Initial Experience With Video-Assisted Anal Fistula Treatment in the Philippines

Marc Paul J. Lopez,Mark Augustine S. Onglao,Hermogenes J. Monroy III 대한대장항문학회 2020 Annals of Coloproctolgy Vol.36 No.2

Purpose: We determined the outcomes of patients undergoing video-assisted anal fistula treatment (VAAFT) for fistula-in-ano at the Philippine General Hospital. Methods: Twenty consecutive adult patients who underwent the VAAFT procedure from 2016–2018 were included in this investigation. Information detailing baseline demographic and clinical data, fistula type and classification, and previous surgeries were retrieved from in-hospital and operative records. Operative time, identification of the internal opening, method of internal opening closure, and occurrence of immediate postoperative complications were determined. The status of the fistula was assessed at one month, 3 months, and 6 months postoperatively based on outpatient follow-up records. The primary outcomes were healing rate and recurrence rate. Secondary outcomes were 30-day morbidity, postoperative complications, and incontinence using the Wexner score. Results: Eighteen patients (90%) had a preoperative diagnosis of complex fistula, and 13 patients (65%) had undergone a previous fistula surgery. Primary healing rate was 55% at 1 month, 63.16% at 3 months, and 78.95% at 6 months postoperatively. Eighteen patients (94.74%) maintained continence (Wexner score = 0) at 6 months. Conclusion: Our study results suggest that VAAFT is a safe, minimally invasive technique for treatment of anal fistula and can preserve anal sphincter function. The technique has an acceptable healing rate with minimal complications.

A nonlinear controller based on saturation functions with variable parameters to stabilize an AUV

Campos, E.,Monroy, J.,Abundis, H.,Chemori, A.,Creuze, V.,Torres, J. The Society of Naval Architects of Korea 2019 International Journal of Naval Architecture and Oc Vol.11 No.1

This paper deals with a nonlinear controller based on saturation functions with variable parameters for set-point regulation and trajectory tracking control of an Autonomous Underwater Vehicle (AUV). In many cases, saturation functions with constant parameters are used to limit the input signals generated by a classical PD (Proportional-Derivative) controller to avoid damaging the actuators; however this abrupt bounded harms the performance of the controller. We, therefore, propose to replace the conventional saturation function, with constant parameters, by a saturation function with variable parameters to limit the signals of a PD controller, which is the base of the nonlinear PD with gravitational/buoyancy compensation and the nonlinear PD + controllers that we propose in this paper. Consequently, the mathematical model is obtained, considering the featuring operation of the underwater vehicle LIRMIA 2, to do the stability analysis of the closed-loop system with the proposed nonlinear controllers using the Lyapunov arguments. The experimental results show the performance of an AUV (LIRMIA 2) for the depth control problems in the case of set-point regulation and trajectory tracking control.

A nonlinear controller based on saturation functions with variable parameters to stabilize an AUV

E. Campos,J. Monroy,H. Abundis,A. Chemori,V. Creuze,J. Torres 대한조선학회 2019 International Journal of Naval Architecture and Oc Vol.11 No.1

This paper deals with a nonlinear controller based on saturation functions with variable parameters for set-point regulation and trajectory tracking control of an Autonomous Underwater Vehicle (AUV). In many cases, saturation functions with constant parameters are used to limit the input signals generated by a classical PD (Proportional-Derivative) controller to avoid damaging the actuators; however this abrupt bounded harms the performance of the controller. We, therefore, propose to replace the conventional saturation function, with constant parameters, by a saturation function with variable parameters to limit the signals of a PD controller, which is the base of the nonlinear PD with gravitational/ buoyancy compensation and the nonlinear PD þ controllers that we propose in this paper. Consequently, the mathematical model is obtained, considering the featuring operation of the underwater vehicle LIRMIA 2, to do the stability analysis of the closed-loop system with the proposed nonlinear controllers using the Lyapunov arguments. The experimental results show the performance of an AUV (LIRMIA 2) for the depth control problems in the case of set-point regulation and trajectory tracking control.

Effects of the Selective Laser Melting Manufacturing Process on the Properties of CoCrMo Single Tracks

Karla P. Monroy,Jordi Delgado,Lídia Sereno,Joaquim Ciurana,Nicolas J. Hendrichs 대한금속·재료학회 2014 METALS AND MATERIALS International Vol.20 No.5

Selective Laser Melting (SLM) is an additive technology that produces solid parts by selectively meltingthin layers of metallic powder. SLM can produce significant differences in the final properties due to themelting-consolidation phenomena of the process, which can be controlled by the appropriate parameters. Therefore, the objective of this study was to create a link between the process conditions and the resultingproperties by experimenting in an own-developed SLM machine using CoCrMo powder as material. The fabricated samples were characterized by density, hardness and microstructural properties. The experimentalresults proved the capability of the SLM technique to build high dense samples. The hardnessresults gave evidence of a superior outcome compared to conventional processes. Finally, it was found thatgrain size was defined by scanning speed. Based on the results, a better understanding of the processingprinciples given by the parameters was achieved and improved fabrication quality was promoted.

