Office of Technology Transfer – University of Michigan

Two-Phase Technique to Remove Calcified Plaques and Restore Blood Flow Coupled to A Catheter Temperature Control System in Atherectomy

Technology #7229

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Hitinder S. Gurm
Managed By
Janani Ramaswamy
Licensing Specialist, Medical Deviceses 734-763-9081
Patent Protection
US Patent Pending
Grinding wheel motion, force, temperature, and material removal in rotational atherectomy of calcified plaque
ScienceDirect - CIRP Annals - Manufacturing Technology, Volume 65, Issue 1, 2016, Pages 345–348, 2016

The technology disclosed is a novel two-phase atherectomy technique to restore blood flow with minimized cutting force and temperature rise. The method can be used as a safer alternative to existing atherectomy techniques.

Cardiovascular disease is the leading cause of morbidity and mortality worldwide. Cardiovascular disease is predominantly cased by atherosclerosis—a condition where calcified plaques build up inside the arteries. Atherosclerosis accounts for roughly 32% of deaths worldwide, and has a 13.8% prevalence among adults 20yr old and above. Atherectomy, an endovascular surgery, is used to treat atherosclerosis. There are multiple atherectomy techniques used today, such as orbital, rotational, laser, and directional. Rotational atherectomy (RA) is a commonly used atherectomy technique currently available. This technique utilizes a grinding wheel on a catheter to remove plaques in blood vessels and restore blood flow. The grinding wheel is driven by a long flexible drive shaft and rotates around a stationary guidewire. Various complications that are associated with current RA techniques are: restenosis, myocardial infarction, dissection, perforation, slow-flow/no-reflow, vasospasm, grinding wheel entrapment. Improvements to RA techniques have been limited to grinding wheel design and rotational speed, but there remains a lack of knowledge in the grinding process and plaque removal mechanism.

A safer, two-phase atherectomy technique to restore blood patency

The technology comprises of a two-phase atherectomy technique that results in safe calcified plaque removal. Phase 1 allows advancement of the technology through the calcified plaque followed by generation of plaque micro-fractures in phase 2. After phases 1 and 2 the plaque is safely removed. A major problem with current RA methods (Diamondback 360, SilverHawk, TurboHawk) is increased risk of blood coagulation and thermal injury caused by temperature rise. A catheter temperature control system is coupled to the technology to provide sufficient cooling during phases 1 and 2. The invention comprises of two embodiments for effectively controlling this cooling system.


  • Rotational atherectomy
  • Orbital atherectomy
  • Temperature sensitive catheter based surgery


  • Controlled cutting force
  • Real-time temperature control to avoid thermal damage