Channel Puncturing Research Articles

On Postoperative Nursing of Middle Meningeal Artery Embolization Combined with Hard Passage Puncture Drainage of Chronic Subdural Hematoma

Objective — To conduct analysis and summary on the nursing experience of 5 patients with chronic subdural hematoma treated by middle meningeal artery embolization and puncture and drainage of hard passage. Methods — 5 patients with chronic subdural hematoma were treated by middle meningeal artery embolization with puncture and drainage of hard passage based chronic subdural hematoma under local anesthesia. Besides, vital signs should be monitored, consciousness and pupil can also be observed, more attention was paid to postoperative nursing after embolization and hard channel puncture and drainage, as well as the prevention of complications. Results — 5 patients were well recovered after operation, and 1 patient developed urinary retention, which was relieved after given active nursing measures. Conclusion — Middle meningeal artery embolization with puncture and drainage for chronic subdural hematoma can be adopted to improve the quality of life of patients, enhance prognosis, as a result, avoiding recurrence. Top priority given to nursing after operation serves as the key to patients' rehabilitation.

A 3D multi-modal intelligent intervention system using electromagnetic navigation for real-time positioning and ultrasound images: a prospective randomized controlled trial.

BackgroundAnesthesia, nerve block, therapeutic injections, and biopsies all require an acupuncture intervention. However, traditional two-dimensional (2D) ultrasound-guided needle puncture is often challenging and therefore requires the use of three-dimensional (3D) ultrasound images to accurately identify and evaluate the patient’s anatomical structure.MethodsIn this study, a 3D multi-modal intelligent intervention system using electromagnetic navigation for real-time positioning and ultrasound images was described. A total of 190 cases requiring puncture were randomly divided into control (conventional 2D ultrasound instrument) and experimental (novel 3D ultrasound imedis9000) groups. The advantages and disadvantages of the two puncture methods were prospectively analyzed in the 190 cases, and the feasibility of electromagnetic navigation real-time positioning was compared to ultrasound imaging.ResultsThis study included 190 cases from two centers that required puncture treatment and were randomly assigned to the control (conventional 2D ultrasound instrument; n=95) or the experimental (novel 3D ultrasound imedis9000; n=95) groups. Percutaneous vascular puncture, percutaneous biopsy, percutaneous bile duct puncture, thoracic paravertebral nerve block, and sciatic nerve block operations were performed separately. The results indicated that the puncture time and number of trials in the experimental group were significantly lower than those in the control group. No significant difference was identified in the basic vital signs between the two groups before and after surgery. The success rate of the novel 3D ultrasound imedis9000 was 100%, and the success rate of the conventional 2D ultrasound instrument was 95.7%. Furthermore, the results also showed that the novel 3D ultrasound imedis9000 and the matching coaxial positioning channel puncture needle had low pain, good toughness and strength, and great convenience.ConclusionsThe new 3D multi-modal intelligent intervention system using electromagnetic navigation real-time positioning and ultrasound images has significant advantages compared with conventional 2D ultrasound in terms of puncture time, number of trials, operation difficulty, and convenience, and is worthy of further promotion and use in clinics.Trial RegistrationBeijing Municipal Drug Administration, 20190015.

Terahertz-Band MIMO-NOMA: Adaptive Superposition Coding and Subspace Detection

We consider the problem of efficient ultra-massive multiple-input multiple-output (UM-MIMO) data detection in terahertz (THz)-band non-orthogonal multiple access (NOMA) systems. We argue that the most common THz NOMA configuration is power-domain superposition coding over quasi-optical doubly-massive MIMO channels. We propose spatial tuning techniques that modify antenna subarray arrangements to enhance channel conditions. Towards recovering the superposed data at the receiver side, we propose a family of data detectors based on low-complexity channel matrix puncturing, in which higher-order detectors are dynamically formed from lower-order component detectors. We first detail the proposed solutions for the case of superposition coding of multiple streams in point-to-point THz MIMO links. We then extend the study to multi-user NOMA, in which randomly distributed users get grouped into narrow cell sectors and are allocated different power levels depending on their proximity to the base station. We show that successive interference cancellation is carried with minimal performance and complexity costs under spatial tuning. We derive approximate bit error rate (BER) equations, and we propose an architectural design to illustrate complexity reductions. Under typical THz conditions, channel puncturing introduces more than an order of magnitude reduction in BER at high signal-to-noise ratios while reducing complexity by approximately 90%.

Low-Complexity Soft-Output MIMO Detectors Based on Optimal Channel Puncturing

Channel puncturing transforms a multiple-input multiple-output (MIMO) channel into a sparse lower-triangular form using the so-called WL decomposition scheme in order to reduce tree-based detection complexity. We propose computationally efficient soft-output detectors based on two forms of channel puncturing: augmented and two-sided. The augmented WL detector (AWLD) employs a punctured channel derived by triangularizing the true channel in augmented form, followed by left-sided Gaussian elimination. The two-sided WL detector (dubbed WLZ) employs right-sided reduction and left-sided elimination to puncture the channel. We prove that augmented channel puncturing is optimal in maximizing the lower-bound on the achievable information rate (AIR) based on a new mismatched detection model. We show that the AWLD decomposes into an MMSE prefilter and channel gain compensation stages, followed by a regular WL detector (WLD) that computes least-squares soft-decision estimates. Similarly, WLZ decomposes into a pre-processing reduction step followed by WLD. AWLD attains the same performance as the existing AIR-based partial marginalization (PM) detector, but with less computational complexity. We empirically show that WLZ attains the best complexity-performance tradeoff among tree-based detectors.

