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.

Richard Treadwell, President & CEO
Richard is an accomplished senior executive with more than 22 years of operating experience and a deep understanding of general management in healthcare. He has held functional leadership roles in marketing, business development, engineering and product development. As a founder of two Bay Area-based startups, he has demonstrated entrepreneurial acumen with fundraising, P&L and operating leadership. Richard has achieved consistent excellent results across a broad range of medical device therapeutic areas, including interventional cardiology at Biosensors International, cardiac surgery at Embol-X, pulse-oximetry at Nellcor, orthodontic support at Align Technology/General Orthodontic and otolaryngology at Aardvark Medical. Richard holds an MBA from The Wharton School at the University of Pennsylvania, as well as an MA in International Relations from the Johns Hopkins School of Advanced International Studies (SAIS) and a BS from Stanford University in Engineering (Product Design).

Louie Fielding, Co-Founder and Chief Operating Officer
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, Co-Founder and 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.

Job Opportunities

Qualified candidates, please submit a current CV and cover letter to jobs@LimiFlex.com

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

  • Jun 21, 2018 - LimiFlex IDE study site Boulder Neurosurgical Associates featured in BizWest article
  • May 28, 2018 - First LimiFlex procedure performed at Kaiser Permanente Oakland Medical Center by Dr. Ravi Bains and Dr. Calvin Kuo
  • Mar 19, 2018 - Richard Treadwell joins Empirical Spine as President and CEO
  • Dec 12, 2017 - First LimiFlex procedure performed at Boulder Neurosurgical Associates by Dr. Alan Villavicencio
  • 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