Passive Radar Tracking in Clutter Using Range and Range-Rate Measurements.

Passive bistatic radar research is essential for accurate 3D target tracking, especially in the presence of missing or low-quality bearing information. Traditional extended Kalman filter (EKF) methods often introduce bias in such scenarios. To overcome this limitation, we propose employing the unscented Kalman filter (UKF) for handling the nonlinearities in 3D tracking, utilizing range and range-rate measurements. Additionally, we incorporate the probabilistic data association (PDA) algorithm with the UKF to handle cluttered environments. Through extensive simulations, we demonstrate a successful implementation of the UKF-PDA framework, showing that the proposed method effectively reduces bias and significantly advances tracking capabilities in passive bistatic radars.

Cooperative Fusion Based Passive Multistatic Radar Detection.

Passive multistatic radars have gained a lot of interest in recent years as they offer many benefits contrary to conventional radars. Here in this research, our aim is detection of target in a passive multistatic radar system. The system contains a single transmitter and multiple spatially distributed receivers comprised of both the surveillance and reference antennas. The system consists of two main parts: 1. Local receiver, and 2. Fusion center. Each local receiver detects the signal, processes it, and passes the information to the fusion center for final detection. To take the advantage of spatial diversity, we apply major fusion techniques consisting of hard fusion and soft fusion for the case of multistatic passive radars. Hard fusion techniques are analyzed for the case of different local radar detectors. In terms of soft fusion, a blind technique called equal gain soft fusion technique with random matrix theory-based local detector is analytically and theoretically analyzed under null hypothesis along with the calculation of detection threshold. Furthermore, six novel random matrix theory-based soft fusion techniques are proposed. All the techniques are blind in nature and hence do not require any knowledge of transmitted signal or channel information. Simulation results illustrate that proposed fusion techniques increase detection performance to a reasonable extent compared to other blind fusion techniques.

Presentation of Neurolytic Effect of 10% Lidocaine after Perineural Ultrasound Guided Injection of a Canine Sciatic Nerve: A Pilot Study.

BACKGROUND: Phenol and alcohol have been used to ablate nerves to treat pain but are not specific for nerves and can damage surrounding soft tissue. Lidocaine at concentrations > 8% injected intrathecal in the animal model has been shown to be neurotoxic. Tests the hypothesis that 10% lidocaine is neurolytic after a peri-neural blockade in an ex vivo experiment on the canine sciatic nerve. METHODS: Under ultrasound, one canine sciatic nerve was injected peri-neurally with 10 cc saline and another with 10 cc of 10% lidocaine. After 20 minutes, the sciatic nerve was dissected with gross inspection. A 3 cm segment was excised and preserved in 10% buffered formalin fixative solution. Both samples underwent progressive dehydration and infusion of paraffin after which they were placed on paraffin blocks. The sections were cut at 4 µm and stained with hemoxylin and eosin. Microscopic review was performed by a pathologist from Henry Ford Hospital who was blinded to which experimental group each sample was in. RESULTS: The lidocaine injected nerve demonstrated loss of gross architecture on visual inspection while the saline injected nerve did not. No gross changes were seen in the surrounding soft tissue seen in either group. The lidocaine injected sample showed basophilic degeneration with marked cytoplasmic vacuolation in the nerve fibers with separation of individual fibers and endoneurial edema. The saline injected sample showed normal neural tissue. CONCLUSIONS: Ten percent lidocaine causes rapid neurolytic changes with ultrasound guided peri-neural injection. The study was limited by only a single nerve being tested with acute exposure.

Effect of musculoskeletal pain on sleep architecture in patients with obstructive sleep apnea.

RATIONALE: Obstructive sleep apnea and chronic musculoskeletal pain both affect sleep. Sleep architecture of patients suffering from both is largely unknown. OBJECTIVES: This study seeks to define the sleep architecture of patients with chronic musculoskeletal pain and obstructive sleep apnea. METHODS: Patients with obstructive sleep apnea diagnosed by sleep study during the past 3 years were included. Patients with clinical documentation of chronic musculoskeletal pain constituted cases, while others were classified as controls. MEASUREMENTS: Demographics, clinical factors affecting sleep, medications affecting sleep, Epworth sleepiness scores, and polysomnographic parameters; total sleep time, sleep efficiency, sleep stages, rapid eye movement (REM) sleep onset, apnea-hypopnea index, arousal index, and periodic leg movements were recorded. RESULTS: There were 393 subjects: 200 cases (obstructive sleep apnea and chronic musculoskeletal pain) and 193 controls (obstructive sleep apnea alone). There was significant difference in total sleep time (274.5 ± 62.5 vs. 302.2 ± 60.1 min, p = 0.0001), sleep efficiency (73.54 ± 15.8 vs. 78.76 ± 14.3%, p = 0.0003), and REM sleep onset (148.18 ± 80.5 vs. 124.8 ± 70.9 min, p = 0.006). Subgroup analysis within the obstructive sleep apnea with chronic musculoskeletal pain group revealed that subjects had better total sleep time and sleep efficiency if they were on REM sleep affecting medications (suppressants and stimulants). Those on REM sleep suppressants slept 25.7 min longer and had 6.4% more efficient sleep than those not on REM suppressants (p = 0.0034 and p = 0.0037). CONCLUSION: Patients with obstructive sleep apnea and chronic musculoskeletal pain sleep not only significantly less but also with inferior sleep quality. Their REM sleep is also less in duration and its onset is delayed. Despite low TST and SE, these patients may not exhibit sleepiness.

