A Design of Adaptive Control and Communication Protocol for SWIPT System in 180 nm CMOS Process for Sensor Applications.

This paper presents an adaptive control and communication protocol (ACCP) for the ultra-low power simultaneous wireless information and power transfer (SWIPT) system for sensor applications. The SWIPT system-related operations depend on harvested radio frequency (RF) energy from the ambient environment. The necessary power for SWIPT system operation is not always available and it depends on the available RF energy in the ambient environment, transmitted RF power from the SWIPT transmitter, and the distance from the transmitter and channel conditions. Thus, an efficient control and communication protocol is required which can control the SWIPT system for sensor applications which mainly consists of a transmitter and a receiver. Multiple data frame structures are used to optimize the exchange of bits for the communication and control of the SWIPT system. Both SWIPT transmitter and receiver are capable of using multiple modulation schemes which can be switched depending on the channel condition and the available RF energy in the ambient environment. This provides support for automatic switching between the time switching scheme and power splitting scheme for the distribution of received RF power in the SWIPT receiver. It also adjusts the digital clock frequency at the SWIPT receiver according to the harvested power level to optimize the power consumption. The SWIPT receiver controller with ACCP is implemented in 180 nm CMOS technology. The RF frequency of the SWIPT operation is 5.8 GHz. Digital clock frequency at the SWIPT receiver can be adjusted between 32 kHz and 2 MHz which provides data rates from 8 to 500 kbps, respectively. The power consumption and area utilization are 12.3 µW and 0.81 mm².

A Fully Integrated Bluetooth Low-Energy Transceiver with Integrated Single Pole Double Throw and Power Management Unit for IoT Sensors.

This paper presents a low power Gaussian Frequency-Shift Keying (GFSK) transceiver (TRX) with high efficiency power management unit and integrated Single-Pole Double-Throw switch for Bluetooth low energy application. Receiver (RX) is implemented with the RF front-end with an inductor-less low-noise transconductance amplifier and 25% duty-cycle current-driven passive mixers, and low-IF baseband analog with a complex Band Pass Filter(BPF). A transmitter (TX) employs an analog phase-locked loop (PLL) with one-point GFSK modulation and class-D digital Power Amplifier (PA) to reduce current consumption. In the analog PLL, low power Voltage Controlled Oscillator (VCO) is designed and the automatic bandwidth calibration is proposed to optimize bandwidth, settling time, and phase noise by adjusting the charge pump current, VCO gain, and resistor and capacitor values of the loop filter. The Analog Digital Converter (ADC) adopts straightforward architecture to reduce current consumption. The DC-DC buck converter operates by automatically selecting an optimum mode among triple modes, Pulse Width Modulation (PWM), Pulse Frequency Modulation (PFM), and retention, depending on load current. The TRX is implemented using 1P6M 55-nm Complementary Metal-Oxide-Semiconductor (CMOS) technology and the die area is 1.79 mm2. TRX consumes 5 mW on RX and 6 mW on the TX when PA is 0-dBm. Measured sensitivity of RX is -95 dBm at 2.44 GHz. Efficiency of the DC-DC buck converter is over 89% when the load current is higher than 2.5 mA in the PWM mode. Quiescent current consumption is 400 nA from a supply voltage of 3 V in the retention mode.

The influence of feed energy density and a formulated additive on rumen and rectal temperature in hanwoo steers.

