Evaluation of Single-Chip, Real-Time Tomographic Data Processing on FPGA SoC Devices.

A novel approach to tomographic data processing has been developed and evaluated using the Jagiellonian positron emission tomography scanner as an example. We propose a system in which there is no need for powerful, local to the scanner processing facility, capable to reconstruct images on the fly. Instead, we introduce a field programmable gate array system-on-chip platform connected directly to data streams coming from the scanner, which can perform event building, filtering, coincidence search, and region-of-response reconstruction by the programmable logic and visualization by the integrated processors. The platform significantly reduces data volume converting raw data to a list-mode representation, while generating visualization on the fly.

Nasogastric Tube Insertion in Anesthetized Intubated Patients Undergoing Laparoscopic Hysterectomies: A Comparative Study of Three Techniques.

BACKGROUND: Insertion of a nasogastric tube (NGT) in an anesthetized, comatose intubated patient is not always as easy as in a conscious, cooperative patient. Various techniques have been tried with varying success. The aim of this randomized study was to compare and evaluate the two techniques of NGT insertion with the conventional technique of insertion with respect to success rate, time taken for insertion and adverse effects. MATERIALS AND METHODS: Patients admitted for laparoscopic hysterectomy were chosen and then were divided into three equal groups of forty each, by randomized technique. Group C included patients in whom conventional method was used to insert NGT. Group R where reverse Sellick's technique was used. Group F where neck flexion with lateral pressure was used. RESULTS: Both the techniques were better than the conventional method. Among both the techniques, reverse Sellick's technique was the best method but not without adverse effects. The required insertion time was very less and success in the first attempt was more in the group where reverse Sellick's was used. CONCLUSION: Modified techniques of NGT insertion were better than the conventional method. Further studies after eliminating major limitations are required to really find a superior technique.

Calculation of the time resolution of the J-PET tomograph using kernel density estimation.

In this paper we estimate the time resolution of the J-PET scanner built from plastic scintillators. We incorporate the method of signal processing using the Tikhonov regularization framework and the kernel density estimation method. We obtain simple, closed-form analytical formulae for time resolution. The proposed method is validated using signals registered by means of the single detection unit of the J-PET tomograph built from a 30 cm long plastic scintillator strip. It is shown that the experimental and theoretical results obtained for the J-PET scanner equipped with vacuum tube photomultipliers are consistent.

Postoperative pain relief with epidural buprenorphine versus epidural butorphanol in laparoscopic hysterectomies: A comparative study.

BACKGROUND: The purpose of this study was to compare the safety and efficacy of postoperative analgesia with epidural buprenorphine and butorphanol tartrate. METHODS: Sixty patients who were scheduled for elective laparoscopic hysterectomies were randomly enrolled in the study. At the end of the surgery, in study Group A 1 ml (0.3 mg) of buprenorphine and in Group B 1 ml (1 mg) of butorphanol tartrate both diluted to 10 ml with normal saline was injected through the epidural catheter. Visual analog pain scales (VAPSs) were assessed every hour till the 6(th) h, then 2(nd) hourly till the 12(th) h. To assess sedation, Ramsay sedation score was used. The total duration of postoperative analgesia was taken as the period from the time of giving epidural drug until the patients first complain of pain and the VAPS is more than 6. Patients were observed for any side effects such as respiratory depression, nausea, vomiting, hypotension, bradycardia, pruritus, and headache. RESULTS: Buprenorphine had a longer duration of analgesia when compared to butorphanol tartrate (586.17 ± 73.64 vs. 342.53 ± 47.42 [P < 0.001]). Nausea, vomiting (13% vs. 10%), and headache (20% vs. 13%) were more in buprenorphine group; however, sedation score and pruritus (3% vs. 6%) were found to be more with butorphanol. CONCLUSION: Epidural buprenorphine significantly reduced pain and increased the quality of analgesia with a longer duration of action and was a better alternative to butorphanol for postoperative pain relief.

Time resolution of the plastic scintillator strips with matrix photomultiplier readout for J-PET tomograph.

Recent tests of a single module of the Jagiellonian Positron Emission Tomography system (J-PET) consisting of 30 cm long plastic scintillator strips have proven its applicability for the detection of annihilation quanta (0.511 MeV) with a coincidence resolving time (CRT) of 0.266 ns. The achieved resolution is almost by a factor of two better with respect to the current TOF-PET detectors and it can still be improved since, as it is shown in this article, the intrinsic limit of time resolution for the determination of time of the interaction of 0.511 MeV gamma quanta in plastic scintillators is much lower. As the major point of the article, a method allowing to record timestamps of several photons, at two ends of the scintillator strip, by means of matrix of silicon photomultipliers (SiPM) is introduced. As a result of simulations, conducted with the number of SiPM varying from 4 to 42, it is shown that the improvement of timing resolution saturates with the growing number of photomultipliers, and that the [Formula: see text] configuration at two ends allowing to read twenty timestamps, constitutes an optimal solution. The conducted simulations accounted for the emission time distribution, photon transport and absorption inside the scintillator, as well as quantum efficiency and transit time spread of photosensors, and were checked based on the experimental results. Application of the [Formula: see text] matrix of SiPM allows for achieving the coincidence resolving time in positron emission tomography of [Formula: see text]0.170 ns for 15 cm axial field-of-view (AFOV) and [Formula: see text]0.365 ns for 100 cm AFOV. The results open perspectives for construction of a cost-effective TOF-PET scanner with significantly better TOF resolution and larger AFOV with respect to the current TOF-PET modalities.