A Ripple Rejection Inherited RPWM for VSI Working with Fluctuating DC Link Voltage

Jarin, T.,Subburaj, P.,Bright, Shibu J V The Korean Institute of Electrical Engineers 2015 Journal of Electrical Engineering & Technology Vol.10 No.5

A two stage ac drive configuration consisting of a single-phase line commutated rectifier and a three-phase voltage source inverter (VSI) is very common in low and medium power applications. The deterministic pulse width modulation (PWM) methods like sinusoidal PWM (SPWM) could not be considered as an ideal choice for modern drives since they result mechanical vibration and acoustic noise, and limit the application scope. This is due to the incapability of the deterministic PWM strategies in sprawling the harmonic power. The random PWM (RPWM) approaches could solve this issue by creating continuous harmonic profile instead of discrete clusters of dominant harmonics. Insufficient filtering at dc link results in the amplitude distortion of the input dc voltage to the VSI and has the most significant impact on the spectral errors (difference between theoretical and practical spectra). It is obvious that the sprawling effect of RPWM undoubtedly influenced by input fluctuation and the discrete harmonic clusters may reappear. The influence of dc link fluctuation on harmonics and their spreading effect in the VSI remains invalidated. A case study is done with four different filter capacitor values in this paper and results are compared with the constant dc input operation. This paper also proposes an ingenious RPWM, a ripple dosed sinusoidal reference-random carrier PWM (RDSRRCPWM), which has the innate capacity of suppressing the effect of input fluctuation in the output than the other modern PWM methods. MATLAB based simulation study reveals the fundamental component, total harmonic distortion (THD) and harmonic spread factor (HSF) for various modulation indices. The non-ideal dc link is managed well with the developed RDSRRCPWM applied to the VSI and tested in a proto type VSI using the field programmable gate array (FPGA).

Mortality, Length of Stay, and Cost Associated with Hospitalized Adult Cancer Patients with Febrile Neutropenia

Chindaprasirt, Jarin,Wanitpongpun, Chinadol,Limpawattana, Panita,Thepsuthammarat, Kaewjai,Sripakdee, Warunsuda,Wirasorn, Kosin,Sookprasert, Aumkhae Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.2

Background: Febrile neutropenia (FN) is a serious complication following chemotherapy and is associated with significant mortality and financial expenditure. The aim of this study was to evaluate risk factors for longer length of stay (LOS) and mortality and cost of treatment among hospitalized adults with cancer who developed febrile neutropenia in Thailand. Materials and Methods: Information on illness of inpatients and casualties came from hospitals nationwide and from hospital withdrawals from the 3 health insurance schemes in fiscal 2010. The data covered 96% of the population and were analyzed by age groups, hospital level, and insurance year schemes in patients with febrile neutropenia. Results: A total of 5,809 patients were identified in the study. The mortality rate was 14%. The median LOS was 8.67 days and 69% of patients stayed for longer than 5 days. On bivariate analysis, age, cancer type, and infectious complications (bacteremia/sepsis, hypotension, fungal infections, and pneumonia) were significantly associated with longer LOS and death. On multivariate analysis, acute leukemia and infectious complications were linked with longer LOS and death significantly. The median cost of hospitalized FN was THB 33,686 (USD 1,122) with the highest cost observed in acute leukemia patients. Conclusions: FN in adult patients results in significant mortality in hospitalized Thai patients. Factors associated with increased mortality include older age (>70), acute leukemia, comorbidity, and infectious complications.

Burdens among Caregivers of Older Adults with Advanced Cancer and Risk Factors

Chindaprasirt, Jarin,Limpawattana, Panita,Pakkaratho, Pornvaree,Wirasorn, Kosin,Sookprasert, Aumkhae,Kongbunkiat, Kannikar,Sawanyawisuth, Kittisak Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.4

Family caregivers of older cancer patients face many challenges in managing illness. The burden impacts physical, emotional, spiritual, and social health. The objective of this study was to identify burden among caregivers of older patients with advanced cancer, and associated factors. Materials and Methods: Caregivers of older cancer patients were randomly interviewed from March-September 2012. Information on baseline characteristics and caregiver burden using the Zarit Burden Inventory (ZBI) was collected. Descriptive statistics were used to analyze baseline data, with univariate and multiple linear regression to analyze factors associated with higher burden. Results: One hundred and fifty participants were assessed. The mean ZBI was $19.2{\pm}12.9$ (95%CI, 17.1, 21.2). Two-thirds of caregivers reported no burden (63%) and the main impact variable on ZBI was guilt. High burdens were associated with single caregiver, relationship with the patient as siblings, presence of migraines, and cancer types of the patients. Conclusions: Caregiver burden of Thai cancer patients is low. This unexpected small number could be the result of the socio-cultural viewpoint. Assessment of caregivers and focusing on related factors should be incorporated into treatment plans.

