Mechanism of degradation of AgCl coating on biopotential sensors

AgCl coated Ag foil has been widely used as the biopotential sensor to diagnose problems of the human heart. Evidence shows that quality of AgCl on the electrode could experience degradation during the process of long-term monitoring for irregular activities of the heart. To study the degradation of AgCl/Ag electrode, new and used electrodes were collected. Electrochemical tests such as open-circuit potential (OCP), cathodic stripping, electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), and X-ray mapping of elemental distribution were applied to understand the electrochemical properties of the sensors during the progress of degradation. Results revealed that OCP values shift from positive potential of new sensor to negative potential of used sensor (OCP(new): +30 mV; OCP(used): -300 mV, p < 0.05) and a significant difference in impedance (Impedance(new): 3000 Omega; Impedance(used): 1 MOmega, p < 0.05). Ratio of the average AgCl thickness on good and bad eletrocardiographic (ECG or EKG) electrodes is 4.83 (p < 0.05). Simulated degradation by exposing the biosensor to deaerated sweat solution and by cathodic stripping of AgCl proposed that the degradation occurs by cathodic reduction of AgCl due to the presence of hydrogen ions in the low pH value of human sweat under deaerated condition.     

Eosinophilic heart disease with vasculitis: supported by HeartMate left ventricular assist device and heart transplantation

Eosinophilic heart disease is rarely seen in clinical practice. We report a patient with eosinophilic heart disease who presented with acute myocardial infarction and congestive heart failure. Because of lack of a donor organ and progressive deterioration of his general condition in spite of intraaortic balloon pumping, a left ventricular assist device (HeartMate 1000 IP; Thermo Cardiosystems Inc, Woburn, MA) was implanted before development of irreversible multiple organ failure and was followed by heart transplantation.     

Midterm result of custom-made iliac branch device for common iliac aneurysm with and without abdominal aortic aneurysm

Open in a separate window OBJECTIVESAlthough commercial iliac branch devices offer a new and valid endovascular approach to treating iliac aneurysm and effectively preserve antegrade flow of the internal iliac artery, their use may not be suited for all types of challenging anatomy, especially isolated common iliac artery aneurysm. Our custom-made iliac bifurcation device has a unique design and excludes both combined and isolated iliac branch aneurysm. This study validated the efficacy and safety of the custom device by comparing clinical outcomes between groups receiving commercial and custom devices.METHODSData of consecutive patients receiving iliac bifurcation device implantation for iliac aneurysm with or without concomitant endovascular repair for abdominal aortic aneurysm from January 2010 to May 2019 were reviewed.RESULTSIliac bifurcation device implantation with or without concomitant abdominal aortic aneurysm stent grafting was completed in 46 patients (commercial, n = 35; custom, n = 11). No significant differences were observed regarding postoperative complications, occlusion or endoleak. Comparisons of primary (80.8% vs 85.7%, P = 0.88) and secondary (86.5% vs 85.7%, P = 0.85) patency and freedom from reintervention (88.2% vs 100%, P = 0.33), all-cause mortality (78.6% vs 100%, P = 0.25) and aneurysm-related mortality (100% vs 100%, P = 1.00) also indicated no differences at a 5-year surveillance point. Furthermore, the iliac aneurysms of the groups displayed similar shrinkage 1 year after procedures.CONCLUSIONSFor iliac aneurysm, the novel custom-made iliac bifurcation device is an adaptable design not inferior to commercial devices with regard to postoperative complications, bridge occlusion, endoleak and short-term aneurysm remodelling. It provides an alternative for treatment, particularly when certain anatomic challenges are present.Clinical trial registration2018-07-050BC, 2017-01-023ACF.     

Power spectral analysis of finger plethysmographic waveform in patients with coronary artery disease and after coronary artery bypass graft surgery.

