CSE Group Research Articles

Philips QT Interval Measurement Algorithms for Diagnostic, Ambulatory, and Patient Monitoring ECG Applications

Commonly used techniques for QT measurement that identify T wave end using amplitude thresholds or the tangent method are sensitive to baseline drift and to variations of terminal T wave shape. Such QT measurement techniques commonly underestimate or overestimate the "true" QT interval. To find the end of the T wave, the new Philips QT interval measurement algorithms use the distance from an ancillary line drawn from the peak of the T wave to a point beyond the expected inflection point at the end of the T wave. We have adapted and optimized modifications of this basic approach for use in three different ECG application areas: resting diagnostic, ambulatory Holter, and in-hospital patient monitoring. The Philips DXL resting diagnostic algorithm uses an alpha-trimming technique and a measure of central tendency to determine the median QT value of eight most reliable leads. In ambulatory Holter ECG analysis, generally only two or three channels are available. QT is measured on a root-mean-square vector magnitude signal. Finally, QT measurement in the real time in-hospital application is among the most challenging areas of QT measurement. The Philips real time QT interval measurement algorithm employs features from both Philips DXL 12-lead and ambulatory Holter QT algorithms with further enhancements. The diagnostic 12-lead algorithm has been tested against the gold standard measurement database established by the CSE group with results surpassing the industrial ECG measurement accuracy standards. Holter and monitoring algorithm performance data on the PhysioNet QT database were shown to be similar to the manual measurements by two cardiologists. The three variations of the QT measurement algorithm we developed are suitable for diagnostic 12-lead, Holter, and patient monitoring applications.

A Randomized Trial of Breakthrough Pain During Combined Spinal-Epidural Versus Epidural Labor Analgesia in Parous Women

There is controversy regarding the benefits and risks of combined spinal-epidural compared with epidural analgesia (CSE, EPID) for labor analgesia. We hypothesized that CSE would result in fewer patient requests for top-up doses compared to EPID. One-hundred ASA physical status I or II parous women at term in early labor (<5 cm cervical dilation) requesting analgesia were randomized in double-blind fashion to the EPID group (epidural bupivacaine 2.5 mg/mL, 3 mL, followed by bupivacaine 1.25 mg/mL, 10 mL with fentanyl 50 microg) or the CSE group (intrathecal bupivacaine 2.5 mg with fentanyl 25 microg). Both groups received identical infusions of bupivacaine 0.625 mg/mL with fentanyl 2 microg/mL at 12 mL/h. The primary outcome variable was the number of top-up doses requested to treat breakthrough pain. There was no significant difference between the two groups in the percentage of patients requesting top-up doses (44% CSE vs 51% EPID; 95% confidence interval of the difference -28% to +14%) nor in the need for multiple top-up doses (14% CSE vs 15% EPID). Visual analog scale scores were lower in the CSE group compared to the EPID group at 10 min after initiation of analgesia [median 0 cm (0, 0) vs 4 cm (1, 6) respectively, P < 0.001] and at 30 min [0 cm (0, 0) vs 0 cm (0, 1), respectively, P = 0.03]. We did not find a difference in the need for top-up doses in parous patients; however, CSE provided better analgesia in the first 30 min compared to EPID.

The effect of Crataegus oxycantha special extract WS 1442 on clinical progression in patients with mild to moderate symptoms of heart failure☆

To examine whether hawthorn (Crataegus Special Extract WS 1442 {CSE}) inhibits progression in heart failure (HF) patients. We performed a retrospective analysis of data from the HERB CHF study in which patients with mild to moderate HF were randomised to either CSE 900 mg or placebo for 6 months. The primary outcome was time to progression of HF (HF death, hospitalisation, or sustained increase in diuretics) as assessed by log-rank tests and by Cox modelling. Progression of HF occurred in 46.6% of the CSE and 43.3% of the placebo groups (OR 1.14, 95% CI=0.56, 2.35: p=0.86). Patients receiving CSE were 3.9 times (95% CI=1.1-13.7: p=0.035) more likely to experience HF progression at baseline. In adjusted analysis, the risk of having early HF progression in the CSE group increased to 6.4 (95% CI=1.5, 26.5: p=0.011). In patients with LVEF< or =35%, those taking CSE were at significantly greater risk (3.2, 95% CI=1.3, 8.3: p=0.02) than the placebo group. CSE does not reduce heart failure progression in patients who have HF. CSE appears to increase the early risk of HF progression.

