Neuro-evolutionary based controller design for linear and non-linear systems

Samarth Singh,Kaushal Kishore,S A Akbar 제어로봇시스템학회 2021 제어로봇시스템학회 국제학술대회 논문집 Vol.2021 No.10

In the present work a Neuro-Evolution based approach has been used to train a neural network for control of some sample systems. This method makes use of Genetic algorithm, here it is generating a population of neural networks and introduces mutation for producing better off-springs for the next generation. The approach is kind of black box optimization and do not require any back propagation for training. It makes use of fitness function to evaluate performance of off-springs, this fitness function is based on a novel reward function which allows for quick and smooth settling of the sample system towards set point. In order to address dynamics of the system’s time sequenced error has been taken as exogenous input for the neural network. The method has been tested on a linear first order system and a system having non linearity.

Atypical Radiographic Presentation of Aggressive Vertebral Haemangioma: Experience of Two Cases

Samarth Mittal,Syed Ifthekar,Kaustubh Ahuja,Gagandeep Yadav,Subhajit Maji,Sonal Saran,Pankaj Kandwal 대한척추외과학회 2021 대한척추외과학회지 Vol.28 No.1

Study Design: Case report Objective: We report two cases of vertebral body haemangioma with atypical radiological features causing neurological deficit. Summary of Literature Review: Vertebral haemangiomas are usually asymptomatic and are discovered incidentally during imaging. However, complications such as pain, neurological deficit, vertebral body fracture can arise due to different mechanisms. Materials and Method: We report two cases of vertebral hemangioma of dorsal spine with atypical radiological features. Results: Good pain relief, neurological recovery and functional outcome was achieved by embolization and surgical decompression/ tumor resection along with stabilization in case of aggressive vertebral hemangioma. Aggressive vertebral hemangioma may present with atypical radiographic features. Conclusions: Aggressive vertebral haemangioma may have atypical radiographic presentation. Surgical decompression is one of the preferred treatment of it.

Mucormycosis Management in COVID-19 Era: Is Immediate Surgical Debridement and Reconstruction the Answer?

Samarth Gupta,Pradeep Goil,Arbab Mohammad,Joseph M. Escandón 대한성형외과학회 2022 Archives of Plastic Surgery Vol.49 No.3

Background Excessive use of corticosteroids therapy along with gross immunocompromised conditions in the novel coronavirus disease 2019 (COVID-19) pandemic has raised the risks of contracting opportunistic fungal infections. Here, we describe our experience with the implementation of a surgical protocol to treat and reconstruct rhino-orbital-cerebral mucormycosis. Methods A retrospective review of our prospectively maintained database was conducted on consecutive patients diagnosed with mucormycosis undergoing immediate reconstruction utilizing our “Mucormycosis Management Protocol.” All patients included in this study underwent reconstruction after recovering fromCOVID-19. Wide local excision was performed in all cases removing all suspected and edematous tissue. Reconstruction was done primarily after clear margins were achieved on clinical assessment under a cover of injectable liposomal amphotericin B. Results Fourteen patients were included. The average age was 43.6 years and followup was 24.3 days. Thirteen patients had been admitted for inpatient care of COVID-19. Steroid therapy was implemented for 2 weeks in 11 patients and for 3 weeks in 3 patients. Eight patients (57.1%) had a maxillectomy and mucosal lining resection with/without skin excision, and six patients (42.8%) underwent maxillectomy and wide tissue excision (maxillectomy and partial zygomatic resection, orbital exenteration, orbital floor resection, nose debridement, or skull base debridement). Anterolateral thigh (ALT) flapswere used to cover defects in all patients. All flaps survived. No major or minor complications occurred. No recurrence of mucormycosis was noted. Conclusion The approach presented in this study indicates that immediate reconstruction is safe and reliable in cases when appropriate tissue resection is accomplished. Further studies are required to verify the external validity of these findings.