The present study investigated the optimum blending condition of protected fat, choline and yeast culture for lowering of rumen temperature. The Box Benken experimental design, a fractional factorial arrangement, and response surface methodology were employed. The optimum blending condition was determined using the rumen simulated in vitro fermentation. An additive formulated on the optimum condition contained 50% of protected fat, 25% of yeast culture, 5% of choline, 7% of organic zinc, 6.5% of cinnamon, and 6.5% of stevioside. The feed additive was supplemented at a rate of 0.1% of diet (orchard grass:concentrate, 3:7) and compared with a control which had no additive. The treatment resulted in lower volatile fatty acid (VFA) concentration and biogas than the control. To investigate the effect of the optimized additive and feed energy levels on rumen and rectal temperatures, four rumen cannulated Hanwoo (Korean native beef breed) steers were in a 4×4 Latin square design. Energy levels were varied to low and high by altering the ratio of forage to concentrate in diet: low energy (6:4) and high energy (4:6). The additive was added at a rate of 0.1% of the diet. The following parameters were measured; feed intake, rumen and rectal temperatures, ruminal pH and VFA concentration. This study was conducted in an environmentally controlled house with temperature set at 30°C and relative humidity levels of 70%. Steers were housed individually in raised crates to facilitate collection of urine and feces. The adaptation period was for 14 days, 2 days for sampling and 7 days for resting the animals. The additive significantly reduced both rumen (p<0.01) and rectal temperatures (p<0.001) without depressed feed intake. There were interactions (p<0.01) between energy level and additive on ruminal temperature. Neither additive nor energy level had an effect on total VFA concentration. The additive however, significantly increased (p<0.01) propionate and subsequently had lower acetate:propionate (A/P) ratios than non-additive supplementation. High concentrate diets had significantly lower pH. Interactions between energy and additive were observed (p<0.01) in ammonia nitrogen production. Supplementation of diets with the additive resulted in lower rumen and rectal temperatures, hence the additive showed promise in alleviating undesirable effects of heat stress in cattle.

Impact of Atrial Fibrillation on Patients Undergoing Transcatheter Aortic Valve Implantation (TAVI): The K-TAVI Registry.

PURPOSE: The incidence and prognostic implications of atrial fibrillation (AF) in patients with severe aortic stenosis (AS) undergoing transcatheter aortic valve implantation (TAVI) are controversial, especially for Korean patients. Furthermore, the pattern of antithrombotic therapy for these patients is unknown. The present study sought to identify the impact of AF on Korean patients undergoing TAVI and demonstrate the status of antithrombotic therapy for these patients. MATERIALS AND METHODS: A total of 660 patients who underwent TAVI for severe AS were recruited from the nationwide K-TAVI registry in Korea. The enrolled patients were stratified into sinus rhythm (SR) and AF groups. The primary endpoint was all-cause death at 1-year. RESULTS: AF was recorded in 135 patients [pre-existing AF 108 (16.4%) and new-onset AF 27 (4.1%)]. The rate of all-cause death at 1 year was significantly higher in patients with AF than in those with SR [16.2% vs. 6.4%, adjusted hazard ratio (HR): 2.207, 95% confidence interval (CI): 1.182-4.120, p=0.013], regardless of the onset timing of AF. The rate of new pacemaker insertion at 1 year was also significantly higher in patients with AF than in those with SR (14.0% vs. 5.5%, adjusted HR: 3.137, 95%CI: 1.621-6.071, p=0.001). Among AF patients, substantial number of patients received the combination of multiple antithrombotic agents (77.8%), and the most common combination was that of aspirin and clopidogrel (38.1%). CONCLUSION: AF was an independent predictor of 1-year mortality and new pacemaker insertion in Korean patients undergoing TAVI.

Angiographic and intravascular ultrasound follow up of paclitaxel- and sirolimus-eluting stent after poststent high-pressure balloon dilation: from the poststent optimal stent expansion trial.

OBJECTIVES: The aims of this study were to identify the efficacy of optimal stent expansion (OSE) according to the Multicenter Ultrasound Stenting in Coronaries Study (MUSIC Study) criteria in drug-eluting stent (DES) and compare paclitaxel-eluting stent (PES) to sirolimus-eluting stent (SES). BACKGROUND: Although poststent high-pressure balloon dilatation is proposed after bare metal stent implantation according to OSE, defined by the criteria of the MUSIC Study, very little data are available in DES. METHODS: Two hundred fifty patients (M:F = 149:101; age, 61.5 ± 9.2 years) who underwent 9-month follow-up angiography in the Poststent Optimal Stent Expansion Trial (POET) were included in this study. We assessed angiographic in-stent restenosis (ISR) and neointima volume (NV) using IVUS at 9 months. RESULTS: At 9-month follow up, there were no significant differences in ISR and NV index (NV/stent length, mm(2) ) between patients with and without OSE. However, the rate of ISR and NV index were higher in PES [ISR: 18 (13.7%) and 4 (3.4%), P = 0.004; NV index: 1.02 ± 0.99 mm(2) and 0.21 ± 0.37, P < 0.001 in PES and SES]. CONCLUSIONS: OSE according to the MUSIC Study criteria was not related to ISR and NV in the DES era but PES had a significantly higher ISR rate and NV than SES after poststent high-pressure balloon dilatation.

