Assessment of experimental OpenCV tracking algorithms for ultrasound videos.

This study aims to compare the tracking algorithms provided by the OpenCV library to use on ultrasound video. Despite the widespread application of this computer vision library, few works describe the attempts to use it to track the movement of liver tumors on ultrasound video. Movements of the neoplasms caused by the patient`s breath interfere with the positioning of the instruments during the process of biopsy and radio-frequency ablation. The main hypothesis of the experiment was that tracking neoplasms and correcting the position of the manipulator in case of using robotic-assisted surgery will allow positioning the instruments more precisely. Another goal of the experiment was to check if it is possible to ensure real-time tracking with at least 25 processed frames per second for standard definition video. OpenCV version 4.5.0 was used with 7 tracking algorithms from the extra modules package. They are: Boosting, CSRT, KCF, MedianFlow, MIL, MOSSE, TLD. More than 5600 frames of standard definition were processed during the experiment. Analysis of the results shows that two algorithms-CSRT and KCF-could solve the problem of tumor tracking. They lead the test with 70% and more of Intersection over Union and more than 85% successful searches. They could also be used in real-time processing with an average processing speed of up to frames per second in CSRT and 100 + frames per second for KCF. Tracking results reach the average deviation between centers of neoplasms to 2 mm and maximum deviation less than 5 mm. This experiment also shows that no frames made CSRT and KCF algorithms fail simultaneously. So, the hypothesis for future work is combining these algorithms to work together, with one of them-CSRT-as support for the KCF tracker on the rarely failed frames.

[Epithelial-stromal interactions in pancreatic adenocarcinoma: the role of stroma in disease progression]. / Epitelial'no-stromal'nye vzaimodeistviya v adenokartsinome podzheludochnoi zhelezy: rol' stromy v progressirovanii zabolevaniya.

Pancreatic ductal adenocarcinoma (PDAC) is the most common and difficult to treat form of pancreas cancer. PDAC and other solid cancers contain both tumor cells and normal connective tissue cells called stromal cells, which are responsible for the excess production of extracellular matrix. It is known that in more than 90% of PDAC tumors and in many other types of cancer, mutations of the KRAS gene are observed, the reciprocal signaling of which has been shown between tumor and stromal cells in vitro. Pancreatic stromal stellate cells are considered precursors of activated or tumor-associated fibroblasts (CAFs), which are an increasing population of cells that proliferate in situ or are recruited into the tumor. CAFs are a heterogeneous population of stromal fibroblasts with different molecular profiles that change during tumorigenesis. Both immunosuppressive and immunosuppressive subsets of CAFs can coexist in the stroma of a single tumor. Based on the heterogeneity of the intertumor stroma, attempts are being made to classify PDAC and predict the course of the disease.

[Multidisciplinary approach to surgical treatment of patients with superficial abdominal obesity]. / Mul'tidistsiplinarnyi podkhod k khirurgicheskomu lecheniyu patsientov s poverkhnostnym abdominal'nym ozhireniem.

OBJECTIVE: To analyze an effectiveness of laparoscopic surgery with simultaneous abdominoplasty in patients with superficial abdominal obesity. MATERIAL AND METHODS: Laparoscopic abdominal, retroperitoneal and pelvic surgery with simultaneous abdominoplasty was performed in 25 patients with body mass index >40 kg/m2. RESULTS: Surgery time and intraoperative blood loss were significantly higher after simultaneous surgery (p<0.05). However, these differences did not influence postoperative period. Duration of analgesic therapy, activation of patients and length of hospital-stay, as well as overall postoperative morbidity were similar in both groups (p>0.05). Simultaneous abdominoplasty resulted significantly better quality of life according to almost all parameters (p<0.05). CONCLUSION: According to certain indications, abdominoplasty is advisable as the first stage of simultaneous surgery in patients with large subcutaneous fat apron after bariatric surgery or in those with primary superficial abdominal obesity. The positive aspects of abdominoplasty are simplification of laparoscopic stage, reduced intra-abdominal pressure in postoperative period, excellent and good aesthetic effect and improved quality of life.

