About Us

Empirical Spine and LimiFlex™ History

The concept for the LimiFlex™ Paraspinous Tension Band was first invented by company co-founders Louie Fielding and Todd Alamin, MD in the Stanford University Biodesign Innovation program. The LimiFlex™ Paraspinous Tension Band was designed to provide stabilization without compromising spinal function, for patients with degenerative lumbar spinal disorders requiring segmental stabilization for which the current standard surgical option is spinal fusion.

After receiving the CE mark in 2009, the LimiFlex™ Paraspinous Tension Band was used to treat more than 2,000 patients, primarily in Europe. A clinical trial has been approved by the United States FDA under an Investigational Device Exemption (IDE) to study use of LimiFlex™ in patients with lumbar spinal stenosis with up to Grade I degenerative spondylolisthesis.

Our Mission

Provide patients with a unique spinal stabilization system as an alternative to fusion, delivering better clinical outcomes for lower overall healthcare costs.

Management Team

The management team of Empirical Spine represents global experience in orthopedics and spinal surgery.

Louie Fielding, President & CEO
Louie Fielding is an original inventor of the LimiFlex Paraspinous Tension Band, conceived in the Biodesign program at Stanford University while pursuing a Masters in mechanical engineering. As co-founder and director of R&D of Empircal Spine, Louie led product development, verification and validation activities; managed the IP portfolio; authored several peer-reviewed articles and FDA submissions; and holds more than 20 patents. Prior to Empirical Spine, Louie led the mechanical design team in the Intel Digital Health Group, developing solutions for remote health care delivery. Louie received his M.S. in Mechanical Engineering from Stanford University and his B.S. from the University of Washington.

Todd F. Alamin, MD, Associate Professor, Medical Director
Todd Alamin is an Associate Professor and an active orthopaedic spine surgeon at Stanford University, School of Medicine, Department of Orthopaedics in California. He is an original inventor of the LimiFlex Paraspinous Tension Band, co-founder of Empirical Spine, and has extensive involvement in the R&D and clinical study development of the LimiFlex technology.

Dr. Alamin is also the inventor of the Functional Anesthetic Discogram (FAD) to accurately diagnose discogenic low back pain. The diagnostic technology uses a catheter-based system to deliver mild anesthetic to candidate disks while patients load their spines in positions that cause pain. During the procedure, if the pain from normal loading is relieved by anesthetic delivery to the degenerated disk, then the disk can be identified for further treatment. Dr. Alamin founded InnoSpine, Inc. to develop the technology, which was acquired by Kyphon, Inc. in 2006.

Dr. Alamin received his MD from Yale University School of Medicine and his B.S. from Stanford University.

Duke Rohlen, Executive Chairman
Duke Rohlen is a serial medical device entrepreneur, with 15 years of experience as an executive in medical device companies and $1.5B in exits since 2007. Currently Duke serves as Chairman and CEO of Spirox, Inc. and Chairman and CEO of Advanced Cardiac Therapeutics. Prior to Spirox and Advanced Cardiac Therapeutics, Duke served as founder and CEO of CV Ingenuity where he raised $30.0 million of venture capital prior to selling the company to Covidien (now Medtronic) in 2013 for ~$300.0 million. Prior to CV Ingenuity, Duke served in a variety of roles at FoxHollow Technologies prior to being named President. Duke helped drive annual sales to ~$200.0 million, helped the Company through an IPO, conceived of and structured a $300.0 million collaboration with Merck Pharmaceuticals, and ultimately led the sale of the company to EV3 (now Medtronic) for $780.0 million in 2008. Prior to working at FoxHollow, Duke held senior management positions at two other medical technology companies and served as an entrepreneur-in-residence at the private equity firm, Alta Partners. Duke began his professional career as the founder and President of a 9 unit, ~$20.0 million per year restaurant company. Duke received an M.B.A. from Harvard Business School and a B.A. from Stanford University.

Intellectual Property

36 issued and more additional pending patents demonstrate Empirical Spine’s solid technology platform and allow for extended usage of the LimiFlex™ technology in the future.

This page is intended to serve as notice under 35 U.S.C. § 287(a).

The LimiFlex™ Paraspinous Tension Band and LimiFlex™ Instruments are protected by U.S. Pat. Numbers:


Further patents pending.

News and Media

  • Oct 10, 2017 - First LimiFlex procedure performed at Stanford by Dr. Kirk Wood
  • Sep 27, 2017 - First LimiFlex procedure in the US IDE study performed by Dr. Rick Sasso at Indiana Spine Group
  • Mar 21, 2017 - Empirical Spine announces initiation of IDE pivotal study of the LimiFlex Paraspinous Tension Band
  • Jan 17, 2017 - Empirical Spine closes Series A financing
  • Dec 01, 2015 - Clinical Publication in The Spine Journal
  • Aug 01, 2015 - Clinical Publication in Zeitschrift fur Orthopädie und Unfallchirurgie
  • Dec 01, 2013 - Article on Biomechanics in European Spine Journal 22:2710-2718

Contact Us

Empirical Spine, Inc.
PO Box 885
San Carlos, CA 94070

Phone: +1 (650) 585-6307
Fax: +1 (650) 585-6307
Email: info@limiflex.com