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Team Members:
  • Brett Wolfinger
  • Adit Murali
  • Kat Mayer
  • Anil Palepu
  • Lexie Scholtz
  • Cassie Parent
  • Christine Ji
  • Jacob Feitelberg
  • Elizabeth Logsdon, PhD
  • Kofi Boahene, MD
  • Ryan Collar, MD, MBA
  • Nicholas Calotta, MD
  • Devin O’Brien-Coon, MD, MSE
  • Jerry Prince, PhD
  • Dan Greenberg, MBA, MS, CMRP
  • David Narrow, MSE
  • Michelle Zwernemann, MSE


During an operation, the surgical team must keep track of the number of items used during the procedure to ensure that none are unintentionally retained inside the patient once the procedure is finished. In an estimated 81% of cases where a retained surgical item (RSI) is discovered, the manual count is thought to be correct. The count itself happens at the beginning of a procedure and is commonly documented on a whiteboard for reference. Recounts are performed throughout the procedure, most notably during changes of shift as well as at the end of the operation. If at any point the count does not match the reference established at the beginning, OR staff must stop the surgery to locate the missing instrument. If a change in staff occurs between a miscount and the last correct count, relieved staff members are contacted about the status of previously counted instruments, sometimes several hours later, thus requiring them to remain on call for the duration of the case.
MonitOR is a team of Johns Hopkins engineering students building a computer vision based system to tackle the problem of RSIs. Our system synthesizes data from cameras mounted throughout the operating room to provide a live snapshot of instruments in and around the patient. Additionally, our system will collect data on instrument usage and flow that can be leveraged to cut costs incurred further downstream.

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