A Ripple Rejection Inherited RPWM for VSI Working with Fluctuating DC Link Voltage

T. Jarin,P. Subburaj,Shibu J V Bright 대한전기학회 2015 Journal of Electrical Engineering & Technology Vol.10 No.5

A two stage ac drive configuration consisting of a single-phase line commutated rectifier and a three-phase voltage source inverter (VSI) is very common in low and medium power applications. The deterministic pulse width modulation (PWM) methods like sinusoidal PWM (SPWM) could not be considered as an ideal choice for modern drives since they result mechanical vibration and acoustic noise, and limit the application scope. This is due to the incapability of the deterministic PWM strategies in sprawling the harmonic power. The random PWM (RPWM) approaches could solve this issue by creating continuous harmonic profile instead of discrete clusters of dominant harmonics. Insufficient filtering at dc link results in the amplitude distortion of the input dc voltage to the VSI and has the most significant impact on the spectral errors (difference between theoretical and practical spectra). It is obvious that the sprawling effect of RPWM undoubtedly influenced by input fluctuation and the discrete harmonic clusters may reappear. The influence of dc link fluctuation on harmonics and their spreading effect in the VSI remains invalidated. A case study is done with four different filter capacitor values in this paper and results are compared with the constant dc input operation. This paper also proposes an ingenious RPWM, a ripple dosed sinusoidal referencerandom carrier PWM (RDSRRCPWM), which has the innate capacity of suppressing the effect of input fluctuation in the output than the other modern PWM methods. MATLAB based simulation study reveals the fundamental component, total harmonic distortion (THD) and harmonic spread factor (HSF) for various modulation indices. The non-ideal dc link is managed well with the developed RDSRRCPWM applied to the VSI and tested in a proto type VSI using the field programmable gate array (FPGA).

Brain Metastases from Cholangiocarcinoma: a First Case Series in Thailand

Chindaprasirt, Jarin,Sookprasert, Aumkhae,Sawanyawisuth, Kittisak,Limpawattana, Panita,Tiamkao, Somsak Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.5

Background: Brain metastasis from cholangiocarcinoma (CCA) is a rare but fatal event. To the best of our knowledge, only few cases have been reported. Herein, we report the incident rate and a first case series of brain metastases from CCA. Methods: Between January 2006 and December 2010 5,164 patients were treated at Srinagarind hospital, Khon Kaen University; of those, 8 patients developed brain metastasis. Here we reviewed clinical data and survival times. Results: The incident rate of brain metastases from CCA was 0.15%. The median age of the patients was 60 years. Tumor subtypes were intrahepatic in 6 and hilar in 2 patients. All suffered from symptoms related to brain metastasis. Three patients were treated with whole-brain radiation therapy (WBRT), one of whom also underwent surgery. The median survival after the diagnosis of brain metastasis was 9.5 weeks (1-28 weeks). The longest survival observed in a patient in RPA class I with two brain lesions and received WBRT. Conclusion: This is a first case series of brain metastases from CCA with the incident rate of 0.15%. It is rare and associated with short survival time.

Sarcopenia in Cancer Patients

Chindapasirt, Jarin Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.18

Sarcopenia, characterized by a decline of skeletal muscle plus low muscle strength and/or physical performance, has emerged to be an important prognostic factor for advanced cancer patients. It is associated with poor performance status, toxicity from chemotherapy, and shorter time of tumor control. There is limited data about sarcopenia in cancer patients and associated factors. Moreover, the knowledge about the changes of muscle mass during chemotherapy and its impact to response and toxicity to chemotherapy is still lacking. This review aimed to provide understanding about sarcopenia and to emphasize its importance to cancer treatment.

