Cases Of Malfunction Research Articles

Abstract 149: Double Sequential External Defibrillation in Refractory Ventricular Fibrillation: The Dose VF Pilot Randomized Controlled Trial

Background: Despite significant advances in resuscitation efforts, there are some patients who remain in ventricular fibrillation (VF) after multiple defibrillation attempts during out-of-hospital cardiac arrest (OHCA). Double sequential external defibrillation (DSED) and vector change defibrillation (VC) have been proposed as alternate therapeutic strategies for OHCA patients in shock-refractory VF. Objective: To determine the feasibility, safety and sample size required for a larger, multicentered, 3-arm, cluster randomized controlled trial (RCT) with 2 crossovers comparing DSED or VC to standard defibrillation (control group) for OHCA patients presenting in shock-refractory VF. Methods: We conducted a pilot cluster randomized controlled trial with crossover including all consecutive treated adult OHCA patients who presented in VF and received a minimum of three successive shocks. In addition to standard cardiac arrest care, each EMS agency was randomly assigned to provide standard defibrillation (control), DSED, or VC, followed by crossover to an alternate defibrillation strategy after 6 months. Results: Prior to the launch of the trial, 2,500 paramedics received in-person training in the techniques of DSED and VC defibrillation using a combination of didactic, video and simulated scenarios. Between March 2018 and June 2019, 113 patients were enrolled in 4 Canadian EMS agencies, with zero missed cases. Monthly enrollment varied from 1 to 6 cases per agency. With respect to feasibility, 96% of cases were compliant with the study protocol, and only five (4.4%) cases received a defibrillation strategy that differed from the allocation schedule. There were no reported cases of defibrillator malfunction, no concerns expressed by paramedics, patients, families, or ED staff about the trial, and no reported cases of skin burns or difficulty with pad placement. Conclusions: Findings from our pilot implementation trial suggest the DOSE VF protocol is feasible and safe. The results of this internal pilot trial will allow us to calculate a sample size for a definitive multicenter cluster RCT with crossovers to determine if these alternate defibrillation strategies for OHCA shock refractory VF will impact patient-centered, clinical outcomes.

POLICY CHANGES AFTER A RARE COMPLICATION OF EBUS-TBNA: EXPECTORATION OF A METAL SHEATH

SESSION TITLE: Wednesday Fellows Case Report Posters SESSION TYPE: Fellow Case Report Posters PRESENTED ON: 10/23/2019 09:45 AM - 10:45 AM INTRODUCTION: Since the first application of ultrasound in the airway in 1992, endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) has become a widely-used effective and minimally invasive method of diagnosing and staging mediastinal lymph nodes and masses. The procedure is generally well-tolerated. Major complications involving EBUS-TBNA are low, but there are increasing reports of procedure-related complications. We present a case of a retained inner metal sheath of the Olympus EBUS-TNBA needle catheter after instrument malfunction. CASE PRESENTATION: A 47-year old male was referred for EBUS-TBNA for worsening cough for the past year. A computed tomography of the chest revealed bilateral hilar and mediastinal adenopathy concerning for sarcoidosis. Endobronchial ultrasound was used to assist with guiding biopsy of hilar and mediastinal regions. An EBUS-TBNA was performed using an Olympus EBUS-TBNA 22-gauge needle. Specimens were obtained from the 7, 10R, and 11L lymph nodes. During sampling of the left interlobar lymph node, there was unexpected resistance when attempting to advance the needle. The needle was repositioned and the lymph node was aspirated without further difficulty. Rapid On-Site Evaluation revealed non-necrotic granulomatous tissue of the subcarinal lymph node. The tracheobronchial tree was examined to at least the first sub-segmental level. Bronchial mucosa and anatomy were normal with no endobronchial lesions, secretions or foreign bodies visualized. The patient tolerated the procedure well and was discharged. On his way home, the patient reported expectorating “a metal sheath.” The Olympus EBUS-TBNA needle catheter was examined and it was discovered that the inner metal sheath located in the distal plastic sheath of the needle catheter was missing which corresponded to the inner metal sheath of the needle catheter. The patient did not have any complications from this event. DISCUSSION: EBUS-TBNA is the preferred modality in the diagnosis and staging of mediastinal lymph nodes and masses with high specificity and sensitivity. Serious EBUS complication rates range from 0.15-0.16%, including mediastinal abscess, empyema, needle fracture, and hemo-pneumomediastinum, Literature review showed a single case report of an expectorated “stent” from EBUS-TBNA. Due to the malfunction of the needle catheter, a root-cause analysis was performed and protocol changes were subsequently made to our institutional policy. CONCLUSIONS: EBUS-TBNA is accepted as a safe, well-tolerated procedure with low major complication rates. Our case is only the second reported case of assembly malfunction causing unexpected deployment of the inner metal sheath into the bronchi. While no serious complications resulted from this, providers performing EBUS-TBNA need to be aware of this potential device malfunction. We recommend routine inspection of the needle apparatus pre- and post-procedure. Reference #1: Caglayan BYilmaz A, et al. Complications of Convex-Probe Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration: A Multi-Center Retrospective Study. Respir Care. 2016 Feb;61(2):243-8. Reference #2: Zamora FD, Moughrabieh A, et al. An Expectorated "Stent": An Unexpected Complication of EBUS-TBNA. J Bronchology Interv Pulmonol. 2017 Jul;24(3):250-252. Reference #3: Asano F, Aoe M, Ohsaki Y, et al. Complications associated with endobronchial ultrasound-guided transbronchial needle aspiration: a nationwide survey by the Japan Society for Respiratory Endoscopy. Respir Res. 2013;14:50 DISCLOSURES: No relevant relationships by Michael Ayers, source=Web Response No relevant relationships by Ngoc-Tram Ha, source=Web Response No relevant relationships by Cynthia Tsai, source=Web Response