Deformity Correction with Interbody Fusion Using Lateral versus Posterior Approach in Adult Degenerative Scoliosis: A Systematic Review and Observational Meta-analysis

Mittal Samarth,Sudhakar Pudipeddi Venkata,Ahuja Kaustubh,Ifthekar Syed,Yadav Gagandeep,Sinha Shivendra,Goyal Nikhil,Verma Vishal,Sarkar Bhaskar,Kandwal Pankaj 대한척추외과학회 2023 Asian Spine Journal Vol.17 No.2

This study was designed to systematically review and meta-analyze the functional and radiological outcomes between lateral and posterior approaches in adult degenerative scoliosis (ADS). Both lateral (lumbar, extreme, and oblique) and posterior interbody fusion (posterior lumbar and transforaminal) are used for deformity correction in patients with ADS with unclear comparison in this cohort of patients in the existing literature. A literature search using three electronic databases was performed to identify studies that reported outcomes of lateral (group L) and posterior interbody fusion (group P) in patients with ADS with curves of 10°–40°. Group P was further subdivided into minimally invasive surgery (MIS-P) and open posterior (Op-P) subgroups. Data on functional, radiological, and operative outcomes, length of hospital stay (LOHS), fusion rates, and complications were extracted and meta-analyzed using the random-effects model. A total of 18 studies (732 patients) met the inclusion criteria. No significant difference was found in functional and radiological outcomes between the two groups on data pooling. Total operative time in the MIS-P subgroup was less than that of group L (233.86 minutes vs. 401 minutes, p <0.05). The total blood loss in group L was less than that in the Op-P subgroup(477 mL vs. 1,325.6 mL, p <0.05). Group L had significantly less LOHS than the Op-P subgroup (4.15 days vs. 13.5 days, p <0.05). No significant difference was seen in fusion rates, but complications were seen except for transient sensorimotor weakness (group L: 24.3%, group P: 5.6%; p <0.05). Complications, such as postoperative thigh pain (7.7%), visceral injuries (2%), and retrograde ejaculation (3.7%), were seen only in group L while adjacent segment degeneration was seen only in group P (8.6%). Lateral approach has an advantage in blood loss and LOHS over the Op-P subgroup. The MIS-P subgroup has less operative time than group L, but with comparable blood loss and LOHS. No significant difference was found in functional, radiological, fusion rates, pseudoarthrosis, and complications, except for transient sensorimotor deficits. Few complications were approach-specific in each group.

척추 종양수술에서 적절한 수술적 절제연을 얻기 위한 수술 중 네비게이션의 역할: 증례 연구

김상일,Samarth Mittal,고영일,고명섭,김영훈 대한척추외과학회 2024 대한척추외과학회지 Vol.31 No.1

연구 계획: 증례 연구목적: 본 연구는 척추 종양 수술 시 O-arm 네비게이션을 이용하였을 때 적절한 수술 절제연을 얻는 비율과 종양학적결 과에 대하여 확인하고자 하였다. 선행 연구문헌의 요약: 최근 척추 종양 수술 영역에서 수술 중 컴퓨터 단층촬영(CT) 기반의 네비게이션을 이용한 수술이 이루어지고 있다. 하지만 이러한수술방법이 수술 과정에 실제로 도움이 되고 더 나은 임상결과를 보여주는지 여부는 명확하지 않다. 결과: 네비게이션과 관련된 수술 중 합병증은 발생하지 않았다. 종양학적 결과에서는 6명의 환자가 생존하였으며, 이 중 5명은 질병의 증거가 없는 상태로 생존하였으며, 한명의 환자는 질병을 가진 채로 생존하였다. 한명의 환자는 6개월 추시 후 사망하였다. 네비게이션 이용 수술은 7명 중 6명의 환자에서(85.7%) 외과적 음성 절제연을 얻는데 도움이 되는 것으로 확인 되었으며, 종양의 단독 전이가 있는 환자 중 한명에서 절제연이 종양을 포함한 것으로확인되었다. 생존한 환자 6명 중에서 천골 골육종 환자 1명이(16.7%) 위성병변으로 국소재발이 발생하였고, 재수술을 실시했다. 결론: 척추 종양에 대한 CT 기반 네비게이션 수술은 정확한 재건술 뿐만 아니라 수술적 절제연의 결정에 유용할 수 있다. 수술 전 철저한 영상의학적 검토와 수술 중 네비게이션의 이용은 안전한 절제연을 얻는데 도움이 될 수 있다. 약칭 제목: 네비게이션을 이용한 척추 종양 절제술 Study Design: Case series Objective: This study aimed to assess the proportion of adequate surgical margins in spine tumor resection procedures using O-arm navigation-assisted surgery, and to examine the associated oncologic outcomes. Summary of Literature Review: Computed tomography (CT)-based intraoperative navigation has been relatively recently adopted for spine tumor surgery. However, whether navigation-assisted surgery shortens procedures and leads to better clinical outcomes remains unclear. Materials and Methods: A retrospective review was conducted on seven patients who underwent tumor resection with O-arm navigation assistance. Clinical data such as general demographic characteristics, intraoperative efficacy of this system for reconstruction, perioperative complications, oncologic outcomes, and pathological reviews of the surgical margins were collected. Results: No intraoperative complications were associated with the use of the navigation system. In terms of oncological outcomes, six patients survived, with five showing no evidence of disease and one remaining alive with disease. One patient died after a 6-month follow-up period. Navigation proved beneficial in achieving negative resection margins in six out of seven patients (85.7%), while only one patient with solitary metastasis showed margin involvement of the tumor. Among the six surviving patients, one with sacral osteosarcoma (16.7%) experienced local recurrence due to a satellite lesion, leading to revision surgery. Conclusions: CT-based navigation-assisted surgery for spinal tumors could be useful not only for accurate reconstruction, but also for determining the surgical margin. A thorough preoperative radiological review and intraoperative navigation could provide additional benefits for a safe resection margin.

