The story of how a little startup, Lento Medical Innovation, aims to solve the TKA problem.

A humble beginning with vision, perseverance, and teamwork

Lento’s PtoleMedic System for Pre-operative Personalized Surgery Plan

Once upon a time, there was an engineer who dreamed of a world where every joint replacement surgery returned with a high-quality outcome, with smiling patients walking and sitting painlessly, happy families, and accomplished surgeons.  His name was Ilwan (Ben) Park.

After finishing post-graduate studies at UC Berkeley with a Ph.D. in Mechanical Engineering, Ben pursued different career routes until he landed in an orthopedic robotic company in 1990s.  As the technical lead in the first several human cases with robotic in Total Knee Replacement (TKR) surgery, Ben had a foundational realization: attaining precision in TKR did not need more precise tools (such as robots), but rather a more precise and personalized plan with effective execution.

Ben began a quest to address “precision” planning in total joint replacement surgery.  He observed those closest to him. His mom’s friends, mostly between 60 to 80-year-old, suffered from low quality of life either due to shortcoming of their TKR surgery or the aversion to undertaking it; many continued to suffer from pain, yet others couldn’t ride a car or get up from their chair without leaning forward on their elbows and shoulder, causing them collateral pain after TKR.  Ben observed all this through his engineer’s eyes and wondered, theorized, and researched.  Twenty plus years later, spending his days studying real-world cases and pondering on many unsolved questions, dreaming of flying vectors and integrals at nights, befriending smart and dedicated people, having created OtisMed (TM), a startup that got acquired by Stryker, Ben started Lento Medical Innovation (TM) in early 2018 as the next level medical startup to realize his vision. Ben’s loyal ex-startup clinical/regulatory expert, David Schlerf, was a co-founder along with his operational/financial right hand, Won Choi.  The name “Lento” was chosen in honor of all the elders unable to flex their knees, “Lento” means “flex” in Latin. They convinced John Lee, the CEO President of AQS and a longtime friend, to invest in Lento.  

Ben persevered on his quest. After consuming Ptolemy circle and da Vinci’s Vitruvian man, several lengthy discussions with his double-PhD-triple-Masters’-degree genius friend, talking with his MD Ph.D. protégé, and consulting his loyal clinical expert, he had another Eureka moment!  Neutral Boundary Alignment (TM) (NBA) was discovered: a total body alignment philosophy that scientifically modeled each individual’s bodily structure and revealed the “native” joint orientation/alignment within a damaged and painful one.  

PtoleKnee Surgical Guides to Help Restore the Native Knee Intra-operatively

This time Ben and the team knew exactly how to build a robust product around Neutral Boundary Alignment. Utilizing the latest technological advancements such as Cloud Computing, automation, Intelligent of Things, and Machine Learning, the first solutions presented by Lento were a novel cloud-based Personalize Surgery pre-operation planning for total joint replacement surgery along with an intra-operative disposable guide for TKR.

In the spring of 2019, the team recognized that Lento startup with a smart technology needed a great execution.  In pursuit of a CEO to lead the efforts, they were introduced to a strategic business leader with a technical mind who had already established a startup in the US and successfully developed global markets.  Leila Bahreinian joined the team as the CEO cofounder to transform the R&D-based Lento into a scalable business: enterprising strategy and execution with high integrity.  With a history in recognizing the voice of customers and team engagement, Leila established Lento’s vision to address real unmet needs and created a business model with the vision to evolve Lento into a scalable and robust business.  Honoring Ptolemy whose theorems were heavily leveraged to discover NBA, Leila and the team rebranded Lento’s solutions as PtoleMedic System (TM) and PtoleKnee Surgical Guide (TM).  Furthermore, Leila initiated Lento’s Clinical Advisory Board consisting of prominent global surgeons in the field along with an Executive Advisory Board to prop Lento to start with prominent opinion leaders.  Now, with a CE Mark clearance for PtoleMedic System and resulting PtoleKnee Surgical Guides, Lento is a train on full throttle, ready to start clinical activities in Europe, raise more money, and disrupt the field of joint replacement surgery.

Starting with knee solutions, Lento is scaling PtoleMedic System for personalized Total Hip Replacement and Ankle Replacement surgery releasing in coming years.  Furthermore, innovating more natural feeling implant designs in addition to Spine solutions, Lento’s product development road is mapped for the next several years. Lento’s manufacturing line is, by design, scalable to local high-demand sites while keeping the innovation secure within its internet-based brain, controlled from headquarters in Houston, Texas.  PtoleMedic system is equipped with a neural network that will be trained as new cases are analyzed, enabling further automation of some aspects of personalized surgery in the future.  

Lento Medical Innovation, Inc. (TM), although young, boasts with key unfair advantages: a relentless CTO who is a true domain expert, a dedicated team, and innovative products. Its proprietary personalized surgery planning is implemented on a controlled and secure cloud-based system to connect with surgeons anywhere in the world; effectively reducing human touch through automation, resulting in increased process output while lowering cost.  Intending to help surgeons precisely restore native joints, Lento took on the challenge in personalized orthopedic surgery to help relieve pain and restore range of motion after joint replacement surgery, to increase the quality of care while reducing overall cost. 

For more information about Lento Medical Innovation, visit their website at or email