Absence of shock therapy related to improper sensing of noise on the defibrillation test during subcutaneous implantable cardioverter–defibrillator implantation: a case report

Background Subcutaneous implantable cardioverter–defibrillator (S-ICD) represents an efficient alternative to transvenous ICD in patients who do not require pacing. The intraoperative defibrillation test (DFT) is recommended during S-ICD implantation to confirm appropriate sensing and successful 65-J termination of induced ventricular fibrillation (VF). However, few cases of oversensing of noise inhibiting therapies have been reported. Case summary We report the case of a 50-year-old man who underwent S-ICD implantation for secondary prevention of sudden cardiac death. Immediately after S-ICD implantation, VF was induced using a 50-Hz burst; however, shock was not delivered owing to sustained noise on the electrogram in the primary vector. Therefore, an external rescue shock was needed at 150 J. We changed the sensing vector from primary to secondary and performed a second DFT. The S-ICD could deliver an appropriate shock and was able to successfully terminate VF without noise markers in the secondary vector. During the second DFT, one back-up pacing was delivered after the shock; the sensing vector then automatically switched from the secondary to the alternate vector. However, noise was observed in the alternate vector despite sinus rhythm restoration. Discussion The present case demonstrated that noise was recorded in two different vectors during DFT, possibly supporting the hypothesis that the muscle spasm of the diaphragm induced by the 50-Hz burst causes oversensing of noise by the S-ICD.

Implantation technique and optimal subcutaneous defibrillator chest position: a PRAETORIAN score-based study

Aims The traditional technique for subcutaneous implantable cardioverter-defibrillator (S-ICD) implantation involves three incisions and a subcutaneous pocket. Recently, a two-incision and intermuscular (IM) technique has been adopted. The PRAETORIAN score is a chest radiograph-based tool that predicts S-ICD conversion testing. We assessed whether the S-ICD implantation technique affects optimal position of the defibrillation system according to the PRAETORIAN score. Methods and results We analysed consecutive patients undergoing S-ICD implantation. The χ2 test and regression analysis were used to determine the association between the PRAETORIAN score and implantation technique. Two hundred and thirteen patients were enrolled. The S-ICD generator was positioned in an IM pocket in 174 patients (81.7%) and the two-incision approach was adopted in 199 (93.4%). According to the PRAETORIAN score, the risk of conversion failure was classified as low in 198 patients (93.0%), intermediate in 13 (6.1%), and high in 2 (0.9%). Patients undergoing the two-incision and IM technique were more likely to have a low (<90) PRAETORIAN score than those undergoing the three-incision and subcutaneous technique (two-incision: 94.0% vs. three-incision: 78.6%; P = 0.004 and IM: 96.0% vs. subcutaneous: 79.5%; P = 0.001). Intermuscular plus two-incision technique was associated with a low-risk PRAETORIAN score (hazard ratio 3.76; 95% confidence interval 1.01–14.02; P = 0.04). Shock impedance was lower in PRAETORIAN low-risk patients than in intermediate-/high-risk categories (66 vs. 96 Ohm; P = 0.001). The PRAETORIAN score did not predict shock failure at 65 J. Conclusion In this cohort of S-ICD recipients, combining the two-incision technique and IM generator implantation yielded the lowest PRAETORIAN score values, indicating optimal defibrillation system position. Clinical trial registration http://clinicaltrials.gov/ Identifier: NCT02275637.