Laparoscopic transperitoneal heminephrectomy for treatment of the nonfunctioning moiety of duplex kidney in adults: A case series

Manmeet Singh,Samarth Agarwal,Apul Goel,Manoj Kumar,Ashish Sharma,Siddharth Pandey,Satynarayan Sankhwar 대한비뇨의학회 2019 Investigative and Clinical Urology Vol.60 No.3

Purpose: We report the results and experience of a tertiary care center in laparoscopic transperitoneal heminephrectomy for the treatment of a non-functioning upper pole moiety of duplex kidney in adults. Materials and Methods: The key point of the technique included the placement of a 6-Fr ureteric catheter in the healthy ureter at the beginning of the procedure under fluoroscopic guidance cystoscopically. A standard laparoscopic 3- to 4-port placement was done after placing the patient in a 45 to 90 degrees lateral decubitus position. The upper pole was mobilized transperitoneally and transected using a harmonic scalpel. Results: A total of 17 patients aged 19 to 44 years underwent laparoscopic upper pole heminephrectomy. All patients had a complete duplicated renal collecting system on the ipsilateral side. Three patients were found to have ureterocele. The average blood loss was minimal (50–150 mL) with a mean of 95 ml. None of the patients required any blood transfusions. The mean operative time was 220 minutes (range, 160–315 minutes). The average length of hospital stay was 3 days (range, 2–4 days). Only 2 patients had Clavien-Dindo grade 3a complications, which were managed by double J stenting and percutaneous aspiration, respectively. Conclusions: Laparoscopic heminephrectomy is playing a cornerstone role in the treatment of the non-functioning moiety of duplex kidneys. The procedure is safe, efficient and offers the typical preoperative and postoperative benefits of laparoscopic surgery. The rate of complications in adults is acceptable and is similar to that reported in pediatric patients.

A prospective study evaluating impact on renal function following percutaneous nephrolithotomy using Tc99m ethylenedicysteine renal scan: Does multiplicity of access tracts play a role?

Ram Yadav,Samarth Agarwal,Satyanarayan Sankhwar,Apul Goel,Manoj Kumar,Manmeet Singh,Ruchir Aeron,Vikas Kumar 대한비뇨의학회 2019 Investigative and Clinical Urology Vol.60 No.1

Purpose: A prospective study evaluating impact of percutaneous nephrolithotomy (PCNL) on renal function following PCNL using ethylenedicysteine (EC) renal scan. Does multiplicity of access tracts play a role?Materials and Methods: A prospective observational study was done and patients undergoing PCNL for renal calculi at our urology department were selected. Renal Tc99m EC scan was done pre-surgery and at 3 months follow-up. An assessment was done on decline in glomerular filtration rate (GFR) in postoperative period based on number of access tracts required. Results: A total of 110 patients were enrolled in the study. The total number of punctures was 170 with 141 being supra-costal puncture and 29 infra-costal. The total number of single punctures were 60 and classified as Group I whereas patients with double puncture and triple puncture (40 and 10 patients, respectively) were classified as Group II. Mean postoperative split renal function (in Tc99m EC scans) of patients of Group I (40.93±19.62%) was found to be higher than that of Group II (32.82±16.98%). Mean change (decline) in GFR for single, double and triple tracts were 2.68 mL/min, 3.80 mL/min, and 4.2 mL/min, respectively. Conclusions: PCNL used for stone removal can improve renal function by eradicating obstruction; however, this procedure may itself negatively impact the functions of the targeted kidney. Our study showed post PCNL decrease in GFR which worsens with an increasing number of accesses.

