475 Is left atrial appendage device compression rate a predictor of incomplete occlusion in patients undergoing watchman device implantation?

Aims Transesophageal echocardiography (TEE) is a standard peri-procedural imaging modality in patients undergoing percutaneous left atrial appendage (LAA) occlusion. An accurate device sizing is pivotal to assess stability and achieve successful closure. In this prospective study, we sought to evaluate the correlation between Watchman device compression rates (DCRs) and risk of incomplete LAA occlusion at follow-up in patients undergoing Watchman device implantation. Methods and results Two-dimensional TEE via a commercially available transducer (Vivid, Philips) was performed during the procedure and within 3 months after the procedure. LAA size, morphology, and DCRs [(original device size—size after deployment)/original device size; %] were assessed in a mid-oesophageal view at 0°, 45°, 90° and 135°, according to company recommendations. Residual leaks ≥ 3 mm were classified as significant. Between 2016 and 2018, 116 patients underwent LAA occlusion with a Watchman device at our institution. The mean age was 74 ± 9 years and 60.4% (n = 70) were males. The average CHA2DS2-VASc and HAS-BLED scores were 4.7 ± 1.7 and 2.5 ± 1.1, respectively. The final device size was 21 mm in 11 (9.5%) patients, 24 mm in 28 (24.1), 27 mm in 27 (23.3%), 30 mm in 26 (22.4%), and 33 mm in 24 (20.7). At follow-up TEE, 16 (13.8%) patients were found to have a significant (≥3 mm) residual leak. The average DCRs measured at different angles in patients with and without leak were not significantly different (24 ± 8% vs. 26 ± 7% at 0°, P = 0.47; 23 ± 9% vs. 25 ± 7% at 45°, P = 0.58; 23 ± 8% vs. 23 ± 6% at 90°, P = 0.61; 22 ± 8% vs. 21 ± 7% at 135°, P = 0.61). At receiver operating characteristic (ROC) analysis, the areas under the curve to discriminate between patients with/without leak were 0.58, 0.57, 0.55, and 0.46 for DCRs measured at 0°, 45°, 90°, and 135° angles. Conclusions Peri-procedural assessment of DCRs does not appear to be an accurate method to predict LAA complete occlusion in patients undergoing Watchman device implantation.

Device for modeling of intra-arterial circulation: application in experimental cardiology

Purpose of study Using an original device for modeling of intra-arterial blood circulation, to study the features of intravascular hemodynamics with a regular heart rhythm and with various rhythm disturbances. Material and methods We used an original device developed by us to simulate intra-arterial circulation (Document of invention No. RU 202780 U1). The main part of the device is a glass tube of a rotameter with a length of 365 mm, an inlet end with a diameter of 20 mm, an outlet end of 16.5 mm, which is a model of an arterial vessel. Flexible silicone tubes are attached to the rotameter on both sides, with free ends connected to an electric pump, with various modes of operation (imitation of pulse waves with regular rhythm, premature ventricular contractions (PVCs), atrial fibrillation (AF). An aqueous solution of glycerin was introduced into a closed system diluted with water corresponding to the viscosity of the blood. A 5 mm long silk thread was alternately installed inside the tube, an intravascular piezoelectric crystal pressure probe connected to an oscilloscope. Also it was injected inside the tube a dye - clerical ink. Results With electric pump, we simulated the spreading of the pulse wave in regular heart rate, PVCs and AF. We observed the effect of a pressure wave (deflection of a silk thread, the appearance of a turbulent flow when using a dye) on the walls of the rotameter, with the formation of standing, reflected waves during the PVCs and AF. The pressure probe registered an increase in pressure inside the tube during the spread of the 1st post-extrasystolic contraction wave up to 58%, the wave after a long pause of more than 2 seconds with AF by 44% compared to the regular rhythm. Conclusion A device for modeling of intra-arterial circulation allows a wide range of experimental work in cardiology, normal and pathological physiology, and biophysics. FUNDunding Acknowledgement Type of funding sources: None.

Reconstruction designs of an early Chinese astronomical clock with a waterwheel steelyard clepsydra

During the 8th century, ancient China began to use a steelyard clepsydra to control the waterwheel, giving it a time-keeping function for use in hydromechanical astronomical clocks. In the Tang Dynasty, the monk I-Hsing (683–723 CE) and Liang Lingzan jointly built a water-powered celestial globe (shuiyun huntian), which, according to historical records, was China's first hydromechanical astronomical clock with a waterwheel steelyard clepsydra. However, the original device has since been lost. The objective of this study is to use the design methodology for the reconstruction of lost ancient machinery to systematically reconstruct this lost clock. The methodology included the study of ancient literature to formulate reconstruction design specifications. Through the process of generalization and specialization, the target device was analyzed to determine its function, and different mechanical configurations that achieved the same function were developed. Thereafter, an atlas of possible mechanical sketches that were consistent with the technological level of ancient times was built. A computer 3D reconstruction of the waterwheel steelyard clepsydra, time-reporting device, and astronomical device was carried out, and 50 possible configurations were developed. One was selected to build a physical model.

Forensic Analysis of Broken and Damaged Mobile Phone - A Crime Case Study

Forensic laboratories are frequently subjected to mobile devices that are assailed by shock or forced damage which might be the result of intentional efforts to destroy proof from the devices or accidental exposure. Chip-off technique is an effective method for data retrieval from such kind of exhibits. However, nowadays all mobiles phones are securely encrypted with full disk encryption (FDE) or file-based encryption (FBE) which makes chip-off forensics an improbable process to successfully retrieve data. In many of these cases, the encryption is on the hardware and hence, the device could be successfully decrypted by bringing it in its original condition. Thus, the original user data can be obtained for investigative purposes. This process can be enabled by replacement of electronic parts of the original device which contains user data and decryption keys i.e. PCB to the new host. This research paper covers a case study of a mobile phone obtained in broken and shattered condition whose diagnosis of PCB and subsequent actions led to data recovery.