Clinical profile and outcome of antibiotic lock therapy for bloodstream infections in pediatric hematology/oncology patients in a tertiary care hospital, Karachi, Pakistan.

BackgroundIntravascular catheters are susceptible to infections, thus requiring catheter removal and leading to increased morbidity and costs. Antibiotic lock therapy (ALT) is a therapeutic technique that is used to salvage the catheter. The aim of this study was to evaluate the outcome of antibiotic lock therapy in bloodstream infections in pediatric hematology/oncology patients in a tertiary care hospital, Karachi.MethodsA retrospective review was performed from January 2013 to December 2017 of pediatric hematology/oncology patients with bloodstream infections and who received ALT at Aga Khan University Hospital. All cases of polymicrobial infections, catheter removal, or malfunction before the completion of ALT were excluded. Descriptive analysis was carried out using SPSS version 20.ResultsA total of nine hematology/oncology patients were eligible. The catheter was salvaged in 7/9 (77.8%) children, and in 2/9 (22.2%) cases, catheter was removed because of persistent bacteremia. The most common organism isolated was Staphylococcus non-aureus species (33.3%). Relapse with a similar pathogen occurred in 2 (22.2%) patients and 2 (22.2%) of them developed an exit-site infection.ConclusionIn our experience, in almost two thirds of the cases, the catheter was salvaged, but disappointingly, relapses were high when the infection was due to Staphylococcus spp. Although this is a small study, our results show that ALT can be a potential safe adjunctive strategy to treat catheter-related bloodstream infections (CRBSI). However, we need larger prospective studies to test the safety and efficacy of ALT to develop specific ALT recommendations and guidelines particularly in children.

Robust Kalman Filter Based Estimation of AUV Dynamics in the Presence Of Sensor Faults

Abstract This article is basically focused on application of the Robust Kalman Filter (RKF) algorithm to the estimation of high speed an autonomous underwater vehicle (AUV) dynamics. In the normal operation conditions of AUV, conventional Kalman filter gives sufficiently good estimation results. However, if the measurements are not reliable because of any kind of malfunction in the estimation system, Kalman Filter (KF) gives inaccurate results and diverges by time. This study, introduces Robust Kalman Filter algorithm with the filter gain correction for the case of measurement malfunctions. By the use of defined variables named as measurement noise scale factor, the faulty measurements are taken into the consideration with a small weight and the estimations are corrected without affecting the characteristic of the accurate ones. In the presented RUKF, the filter gain correction is performed only in the case of malfunctions in the measurement system and in all other cases procedure is run optimally with regular KF.

