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Patent foramen ovale (PFO) has been implicated in the pathogenesis of cryptogenic stroke, arterial desaturation, decompression illness, and migraine headache (MH). This study evaluated the safety of percutaneous transcatheter PFO closure in patients with cryptogenic stroke, transient ischemic attack, or arterial desaturation. Additionally, symptomatic reduction in MH was determined after interatrial shunt closure. Of the 252 patients referred to the University of California, Los Angeles, with PFO, 131 underwent closure of the interatrial communication with a CardioSEAL (n = 30) or Amplatzer (n = 101) device. PFO morphology was evaluated with transesophageal echocardiography. Follow-up was conducted at 1 to 2 months with echocardiography, with clinical assessment annually thereafter. At an average follow-up of 30 months, there was no recurrence of any thromboembolic event (transient ischemic attack, stroke, or peripheral). There was a reduction in MH, defined as the complete resolution of headache or a >50% reduction in the number of headache days, in 85% of patients after PFO closure. Temporary problems after device implantation, including chest discomfort and palpitations, were reported in 23% of patients and occurred more frequently in patients with nickel hypersensitivity (p

We evaluated the short-term safety and efficacy of using the TandemHeart(R) percutaneous ventricular assist device in high-risk patients undergoing aortic valvuloplasty procedures. Aortic valvuloplasty was performed in 4 patients who had no ventricular assist device support and in 7 patients who used the TandemHeart for hemodynamic support. The age range was 65 to 94 years (mean, 83 +/- 11 yr). The mean ejection fraction was 0.30 +/- 0.14. A transseptal antegrade approach to the aortic valve was used in 8 patients and a retrograde approach in the remaining 3. WITH THE TANDEMHEART, ALL PROCEDURES WERE TECHNICALLY SUCCESSFUL: each patient survived at least 1 month after the procedure. The mean total balloon inflation time was 37 +/- 10 sec. The aortic valve area was 0.6 +/- 0.1 cm(2) before the procedure and 0.9 +/- 0.2 cm(2) afterwards (P=0.006). Without TandemHeart support, 1 patient died of cardiac arrest during the procedure. The mean total balloon inflation time was 11 +/- 3 sec. Aortic valve area was 0.6 +/- 0 cm(2) before the procedure and 1.1 +/- 0.3 cm(2) afterwards (P=0.3). No patient developed aortic regurgitation. We conclude that use of the TandemHeart for hemodynamic support during high-risk aortic valvuloplasty is associated with favorable intraprocedural and short-term outcomes. With the TandemHeart in place, balloon placement was precise, and inflation was maintained for up to 45 sec without balloon displacement. These attributes are essential during stent-valve placement, are achieved without rapid ventricular pacing, and may reduce the risk of global ischemia and death.

A simple algorithm for selecting and linking interesting flow vectors across a sequence of frames for computing motion trajectories is presented. Tokens are tracked that have both interesting pixel gray values in the spatial domain and in the optical flow field in the temporal domain. This and operation effectively remove some redundant trajectories. Due to errors introduced during the computation of optical flow, and the linking of such flow vectors across a sequence of frames, the resultant trajectories are not always smooth. A Kalman filtering based approach is discussed for smoothing the trajectories. Isolating the trajectories into sets belonging to individual objects is an important first step that should be taken before any type of shape or motion interpretation can be done. Therefore, a simple algorithm for segmenting motion trajectories is also discussed. When motion trajectories belonging to a single translating object are extended, they intersect at a single point called the focus of expansion (FOE). If the motions of objects are assumed to be independent, each FOE represents one object. Therefore, FOE can be used to segment trajectories belonging to individual objects. A simple but highly robust algorithm for partitioning motion trajectories is presented that does not require the exact location of FOE, but uses some useful properties of FOE. The authors have applied their method for computing and segmenting motion trajectories to a number of real sequences, and have obtained very encouraging results.

The focus of expansion (FOE) of a group of motion trajectories is defined to be a point in the image plane at which the trajectories intersect when they are extended. The FOE observed over a time sequence defines the locus of FOE. We present an analytical approach for the study of dynamic events as they project on the image plane by analyzing the locus of FOE. We have found that the locus of FOE can be used to make qualitative assertions regarding the type of motion. An interesting behavior of the locus of FOE for various types of motion is observed. The cases include a single point, a horizontal, a vertical, and a slopped straight line. We can also determine whether the object has approaching and receding motion or when the object changes its direction of motion. This inference may be used in qualitative computer vision.

It was decided to attempt HD catheter placement in the RIJ vein via a posterior lateral approach with the patient prone. B Introduction: b A significant number of patients with ARDS secondary to Covid-19 pneumonia require prone positioning. The patient developed AKI necessitating hemodialysis (HD) catheter placement. [Extracted from the article]

Research on vision-based navigation of unmanned air vehicles (UAVs) has been in focus in the recent years, both in military and civilian application domains. Vision-based navigation uses features as cues to match successive images and compute the location of the UAV. The method proposed in this paper is an extension to the existing work to automatically compute scale weights of dual-tree complex wavelet transform (DTCWT) coefficients to improve the performance in terms of detection of features as against discrete wavelets or its Fourier counterparts. Existing DTCWT coefficients give improved time-shifted sensitivity, better directional selectivity with local phase information and limited redundancy. However, the drawback of this method is that the results depend on appropriate selection of scale weights α and β, which are different for different scenes. The existing technique incorporates a rule of thumb-based recommended values of α and β, irrespective of the scene which generates too many key-points, making the registration process computationally intensive. As a real-time application, the need of the problem is to extract less number of strong features. Thus, an algorithmic approach to compute optimal values of scale weights considering precision and accuracy is proposed. The method is tested on various synthetic, simulated, and aerial images having different transformations and in the presence of noise between successive images. It is observed that DTCWT descriptor performs the best and gives better results than scale invariant feature transform and Speeded up robust features. [ABSTRACT FROM AUTHOR]