Scalability of Quasi-hysteretic FSM-based Digitally Controlled Single-inductor Dual-string Buck LED Driver To Multiple Strings

There has been growing interest in Single-Inductor Multiple-Output (SIMO) DC-DC converters due to its reduced cost and smaller form factor in comparison with using multiple single-output converters. An application for such a SIMO-based switching converter is to drive multiple LED strings in a multi-channel LED display. This paper proposes a quasi-hysteretic FSM-based digitally controlled Single-Inductor Dual-Output (SIDO) buck switching LED Driver operating in Discontinuous Conduction Mode (DCM) and extends it to drive multiple outputs. Based on the time-multiplexing control scheme in DCM, a theoretical upper limit of the total number of outputs in a SIMO buck switching LED driver for various backlight LED current values can be derived analytically. The advantages of the proposed SIMO LED driver include reducing the controller design complexity by eliminating loop compensation, driving more LED strings without limited by the maximum LED current rating, performing digital dimming with no additional switches required, and optimization of local bus voltage to compensate for variability of LED forward voltage (VF) in each individual LED string with smaller power loss. Loosely-binned LEDs with larger VF variation can therefore be used for reduced LED costs.postprin

Adaptive High-Bandwidth Digitally Controlled Buck Converter with Improved Line and Load Transient Response

Digitally controlled switching converter suffers from bandwidth limitation because of the additional phase delay in the digital feedback control loop. In order to overcome the bandwidth limitation without using a high sampling rate, this paper presents an adaptive third-order digital controller for regulating a voltage-mode buck converter with a modest 2x oversampling ratio. The phase lag due to the ADC conversion time delay is virtually compensated by providing an early estimation of the error voltage for the next sampling time instant, enabling a higher unity-gain bandwidth without compromising stability. An additional pair of low-frequency pole and zero in the third-order controller increases the low-frequency gain, resulting in faster settling time and smaller output voltage deviation during line transient. Both simulation and experimental results demonstrate that the proposed adaptive third-order controller reduces the settling time by 50% in response to a 1 V line transient and 30% in response to a 600 mA load transient, compared to the baseline static second-order controller. The fastest settling time is measured to be around 11.70 s, surpassing the transient performance of conventional digital controllers and approaching that of the state-of-the-art analog-based controllers.postprin

Reset-sensing quasi-V2 single-inductor multiple-output buck converter with reduced cross-regulation

This paper proposes a reset-sensing quasi-V2 single-inductor multiple-output (SIMO) converter with minimal cross-regulation. The conventional quasi-V2 sensing scheme in SIMO converters suffers from serious cross-regulation which is primarily induced by the load differentiation with unbalanced loads. It is shown that the proposed reset-sensing quasi-V2 control scheme can significantly reduce cross-regulation by completely discharging the feed-forward sensing node to zero volts during the idle phase in Discontinuous Conduction Mode (DCM). The cross-regulation with the conventional quasi-V2 single-inductor dual-output (SIDO) converter for a load current step of 150 mA is experimentally verified to be more than 1.25 mV/mA. By employing the proposed quasi-V2 control method, the experimental results demonstrate that the cross-regulation for a load current step of 150 mA is significantly reduced to within 0.087 mV/mA. Hence, with the proposed scheme, a load transient in one output will have a minimal effect on the DC operating point of another output. This enables separate current control at each individually-driven output of a SIMO converter. © IEEE.published_or_final_versio

Colchicine for secondary prevention of ischaemic stroke and atherosclerotic events: a meta-analysis of randomised trials

\ua9 2024 The Authors. Background: Guidelines recommend low-dose colchicine for secondary prevention in cardiovascular disease, but uncertainty remains concerning its efficacy for stroke, efficacy in key subgroups and about uncommon but serious safety outcomes. Methods: In this trial-level meta-analysis, we searched bibliographic databases and trial registries form inception to May 16, 2024. We included randomised trials of colchicine for secondary prevention of ischaemic stroke and major adverse cardiovascular events (MACE: ischaemic stroke, myocardial infarction, coronary revascularisation, or cardiovascular death). Secondary outcomes were serious safety outcomes and mortality. A fixed-effect inverse-variance model was used to generate a pooled estimate of relative risk (RR) with 95% confidence intervals (CI). This study is registered with PROSPERO, CRD42024540320. Findings: Six trials involving 14,934 patients with prior stroke or coronary disease were included. In all patients, colchicine compared with placebo or no colchicine reduced the risk for ischaemic stroke by 27% (132 [1.8%] events versus 186 [2.5%] events, RR 0.73 [95% CI 0.58–0.90]) and MACE by 27% (505 [6.8%] events versus 693 [9.4%] events, with RR 0.73 [0.65–0.81]). Efficacy was consistent in key subgroups (females versus males, age below versus above 70, with versus without diabetes, statin versus non-statin users). Colchicine was not associated with an increase in serious safety outcomes: hospitalisation for pneumonia (109 [1.5%] versus 106 [1.5%], RR 0.99 [0.76–1.30]), cancer (247 [3.5%] versus 255 [3.6%], RR 0.97 [0.82–1.15]), and gastro-intestinal events (153 [2.1%] versus 135 [1.9%]), RR 1.15 [0.91–1.44]. There was no difference in all-cause death (201 [2.7%] versus 181 [2.4%], RR 1.09 [0.89–1.33]), cardiovascular death (70 [0.9%] versus 80 [1.1%], RR 0.89 [0.65–1.23]), or non-cardiovascular death (131 [1.8%] versus 101 [1.4%], RR 1.26 [0.98–1.64]). Interpretation: In patients with prior stroke or coronary disease, colchicine reduced ischaemic stroke and MACE, with consistent treatment effect in key subgroups, and did not increase serious safety events or death. Funding: There was no funding source for this study

