VISITSVisual Surgical Instrument

Tracking System

PostPC Course PostPC Course ProjectProject

Yishai Beeri Yishai Beeri

Dudi EineyDudi Einey

Problem: Retained Instruments

Instruments forgotten Instruments forgotten inside patientsinside patients

Happens in average Happens in average more than once a more than once a year for a large year for a large hospitalhospital

Problem: Retained Instruments

Estimated 1500 cases / year in the USEstimated 1500 cases / year in the USAccount for over 50% of malpractice claimsAccount for over 50% of malpractice claimsAverage of $60,000 compensation feesAverage of $60,000 compensation fees• Total hospital loss – about doubleTotal hospital loss – about double Several past cases of deathSeveral past cases of deathHospital reputationHospital reputationimplicationimplication

It’s a Real Problem

2/3 of incidents occurred even though 2/3 of incidents occurred even though equipment was counted before and after equipment was counted before and after procedureprocedure

Most were sponges and needles, but also Most were sponges and needles, but also metal clamps, electrodes and retractorsmetal clamps, electrodes and retractors

Most (70%) patients needed additional Most (70%) patients needed additional surgery to remove objectsurgery to remove object

Incidents are rare – but have a huge impactIncidents are rare – but have a huge impactIncidents are rare – but have a huge impactIncidents are rare – but have a huge impact

Risk Factors and Implications

Problem worse for fat patientsProblem worse for fat patients

Promoted by fatigue, emergencies or Promoted by fatigue, emergencies or complicationscomplications

Risk Factors and Implications

Emergency cases 9 times more likely

Complications requiring change in procedure

4 times more likely

More than one surgical team

3.5 times more likely

Current Approaches

Ignore the problemIgnore the problemDoes not make the problem go awayDoes not make the problem go away

Increase liability (no best effort)Increase liability (no best effort)

Count instruments before and after surgeryCount instruments before and after surgeryError prone, fails to deliver desired resultsError prone, fails to deliver desired results

88% of incidents had a “good” count!88% of incidents had a “good” count!

Doctors do not rely on nurse countsDoctors do not rely on nurse counts

Current Approaches – cont.

[Semi]automatic instrument tracking[Semi]automatic instrument trackingRequires changed or specially made instrumentsRequires changed or specially made instruments

Time consuming – manually scan each instrumentTime consuming – manually scan each instrument

Post Operational Imaging

Recommended only as complementary measureRecommended only as complementary measure

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

Post Operational Radiography

Sponges etc. have Sponges etc. have radiological markers radiological markers to help find them in to help find them in post-operation imagespost-operation images

Solution: Use Vision Technology

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

Identify instruments on trays and disposal surfaces before, during and after surgery

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”x10” 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 2D, 3D 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 2D 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

Instruments may lie overlapping one another

Since original shapes are known, identification is possible:

Vision Challenges: Objects Overlap

Many objects to detect in one frame

Current vision technology can handle this - even in motion:

Vision Challenges: Multiple Objects

VISITS – Cost and Deployment

Less than $300 per camera

Less than $10K for entire system

Hassle-free installation

Virtually no training required

Fits in existing administrative OR procedures

Reduces time of manual counts

Reduces instrument loss

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

VISITS - Summary