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Background: Previous animal studies have shown no significant vascular injury from pulsed electrical field (PEF) ablation. We sought to assess the effect of PEF on swine coronary arteries. Methods: We performed intracoronary and epicardial (near the coronary artery) PEF ablations in swine pretreated with dual antiplatelet and antiarrhythmic therapy. Intracoronary PEF was delivered using MapiT catheters (Biotronik, Berlin), whereas epicardial PEF was delivered using EPT catheters (Boston Scientific, MA). PEF pulse duration was microseconds (Nanoknife 3.0, Angio Dynamics, NY) or nanoseconds (CellFX, Pulse Biosciences, CA). Results: We performed 39 intracoronary ablations in 10 swine and 20 epicardial-pericoronary ablations in 4 separate swine. Intracoronary PEF was delivered at higher energy compared with epicardial PEF (46 [interquartile range, IQR 20–85] J versus 10 [IQR 10–11] J, P < 0.01). Reversible coronary spasm occurred in 49% intracoronary ablations and 45% epicardial ablations ( P =0.80). At the end study, fixed coronary stenosis was demonstrated in 44% intracoronary ablations (80% for microsecond PEF and 18% for nanosecond PEF) and 0% epicardial ablations. Visible hemorrhagic and/or fibrotic myocardial lesions were observed at necropsy with similar frequency between intracoronary and epicardial PEF (45% versus 50%, P =0.70). Nanosecond PEF (49 ablations in 11 swine), when compared with microsecond PEF (10 intracoronary ablations in 3 swine), resulted in lower energy delivery (21 [IQR 10–46] J versus 129 [IQR 24–143] J, P =0.03) and less incidence of fixed coronary stenosis (18% versus 80%, P =0.04). Conclusions: In the swine model, intracoronary PEF resulted both in significant coronary spasm and fixed coronary stenosis. Epicardial PEF, delivered at lower energy, resulted in reversible spasm but no fixed coronary stenosis.

This paper presents our on-going research at bringing the state-of-the-art in vision and robotics technologies to enhance the emerging minimally invasive surgery, in particular the laparoscopic surgical procedure. A framework that utilizes intelligent visual modeling, recognition, and servoing capabilities for assisting the surgeon in maneuvering the scope (camera) in laparoscopy is proposed. The proposed framework integrates top-down model guidance, bottom-up image analysis, and surgeon-in-the-loop monitoring for added patient safety. For the top-down directives, high-level models are used to represent the abdominal anatomy and to encode choreographed scope movement sequences based on the surgeon’s knowledge. For the bottom-up analysis, vision algorithms are designed for image analysis, modeling, and matching in a flexible, deformable environment (the abdominal cavity). For reconciling the top-down and bottom-up activities, robot servoing mechanisms are realized for executing choreographed scope movements with active vision guidance. The proposed choreographed scope maneuvering concept facilitates the surgeon’s control of his/her visual feedback in a handless manner, reduces the risk to the patient from inappropriate scope movements by an assistant, and allows the operation to be performed faster and with greater ease. In this paper, we describe the new framework and present some preliminary results on laparoscopic image analysis for segmentation and instrument localization, and on instrument tracking.

T he merger of medicine and technology often relies upon serendipity--a given set of circumstances, a chance meeting. Such is the case with robotic applications to surgery. The cessation of the Cold Wa.r has left many corporations that had been engaged in research projects for the defense industry without gainful employment. At the same time, the development of laparoscopic surgery and diminishing financial resources in medicine created the need for creative solutions to specific problems, such as the development that is the subject of this article.

This paper describes a practical and reliable image analysis and tracking algorithm to achieve automated instrument localization and scope maneuvering in robotically assisted laparoscopic surgery. Laparoscopy is a minimally invasive surgical procedure that utilizes multiple small incisions on the patient's body through which the surgeon inserts tools and a videoscope in order to conduct an operation. The scope relays images of internal organs to a camera, and the images are displayed on a video screen. The surgeon performs the operation by viewing the scope images rather than performing the traditional “open” procedure, where a large incision is made on the patient's body for direct viewing.The current mode of laparoscopy employs an assistant to hold the scope and position it in response to the surgeon's verbal commands. However, this results in suboptimal visual feedback, because the scope is often aimed incorrectly and vibrates due to hand trembling. We have developed a robotic laparoscope positioner to...

This paper describes a practical and reliable image analysis and tracking algorithm to achieve automated instrument localization and scope manoeuvring in endoscopic surgery.

This was a single-site cohort study to evaluate the safety of a new transcervical device (VizAblate™) combining real-time intrauterine sonography with radiofrequency (RF) ablation for the treatment of fibroids. Nineteen women with uterine fibroids received treatment with the VizAblate System in a closed abdomen setting prior to hysterectomy. Twelve of these subjects underwent an immediate abdominal hysterectomy after radiofrequency ablation (acute group), while the remaining seven underwent hysterectomy on post-ablation days 16 and 17 (subacute group). Uteri were sectioned and stained with the viability stain triphenyltetrazolium chloride (TTC) to quantify fibroid ablation dimensions and assess the serosa for thermal injury. Subjects in the subacute group were treated with the VizAblate System under conscious sedation; they provided pain and tolerability data for the interval from ablation through hysterectomy, and indicated overall procedural satisfaction. Twenty-two ablations ranging from 1.8 to 36.2 cm3 were created among 19 subjects within 20 fibroids and one region of adenomyosis. There were no complications or thermal serosal injury. For subjects in the subacute group receiving one ablation, the mean total procedure time was 25.8 ± 6.0 min (range 18–32 min). All subjects in the subacute group were discharged within 2 h of the VizAblate procedure. For fibroids ≤ 5 cm, 67.2% ± 27.0% of the fibroid volume was ablated (range 15–100%; median 75%). Transcervical RF ablation of fibroids under intrauterine sonographic guidance with the VizAblate system can be accomplished with a high degree of reliability and without adverse events.

This paper describes a practical and reliable image analysis and tracking algorithm to achieve automated instrument localization and scope maneuvering in robotically assisted laparoscopic surgery. Laparoscopy is a minimally invasive surgical procedure that utilizes multiple small incisions on the patient's body through which the surgeon inserts tools and a videoscope in order to conduct an operation. The scope relays images of internal organs to a camera, and the images are displayed on a video screen. The surgeon performs the operation by viewing the scope images rather than performing the traditional “open” procedure, where a large incision is made on the patient's body for direct viewing. The current mode of laparoscopy employs an assistant to hold the scope and position it in response to the surgeon's verbal commands. However, this results in suboptimal visual feedback, because the scope is often aimed incorrectly and vibrates due to hand trembling. We have developed a robotic laparoscope positioner to replace the assistant. The surgeon commands the robotic positioner through a hand/foot controller interface. To further simplify the human-machine interface that controls the robotic scope positioner, we report here a novel scope-positioning scheme using automated image analysis and robotic visual servoing. The scheme enables the surgeon to control visual feedback and to perform surgery more efficiently without requiring additional use of the hands. J Image Guid Surg 1:308–325 (1995). © 1996 Wiley-Liss, Inc.

A robotic system which controls the movement of a surgical instrument in response to voice commands from the user. The robotic system has a computer controlled arm that holds the surgical instrument. The user provides voice commands to the computer through a microphone. The computer contains a phrase recognizer that matches the user' speech with words stored in the computer. Matched words are then processed to determine whether the user has spoken a robot command. If the user has spoken a recognized robot command the computer will move the robotic arm in accordance with the command.