BACKGROUND: The aim of the present study was to assess the clinical significance of spectral analysis of plethysmographic waveform in patients with coronary artery disease (CAD) and after coronary artery bypass graft (CABG) surgery. METHODS AND RESULTS: The study group comprised 26 healthy subjects, 15 CAD patients, and 24 CAD patients after CABG. Finger plethysmographic waveforms from both right and left index fingers were recorded and analyzed using power spectral analysis. The total power of the right pulse was found to be higher than that of left pulse in the 3 groups of subjects. In CABG patients, the total power of both pulses was increased, the right-to-left ratio of bilateral total power was decreased, and the power of the harmonics of the right pulse shifted from high-frequency to low-frequency. The normalized power of the 4th harmonic of the left pulse and of the 3rd and 4th harmonics of right pulse decreased, whereas that of the 1st harmonic of right pulse increased in CABG patients. Several harmonics correlated significantly to some heart rate variability measures in both controls and CAD patients, but not in CABG patients. CONCLUSIONS: The increase in the total power of both pulses, the shift of the normalized power of harmonics of the right pulse from high- to low-frequency, and the decrease in the right-to-left ratio of the total power of both pulses are the 3 significant changes in the power spectra of the pulses in CAD patients after CABG. The plethysmographic waveform of normal controls and CAD patients may be modulated by the autonomic nervous system, and in CAD patients the CABG surgery may have diminished the effect of autonomic nervous modulation on the pulse waveforms.     

Quantitative evaluation of thrombosis by electrochemical methodology

Electrochemical reactions between blood and metal electrodes have been studied since 1928. Little is known about the actual current density induced during the reaction. In this study, an in situ continuous monitoring method was developed to detect the progress of thrombosis on an oxidized 316L stainless steel coil was deployed inside the artery. Three stages of current density were observed on a 316L wire passivated with polycrystalline oxide film. In contrast, no significant current density was detected for a wire passivated with amorphous oxide film. Results showed that this in situ electrochemical monitoring method is sensitive to the passivated film on the stainless steel coil and could provide efficient and reliable information on the control of thrombosis on cardiovascular devices.     

A Modified Ferguson Hemorrhoidectomy for Circumferential Prolapsed Hemorrhoids with Skin Tags

Purpose We describe a modification of the Ferguson hemorrhoidectomy for circumferential prolapsed hemorrhoids. This details the operative procedure and compares the results of other radical methods in patients with circumferential hemorrhoidal disease. Methods A total of 738 patients (mean age, 43 (range, 19–83) years) were treated with our modified Ferguson method under sedative analgesia between 1989 and 2004: 576 patients had Grade III and 162 patients had Grade IV hemorrhoids, and 131 patients also had a partial lateral internal sphincterotomy to correct anal hypertonia. Results Postoperative bleeding occurred in 16 patients, 3 of whom required surgical hemostasis. Fecal impaction occurred in 11 patients and wound complications in 6 patients. Thirty-two patients needed bladder catheterization because of acute urinary retention. The median follow-up was 13.2 months in our outpatient department. One patient developed mild gas incontinence, five developed anal stenosis, and three had an anal fissure. Only three patients had recurrent skin tags, which did not affect their quality of life. Conclusions Our modified Ferguson method represents a good choice for radical treatment of circumferential prolapsed hemorrhoids because it is easy to perform, has few complications, and provides satisfying results. Reprints are not available.     

Etiology of acute pancreatitis--a multi-center study in Taiwan

BACKGROUND/AIMS: Little is known about the etiology of acute pancreatitis in Taiwan. The aim of this study was to evaluate the current etiology of acute pancreatitis in Taiwan by a multi-center cooperative study. METHODOLOGY: Patients with acute pancreatitis were collected from 8 major leading hospitals located at northern, southern, middle and eastern Taiwan from July 1, 1998 to June 30, 2000. The diagnosis of acute pancreatitis was based on characteristic clinical signs and symptoms and three-fold elevation of serum amylase/lipase level or positive evidence in imaging studies. The etiology was attributed to alcohol, gallstones, hypertriglyceridemia, miscellaneous causes, and idiopathic causes. RESULTS: In total 1,193 patients with acute pancreatitis were identified. There were 852 (71.4%) men and 341 (28.6%) women with a mean age of 52.5 years, ranging from 9 to 100 years. Etiology was identified as alcohol in 423 (33.6%), gallstones in 407 (34.1%), hypertriglyceridemia in 147 (12.3%), miscellaneous causes in 109 (9.1%), and idiopathic causes in 107 (9.0%). Patients with alcohol-related acute pancreatitis were the youngest (mean age: 41.5 years), while those with gallstone pancreatitis were the eldest (mean age: 64.1 years) (p < 0.001). The predominant cause of acute pancreatitis in women is gallstones, while alcohol is the leading cause of acute pancreatitis in Taiwanese males. In northern Taiwan, gallstone is the major cause of acute pancreatitis, while alcohol is the predominant etiology in middle, southern, and eastern Taiwan. CONCLUSIONS: Alcohol has become the predominant cause of acute pancreatitis in Taiwan recently. Ecological and gender differences play important roles in the etiology of acute pancreatitis in Taiwan.