Physical simulation of intra-arterial circulation using an experimental bench

The article describes the device and possibilities of application of the original device developed by us for simulation of intra-arterial circulation. The principles of operation of the device, a wide range of experimental and clinical studies in which it can be applied are outlined. The use of this useful model is illustrated by clinical examples.

Modeling of restenosis of main arteries after the intravascular stenting interventions

Objectives to study the mechanism of restenosis after the intra-arterial stenting using the original device for modeling of intra-arterial blood flow. Material and methods. To perform the experiment, we have created the original device simulating the intra-arterial blood flow. A glass tube of rotameter was the imitation of the arterial vessel. The closed system was filled with the liquid imitating blood, specifically the solution of glycerin the same viscosity as the human blood plasma. Using our original model of intra-artetial blood flow, we were able to study the intra-arterial hemodynamics under different conditions of cardiovascular system functioning, including arrhythmias. Results. In extrasystolic arrhythmia, during the spread of the first post-extrasystolic wave, we observed the intensive impact of pressure wave (the indicator was the silk thread) on the vessel walls with forming of reflected and standing waves. Putting the piezo crystal probe of pressure inside the tube, we verified our observations. The increase of pressure during the spread of the first post-extrasystolic wave in multiple measurements had a mean value of 160% in comparison with the pressure during the regular heart rhythm. Conclusion. The hydraulic shock appears during the spread of the first post-extrasystolic wave in the arterial vessel. Its effect on hemodynamics grows in case of the frequent extrasystoles and allorhythmia. The mechanical impact of hydraulic shock in extrasystoles can be the starting point of the restenosis onset and progressing in the intra-arterial stent.

Improvement and Experiment for Online Measurement of Droplet Mass Deposit

HighlightsA measurement device for droplet mass deposit was improved to enhance its performance.A wireless data transmission system was used to achieve convenient data sharing.A user interface was designed for display and analysis of the measurement results.A positioning mechanism was designed for arranging measurement devices promptly.Abstract. Measurement of droplet mass deposit is important in spray research and spray performance evaluation. In this article, an online measurement device for droplet mass deposit was improved based on the original design. The measurement resolution, precision, and data stability were improved by optimization of the structure and components and by data filtering. The resolution reached 0.00067 mg cm-2. Comparison tests showed that the relative error between the original device and an analytical balance was 6.68% to 8.48%, and the relative error between the improved device and the analytical balance was 5.24% to 6.15%. Compared with the original device, the relative error decreased and the precision improved. The relative error between the improved device and a tracer method was 5.11% to 6.99%, and the precision of the improved device was close to that of the tracer method. A positioning mechanism was designed to arrange measurement devices promptly in the test area, and a wireless data transmission system was used to achieve convenient data sharing. A user interface was designed to display the results in the form of tables and contour maps. Tests were conducted to measure the droplet mass deposit distribution of one nozzle, the droplet mass deposit distribution in a tree canopy, and the uniformity of the droplet mass deposit distribution in a small horizontal area. The results showed that the improved measurement device could provide data promptly and conveniently for spray research and spray performance evaluation. Keywords: Device improvement, Mass distribution, Wireless communication.

Six-Side Molded Panel-Level Chip-Scale Package with Multiple Diced Wafers

In this study, the design, materials, process, assembly, and reliability of a six-side molded panel-level chip-scale package (PLCSP) are presented. Emphasis is placed on the fabrication of the redistribution layers (RDLs) of the PLCSP on a large temporary panel with multiple device wafers. Because all the printed circuited board (PCB) panels are in rectangular shape, some of the device wafers are diced into two or more pieces so the panel is fully utilized. Thus, it is very high throughput. Because all the processes/equipment are PCB processes/equipment (not semiconductor process/equipment), it is a very low-cost process. After the fabrication of RDLs, the wafers from the PCB panel were debonded. It is followed by solder ball mounting and fabricating the six-side molded PLCSP from the original device wafers with RDLs. The drop test and the results including failure analysis of the PLCSP are presented. Thermal cycling of the six-side molded PLCSP PCB assembly is performed by a nonlinear temperature- and time-dependent finite-element simulation.

Six-Side Molded Panel-Level Chip Scale Package with Multiple Diced Wafers

In this study, the design, materials, process, assembly, and reliability of a 6-side molded panel-level chip scale package (PLCSP) are presented. Emphasis is placed on the fabrication of the RDLs (redistribution layers) of the PLCSP on a large temporary panel with multiple device wafers. Since all the printed circuited board (PCB) panels are in rectangular shape, some of the device wafers are diced into two or more pieces so the panel is fully utilized. Thus, it is very high throughput. Since all the processes/equipment are PCB process/equipment (not semiconductor process/equipment), it is a very low cost process. After the fabrication of RDLs, the wafers from the PCB panel are debonded. It is followed by solder ball mounting and fabricating the 6-side molded PLCSP from the original device wafers with RDLs. The drop test and the results including failure analysis of the PLCSP are presented. Thermal cycling of the 6-side molded PLCSP PCB assembly is performed by a nonlinear temperature- and time-dependent finite-element simulation.