Sequential Combined Spinal Epidural Block Superior To Epidural Block For Total Abdominal Hysterectomy In Patient And Surgeons Perspective: Double Blind Randomized Control Trial

Introduction: The aim of this study was to compare sequential combined spinal epidural with epidural block for total abdominal hysterectomy to assess quality of block in terms of surgeon and patient's satisfaction. Methods: 100 patients of ASA grade I & II were randomly divided into 2 groups. Group A patients received CSE using “needle through needle technique” and were given 2.5 ml of 0.5% hyperbaric bupivacaine for spinal block. Group B patients received epidural block through catheter using 15 ml of 0.5% plain bupivacaine. In all patients, subsequent dosage of 0.5% plain bupivacaine (1.5 ml per unblocked segment) was administered to achieve a block up to T4-5. The quality of block was rated from excellent to poor by surgeon and anesthetist. Patient satisfaction was rated on 0 to 100 linear visual analog scale. Results: The surgical analgesia and motor blockade occurred significantly early in CSE group. The quality of analgesia as assessed by anesthetist was excellent in 92% of patients in group A as compared to 30% in group B (p=0.000). In 88% cases in CSE group surgical conditions were reported as excellent by surgeons as compared to only 36% in epidural group. VAS scores for patient satisfaction were also much lower in CSE group (11.2±7.304 versus 26.4±22.94 in epidural group) (p=0.000). Conclusion: The quality of block is superior in CSE as compared to epidural block and associated with greater degree of patient and surgeon satisfaction.

Effect of dentinal surface preparation on bond strength of self-etching adhesive systems

The aim of this study was to evaluate the effects of dentin surface treatments on the tensile bond strength (TBS) of the self-etching primer Clearfil SE Bond (CSE) and the one-step self-etching One-Up Bond F (OUB). The exposed flat dentin surfaces of twenty-four sound third molars were prepared with diamond bur at high-speed, carbide bur at low-speed or wet ground with #600 grit SiC paper. The adhesive systems were applied to the dentin surfaces and light-cured according to the manufacturers' instructions. A 6-mm high composite crown was incrementally built-up and each increment was light-cured for 40 seconds. After being stored in water (37 degrees C/24 h), the samples were serially sectioned parallel to the long axis, forming beams (n = 20) with a cross-sectional area of approximately 0.8 mm(2). The specimens were tested in a Universal Testing Machine at 0.5 mm/min. The cross-sectional area was measured and the results (MPa) were analyzed by two-way ANOVA and Tukey Test (p < 0.05). Overall, the groups treated with CSE exhibited the highest TBS for all surface treatments. Dentin surfaces prepared with carbide bur at low speed reduced TBS in the CSE group; however, OUB was not affected by surface treatments. The effect of surface abrasive methods on TBS was material-dependent.

Regional versus general anesthesia for donor nephrectomy: Effects on graft function

Various general and regional anesthesia methods are used successfully in living-donor kidneytransplantation. This study compared kidney graft function after general versus combined spinal-epiduralanesthesia for donor nephrectomy. The study groups included recipients who received graftsfrom donors who had undergone nephrectomy under general anesthesia (GA group; n = 10), andrecipients who received grafts from donors who had combined spinal-epidural anesthesia (CSEgroup, n = 10). Standard continuous epidural anesthesia was administered during all transplantations.Graft function was assessed using scintigraphy and Doppler ultrasonography on days 3 and 7. Urinelevels of microalbumin, creatinine, and creatinine clearance rate were measured/calculated in 24-hoururine samples collected on postoperative days 3 and 7. There were no differences on either day 3 orday 7 with respect to glomerular filtration rate, microalbuminuria, or creatinine clearance rate ( P > .05for all). There were also no differences between the groups with respect to other scintigraphic findingson day 3 or day 7 ( P > .05 for all). Ultrasonography on day 7 showed significantly higher mean peaksystolic flow in the main renal artery in the CSE group than in the GA group ( P = .035). The resultssuggest that GA and CSE for donor nephrectomy have similar effects on kidney graft function inrecipients.

