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Abstract The main manifestations of Takotsubo syndrome (TTS) are a spherical expansion of the left ventricle or near the apex and decreased systolic function. TTS is mostly thought to be induced by emotional stress, and the induction of TTS by severe infection is not often reported. A 72-year-old female patient with liver abscess reported herein was admitted due to repeated fever with a history of hypertension and impaired glucose tolerance. Her severe infection caused TTS, and her blood pressure dropped to 80/40 mmHg. IABP treatment was performed immediately and continued for 10 days, and comprehensive medication was administered. Based on her disease course and her smooth recovery, general insights and learnings may be: Adding to mental and other pathological stress reaction, serious infections from pathogenic microorganism could be of great important causation of stress reaction leading to TTS, while basic diseases such as coronary heart disease, hypertension, and diabetes were be of promoting factors; In addition to effective drug therapies for TTS, the importance of the timely using of IABP should be emphasized.

Abstract Background X-ray fluoroscopy has been the primary cardiac imaging modality in permanent pacemaker implantation (PPI) operations, but it inevitably results in radiation exposure for both operators and patients. Fluoroscopy is considered a contraindication, especially in certain circumstances, such as gestation, during which the fetus is most sensitive to radiation exposure. Therefore, measures to avoid radiation exposure are necessary, and a more safe and feasible approach is needed for this procedure. Since the EnSite NavX mapping system (ENMS) can create the required geometric contours of those relevant cardiac structures and chambers, it can be used as an alternative to X-ray fluoroscopy in PPI. In addition, because the displacement of atrial leads is a common complication of PPI, lead displacement may occur more readily without fluoroscopic guidance. Therefore, reliable measures are required to prevent leads from displacement. Case introduction A 41-year-old woman at the 15th week of gestation was referred to our department with recurrent episodes of syncope and amaurosis fugax for 2 years. Holter monitoring showed sinus rhythm, Mobitz Type II atrioventricular block and high-grade atrioventricular block with ventricular arrest up to 4945 ms. A dual-chamber PPI was performed successfully for the patient under the guidance of the ENMS instead of fluoroscopy. Displacement of atrial lead was effectively avoided by bending the top of atrial lead before implantation and making it a U-shape during operation, which left space for possible subsequent external pulling stress. Conclusions For PPI, ENMS is a feasible and reliable alternative to traditional X-ray fluoroscopy, especially when performing operations on pregnant patients. By bending the top of the active-fixation atrial lead into a U-shape during operation, the displacement of atrial lead may be avoided.

Augmented reality surgery systems are playing an increasing role in the operating room, but applying such systems to neurosurgery presents particular challenges. In addition to using augmented reality technology to display the position of the surgical target position in 3D in real time, the application must also display the scalpel entry point and scalpel orientation, with accurate superposition on the patient. To improve the intuitiveness, efficiency, and accuracy of extra-ventricular drain surgery, this paper proposes an augmented reality surgical navigation system which accurately superimposes the surgical target position, scalpel entry point, and scalpel direction on a patient’s head and displays this data on a tablet. The accuracy of the optical measurement system (NDI Polaris Vicra) was first independently tested, and then complemented by the design of functions to help the surgeon quickly identify the surgical target position and determine the preferred entry point. A tablet PC was used to display the superimposed images of the surgical target, entry point, and scalpel on top of the patient, allowing for correct scalpel orientation. Digital imaging and communications in medicine (DICOM) results for the patient’s computed tomography were used to create a phantom and its associated AR model. This model was then imported into the application, which was then executed on the tablet. In the preoperative phase, the technician first spent 5–7 min to superimpose the virtual image of the head and the scalpel. The surgeon then took 2 min to identify the intended target position and entry point position on the tablet, which then dynamically displayed the superimposed image of the head, target position, entry point position, and scalpel (including the scalpel tip and scalpel orientation). Multiple experiments were successfully conducted on the phantom, along with six practical trials of clinical neurosurgical EVD. In the 2D-plane-superposition model, the optical measurement system (NDI Polaris Vicra) provided highly accurate visualization (2.01 ± 1.12 mm). In hospital-based clinical trials, the average technician preparation time was 6 min, while the surgeon required an average of 3.5 min to set the target and entry-point positions and accurately overlay the orientation with an NDI surgical stick. In the preparation phase, the average time required for the DICOM-formatted image processing and program import was 120 ± 30 min. The accuracy of the designed augmented reality optical surgical navigation system met clinical requirements, and can provide a visual and intuitive guide for neurosurgeons. The surgeon can use the tablet application to obtain real-time DICOM-formatted images of the patient, change the position of the surgical entry point, and instantly obtain an updated surgical path and surgical angle. The proposed design can be used as the basis for various augmented reality brain surgery navigation systems in the future.

A wideband filter with a notched band is presented. The proposed filter is formed by cascading three coupling units, and each coupling unit is composed of two curved T-shaped microstrip patches at the top and bottom layers and a circular coupling slot at the mid layer. Overlapping three coupling units could result in a wideband filter with a tunable notched band. To analyse the resonance characteristics, the equivalent circuit model is presented. The notched frequency is 5.8GHz, and within the passband, the insertion and return losses are better than -2dB and -15 dB, respectively. The group delays are 0.08 ns and 0.12 ns correspondingly, and the upper stopband reaches 15GHz. The multi-layer structure leads to a compact size and tight coupling characteristics, and the feasibility and excellent performance of the design is verified. [ABSTRACT FROM AUTHOR]

In this paper, a broadband transition structure from microstrip line to slotline with band-notched characteristic is proposed. To match the 50O microstrip line, 4 Chebyshev impedance transformations are used in the transition structure, and its bandwidth is widened. There is a fan-shaped radial line at the microstrip terminal. A U-shaped slot is etched on the microstrip line with stepped impedance matching to achieve band-notch characteristic. By changing the length of the slot, the band notch is realized at different frequencies. Simulation and optimization of the transition structure are made by using the high frequency simulation software HFSS to achieve the band-notch function at 3.37-3.84 GHz and 10.67-11.14 GHz. In the rest of the band, return loss S11 is less than -15 dB, and voltage standing wave ratio (VSWR) is less than 1.5. [ABSTRACT FROM AUTHOR]

In this paper, two-grid methods for characteristic finite volume element solutions are presented for the semi-linear Sobolev equation. The method is based on the methods of characteristics, two-grid method and the finite volume element method. The nonsymmetric and nonlinear iterations are only executed on the coarse grid (with grid size H). And the fine-grid solution (with grid size h) can be obtained by a single symmetric and linear step. It is proved that the coarse grid can be much coarser than the fine grid. The two-grid methods achieve asymptotically optimal approximation as long as the mesh sizes satisfy h = O(H³). As a result, solving such a large semi-linear Sobolev equations will not be much more difficult than solving one single linearized equation. [ABSTRACT FROM AUTHOR]