Flexitrate regional citrate anticoagulation in continuous venovenous hemodiafiltration: a retrospective analysis

Background Flexitrate, an innovative regional citrate anticoagulation (RCA) protocol, was compared to traditional RCA (tRCA) and Heparin anticoagulation protocols in intensive care patients treated with continuous renal replacement therapy (CRRT). Methods A single-center, retrospective, cohort study, was done in a 26-bed intensive care unit in a large community hospital. Eighty dialysis sessions (Flexitrate = 2852 h, tRCA = 3580 h and Heparin = 2026 h), performed in 53 patients, were evaluated for filter life, RCA control, and metabolic control. Results In the Flexitrate cohort, 3.8% of filters clotted, compared to 16.9% with tRCA and 28.3% with Heparin (p < 0.001 for Flexitrate compared to either tRCA or Heparin). Filter survival was significantly improved with Flexitrate compared to tRCA (HR 0.24, p = 0.018) or Heparin (HR 0.14, p = 0.004). Anticoagulation control was superior with Flexitrate with Patient Ionized Calcium out of target a median of 16% of the time, compared to 27% for tRCA (p < 0.001). Filter Ionized Calcium was out of target a median of 6.8% of the time, compared to 23% for tRCA (p = 0.03). Flexitrate produced significantly less alkalosis, hypernatremia, and hypocalcemia than tRCA, and overall metabolic control was comparable to Heparin anticoagulation. The only adverse metabolic outcome with Flexitrate was increased hypomagnesemia. Conclusions The Flexitrate protocol extended filter life, delivered more consistent anticoagulation, and provided superior metabolic control compared to a tRCA protocol. Filter life was superior to Heparin anticoagulation, with similar metabolic control. A randomized control trial comparing these protocols is recommended.

A Tracking Algorithm for Blind Navigation Based on Robust H Infinity Filter

This paper presents an algorithm for blind and visually impaired people to track their location. A precise positioning system utilizes UWB RFID tags for localization to mark points of interest. Given the joint estimation of TOA and DOA from blind person to station, a robust algorithm based on the extended filter is presented to accurately estimate their current location and moving velocity. This method is effective to the no-Gaussian or biased system model with unknown or not fully known observation error statistics.

Multitarget Tracking by Improved Particle Filter Based on Unscented Transform

This paper considers the problem of multitarget tracking in cluttered environment. To reduce the dependency on the noise priori knowledge, an improved particle filtering (PF) data association approach is presented based on the filter (HF). This approach can achieve higher robustness in the condition that the measurement noise prior is unknown. Because of the limitations of the HF in nonlinear tracking, we first present the unscented filter (HUF) by embedding the unscented transform (UT) into the extended filter (HEF) structure. Then the HUF is incorporated into the Rao-Blackwellized particle filter (RBPF) framework to update the particles. Simulation results are provided to demonstrate the effectiveness of the proposed algorithms in linear and nonlinear multitarget tracking.