ZeptoTrack - Miniature Optical Tracking System for Robotic Surgery and Surgical Navigation

Conventional joint replacement surgery amounts to ~4.5million procedures p.a. and largely remains dependent on surgeon experience and subjective judgments of soft tissue balancing. Complications can arise due to inaccurate placing of implant components and soft-tissue balancing, which can result in a revision procedure trebling the cost of a primary procedure(£6k). Surgical navigation platforms improve component positioning reducing complication rates albeit at a restricted working distance from the patient(<10cm) limiting procedural uptake. Surgical robotics, which is an adaptation of navigation, use a robotic arm or handpiece to improve bone-cutting precision. Although a robot delivers more accurate bone resection, they are only available in centres that can afford the technology and accommodate bulky systems(400-500Kg). Consequently, current surgical navigation and robotic platforms only serve 5-10% of the global market due to concerns over accuracy of current navigation systems, procedural flexibility, and the size and cost of robots.

**Our solution:**ZeptoTrack is a novel multi-pinhole optical tracking system that accurately measures spatial locations of bone and instrument-mounted LED markers with a Fiducial Localization Error(FLE) of 0.2mm up to 80cm using reciprocal tracking supported by a contactless optical encoder "stereo-spacecoder." ZeptoTrack weighs ~45g with dimensions (mm):42x22x11(9.24cm^2) and is supported by Augmented Reality(AR) glasses.

**Application:**ZeptoTrack is a versatile technology that offers:-

* an **ultra-compact** robotics platform(6.9Kg) compared to Stryker(MAKO)/400Kg and Zimmer/Biomet(ROSA)/ 500Kg eliminating bulky "side-view" cameras(450cm^2), and associated line-of-sight issues, and AR-smart glasses that provides accurate handpiece tracking,
* accurate surgical navigation at an **extended working range**(80cm) compared to 10cm for state-of-the-art navigation systems,e.g. Medacta(NextAr),Intellijoint-Surgical(Intellijoint-Knee),etc.

**Team/Expertise:**

* Smith+Nephew(S+N):Medical devices, robotics
* Marturion Electronics(MAR):Low-powered circuits
* Imperial College London(ICL):AR, robotics

**Key Objectives/Focus:**Expedite ZeptoTrack from a wired demonstrator (TRL-4) validated in a laboratory setting with a FLE of 0.5mm after calibration to a wireless navigation platform (TRL-6/7) tested in a hip cadaver to secure corporate S+N funding for follow-on ASIC design and product development.