The effects of strategic and manufacturing flexibilities and supply chain agility on firm performance in the fashion industry

202301 bckwAccepted ManuscriptOthersThe Hong Kong Polytechnic UniversityPublishe

Simultaneous antegrade and retrograde and approach for upper ureteric and renal stones in modified supine valdivia position: initial experience

Poster MP29-35 fulltext on p. A218-A219Background: Management of large impacted proximal ureteric stone remains controversial. Stone free rate for ESWL is decreased in stones > 2 cm. URSL to impacted upper ureteric stones causes a back-pressure effect which flushes stone fragments to the kidney. Percutaneous antegrade ureteroscopy is an acceptable first-line treatment for (i) large impacted upper ureteric stones(ii) in combination with renal stone removal or (iii) in failure of retrograde access to the stone. Both approaches risk migration of stones to either the more distal ureter or into renal pelvis, resulting in residual stones that are difficult to be retrieved. Simultaneous antegrade and retrograde approach for upper ureteric stone and renal stone theoretically brings about the advantages of both approaches, while minimizing the risk of stone migration and residual stones. However, there is paucity of literature on simultaneous and retrograde approach for impacted upper tract stones. Purpose: To present early experience in management of complex upper ureteric and renal stones using a combined percutaneous and ureteroscopic approach in the supine position under local anaesthesia. Materials and methods: 10 patients who underwent simultaneous antegrade and retrograde approach for complex upper urinary tract stones from June 2009 to March 2010 were entered into the study. Demographics, stone characteristics, perioperative parameters, stone clearance rate were prospectively collected. Data was entered into a database, and analyzed. Results: 10 patients (M:F=7:3) underwent simultaneous antegrade and retrograde approach to upper urinary tract stones under local anaesthesia with sedoanalgesia. The mean age was 63 (range: 50 – 80 y.o.) 6 patients had impacted upper ureteric stones, of which two had previously failed URSL. 2 patients had obstructing PUJ stone. 1 patient had large lower pole stone. 1 patient had obstructing lower ureteric stone with multiple stones in upper, mid and lower poles. Mean stone size (maximum diameter) was 23.3 mm (range: 12 - 54 mm). 6 patients had PCN inserted pre-operatively due to sepsis, acute renal failure or pyonephrosis. 9 patients had hydronephrosis documented on pre-op imaging. Sheathless PCNL with Fr 16 nephroscope was performed in 3 patients with well-formed tract. 7 patients required the use of amplatz sheath, ranging from 18 – 30 Fr. All procedures were performed in the modified supine Valdivia position. 50% had ‘tubeless PCNL’with double J catheter inserted. OT time ranged from 64 to 125 min (mean 93.4 min). 7 patients achieved complete stone clearance on postop AP and KUB film. 1 patient with 8 mm residual stone underwent 2nd look PCNL, and was stone-free thereafter. 2 patients had residual stone of 2mm & 4 mm respectively, and preferred conservative management. Mean blood loss was 39ml and hemoglobin drop was 0.6 g. No patients required blood transfusion. Length of stay ranged from 0.5 days to 5 days (mean 2.65 days). 2 patients developed morbidities – post-op fever and hematuria, and were treated as urinary tract infection. Conclusion: Simultaneous antegrade and retrograde approach for complex upper ureteric stones and renal stones is feasible, with high stone-free rates and low morbidity.link_to_OA_fulltextThe 10th Asian Congress of Urology of the Urological Association of Asia, Taipei, Taiwan, 27-31 August 2010. In International Journal of Urology, 2010, v. 17 n. suppl. 1, poster no. MP29-35, p. A218-A21

A rare complication of transrectal ultrasound guided prostate biopsy: rectourethral fistula

