PARALLEL MATRIX MULTIPLICATION CIRCUITS FOR USE IN KALMAN FILTERING

In this work we propose several ways of the CMOS implementation of a circuit for the multiplication of matrices. We mainly focus on parallel and asynchronous solutions, however serial and mixed approaches are also discussed for the comparison. Practical applications are the motivation behind our investigations. They include fast Kalman filtering commonly used in automotive active safety functions, for example. In such filters, numerous time-consuming operations on matrices are performed. An additional problem is the growing amount of data to be processed. It results from the growing number of sensors in the vehicle as fully autonomous driving is developed. Software solutions may prove themselves to be insuffucient in the nearest future. That is why hardware coprocessors are in the area of our interests as they could take over some of the most time-consuming operations. The paper presents possible solutions, tailored to specific problems (sizes of multiplied matrices, number of bits in signals, etc.). The estimates of the performance made on the basis of selected simulation and measurement results show that multiplication of 3×3 matrices with data rate of 20 100 MSps is achievable in the CMOS 130 nm technology

The efficacy of risk scores for predicting abdominal wound dehiscence : a case-controlled validation study

BACKGROUND: The medical literature includes two risk scores predicting the occurrence of abdominal wound dehiscence. These risk indices were validated by the authors on the populations studied. However, whether these scoring systems can accurately predict, abdominal wound dehiscence in other populations remains unclear. METHODS: A retrospective analysis was performed using the medical records of patients treated at a tertiary-care teaching hospital between 2008 and 2011. Patients that underwent laparotomy procedures complicated by the development of postoperative abdominal wound dehiscence were included into the study. For each of the cases, three controls were selected. RESULTS: Among the 1,879 patients undergoing intra-abdominal, 56 patients developed wound dehiscence and 168 patients included in the control group. Calculation of risk scores for all patients, revealed significantly higher scores in the abdominal wound dehiscence group (p < 0.001). The median score was 24 (range: 3–46) and 4.95 (range: 2.2-7.8) vs.10 (range:-3-45) and 3.1 (range:0.4-6.9), for the Veterans Affairs Medical Center (VAMC) and Rotterdam abdominal wound dehiscence risk score in the dehiscence and control groups, respectively. The area under the curve, on the ROC plot, was 0.84 and 0.76; this confirmed a good and moderate predictive value for the risk scores. The fit of the model was good in both cases, as shown by the Hosmer and Lemeshow test. CONCLUSIONS: Both the VAMC and Rotterdam scores can be used for the prediction of abdominal wound dehiscence. However, the VAMC prognostic score had better calibration and discriminative power when applied to the population in this study and taking into consideration our method of control selection

Technique of endovascular repair of iatrogenic subclavian artery injury following subclavian vein catheterization

The iatrogenic subclavian artery injury is a rare but potentially serious complication of subclavian vein cannulation.The use of endovascular techniques is an alternative to surgical repair especially in patients with concomitantdiseases in whom immediate, potentially large surgery would be associated with a high risk of perioperativecomplications. This article discusses technical aspects of endovascular repair of iatrogenic injury of subclavianartery with implantation of covered stents based on two cases. Author’s experience and data from literaturesuggests that endovascular management including covered stent implantation is safe and effective treatmentand should be considered as a method of choice especially among patients in poor general condition and/ormajor comorbidities

Autoamputated leiomyoma of the uterus as a rare cause of the mechanical bowel obstruction - report of a case

Mechanical obstruction of the gastrointestinal tract is one of the most common causes of the emergency surgical intervention. A rare cause of such condition might be the effect of the external pressure on the intestine exerted by i. e. tumor, lymph node package, aneurysm of the abdominal aorta. An extremely rare cause is the pressure of the large loose mass located in the peritoneal cavity called “loose body”. We present a case of the mechanical bowel obstruction caused by a giant loose autoamputated leiomyoma of the uterus lying free in the peritoneal cavity. According to our best knowledge it is the largest described loose body in the literature. Moreover, we present a literature review regarding this issue