VISITS Visual Surgical Instrument Tracking System Post PC

VISITS Visual Surgical Instrument Tracking System Post. PC Course Project Yishai Beeri Dudi Einey

Problem: Retained Instruments forgotten inside patients Happens in average more than once a year for a large hospital

Problem: Retained Instruments Estimated 1500 cases / year in the US Account for over 50% of malpractice claims Average of $60, 000 compensation fees • Total hospital loss – about double Several past cases of death Hospital reputation implication

It’s a Real Problem 2/3 of incidents occurred even though equipment was counted before and after procedure Most were sponges and needles, but also metal clamps, electrodes and retractors Most (70%) patients needed additional surgery to remove object Incidents are rare – but have a huge impact

Risk Factors and Implications Problem worse for fat patients Promoted by fatigue, emergencies or complications

Risk Factors and Implications Emergency cases 9 times more likely Complications requiring change in 4 times more likely procedure More than one surgical team 3. 5 times more likely

Current Approaches Ignore the problem Does not make the problem go away Increase liability (no best effort) Count instruments before and after surgery Error prone, fails to deliver desired results 88% of incidents had a “good” count! Doctors do not rely on nurse counts

Current Approaches – cont. [Semi]automatic instrument tracking Requires changed or specially made instruments Time consuming – manually scan each instrument

Post Operational Imaging Not all instruments easily detected • May require multiple images or image manipulation Costly (from $100 / film), might be harmful Not systematic • What instrument are we looking for? Time consuming, occurs after stitching Recommended only as complementary measure

Post Operational Radiography Sponges etc. have radiological markers to help find them in postoperation images

Solution: Use Vision Technology Identify instruments on trays and disposal surfaces before, during and after surgery Automatically detect missing instruments No change to current instruments Simply mount a non-obtrusive camera in OR ceiling or wall Same handling for all instrument materials

VISITS – how is it used? Take snapshot image of instruments on trays prior to surgery

VISITS – how is it used? Scan additional trays during surgery, as required

VISITS – how is it used? Compare subsequent snapshots (e. g. before stitching) to base. Also cover disposal and other locations System identifies missing instruments

VISITS – how is it used? Operator can manually reconcile discrepancy (e. g. implant, etc. ), rescan or bypass Minimal intrusion to operation procedure

System Components Wall or ceiling mounted digital cameras Several cameras for several instrument “areas” Central computer for processing images Interface via a simple mounted 15”x 10” screen with 2 -5 buttons / touch-screen All important information at a glance

VISITS in the Operating Room Mount cameras on ceiling or wall above tray tables and above operation bed Install UI screen

VISITS - Technology Vision technology used to match images of instruments in snapshot to pre-existing database Database may contain 2 D, 3 D and other models for instruments Connection with hospital networks allows system to anticipate specific instrument sets

Vision Technology Wide variety of currently available techniques: • • • Appearance-based/similarity matching Recognition using 2 D silhouettes Invariant feature matching Regular mesh tessellation Neural networks algorithms A popular and rapidly developing field Better/faster future techniques are imminent

Vision Challenges: Shape Changes Some instruments change shape HMM and other technologies allow detection of varying shapes

Vision Challenges: Objects Overlap Instruments may lie overlapping one another Since original shapes are known, identification is possible:

Vision Challenges: Multiple Objects Many objects to detect in one frame Current vision technology can handle this even in motion:

VISITS – Cost and Deployment Less than $300 per camera Less than $10 K for entire system Hassle-free installation Virtually no training required Fits in existing administrative OR procedures Reduces time of manual counts Reduces instrument loss

VISITS - Summary Harness advanced vision technology to solve a real problem – retained instruments Low TCO, minimal maintenance No interference with surgeon’s work Dramatically reduce liability and avoid image-tarnishing incidents