Diagnosis of Combined Cycle Power Plant Based on Thermoeconomic Analysis: A Computer Simulation Study

In this study, diagnosis of a 300-MW combined cycle power plant under faulty conditions was performed using a thermoeconomic method called modified productive structure analysis. The malfunction and dysfunction, unit cost of irreversibility and lost cost flow rate for each component were calculated for the cases of pre-fixed malfunction and the reference conditions. A commercial simulating software, GateCycleTM (version 6.1.2), was used to estimate the thermodynamic properties under faulty conditions. The relative malfunction (RMF) and the relative difference in the lost cost flow rate between real operation and reference conditions (RDLC) were found to be effective indicators for the identification of faulty components. Simulation results revealed that 0.5% degradation in the isentropic efficiency of air compressor, 2% in gas turbine, 2% in steam turbine and 2% degradation in energy loss in heat exchangers can be identified. Multi-fault scenarios that can be detected by the indicators were also considered. Additional lost exergy due to these types of faulty components, that can be detected by RMF or RDLC, is less than 5% of the exergy lost in the components in the normal condition.

Clinical decision support alert malfunctions: analysis and empirically derived taxonomy.

ObjectiveTo develop an empirically derived taxonomy of clinical decision support (CDS) alert malfunctions.Materials and MethodsWe identified CDS alert malfunctions using a mix of qualitative and quantitative methods: (1) site visits with interviews of chief medical informatics officers, CDS developers, clinical leaders, and CDS end users; (2) surveys of chief medical informatics officers; (3) analysis of CDS firing rates; and (4) analysis of CDS overrides. We used a multi-round, manual, iterative card sort to develop a multi-axial, empirically derived taxonomy of CDS malfunctions.ResultsWe analyzed 68 CDS alert malfunction cases from 14 sites across the United States with diverse electronic health record systems. Four primary axes emerged: the cause of the malfunction, its mode of discovery, when it began, and how it affected rule firing. Build errors, conceptualization errors, and the introduction of new concepts or terms were the most frequent causes. User reports were the predominant mode of discovery. Many malfunctions within our database caused rules to fire for patients for whom they should not have (false positives), but the reverse (false negatives) was also common.DiscussionAcross organizations and electronic health record systems, similar malfunction patterns recurred. Challenges included updates to code sets and values, software issues at the time of system upgrades, difficulties with migration of CDS content between computing environments, and the challenge of correctly conceptualizing and building CDS.ConclusionCDS alert malfunctions are frequent. The empirically derived taxonomy formalizes the common recurring issues that cause these malfunctions, helping CDS developers anticipate and prevent CDS malfunctions before they occur or detect and resolve them expediently.

PEG Push versus Pull Technique: Patient Safety at Stake

There are 2 commonly used techniques for Peroral Endoscopic Gastrostomy (PEG) placement, the push technique and the pull technique. We report a case of equipment malfunction using the push method (Sachs-Vine). A 50 year old female with a history of metastatic endocervical adenocarcinoma was admitted for small bowel obstruction. She was also found to have new abdominal wall and omental lesions on CT. PEG tube placement was scheduled for decompression. After the endoscopic evaluation, the location of the incision was identified by transillumination as well as finger indentation and ballottement. Through sterile methods, a scout needle was used to define the tract. A trocar was introduced through the gastric wall. A guide string was then introduced and snared. The endoscope was removed with the wire in place. Gastrostomy tube was fed over the wire until the tip reached the abdominal wall. As the tubing was being pulled through and the dilator reached the level of the abdominal wall, it broke causing the bumper end to become lodged in the back of the oropharynx. This caused airway compromise and transient desaturation down to 60%. The broken tubing was located and removed with rat tooth forceps and a new PEG placed successfully using the Pull method (Ponsky). There are multiple percutaneous techniques used for PEG tube placement including the Pull method, Push method, introducer (Russell) method, and the Versa which uses T-fasteners. With the pull method, the tube is tapered at the end with a loop that is connected and it is pulled down and out through the abdominal wall with the wire. With the Push method, the tube is fed over the wire, this requires the tube to be much longer and is made of two pieces connected together with a small dilator. Both the Push and Pull method are used regularly with no significant difference in complications reported. Although this may be a rare complication, considering the already deteriorated state of many patients getting PEG tube placement and the possible deadly consequences of this complication, choosing the Pull method over the Push method is something to be considered especially in patients with abdominal wall abnormalities.