Scar formation after lower eyelid incision for reconstruction of the inferior orbital wall related to the lower eyelid crease or ridge in Asians.

BACKGROUND: Transcutaneous lower eyelid approaches are associated with a risk of postoperative scarring depending on the distance between the incision line and the lower eyelid margin. The lower eyelid crease of Caucasians corresponds to a ridge-shaped fold in young Asians. However, this relationship has not been sufficiently evaluated in the latter. The authors, therefore, investigated the location of the scar and the lower eyelid crease or ridge to find the optimal location for the incision line. METHODS: This study included 60 out of 139 patients who underwent inferior orbital wall reconstruction through a lower eyelid skin incision between July 2019 and June 2020. According to the location of the scar, the patients were classified into three groups: group A ( ≥ 2 mm above the lower eyelid crease or ridge), group B (within the lower eyelid crease or ridge to 2 mm above the lower eyelid crease or ridge), and group C (within the lower eyelid crease or ridge to 2 mm below the lower eyelid crease or ridge). At 6 or 12 months after surgery, the Patient and Observer Scar Assessment Scale (POSAS) score was obtained, the distance between the lower eyelid margin and the scar (DMS) and the distance between the margins of the peripheral pupil and the lower eyelid (DMPE) were measured, and the occurrence of ectropion was evaluated. RESULTS: Group B had the lowest POSAS score (A: 22.7 ± 8.0, B: 20.9 ± 2.4, C: 32.5 ± 4.1, p < 0.001). Linear regression analysis showed that the DMS was positively correlated with the POSAS score (p < 0.001) and that the risk of DMPE widening increased as the DMS decreased (p = 0.029). None of the patients had ectropion. CONCLUSION: When using the transcutaneous approach for inferior orbital wall reconstruction, the optimal incision site is within the lower eyelid crease or ridge to 2 mm above the lower eyelid crease or ridge.

Comparison of the effect of preinterventional arterial remodeling on intimal hyperplasia after implantation of a sirolimus- or paclitaxel-eluting stent.

BACKGROUND: We compared the effect of arterial remodeling on intimal hyperplasia (IH) after the implantation of a sirolimus-eluting stent (SES) and a paclitaxel-eluting stent (PES). METHODS: The study population consisted of patients with positive or intermediate remodeling and negative remodeling. RESULTS: Sixty-nine patients had positive or intermediate remodeling and 107 patients had negative remodeling. At follow-up, late loss was significantly larger (0.58 +/- 0.65 vs. 0.38 +/- 0.55 mm; p = 0.026) in the patients with positive or intermediate remodeling. The IH volume (22.6 +/- 26.2 vs. 12.4 +/- 17.4 mm(3); p = 0.002) and the percent IH (12.9 +/- 14.8 vs. 7.0 +/- 9.6%; p = 0.002) were significantly higher in the patients with positive or intermediate remodeling. Compared to negative remodeling, the IH volume was higher in the PES patients with positive or intermediate remodeling, but this difference was not noted in the SES patients. Multiple-regression analysis revealed that arterial remodeling was a significant independent variable for predicting IH volume in the PES patients (p = 0.018). A positive correlation was found between the remodeling index and the IH volume in the PES patients (r = 0.234, p = 0.028), but not in the SES patients. CONCLUSIONS: This prospective observational intravascular ultrasound study showed that drug-eluting stents may have a different effect on reducing IH accumulation in lesions with preinterventional positive remodeling characteristics which may be related to the different properties of the drug and delivery platform.

Intravascular ultrasound evaluation of optimal drug-eluting stent expansion after poststent balloon dilation using a noncompliant balloon versus a semicompliant balloon (from the Poststent Optimal Stent Expansion Trial [POET]).