Poster PP29-62 fulltext on p. A324Introduction: Transrectal ultrasound guided prostate biopsy (TRUS Bx) is the standard procedure for investigation of raised prostate specific antigen (PSA) levels or abnormal digital rectal examination (DRE) findings. It is considered a safe and effective diagnostic tool. However, TRUS Bx is not completely free from serious complications. We report a case of rectourethral fistula (RUF) post TRUS Bx, presenting with sepsis. Case report: A 84 gentleman with good past health presented with incidental finding of raised PSA level of 35 ug/L. DRE showed an enlarged, hard and fixed right lobe of prostate, with obliteration of median groove. TRUS Bx was arranged. Three days of oral ciprofloxacin 500mg bd as antibiotics prophylaxis and fleet enema were given before the procedure. Sextant TRUS Bx was performed by radiologist. The prostate gland was markedly enlarged, > 200ml in volume; with irregular outline and distorted internal anatomy. Pathology came back to be adenocarcinoma of prostate, GS 4 +4 over all six cores. Bone scan showed bone metastasis over sacro-coccygeal and bilateral acetabular regions. He was readmitted for post- TRUS Bx fever 2 days afterwards, which did not subside with intravenous antibiotics: Sulperazone (Cefoperazone/ sulbactam) and metronidazole. Urine culture yielded insignificant count, whereas blood C/St grew Bacteroides species. White cell count was persistently elevated at 24.5 ×10^9/L. He developed abdominal distension and DRE showed irregular mucosa over anterior rectal wall CT abdomen & pelvis with contrast showed prostate abscess, rectal perforation with intestinal obstruction, and enlarged prostate with lost of fat plane with seminal vesicles. Defunctioning transverse colostomy was performed due to overt sepsis and an attempt to allow the fistula to heal. Reassessment CT scan 2 months later showed no residual prostate abscess. Loopogram via rectum and transverse colostomy showed no leakage of contrast into urinary system. Closure of colostomy is pending. Concerning the treatment of CA prostate, he opted for hormonal treatment with LHRH agonist. The latest PSA is <0.1 ug/L. Discussion: The most common cause of RUF in modern series is post-radical prostatectomy. Other causes include cryotherapy, pelvic radiotherapy and anorectal surgery. It is rare for rectourethral fistula to occur post TRUS prostate biopsy. Patients with RUF present with urine per rectum, pneumaturia, recurrent urinary tract infections or fecularia, or rarely, as in our case – overt sepsis. There are two approaches in the management of RUF: conservative Vs surgical. Conservative management includes faecal diversion with colostomy and either suprapubic cystostomy or indwelling urethral catheter. The rationale behind conservative management is to allow symptomatic control and attempts to allow spontaneous healing of the fistula. However, conservative management is unpredictable and the time to allow healing is unknown. In our case, the RUF healed with a period of defunctioning colostomy. Conclusion: We have described a case of rectourethral fistula after TRUS Bx, which resolved with defunctioning colostomy and antibiotics. To our knowledge, this is the first reported case of post TRUS Bx rectourethral fistula.link_to_OA_fulltextThe 10th Asian Congress of Urology of the Urological Association of Asia, Taipei, Taiwan, 27-31 August 2010. In International Journal of Urology, 2010, v. 17 n. suppl 1, poster no. PP29-62, p. A32

Combined auditory and optogenetic fMRI for investigation of visual cortical descending modulation of auditory midbrain processing

Scientific Session - fMRI Basic Neuroscience, Including Optogenetics: no. 0481In the auditory system, the midbrain inferior colliculus (IC) receives massive corticofugal projections, yet their functional implications remain unclear. Previous studies utilizing single neuron recordings and electrical activation or cryogenical inactivation of the cortex could not provide a cell-type specific understanding of the large-scale corticofugal modulation effects. This study combines auditory and optogenetic fMRI to investigate the corticofugal influences on auditory midbrain processing. Large-view fMRI was used to monitor the IC noise response during cell-type specific optogenetic stimulation of the VC. The results demonstrate the feasibility of this novel approach and show that VC normally facilitates auditory midbrain responses

Optogenetically-Evoked Somatosensory Inputs Enhance sound Processing in the Auditory System

Combined Educational & Scientific Session: Combining fMRI with Advanced Neurotechniques - abstract no. 0110Brain-wide cross-modal interactions are important for building an accurate perception of the external world. Yet, whether and how somatosensory inputs influence the auditory processing remains unclear. Our recent study showed that low frequency optogenetic stimulation of somatosensory thalamus induced activation in auditory cortex (AC), but did not explore the functional effects on auditory system. This study investigated whether propagation of low frequency inputs from somatosensory system influences auditory processing. The results demonstrated that low frequency long-range propagation from somatosensory system enhanced auditory responses in most auditory structures, including lateral lemniscus, inferior colliculus, medial geniculate body and AC