A design process for a 3D printed patient-specific applicator for HDR brachytherapy of the orbit

BackgroundThis report describes a process for designing a 3D printed patient-specific applicator for HDR brachytherapy of the orbit.Case presentationA 34-year-old man with recurrent melanoma of the orbit was referred for consideration of re-irradiation. An applicator for HDR brachytherapy was designed based on the computed tomography (CT) of patient anatomy. The body contour was used to generate an applicator with a flush fit against the patient’s skin while the planning target volume (PTV) was used to devise channels that allow for access and coverage of the tumor bed. An end-to-end dosimetric test was devised to determine feasibility for clinical use. The applicator was designed to conform to the volume and contours inside the orbital cavity. Support wings placed flush with the patient skin provided stability and reproducibility, while 16 source channels of varying length were needed for sufficient access to the target. A solid sheath, printed as an outer support-wall for each channel, prevented bending or accidental puncturing of the surface of the applicator.ConclusionsQuality assurance tests demonstrated feasibility for clinical use. Our experience with available 3D printing technology used to generate an applicator for the orbit may provide guidance for how materials of suitable biomechanical and radiation properties can be used in brachytherapy.

Observation on therapeutic effect of stereotactic soft channel puncture and drainage on hypertensive cerebral hemorrhage.

To evaluate and analyze the therapeutic effect of stereotactic soft channel puncture and drainage on hypertensive cerebral hemorrhage. Sixty patients with hypertensive cerebral hemorrhage admitted to our hospital from September 2014 to September 2019 were selected for study and randomly divided into study group (n=30) and routine group (n=30) according to admission number. Two groups of patients were given basic treatment after admission, while routine group patients were given small bone window hematoma removal, study group patients were given stereotactic soft channel puncture and drainage, and the clinical effects of the two groups were analyzed. The total effective rate of the study group was 96.67%, which was significantly higher than that of the routine group (80.00%), and the difference was statistically significant (P<0.05). The level of independent living in the study group was significantly higher than that in the conventional group, and the level of neurological deficit was lower than that in the conventional group, with statistically significant difference (P<0.05). Before treatment, there was no significant difference in the hematoma volume between the two groups (P>0.05). after treatment for 1, 2 and 4 weeks, the hematoma volume of the two groups decreased, and the hematoma volume of the study group was significantly less than that of the conventional group, with significant difference (P<0.05). There was no difference in CD3+ positive cell rate and CD8+ positive cell rate between the two groups before treatment (P>0.05). After treatment, the CD8+ positive cell rate in the study group was lower than that in the conventional group, and the CD3+ positive cell rate was higher than that in the conventional group, with statistically significant difference (P<0.05). The incidence of postoperative complications such as pulmonary infection, urinary tract infection, liver and kidney dysfunction in the study group was lower than that in the conventional group, and the difference was statistically significant (P<0.05). Stereotactic soft-channel puncture and drainage has the advantages of less trauma, less bleeding, fewer complications and rapid postoperative recovery. It can be used for the treatment of hypertensive cerebral hemorrhage, promote the recovery of neurological function of patients, improve independent living standard and effectively improve prognosis.

Large MIMO Detection Schemes Based on Channel Puncturing: Performance and Complexity Analysis

A family of low-complexity detection schemes based on channel matrix puncturing targeted for large multiple-input multiple-output (MIMO) systems is proposed. It is well known that the computational cost of MIMO detection based on QR decomposition is directly proportional to the number of non-zero entries involved in back-substitution and slicing operations in the triangularized channel matrix, which can be too high for low-latency applications involving large MIMO dimensions. By systematically puncturing the channel to have a specific structure, it is demonstrated that the detection process can be accelerated by employing standard schemes, such as chase detection, list detection, nulling-and-cancellation detection, and sub-space detection on the transformed matrix. The performance of these schemes is characterized and analyzed mathematically, and bounds on the achievable diversity gain and probability of bit error are derived. Surprisingly, it is shown that puncturing does not negatively impact the receive diversity gain in hard-output detectors. The analysis is extended to soft-output detection when computing per-layer bit log-likelihood ratios; it is shown that significant performance gains are attainable by ordering the layer of interest to be at the root when puncturing the channel. Simulations of coded and uncoded scenarios certify that the proposed schemes scale up efficiently both in the number of antennas and constellation size, as well as in the presence of correlated channels. In particular, soft-output per-layer sub-space detection is shown to achieve a 2.5 dB signal-to-noise ratio gain at 10−4 bit error rate in 256-quadratic-amplitude modulation $16\times 16$ MIMO, while saving 77% of nulling-and-cancellation computations.

Dual Turbo MIMO-OFDM Channel Estimation Based on Puncher Technique via UWA Channels

In this study, various techniques of UWA (Underwater Acoustic, UWA) channel estimation for underwater MIMO-OFDM system are studied. Dual turbo channel estimation algorithm based on channel puncture technique is proposed. In order to judge the criteria of channel compensation, difference between the raw received signal and the re-coded information signal is carried out. The uncertain sub-channels are punched by using channel puncture technique and replaced by the responses estimated by MMSE (Minimum Mean Square Error, MMSE) or OMP (Orthogonal Matching Pursuit, OMP) algorithms. Compared with the conventional existing algorithms, the proposed algorithm can effectively reduce the occupancy of pilots, offer confined error propagation and significantly increase the stability of the system with Monte Caro simulation. The results of in-tank-experiment further indorse the reliable performance with improved efficiency of 1.51 bits/s/Hz.