2-Year Outcomes After Transcatheter Mitral Valve Replacement

ObjectivesThis study sought to determine late (2-year) outcomes following transcatheter mitral valve replacement (TMVR) with the FORTIS valve (Edwards Lifesciences, Irvine, California). BackgroundNo data exist on long-term clinical outcomes following TMVR in patients with severe native mitral regurgitation (MR). MethodsThis multicenter registry included consecutive patients with severe MR who underwent TMVR with the FORTIS valve under a compassionate clinical use program. Clinical and echocardiographic data were collected at baseline, 30-day, and 1- and 2-year follow-up. ResultsThirteen patients (71 ± 8 years, 10 men, logistic European System for Cardiac Operative Risk Evaluation score = 23.7 ± 12.1%) with severe MR were included. MR was of ischemic origin in most (76.9%) patients, and the mean left ventricular ejection fraction was 34 ± 9%. Technical success was achieved in 10 patients (76.9%), and 5 patients (38.5%) died within the 30 days following the procedure. At 30-day follow-up, mean transmitral gradient was 3 ± 1 mm Hg, and there were no cases of moderate-severe residual MR or left ventricular outflow tract obstruction. Two patients died during the follow-up period due to terminal heart failure, leading to an all-cause mortality rate of 54% at 2-year follow-up. At 2-year follow-up, all patients but 1 were in New York Heart Association functional class II, and there were no cases of valve malfunction (increasing gradients or MR recurrence). Computed tomography exams performed at 2-year follow-up in 3 patients showed no valve prosthesis fractures or displacement. ConclusionsTMVR with the FORTIS valve was feasible. MR reduction after TMVR was maintained at 2-year follow-up and no late device-related events were observed.

Frequency of pacemaker malfunction associated with monopolar electrosurgery during pulse generator replacement or upgrade surgery

The aim of this study is to investigate the frequency of electrosurgery-related pacemaker malfunction. A retrospective study was conducted to investigate electrosurgery-related pacemaker malfunction in consecutive patients undergoing pulse generator (PG) replacement or upgrade from two large hospitals in Minneapolis, MN between January 2011 and January 2014. The occurrence of this pacemaker malfunction was then studied by using MAUDE database for all four major device vendors. A total of 1398 consecutive patients from 2 large tertiary referral centers in Minneapolis, MN undergoing PG replacement or upgrade surgery were retrospectively studied. Four patients (0.3% of all patients), all with pacemakers from St Jude Medical (2.8%, 4 of 142) had output failure or inappropriately low pacing rate below 30bpm during electrosurgery, despite being programmed in an asynchronous mode. During the same period, 1174 cases of pacemaker malfunctions were reported on the same models in MAUDE database, 37 of which (3.2%) were electrosurgery-related. Twenty-four cases (65%) had output failure or inappropriate low pacing rate. The distribution of adverse events was loss of pacing (59.5%), reversion to backup pacing (32.4%), inappropriate low pacing rate (5.4%), and ventricular fibrillation (2.7%). The majority of these (78.5%) occurred during PG replacement at ERI or upgrade surgery. No electrosurgery-related malfunction was found in MAUDE database on 862 pacemaker malfunction cases during the same period from other vendors. Electrosurgery during PG replacement or upgrade surgery can trigger output failure or inappropriate low pacing rate in certain models of modern pacemakers. Cautions should be taken for pacemaker-dependent patients.

Premature Consolidation with Resultant Implant Failure Using PRECICE Femoral Nail Lengthening: A Case Report.

Posttraumatic limb-length discrepancies secondary to femoral malunion can be treated with a variety of external or internal lengthening systems. The PRECICE nail is an intramedullary device featuring an external remote control to activate a magnetically driven internal distraction mechanism. While this intramedullary system avoids the soft-tissue complications common to external lengthening, it has unique mechanisms of failure that are difficult to diagnose and that require a systematic approach. In this case report, we describe a failure to lengthen with the PRECICE femoral nail and the subsequent steps taken to determine the root cause. We believe that this failure represents the first reported case of malfunction of the PRECICE femoral nail distraction mechanism since its 2013 redesign.

Cerebrospinal fluid shunt malfunction not associated with ventricular enlargement. A case report and literature review

Substantiation of the shunt failure diagnosis and subsequent consideration of indications for surgical elimination of the malfunction is a laborious and challenging process. Identification of a malfunction in doubtful cases requires, in addition to standard examinations, extra diagnostic procedures, which may delay making a decision for several weeks to several months. The article describes a case of mechanical CSF shunt malfunction (breakage and failure of a peritoneal catheter in a 7-year-old girl) with intracranial hypertension symptoms, but without typical enlargement of the brain ventricles. According to the medical history, congenital hydrocephalus in the child was accompanied by an inflammatory process of bacterial and viral etiology. The absence of brain ventricle enlargement was shown not to exclude a probability of shunt malfunction. In this case, a specific phenomenon, an intraparenchymatous cerebrospinal fluid "lake" surrounding a ventricular catheter, was observed. Shunting recovery did not lead to a significant reduction in the phenomenon size. Causes underlying this phenomenon require further investigation.