Heuristic Guided Artificial Potential Field for Avoidance of Small Obstacles

Sagar Dalai,Mahammad Irfan,Samarth Singh,Kaushal Kishore,Dr. S.A Akbar 제어로봇시스템학회 2021 제어로봇시스템학회 국제학술대회 논문집 Vol.2021 No.10

In this paper, a modified heuristic guided Artificial Potential Field (APF) based algorithm has been proposed to find a practical trajectory for an Autonomous Unmanned Aerial Vehicle (UAV) path planning. The local minima are encountered in the conventional APF algorithm due to the cancellation of attractive and repulsive potential while avoiding unknown obstacles within the desired path, which results in the trapping of the agent before reaching the goal. Consequently, the traditional APF technique is therefore no longer advantageous in such cases. So in this proposed perpendicular approach based on APF helps to avoid such local minima. The advantage of the newly proposed method is the low computing time that lines up with the standard global path planner method. The proposed algorithm is tested and validated against existing general potential field techniques for different simulation scenarios in a 3D simulated environment using ROS and Gazebo supported PX4-SITL. The results have been presented for drone navigation and obstacle avoidance for the different scenarios in a simulated environment.

The Impact of Surgical Timing of Hip Fracture on Mortality: Do the Cause and Duration of Delay Matter?

Jaiben George,Vijay Sharma,Kamran Farooque,Samarth Mittal,Vivek Trikha,Rajesh Malhotra 대한고관절학회 2023 Hip and Pelvis Vol.35 No.3

Purpose: Delay in performance of hip fracture surgery can be caused by medical and/or administrative reasons. Although early surgery is recommended, it is unclear what constitutes a delayed surgery and whether the impact of delayed surgery can differ depending on the reason for the delay. Materials and Methods: A total of 269 consecutive hip fracture patients over 50 years of age who underwent surgery were prospectively enrolled. They were divided into two groups: early and delayed (time from reaching the hospital to surgery less than or more than 48 hours). Patients were also categorized as fit or unfit based on anesthetic fitness. One-year mortality was recorded, and regression analyses were performed to assess the impact of delay on mortality. Results: A total of 153 patients (56.9%) had delayed surgery with a mean time to surgery of 87±70 hours. A total of 115 patients (42.8%) were considered medically fit to undergo surgery. No difference in one-year mortality was observed between patients with early surgery and those with delayed surgery (P=0.854). However, when assessment of the time to surgery was performed in a continuous manner, mortality increased with prolonged time to surgery, particularly in unfit patients, and higher mortality was observed when the delay exceeded six days (fit: P=0.117; unfit: P=0.035). Conclusion: The effect of delay on mortality was predominantly observed in patients who were not considered medically fit, suggesting that surgical delays might have a greater impact on patients with medical reasons for delay.

Determination of Carrier Concentration in Ga1-xMnxAs Using Raman Spectrocopy

명제 성,A Mascarenhas,Cheongy Cheongy,N Samarth,S. H. Chunz 한국물리학회 2003 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.42 No.III

Ga$_{1-x}$Mn$_{x}$As with Curie temperatures ($T_c$) as high as 110 K has recently emerged as an important spintronic semiconductor material. The ferromagnetism in this material arises from the exchange interaction between the free carriers (holes) generated by Mn doping and the Mn$^{2+}$ ions. However, the accurate determination of the carrier concentration in Ga$_{1-x}$Mn$_{x}$As using standard transport techniques is extremely difficult because of the dominant anomalous Hall effect. We have performed spectroscopic measurements of the hole density in four Ga$_{1-x}$Mn$_{x}$As samples ($x = 0, 0.038, 0.061, 0.083$) using Raman scattering intensity analysis of the coupled plasmon-LO-phonon mode and the unscreened LO phonon. The unscreened LO phonon frequency linearly decreases as the Mn concentration increases up to 8.3 \%. The hole density determined from the Raman scattering exhibits a direct correlation to the observed $T_c$, providing an unambiguous means of determining the hole density in this important new class of ferromagnetic semiconductors.