Browsing by Author "Waters, Joshua A."

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    Pancreatic Cysts Identification Using Unstructured Information Management Architecture
    (Office of the Vice Chancellor for Research, 2013-04-05) Mehrabi, Saeed; Schmidt, C. Max; Waters, Joshua A.; Beesley, Chris; Krishnan, Anand; Kesterson, Joe; Dexter, Paul; Al-Haddad, Mohammed A.; Palakal, Mathew
    Pancreatic cancer is one of the deadliest cancers, mostly diagnosed at late stages. Patients with pancreatic cysts are at higher risk of developing cancer and surveillance of these patients can help with early diagnosis. Much information about pancreatic cysts can be found in free text format in various medical narratives. In this retrospective study, a corpus of 1064 records from 44 patients at Indiana University Hospital from 1990 to 2012 was collected. A natural language processing system was developed and used to identify patients with pancreatic cysts. The input goes through series of tasks within the Unstructured Information Management Architecture (UIMA) framework consisting of report separation, metadata detection, sentence detection, concept annotation and writing into the database. Metadata such as medical record number (MRN), report id, report name, report date, report body were extracted from each report. Sentences were detected and concepts within each sentence were extracted using regular expression. Regular expression is a pattern of characters matching specific string of text. Our medical team assembled concepts that are used to identify pancreatic cysts in medical reports and additional keywords were added by searching through literature and Unified Medical Language System (UMLS) knowledge base. The Negex Algorithm was used to find out negation status of concepts. The 1064 reports were divided into sets of train and test sets. Two pancreatic-cyst surgeons created the gold standard data (Inter annotator agreement K=88%). The training set was analyzed to modify the regular expression. The concept identification using the NegEx algorithm resulted in precision and recall of 98.9% and 89% respectively. In order to improve the performance of negation detection, Stanford Dependency parser (SDP) was used. SDP finds out how words are related to each other in a sentence. SDP based negation algorithm improved the recall to 95.7%.
  • Thumbnail Image
    Item
    Robotic Approach to Colon Resection
    (Elsevier, 2016-09) Waters, Joshua A.; Francone, Todd D.; Department of Surgery, IU School of Medicine
    Robotic surgical techniques are being increasingly adopted as a tool in the minimally invasive armamentarium of the colorectal surgeon. These platforms present numerous potential advantages in visualization, precise dissection, and tissue manipulation while potentially reducing operator fatigue. They may also reduce the learning curve and rate of conversion, though the short- and long-term benefits of this approach in non-pelvic colorectal surgery, and the cost–benefit balance remain an ongoing debate. Adherence to established principles of laparoscopic colon surgery, a robust understanding of the operative anatomy, and proper patient preparation and setup are critical for the efficient and effective utilization of a robotic approach for colon resection.
  • Thumbnail Image
    Item
    Use of rectal mucosal grafts in substitution urethroplasty: an early series
    (AME Publishing Company, 2018-12) Monn, M. Francesca; Waters, Joshua A.; Mellon, Matthew J.; Urology, School of Medicine
    Background: To evaluate the feasibility of use of rectal mucosal grafts for augmentation urethroplasty. Methods: A series of five patients who underwent rectal mucosal graft urethroplasty for urethral stricture disease were identified. Descriptive statistics were used to describe these patients. Primary endpoints were recurrence of stricture and perioperative morbidity. Results: Five patients underwent rectal mucosal graft augmentation urethroplasty. Four had a history of prior buccal mucosal graft (BMG) urethroplasty and one had a history of head and neck cancer. Rectal mucosa was noted to be thinner and required more tailoring than buccal mucosa. All patients had patent urethras at time of postoperative retrograde urethrogram. A small diverticulum was noted in one patient with no further sequelae. No complications from rectal mucosal graft harvest were noted. All patients with prior buccal grafting subjectively preferred the rectal graft due to fewer side effects. Subjectively, patients with prior buccal grafts preferred the post-operative recovery following rectal mucosal graft urethroplasty. Conclusions: Rectal mucosal graft augmentation urethroplasty is a safe alternative in patients with contraindications to buccal grafting with limited morbidity.