The effect of vitamin E on stress-induced changes in visual evoked potentials (VEPs) in rats exposed to different experimental stress models.

The aim of the study was to investigate the effects of vitamin E on stress-induced changes in visual evoked potentials (VEPs) and lipid peroxidation. Eight experimental groups of 10 rats per group were formed. These consisted of the control group (C); the group treated with vitamin E (E); groups exposed to cold stress (CS), immobilization stress (IS) and both cold and immobilization stress (CIS), and groups exposed to equivalent stresses and treated with vitamin E (CSE, ISE, CISE). Vitamin E was injected intramuscularly in a dose of 30 mg/kg/day. Following chronic stress (15 days), plasma corticosterone concentrations in all experimental groups were significantly increased over those in C group. Vitamin E significantly decreased corticosterone levels in all stress groups compared with their respective control groups. Brain nitrite levels were significantly more elevated in all stress groups than in the C group. Vitamin E reduced retina and brain nitrite levels in all stress and E groups compared with their respective control groups. Vitamin E decreased glutathione peroxidase (GSH-Px) activity in retina and brain tissues in the CSE group, but increased it in the ISE group compared with their respective control groups. Lipid peroxidation was increased in brain and retina tissues in all stress groups as indicated by the significant increase in thiobarbituric acid-reactive substance (TBARS) levels with respect to the C group. Vitamin E produced a significant decrease in brain and retina TBARS levels in all stress groups with respect to their corresponding control groups. The mean latencies of P1, N1, P2, N2 and P3 components were significantly prolonged in all stress groups compared with the C group. Vitamin E returned the VEP latencies in the stress groups to control values. Our findings clearly indicated that vitamin E has the potential to prevent VEP changes caused by stress.

Feature extraction from ECG signals using wavelet transforms for disease diagnostics

This paper deals with a modified combined wavelet transform technique that has been developed to analyse multilead electrocardiogram signals for cardiac disease diagnostics. Two wavelets have been used, i.e. a quadratic spline wavelet (QSWT) for QRS detection and the Daubechies six coefficient (DU6) wavelet for P and T detection. After detecting the fundamental electrocardiogram waves, the desired electrocardiogram parameters for disease diagnostics are extracted. The software has been validated by extensive testing using the CSE DS-3 database and the MIT/BIH database. A procedure has been evolved using electrocardiogram parameters with a point scoring system for diagnosis of cardiac diseases, namely tachycardia, bradycardia left ventricular hypertrophy, and right ventricular hypertrophy. As the diagnostic results are not yet disclosed by the CSE group, two alternate diagnostic criteria have been used to check the diagnostic authenticity of the test results. The consistency and reliability of the identified and measured parameters were confirmed when both the diagnostic criteria gave the same results

Photolysis of pentacarbonyl(selenocarbonyl)chromium(0), Cr(CO)5(CSe), in an Argon matrix at 20 K

AbstractU. v. photolysis (254 and 366 nm) of Cr(CO)5(CSe) isolated in an argon matrix at ca. 20 K produces a mixture of two isomeric forms of Cr(CO)4(CSe), Cr(CO)6 and molecular CO. The two Cr(CO)4(CSe) isomers are assigned square pyramidal geometries (CSe group axial, C4v symmetry; CSe group equatorial, Cs symmetry) by comparison with the results from a previous matrix isolation i.r. study of the products formed in the u.v. photolysis of the analogous thiocarbonyl complex, Cr(CO)5(CS). On further irradiation of the Cr(CO)4(CSe) species with visible light (λ &gt; 425 nm), the parent Cr(CO)5(CSe) molecule is regenerated.