Peter D. Stevens

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In this paper, we give new results concerning pole-assignability by static and dynamic output feed-back, based on the interpretation of transfer functions, feedback laws, poles and zeroes ([3], [5], [12], [19]) in terms of the incidence geometry of m-planes and p-planes in (m+p)-space. As an illustration of the most basic ideas, we give a short proof of the(More)
PURPOSE Pancreatic cancer is a virtually uniformly fatal disease. We aimed to determine if screening to identify curable neoplasms is effective when offered to patients at high risk. EXPERIMENTAL DESIGN Patients at high risk of pancreatic cancer were prospectively enrolled into a screening program. Endoscopic ultrasound (EUS), magnetic resonance imaging(More)
BACKGROUND AND STUDY AIMS The accurate diagnosis of indeterminate pancreaticobiliary strictures presents a clinical dilemma. Probe-based confocal laser endomicroscopy (pCLE) offers real-time in vivo microscopic tissue examination that may increase sensitivity for the detection of malignancy. the objective of this study was to develop and validate a standard(More)
Radiofrequency ablation (RFA) is an effective means of eradicating Barrett’s esophagus (BE), both with and without associated dysplasia. Several studies have documented high initial success rates with RFA. However, there is limited data on IM detection rates after eradication. To determine the rate of detection of intestinal metaplasia (IM) after successful(More)
BACKGROUND The feasibility of single-operator cholangioscopy (SOC) for biliary diagnostic and therapeutic procedures was previously reported. OBJECTIVE To confirm the utility of SOC in more widespread clinical use. DESIGN Prospective clinical cohort study. SETTING Fifteen endoscopy referral centers in the United States and Europe. PATIENTS Two(More)
We evaluated the efficacy and safety of capecitabine and temozolomide (CAPTEM) in patients with metastatic neuroendocrine tumors (NETs) to the liver. This regimen was based on our studies with carcinoid cell lines that showed synergistic cytotoxicity with sequence-specific dosing of 5-fluorouracil preceding temozolomide (TMZ). A retrospective review was(More)
BACKGROUND The GI Mentor is a virtual reality simulator that uses force feedback technology to create a realistic training experience. OBJECTIVE To define the benefit of training on the GI Mentor on competency acquisition in colonoscopy. DESIGN Randomized, controlled, blinded, multicenter trial. SETTING Academic medical centers with accredited(More)
Natural orifice transluminal endoscopic surgery (NOTES) is considered the new frontier for minimally invasive surgery. NOTES procedures such as peritoneoscopy, splenectomy, and cholecystectomy in animal models have been described. The aim of our experiment was to determine the feasibility and technical aspects of a new endoluminal surgical procedure. After(More)
INTRODUCTION Initial excitement for Natural Orifice Transluminal Endoscopic Surgery (NOTES) has been partly tempered by the reality that a NOTES procedure without laparoscopic or needleoscopic-assistance has not been performed by most groups. After safely performing laparoscopically-assisted transvaginal cholecystectomy in an IACUC-approved porcine model,(More)