Treatment for sleep apnea by continuous positive airway pressure improves levels of inflammatory markers - a meta-analysis.

BACKGROUND: Obstructive sleep apnea (OSA) is associated with coronary artery disease (CAD). Intermittent hypoxia associated with OSA increases sympathetic activity and may cause systemic inflammation, which may contribute to CAD in patients with OSA. Treatment with continuous positive airway pressure (CPAP) has been shown to change levels of inflammatory markers. We analyzed data from published studies by a systematic meta-analysis. OBJECTIVE: To asses if treatment for sleep apnea by CPAP will affect levels of inflammatory markers. DATA RESOURCES: PubMed, Embase and Cochrane library. METHODS: Study eligibility criteria full text English studies of adult, human subjects, addressing values of at least one of the inflammatory markers before and after CPAP treatment. We used the definition of OSA as an apnea-hypopnea index (AHI) of ≥ 5/h, reported values in mean and standard deviation or median with range. PARTICIPANTS: Adult, human. INTERVENTIONS: CPAP treatment for OSA. STUDY APPRAISAL AND SYNTHESIS METHOD: A total of 3835 studies were reviewed for inclusion, while 23 studies pooled for analysis. A total of 14 studies with 771 patients were pooled for C-reactive protein (CRP); 9 studies with 209 patients were pooled for tumor necrosis factor-alpha (TNF-α); and 8 studies with 165 patients were pooled for interleukin-6 (IL-6). ENDPOINT DEFINITIONS: THE FOLLOWING INFLAMMATORY MARKERS WERE CHOSEN: CRP, TNF-α, and IL-6. RESULTS: C-reactive protein: Study level means ranged from 0.18 to 0.85 mg/dl before CPAP treatment and 0.10 to 0.72 mg/dl after CPAP treatment. Mean differences, at a study level, ranged from -0.05 to 0.50. The pooled mean difference was 0.14 [95% confidence interval 0.08 to 0.20, p < 0.00001]. There was heterogeneity in this endpoint (df = 13, p < 0.00001, I(2) = 95%). Tumor necrosis factor-α: Study level means ranged from 1.40 to 50.24 pg/ml before CPAP treatment and 1.80 to 28.63 pg/ml after CPAP treatment. Mean differences, at a study level, ranged from -1.23 to 21.61. The pooled mean difference was 1.14 [95% confidence interval 0.12 to 2.15, p = 0.03]. There was heterogeneity in this endpoint (df = 8, p < 0.00001, I2 = 89%). Interleukin-6: Study level means ranged from 1.2 to 131.66 pg/ml before CPAP treatment and 0.45 to 66.04 pg/ml after CPAP treatment. Mean differences, at a study level, ranged from -0.40 to 65.62. The pooled mean difference was 1.01 [95% confidence interval -0.00 to 2.03, p = 0.05]. There was heterogeneity in this endpoint (df = 7, p < 0.00001, I(2) = 95%). LIMITATIONS: Only published data. Studies pooled were mainly small, non-randomized trials. CONCLUSION: Sleep apnea treatment with CPAP improves levels of inflammatory markers.

Laparoscopic modified Sugarbaker technique results in superior recurrence rate.

BACKGROUND: Parastomal hernia (PH) is a frequent complication of stoma formation, occurring in 35-50% of patients. Recurrence after repair is common, ranging from 24 to 54% of cases. We hypothesized that repair using a laparoscopic modified Sugarbaker technique (SB) would result in a superior recurrence rate when compared with other repairs. METHODS: An Institutional Review Board-approved retrospective review of patients who underwent PH repair between 2004 and 2011 was performed. We collected demographics, factors related to ostomy formation, risk factors for hernia, intraoperative and postoperative information, as well as the absence or presence of PH on their last physical examination or imaging study. RESULTS: Forty-nine PH repairs were performed: 33 (67%) para-ileostomy and 16 (33%) para-colostomy. Repairs included 14 laparoscopic modified SB, 19 laparoscopic keyhole, 11 ostomy re-sitings, and 5 open primary repairs. There was no statistically significant difference between groups when comparing age, BMI, smoking status, steroid use, ostomy type, location, primary diagnoses, or complication rate. Recurrence rates were 0% for SB, 58% for keyhole, 64% for re-siting, and 20% for open repair. When SB was compared with all groups, the incidence of recurrence was significantly lower (p < 0.001) but follow-up was as well (7.2 vs 32.7 months). When analysis was restricted to the 28 repairs performed between 2009 and 2011, there was no significant difference between the groups in terms of demographics or follow-up period (7.2 months for SB group versus 11.8 months for all others), but again there was a significant difference in recurrence (0 of 14 for the SB group vs 8 of 14, p < 0.01). In addition, there were no differences in postoperative complication rates among all techniques. CONCLUSION: The modified SB technique may offer patients a significant decrease in the risk of recurrence compared with other PH repair techniques with no significant increase in postoperative complications.