All-Optical Data Vortex Node Using an MZI-SOA Switch Array

Hyun-Do Jung,Monroy, I.T.,Koonen, A.M.J.,Tangdiongga, E. IEEE 2007 IEEE photonics technology letters Vol.19 No.21-24

<P>We propose and demonstrate a new structure of a Data Vortex switch node for all-optical routing of wavelength-division-multiplexing (WDM) 10-Gb/s optical packets. The proposed node consists of two Mach-Zehnder interferometers with integrated semiconductor optical amplifier: an optical and gate and a high-speed optical switch. In the experiment, WDM 10-Gb/s data packets are successfully routed with 1-dB power penalty at a bit-error rate of 10<SUP>-9</SUP>.</P>

Modifications to Treatment Plan of Rectal Cancer in Response to COVID-19 at the Philippine General Hospital

Sofia Isabel T. Manlubatan,Marc Paul J. Lopez,Mark Augustine S. Onglao,Hermogenes J. Monroy III 대한대장항문학회 2021 Annals of Coloproctolgy Vol.37 No.4

Purpose: The coronavirus disease 2019 (COVID-19) pandemic has strained healthcare resources worldwide. Despite the high number of cases, cancer management should remain one of the priorities of healthcare, as any delay would potentially cause disease progression.Methods: This was an observational study that included nonmetastatic rectal cancer patients managed at the Philippine General Hospital from March 16 to May 31, 2020, coinciding with the lockdown. The treatment received and their outcomes were investigated.Results: Of the 52 patients included, the majority were female (57.7%), belonging to the age group of 50 to 69 years (53.8%), and residing outside the capital (59.6%). On follow-up, 23.1% had no disease progression, 17.3% had local progression, 28.8% had metastatic progression, 19.2% have died, and 11.5% were lost to follow up. The initial plan for 47.6% patients was changed. Of the 21 patients with nonmetastatic disease, 2 underwent outright resection. The remaining 19 required neoadjuvant therapy. Eight have completed their neoadjuvant treatment, 8 are undergoing treatment, 2 had their treatment interrupted, and 1 has yet to begin treatment. Among the 9 patients who completed neoadjuvant therapy, only 1 was able to undergo resection on time. The rest were delayed, with a median time of 4 months. One has repeatedly failed to arrive for her surgery due to public transport limitations. There was 1 adjuvant chemotherapy-related mortality.Conclusion: Delays in cancer management resulted in disease progression in several patients. Alternative neoadjuvant treatment options should be considered while taking into account oncologic outcomes, acceptable toxicity, and limitation of potential COVID-19 exposure.

Improved outcomes with implementation of an Enhanced Recovery After Surgery pathway for patients undergoing elective colorectal surgery in the Philippines

Mayou Martin T. Tampo,Mark Augustine S. Onglao,Marc Paul J. Lopez,Marie Dione P. Sacdalan,Ma. Concepcion L. Cruz,Rosielyn T. Apellido,Hermogenes J. Monroy III 대한대장항문학회 2022 Annals of Coloproctolgy Vol.38 No.2

Purpose: This study aims to evaluate surgical outcomes (i.e. length of stay [LOS], 30-day morbidity, mortality, reoperation, and readmission rates) with the use of the Enhanced Recovery After Surgery (ERAS) pathway, and determine its association with the rate of compliance to the different ERAS components. Methods: This was a prospective cohort of patients, who underwent the following elective procedures: stoma reversal (SR), colon resection (CR), and rectal resection (RR). The primary endpoint was to determine the association of compliance to an ERAS pathway and surgical outcomes. These were then retrospectively compared to outcomes prior to the implementation of ERAS. Results: A total of 267 patients were included in the study. The overall compliance to the ERAS component was 92.0% (SR, 91.8%; CR, 93.1%; RR, 90.7%). There was an associated decrease in morbidity rates across all types of surgery, as compliance to ERAS increased. The average total LOS decreased in all groups but was only found to have statistical significance in SR (12.1±6.7 days vs. 10.0±5.4 days, P=0.002) and RR (19.9±11.4 days vs. 16.9±10.5 days, P=0.04) groups. Decreased postoperative LOS was noted in all groups. Morbidity rates were significantly higher after ERAS implementation, but reoperation and mortality rates were found to be similar. Conclusion: Increased compliance to ERAS protocol is associated with a decrease in morbidity across all surgery types. The implementation of an ERAS protocol significantly decreased mean hospital LOS, without any increase in major surgical complications. Having your own hospital ERAS pathway improves documentation and accuracy of reporting surgical complications.

GaN Quantum Dots: Physics and Applications

Le si Dang,B. Daudin,C. Adelmann,E. Martinez,E. Monroy,G. Fishman,H. Mariette,J. Simon,J. L. Rouviere,N. Pelekanos,조용훈 한국물리학회 2003 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.42 No.III

Recent works by our group on hexagonal and cubic GaN/AlN quantum dots grown by molecular beam epitaxy are reviewed. It is shown that the growth of GaN on AlN can occur either in a layer-by-layer mode to form quantum wells or in the Stranski-Krastanow mode to form self-assembled quantum dots. High resolution transmission electron microscopy reveals that quantum dots are truncated pyramids (typically 3 nm high and 15 nm wide), nucleating on top of a wetting layer. The existence of internal electric fields of 7 MV/cm in hexagonal quantum dots is evidenced by observations of various physical effects related to the quantum confined Stark effect, {\it e.g.} energy redshift of the interband transition, decrease of its oscillator strength, or enhancement of the exciton interaction with LO phonons. Prospects for UV and near-IR applications, using interband and intersubband transitions of GaN/AlN quantum dots, respectively, will be discussed also in this presentation.