Metrological Aspects of Peak Expiratory Flow-Meters After Prolonged Use

SESSION TITLE: Pulmonary Physiology Posters SESSION TYPE: Original Investigation Poster PRESENTED ON: Wednesday, October 28, 2015 at 01:30 PM - 02:30 PM PURPOSE: There is scant information about the accuracy and reproducibility of the readings after prolonged use of mechanical peak expiratory flow-meters (PEF-meters) for monitoring of large airway function, both for clinical research purposes and routine management of asthma. The aim of this study was to test the reliability of peak expiratory flow (PEF) values measured with PEF-meters that have been used a prolonged period (two devices of five different types) using a clinical calibration procedure. METHODS: Five types of adult PEF-meters were tested before (new devices) and after a period of use of several years: Assess-Healthscan (8 years), Mini-Wright-Clement Clarke (7 years), Vitalograph-Vitalograph (5 years), PocketPeak-Ferraris (3 years) and Truzone-Monaghan (2 years). Comparisons with values from a Lily pneumotachograph (PT) (Pneumoscreen - E. Jaeger, Germany) were performed. In the first series of comparisons every PEF-meter was connected downstream in series with the PT and the same subject performed 40 partial to maximal forced expiratory maneuvers (MFEM), during a period of 160 minutes. In the second series of comparisons 30 adult patients performed randomized MFEM on each PEF-meter and on the PT, during a period of 30 minutes. RESULTS: ANOVA analysis revealed some differences in the accuracy of the different PEF-meters before and after a prolonged using period: the closest agreements to the PT before were Truzone and Mini-Wright, and after Assess and Mini-Wright. The best reproducibility for the before and after using period values was obtained in Assess and PocketPeak. CONCLUSIONS: The period for using of PEF-meters in a good conditions is much longer than that usually accepted and the replacement of PEF-meters should be restricted to cases of physical damage or obvious malfunction. Our results don't involve in any way the brand name of PEF-meters because we have the possibility to assess only two devices from every PEF-meters type and the number is statistically too small to characterise the brand name of PEF-meter type. CLINICAL IMPLICATIONS: These findings proved that PEF-meters can be used safely a longer period than expected, if their maintenance is flawless. DISCLOSURE: The following authors have nothing to disclose: Paraschiva Postolache, Octavian Petrescu, Floarea Mimi Nitu, Roxana Maria Nemes No Product/Research Disclosure Information

A prospective evaluation on external jugular vein cut-down approach for TIVAD implantation.

BackgroundTotally implantable venous access devices can be implanted both by percutaneous approaches and by surgical approaches with cephalic vein or external jugular vein cut-down techniques that are related to low intraoperative complication rates. The authors report a prospective evaluation of 83 consecutive external jugular vein cut-down approaches for totally implantable venous access devices implantation.MethodsEighty three consecutive patients (28 M, 55 F, mean age 54.2) suffering from solid tumors (58) or hematologic diseases (25) were consecutively submitted to totally implantable venous access devices insertion through external jugular vein cut-down approach (75 on right side, 8 on left side).ResultsAll devices were surgically implanted; no instances of intraoperative complications were detected. After a minimum follow-up of 150 days, only one case of wound hematoma and one case of device malfunction due to incorrect catheter angulation were noted.Postoperative patient satisfaction was evaluated by the use of specific questionnaire that demonstrated a good satisfaction and compliance (92.8 %) of patients with implanted devices.ConclusionsDespite the lack of controlled studies comparing external jugular vein cut-down approach vs other approaches, this approach should be considered as a tool for long-term central vein catheters positioning, both as an alternative and for primary approach.

