable even for seasoned founders.

Luxembourg continues to play an important role in the company’s development, with funding opportunities and proximity to Luxinnovation and the Ministry of the Economy.  

If you have a good startup project in Luxembourg, you will get all the support you need.” Roger Assaker, MDsim

His advice to aspiring founders: “Do not hesitate, do not be afraid. The biggest hurdle is in your own mind before starting,” he says. “Go for it.”