Browsing by Subject "Robotic"

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    Minimally invasive surgery in the management of resectable thymoma: a retrospective analysis from the National Cancer Database
    (AME, 2021) Salfity, Hai V.; Timsina, Lava; Ceppa, DuyKhanh P.; Birdas, Thomas J.; Surgery, School of Medicine
    Background: Thymomas are relatively uncommon tumors traditionally resected via open sternotomy. Despite the appeal of minimally invasive techniques, concerns persist regarding their oncologic efficacy. We hypothesized that minimally-invasive thymectomies for resectable thymomas are oncologically safe when compared to open thymectomy. Methods: The National Cancer Database (NCDB) was queried for patients with thymoma undergoing resection as the first mode of treatment between 2010-2015. Patient demographics, tumor characteristics and perioperative outcomes were examined for each approach (robotic, thoracoscopic, or open). The primary endpoints were rates of complete (R0) resection and need for adjuvant radiotherapy. Chi-square and Student's t-test and logistic regression were used for analysis. Results: A total of 2,312 patients were identified. The utilization of myocardial infarction (MI) surgery increased during the study period (robotic: 7.6% to 19.5%; thoracoscopic: 9.3% to 18.4%, both P<0.0001). Median tumor size was higher and mediastinal invasion was more common in open thymectomies. R0 resection was more common in robotic and adjuvant radiotherapy was less frequent in thoracoscopic thymectomies. In multivariate analysis absence of mediastinal invasion (P<0.0001) was the only prognostic factor for R0 resection. Positive margins, mediastinal invasion (both P<0.0001) and younger age (P<0.01) were the only predictors of the need for adjuvant radiotherapy. Conclusions: Utilization of MI approaches for resectable thymoma has increased from 2010 to 2015. After adjusting for tumor size and mediastinal invasion, minimally-invasive thymectomy was not associated with lower R0 resection rates or increased use of adjuvant radiotherapy. MI thymectomy for resectable thymoma is oncologically equivalent to open thymectomy.
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    Multibody dynamics model of a full human body for simulating walking
    (2017-05) Khakpour, Zahra; El-Mounayri, Hazim
    Khakpour, Zahra M.S.M.E., Purdue University, May 2017. Multibody Dynamics Model of A Full Human Body For Simulating Walking, Major Professor: Hazim El-Mounayri. Bipedal robotics is a relatively new research area which is concerned with creating walking robots which have mobility and agility characteristics approaching those of humans. Also, in general, simulation of bipedal walking is important in many other applications such as: design and testing of orthopedic implants; testing human walking rehabilitation strategies and devices; design of equipment and facilities for human/robot use/interaction; design of sports equipment; and improving sports performance & reducing injury. One of the main technical challenges in that bipedal robotics area is developing a walking control strategy which results in a stable and balanced upright walking gait of the robot on level as well as non-level (sloped/rough) terrains. In this thesis the following aspects of the walking control strategy are developed and tested in a high-fidelity multibody dynamics model of a humanoid body model: 1. Kinematic design of a walking gait using cubic Hermite splines to specify the motion of the center of the foot. 2. Inverse kinematics to compute the legs joint angles necessary to generate the walking gait. 3. Inverse dynamics using rotary actuators at the joints with PD (Proportional-Derivative) controllers to control the motion of the leg links. The thee-dimensional multibody dynamics model is built using the DIS (Dynamic Interactions Simulator) code. It consists of 42 rigid bodies representing the legs, hip, spine, ribs, neck, arms, and head. The bodies are connected using 42 revolute joints with a rotational actuator along with a PD controller at each joint. A penalty normal contact force model along with a polygonal contact surface representing the bottom of each foot is used to model contact between the foot and the terrain. Friction is modeled using an asperity-based friction model which approximates Coulomb friction using a variable anchor-point spring in parallel with a velocity dependent friction law. In this thesis, it is assumed in the model that a balance controller already exists to ensure that the walking motion is balanced (i.e. that the robot does not tip over). A multi-body dynamic model of the full human body is developed and the controllers are designed to simulate the walking motion. This includes the design of the geometric model, development of the control system in kinematics approach, and the simulation setup.
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    OTL-38-Guided Fluorescent Imaging in Renal Cell Cancer Robotic Partial Nephrectomy
    (Mary Ann Liebert, Inc., 2017-02-06) Bahler, Clinton D.; Maniar, Viraj; Marley, Kristen N.; Kheyfets, Steven V.; Shum, Cheuk Fan; Sundaram, Chandru P.; Urology, School of Medicine
    Introduction and Objective: The folate receptor (FR) protein is upregulated in numerous epithelial malignancies while having limited expression on normal tissues. This overexpression of FR in renal-cell carcinoma (RCC) can be exploited by attaching nearly any therapeutic or imaging agent for delivery to cancer cells. In one of its first applications, platinum-resistant ovarian cancer, folate was used to deliver pegylated liposomal doxorubicin (a folate-linked vinca alkaloid) and improved progression-free survival versus standard treatment. RCCs are thought to be the second highest FR-expressing cancer. OTL-38 is a folate analogue conjugated with a fluorescent dye that emits light in the near infrared spectrum. This longer wavelength allows for deeper penetration of the fluorescent light through tissues with the potential to better image tumors beneath adipose tissue or deeper into organ parenchyma. We are currently conducting a pilot, phase 2, nonrandomized study in patients with RCC, scheduled to undergo primary, partial, or radical nephrectomy. The aim is to explore the use of OTL-38 and fluorescence imaging to observe RCC at the margins of resection in partial nephrectomy and in lymph node(s) or other metastases for radical nephrectomy. Methods: Currently two patients have participated in the trial to date with an accrual target of 20 patients. The first was a 67-year-old male with an incidental 2.2 cm right-sided renal mass, and the second was a 70-year-old male with an enlarging 2 cm renal mass. Per protocol, both patients were administered OTL-38 in the preoperative area 1 hour before the procedure. Subsequently, both procedures were performed with robotic assistance as per normal routine with the use of Firefly fluorescence to aid in observation of OTL-38 uptake. Results: Intraoperative guidance through OTL-38 demonstrated minimal to no uptake of the OTL-38 as seen by Firefly fluorescence (green color). Surprisingly, the normal renal parenchyma showed strong uptake of OTL-38 as seen by Firefly fluorescence. Both pathology reports revealed conventional clear cell RCC. Immunohistochemistry slides of the tumor revealed only mild staining for folate. In contrast, immunohistochemistry slides of the normal renal parenchyma in the surgical margin revealed a strongly positive stain for folate. Conclusions: In conclusion, our first two patients' renal tumors did not stain strongly for folate; however, the normal renal parenchyma did, which served as an intraoperative guide to confirm a negative margin. Further study of patients will reveal whether folate receptors are, in fact, predominant or not in renal cell cancer.