The Additive Value of Radionuclide Shuntogram to Computed Tomography in Evaluation of CSF Shunts

Background: Placement of cerebrospinal fluid diversions or shunts, is a common neurosurgical procedure indicated for a wide spectrum of conditions impeding the normal flow of cerebrospinal fluid (CSF). The most common systems employed are ventriculoperitoneal, ventriculoatrial and lumboperitoneal shunts. Management of patients with surgically treated hydrocephalus may be challenging, as the clinical presentation of a malfunctioning shunt is often nonspecific, especially in young children. Moreover, conventional radiological examinations, such as shunt series, cerebral ultrasound or CT scans, are sometimes equivocal in diagnosing cases of shunt malfunction, also in determining the site of obstruction. Thus, numerous procedures have been proposed to ascertain shunt function, and localize site of obstruction. Injection of contrast media and radionuclide directly into the shunt device into the lateral ventricles is one of the most common techniques employed, to assist in evaluating shunt function. Patients and methods: A prospective study of 20 patients with suspected shunt malfunction. Their age, sex distribution, clinical presentations, and causes of hydrocephalus were recorded. We evaluated shunt function using CT brain and Radionuclide shuntogram. Shunt malfunction was evaluated by using CT-Brain only, Shuntogram only, and by combining both techniques. We evaluated these techniques regarding their results, dividing them into positive and negative cases, and establishing true and false results by following clinical progression and operative findings. After calculating sensitivity, specificity, predictive values and accuracy of the individual techniques, we determined the added value of combining shuntogram to CT-Brain in diagnosing shunt malfunction. Results: Patients were verified into 15 males (75%) and 5 females (25%), the average age was 5.8 years. In evaluation using CT brain only, the results were 19 true positive results (95%), one case with false positive result (5%) and no negative cases (100% sensitivity and 95% accuracy). In Radionuclide shuntogram, results were: 18 true positive studies (90%); one true negative study (5%), one false negative study (5%) and no false positive results (94.73% sensitivity and 95% accuracy). The combined results of CT brain and Radionuclide shuntogram were 18 true positive cases (where both tests showed positive obstruction), no negative cases, and 2 cases with conflicting results (100% sensitivity and 100% accuracy). The sites of true positive cases verified into 13 distal blocks (65%), 5 proximal blocks (25%) and one case with combined proximal and distal blocks (5%). Conclusion: In adding shuntogram to CT-Brain, the sensitivity and accuracy for diagnosis of shunt obstruction increased. Its advantage over other methods lies in not only diagnosing shunt malfunction but also localizing and qualifying the malfunction, thus aiding the neurosurgeon in targeting the part of the shunt requiring revision. Because of its limitation (time and costs involved in shuntogram technique), it's not used routinely in clinical practice. But, when used in selected cases, it can help avoid unnecessary surgical intervention.

Benefits of brain magnetic resonance imaging over computed tomography in children requiring emergency evaluation of ventriculoperitoneal shunt malfunction: reducing lifetime attributable risk of cancer.

The rapid growth of computed tomography (CT) has resulted in increased concerns of ionizing radiation exposure and its subsequent risk of cancer development. We evaluated the impact of a new protocol using rapid sequence magnetic resonance imaging (rsMRI) instead of CT in children presenting with possible ventriculoperitoneal shunt (VPS) malfunction to promote patient safety. This is a retrospective case series of pediatric patients who received a neuroimaging study for emergency evaluation of possible VPS malfunction at New York University's Tisch Hospital Emergency Department between January 2010 and July 2011. Radiology Charge Master was queried to identify the patient database. The trend in the use of rsMRI and CT was calculated for 3 patient age groups and compared across 3 chronological intervals. The effective dose of ionizing radiation per CT scan was calculated using the CT dose index and dose-length product for each patient. Total of 365 patients with the mean age of 8.87 years received either rsMRI or CT study during the study period. One hundred forty-four of these patients required the imaging studies because of VPS malfunction. Overall, 62% of all VPS malfunction cases used rsMRI instead of CT. The ratio of the number of patients receiving rsMRI divided by CT studies has progressively increased from 1.4:1 to 2.1:1 over 3 chronologic periods. Children with VPS are subject to multiple neuroimaging studies throughout their lifetime. Rapid sequence MRI is an effective alternative to CT while providing no ionizing radiation exposure or risk of developing radiation-induced cancer.

Post-traumatic fractured ventriculo-peritoneal shunt presenting as shunt failure

Shunt malfunction is very common in neurosurgical day-to-day practice. We report for the first time a case of shunt malfunction resulting from breakage of the ventriculo-peritoneal shunt system following a fall and subsequent trauma to the head.