The comparison of the process of manual and robotic positioning of the electrode performing radiofrequency ablation under the control of a surgical navigation system.

This study is aimed at the comparison of the process of manual and robotic positioning of the electrode performing radiofrequency ablation under the control of a surgical navigation system. The main hypothesis of this experiment was that the use of a collaborative manipulator (KUKA iiwa) will allow to position the active part of the electrode relative to the center of the tumor more accurately and from the first attempt. We also monitor the stability of the electrode's velocity during insertion and consider some advantages in ergonomics using the robotic manipulator. We use three more criteria to compare the surgeon's and robotic performance, unlike other studies, where only the target point's accuracy criterion is observed. The main idea is to examine the movement parameters of the electrode that can lead to potential patient trauma. Sphere-shaped tumor phantoms measuring 8 mm in diameter were filled with contrast and inserted in bovine livers. 10 livers were used for the robotic experiment and an equal quantity for manual surgery. The livers were encased in silicone phantoms designed to imitate the liver position in a real patient's abdominal cavity. Analysis of CT data gave the opportunity to find the entry and the target point for each tumor phantom. This data was loaded into a surgical navigation system that was used to track and record the position of the RF-electrode during the operation for further analysis. The standard deviation of points from the programmed linear trajectory totaled in the average 0.3 mm for the robotic experiment and 2.33 mm for the manual operation with a maximum deviation of 0.55 mm and 7.99 mm respectively. Standard deviation from the target point was 2.69 mm for the collaborative method and 2.49 mm for the manual method. The average velocity was 2.97 mm/s for the manipulator and 3.12 mm/s for the manual method, but the standard deviation of the velocity relative to the value of the average velocity was 0.66 mm/s and 3.05 mm/s respectively. Thus, in two criteria out of three, the manipulator is superior to the surgeon, and equality is established in one. Surgeons also noticed advantages in ergonomics performing the procedure using the manipulator. This experiment was produced as part of the work on the developing of a robotic multifunctional surgical complex. We can confirm the potential advantages of using collaborative robotic manipulators for minimally invasive surgery in case of practice for cancer treatment.

[Role of octreotide and prednisolone in prophylactic of poshepatectomy liver failure. Experimental study].

AIM: Comparative morphologic assessment of the liver tissue response to the preoperative infusion of octreotide and prednisolon after the major hepatic resection was studied in rats. MATERIAL AND METHODS: 25 male Wistar rats weighing 230--280 g were used. All rats underwent 70--80% hepatectomy. The rats were divided into three groups according to the infusions before hepatectomy: group 1 (n=7) -- received octreotide, group 2 (n=8) -- prednisolone, group 3 (n=10) -- 0.9% saline solution as the control. Histologic features of the remnant liver were evaluated in the sacrificied rats after 72 hours post-hepatectomy. RESULTS: In the group 1 we observed more rapid decrease of edema and tendency to the accelerated regeneration process of hepatocytes. CONCLUSION: Octreotide infusion before the major hepatic resection may have protective effect on hepatocytes and accelerate the regeneration in the remnant liver.

[Biochemical aspects of the influence of antiorthostatic hypokinesia on the experimental peritonitis].

Eighty white rats were divided into 4 groups: (1) vivarium control, (2) antiorthostatic hypokinesia (AH), (3) peritonitis alone, and (4) AH with peritonitis. Effects of AH were achieved by putting rats on a special stand for a period of 14 days, followed by the formation of peritonitis. After that biochemical parameters of blood samples have been investigated. Combination effects of microgravity and peritonitis is unidirectional and have mutual weights. As illustrated in some cases two-fold increase in the level of the studied parameters in comparison with the control and vivarium peritonitis. Comparative assessment of peritonitis severity revealed that simulated effects of microgravity turn the peritonitis into more complicated forms.

[Physiological effects of microgravity as risk factors of diseases during space flight].

This paper considers to physiological effects of microgravity affecting different organs systems such as cardiovascular, neurohumoral, immune, and musculoskeletal systems. These physiologic changes suggest adverse influence with pathological processes during space flight and associated with high risk of morbidity of cosmonauts.