Clinical Manifestations of Eosinophilic Meningitis Due to Infection with Angiostrongylus cantonensis in Children

Kittisak Sawanyawisuth,Jarin Chindaprasirt,Vichai Senthong,Panita Limpawattana,Narong Auvichayapat,Sompon Tassniyom,Verajit Chotmongkol,Wanchai Maleewong,Pewpan M. Intapan 대한기생충학열대의학회 2013 The Korean Journal of Parasitology Vol.51 No.6

Modified high-flow nasal cannula for children with respiratory distress

Itdhiamornkulchai Sarocha,Preutthipan Aroonwan,Vaewpanich Jarin,Anantasit Nattachai 대한소아청소년과학회 2022 Clinical and Experimental Pediatrics (CEP) Vol.65 No.3

Background: High-flow nasal cannula (HFNC) is a noninvasive respiratory support that provides the optimum flow of an air-oxygen mixture. Several studies demonstrated its usefulness and good safety profile for treating pediatric respiratory distress patients. However, the cost of the commercial HFNC is high; therefore, the modified high-flow nasal cannula was developed.Purpose: This study aimed to compare the effectiveness, safety, and nurses’ satisfaction of the modified system versus the standard commercial HFNC.Methods: This prospective comparative study was performed in a tertiary care hospital. We recruited children aged 1 month to 5 years who developed acute respiratory distress and were admitted to the pediatric intensive care unit. Patients were assigned to 2 groups (modified vs. commercial). The effectiveness and safety assessments included vital signs, respiratory scores, intubation rate, adverse events, and nurses’ satisfaction.Results: A total of 74 patients were treated with HFNC. Thirty- nine patients were assigned to the modified group, while the remaining 35 patients were in the commercial group. Intubation rate and adverse events did not differ significantly between the 2 groups. However, the commercial group had higher nurses’ satisfaction scores than the modified group.Conclusion: Our findings suggest that our low-cost modified HFNC could be a useful respiratory support option for younger children with acute respiratory distress, especially in hospital settings with financial constraints.

Thailand Dyspepsia Guidelines: 2018

Rapat Pittayanon,Somchai Leelakusolvong,Ratha-korn Vilaichone,Jarin Rojborwonwitaya,Sombat Treeprasertsuk,Pisaln Mairiang,Supphamat Chirnaksorn,Taned Chitapanarux,Uayporn Kaosombatwattana,Jaksin Sotti 대한소화기 기능성질환∙운동학회 2019 Journal of Neurogastroenterology and Motility (JNM Vol.25 No.1

The management of dyspepsia in limited-resource areas has not been established. In 2017, key opinion leaders throughout Thailand gathered to review and evaluate the current clinical evidence regarding dyspepsia and to develop consensus statements, rationales, levels of evidence, and grades of recommendation for dyspepsia management in daily clinical practice based on the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach. This guideline is mainly focused on the following 4 topics: (1) evaluation of patients with dyspepsia, (2) management, (3) special issues (overlapping gastroesophageal reflux disease/irritable bowel syndrome and non-steroidal anti-inflammatory drug/aspirin use), and (4) long-term follow-up and management to provide guidance for physicians in Thailand and other limited-resource areas managing such patients.

Predictors for Obesity Hypoventilation Syndrome in Thai Population

sarunya saeseow,Kittisak Sawanyawisuth,Sittichai khamsai,Panita Limpawattana,Jarin Chindaprasirt,Berajit Chotmonkol,Songkwan Silaruks,Vichai Senthong,paiboon chattkul 대한수면학회 2019 sleep medicine research Vol.10 No.1

Background and ObjectiveaaObesity Hypoventilation Syndrome (OHS), is a condition with high morbidity and mortality. Body Mass Index (BMI) of more than 30 kg/m2 is used, to diagnose OHS. As BMI for obesity for Thais is 25 kg/m2, BMI more than 25 kg/m2 is used in our institution, to diagnose OHS. The purpose of this study was to evaluate if BMI of 25 kg/m2 is appropriate crite- rion for OHS in Thai patients. MethodsaaThis study was a retrospective study conducted at Khon Kaen University. Inclusion criteria were adult patients diagnosed with OHS in 2016. Patients diagnosed with obstructive sleep apnea (OSA), were randomly selected as control subjects. The ratio of OHS:OSA, was 1:4. Clinical factors associated with OHS were examined, using multivariate logistic regression analysis. ResultsaaDuring the study period, there were 25 OHS and 108 OSA patients. The OHS group had a significantly higher average BMI (48.9 kg/m2 vs. 29.2 kg/m2), than the OSA group. The OHS group also had higher proportions of patients with pulmonary hypertension (50% vs. 2%), and heart failure (76% vs. 6.5%). There were two independent predictors for OHS, including BMI and serum bicarbonate levels. Adjusted odds ratio (95% CI) for each of these factors was 1.08 (1.01, 1.17) and 1.96 (1.15, 3.34), respectively. Body mass index greater than 25 kg/m2 and serum bicar- bonate more than 25 mEq/L, yielded 100% sensitivity for OHS. ConclusionsaaAppropriate diagnostic criteria for OHS for the Thai population, may be different from those for populations in Western countries.