Evaluation of Some Heavy Metal Contamination in Malva parviflora L. Plant and Soil Obtained from Gardens of College of Agriculture-University of Baghdad

Heavy metals are given significant interest throughout the globe due to their toxic, mutagenic effects even at very low concentrations. Several cases of human diseases, disorders, malfunction and malformation of organs due to metal toxicity have been reported. Reports indicate that lead, cadmium and chromium may cause a wide variety of changes in biological systems, even at very low concentrations. Samples of different parts of Malva parviflora L. (leaves, stems and roots) and associated soils collected with increasing distance of 5, 25, 50, 100m from the gardens surrounding the chemistry labs in college of agriculture university of Baghdad in Abu Ghraib region in Baghdad. The parts of Malva parviflora L. (leaves, stems and roots) and the soil samples at depth 0-20cm were analyzed by atomic absorption spectroscopy after chemical treatment using acid digestion procedures, the pH and the electric conductivity of the soil were also measured. The concentrations Pd, Cr and Cd in the soil and plant of Malva parviflora L. were compared with the maximum allowable limits in different countries and they were beyond the maximum allowable limits in the plant samples but in the soil samples they were below the maximum allowable limits in the case of cadmium and below but very close to the maximum allowable limits of lead and chromium.

변속기 시뮬레이터를 이용한 진단 및 안전작동 알고리즘 분석

As the digital control technologies in automotive industry have advanced, electronic control units(ECUs) play a key-role to improve system performance. Transmission control unit(TCU) is a shifting controller for automatic transmission of which major functions are to determine the shift and manage the shifting process considering the various sensor signal on transmission and driver's commands. As with any ECU in vehicle, TCU performs complex algorithms such as shift control, diagnostic and failsafe functions. However, firmware design analysis is hardly possible by the reverse engineering due to code protection. Transmission simulator is a hardware-in-the-loop simulator which enables TCU to work in normal mode by simulating the electrical signal of TCU interface. In this research, diagnosis and failsafe algorithm implemented on commercialized TCU is analyzed by using the transmission simulator that is developed for wheel loader construction vehicle. This paper gives various experimental results on the proportional solenoid current trajectories for different operating modes, error detection criterion and limphome mode gears for all the possible cases of clutch malfunction. The derived results for conventional TCU can be applied to the development of inherent TCU algorithms and the transmission simulator can also be utilized for the test of TCU to be developed.

Replacement of a String Jejunostomy if the Suture is Lost

The aim of the study was to present the first case of replacement of a string jejunostomy with an enteroscopic percutaneous technique after the string was lost. The replaceable string jejunostomy is a well-established method for the enteral feeding in patients where the swallowing process is impaired and gastroesophageal reflux impedes the option of a gastrostomy. In the frequent case of obstruction, rupture or malfunction of the jejunostomy, it is easily replaced in an outpatient setting without anesthesia, with the help of the string that holds the tip of the feeding tube in place. In our case the string was lost. The jejunostomy was replaced with a fully percutaneous technique with the help of a pediatric cystoscope. This technique is well practicable and obviated the need for a laparotomy in a polymorbid patient. The technique seems promising, but we report an anecdotal case description. Further experience is needed to investigate its safety.

Multi-sensor hybrid fusion algorithm based on adaptive square-root cubature Kalman filter

In the normal operation condition, a conventional square-root cubature Kalman filter (SRCKF) gives sufficiently good estimation results. However, if the measurements are not reliable, the SRCKF may give inaccurate results and diverges by time. This study introduces an adaptive SRCKF algorithm with the filter gain correction for the case of measurement malfunctions. By proposing a switching criterion, an optimal filter is selected from the adaptive and conventional SRCKF according to the measurement quality. A subsystem soft fault detection algorithm is built with the filter residual. Utilizing a clear subsystem fault coefficient, the faulty subsystem is isolated as a result of the system reconstruction. In order to improve the performance of the multi-sensor system, a hybrid fusion algorithm is presented based on the adaptive SRCKF. The state and error covariance matrix are also predicted by the priori fusion estimates, and are updated by the predicted and estimated information of subsystems. The proposed algorithms were applied to the vessel dynamic positioning system simulation. They were compared with normal SRCKF and local estimation weighted fusion algorithm. The simulation results show that the presented adaptive SRCKF improves the robustness of subsystem filtering, and the hybrid fusion algorithm has the better performance. The simulation verifies the effectiveness of the proposed algorithms.