Метод Кротова в задачах оптимального управления замкнутыми квантовыми системами

Математические задачи оптимального управления квантовыми системами привлекают высокий интерес в связи как с фундаментальными проблемами физики, так и с существующими и перспективными приложениями для квантовых технологий. Важной проблемой является разработка методов построения управлений для квантовых систем. Одним из широко используемых методов является метод Кротова, предложенный изначально вне квантового управления в статьях В. Ф. Кротова и И. Н. Фельдмана (1978, 1983 гг.). Этот метод был применен для разработки нового подхода к построению оптимальных управлений для квантовых систем в работах [64] (D. J. Tannor, V. Kazakov, V. Orlov, 1992 г.), [65] (J. Somlói, V. A. Kazakov, D. J. Tannor, 1993 г.) и во многих других работах различных исследователей. Обзор посвящен математическим аспектам этого метода для оптимального управления замкнутыми квантовыми системами. Излагаются различные варианты метода, отличающиеся видом улучшающей функции (как правило, линейной или линейно-квадратичной), ограничениями на спектр управления и на состояния квантовой системы, регуляризаторами и т. д. Обзор описывает приложения метода Кротова к управлению молекулярной динамикой и конденсатом Бозе-Эйнштейна, а также к генерации квантовых вентилей. Проводится сравнение с методами GRAPE (GRadient Ascent Pulse Engineering), CRAB (Chopped Random-Basis), Чжу-Рабица и Мадея-Туриничи. Библиография: 158 названий.

Mechanical Property Determination of a Stereolithographic Resin Subjected to Compressive Loading

This paper presents the findings of destructive compression testing on Formlabs© CLEAR Resin FLGPCL02 and TOUGH Resin FLTOTL03. Compression testing ASTM D695-15 was chosen because of the extreme fragility of the Clear Resin which did not allowed proper tensile testing with our equipment. The material was subjected to a steadily increasing compressive load until complete failure occurred. Five mechanical properties were extracted from stress versus strain curves. The five experimental properties, of Formlabs© CLEAR resin, found were young’s modulus (1.52 GPa) (std = 71 MPa), yield strength (39.6 MPa) (std = 2 MPa), ultimate strength (255 MPa) (std = 35 MPa), strain at fracture (0.509 m/m) (std = 0.0159 m/m), and toughness (49.1 J/m−3) (std = 3.9 J/m−3). The five experimental properties, of Formlabs© TOUGH resin, found were secant modulus (73.9 MPa) (std = 0.87 MPa), yield strength (42.8 MPa) (std = 3.03MPa), ultimate strength (587 MPa) (std = 61 MPa), strain at fracture (0.686 m/m) (std = 0.0097 m/m), and toughness (65 J/m−3) (std = 6 J/m−3). These were then compared to Formlabs© public released values.

Dielectric elastomer generator with diaphragm configuration

The dielectric elastomer generator (VHB 4905, 3M) with diaphragm configuration was investigated with the constant-voltage harvesting scheme in order to investigate its energy harvesting ability. The maximum energy density and energy conversion efficiency is measured to be 65 J/kg and 5.7%, respectively. The relatively low efficiency indicates that higher energy conversion efficiency is impeded by the viscosity of the acrylic elastomer, suggesting that higher conversion efficiency with new low-viscosity elastomer should be available.

Experimental Research on CFRP Laminates with Different Impact Energy Levels

The effects of thickness and impact energy on the impact damage of CFRP laminates were studied in this paper. Impact tests for the CFRP laminates with the size of 600 mm×700 mm with five different thicknesses were subjected to impact fatigue loading at different energy levels from 5 J to 65 J. The crater depth and matrix length were investigated according to different energy levels and different thicknesses. The impact damage was evaluated by visual inspection, three-dimensional microscope. The experimental results reveal that the crater depth and the crack length increase with the increasing impact energy. For the same impact energy, the crater depth and the crack length decreased with the increasing thickness of specimens.

Threshold of Impact Energy on the Medium Leakage of CFRP Laminates

The effects of the thickness and the impact energy on the medium leakage of CFRP laminates were discussed in this paper. Impact tests for CFRP laminates with the size of 600 mm×700 mm with three different thicknesses were subjected to impact energy levels from 5 J to 65 J. The medium leakage and the damaged area were investigated according to different energy levels and thicknesses. The damage area was evaluated by visual inspection and three-dimensional microscope. The experimental results reveal that the impact damage of CFRP laminates tends to be more severe as the impact energy increases, and the impact area and the crater depth increases with the increasing impact energy. For the same impact energy, the impact area and the crater depth decrease with the increasing thickness.