The impact of type of balloon such as noncompliant (NC; Quantum) or semicompliant (SC; Maverick(2)) used after stent dilation on optimal stent expansion (OSE) has not been established for drug-eluting stents (DESs). We conducted a prospective multicenter, randomized study to compare NC with SC balloons after stent balloon dilatation. A total of 301 patients (127 men, 83 women, 62 +/- 9 years of age) treated with a DES (sirolimus-eluting stent [SES], n = 152; paclitaxel-eluting stent, n = 149) were included. OSE followed the definition of the Multicenter Ultrasound Stenting in Coronaries (MUSIC) study. The primary end point was the incidence of OSE using intravascular ultrasound according to type of balloon. Baseline characteristics of each group showed no significant differences. OSE in the SC balloon group was achieved at higher rates than the NC balloon group (53 +/- 35%, vs 73 +/- 48%, p = 0.022 in all stents; 25 +/- 33%, vs 36, 48%, p = 0.051 in SESs). However, any differences in the achievement of OSE between the NC and SC balloon groups were not present in paclitaxel-eluting stents. In conclusion, despite postadjuvant balloon inflations with high pressures, underexpansion of the DES was seen commonly. Between the 2 types of balloon for adjuvant dilation after DES implantation, same-size SC balloons could be more useful for obtaining OSE than NC balloons, especially in SESs.

Relation of ruptured plaque culprit lesion phenotype and outcomes in patients with ST elevation acute myocardial infarction.

We used virtual histology intravascular ultrasound (VH-IVUS) to assess culprit plaque rupture in 172 patients with ST-segment elevation acute myocardial infarction. VH-IVUS-defined thin-capped fibroatheroma (VH-TCFA) had necrotic core (NC) > 10% of plaque area, plaque burden > 40%, and NC in contact with the lumen for ≥ 3 image slices. Ruptured plaques were present in 72 patients, 61% of which were located in the proximal 30 mm of a coronary artery. Thirty-five were classified as VH-TCFA and 37 as non-VH-TCFA. Vessel size, lesion length, plaque burden, minimal lumen area, and frequency of positive remodeling were similar in VH-TCFA and non-VH-TCFA. However, the NC areas within the rupture sites of VH-TCFAs were larger compared to non-VH-TCFAs (p = 0.002), while fibrofatty plaque areas were larger in non-VH-TCFAs (p < 0.0001). Ruptured plaque cavity size was correlated with distal reference lumen area (r = 0.521, p = 0.00002), minimum lumen area (r = 0.595, p < 0.0001), and plaque area (r = 0.267, p = 0.033). Sensitivity and specificity curve analysis showed that a minimum lumen area of 3.5 mm2, a distal reference lumen area of 7.5 mm2, and a maximum NC area of 35% best predicted plaque rupture. Although VH-TCFA (35 of 72) was the most frequent phenotype of plaque rupture in ST-segment elevation myocardial infarction, plaque rupture also occurred in non-VH-TCFA: pathologic intimal thickening (8 of 72), thick-capped fibroatheroma (1 of 72), and fibrotic (14 of 72) and fibrocalcified (14 of 72) plaque. In conclusion, not all culprit plaque ruptures in patients with ST-segment elevation myocardial infarction occur as a result of TCFA rupture; a prominent fibrofatty plaque, especially in a proximal vessel, may be another form of vulnerable plaque. Further study should identify additional factors causing plaque rupture.

Efficacy of high-dose atorvastatin loading before primary percutaneous coronary intervention in ST-segment elevation myocardial infarction: the STATIN STEMI trial.

OBJECTIVES: This study sought to determine the efficacy of high-dose atorvastatin in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI). BACKGROUND: Previous randomized trials have demonstrated that statin pre-treatment reduced major adverse cardiac events (MACEs) in patients with stable angina pectoris and acute coronary syndrome. However, no randomized studies have been carried out with STEMI patients in a primary PCI setting. METHODS: A total 171 patients with STEMI were randomized to 80-mg atorvastatin (n = 86) or 10-mg atorvastatin (n = 85) arms for pre-treatment before PCI. All patients were prescribed clopidogrel (600 mg) before PCI. After PCI, both groups were treated with atorvastatin (10 mg). The primary end point was 30-day incidence of MACE including death, nonfatal MI, and target vessel revascularization. Secondary end points included corrected thrombolysis in myocardial infarction frame count, myocardial blush grade, and ST-segment resolution at 90 min after PCI. RESULTS: MACE occurred in 5 (5.8%) and 9 (10.6%) patients in the 80-mg and 10-mg atorvastatin pre-treatment arms, respectively (p = 0.26). Corrected thrombolysis in myocardial infarction frame count was lower in the 80-mg atorvastatin arm (26.9 +/- 12.3 vs. 34.1 +/- 19.0, p = 0.01). Myocardial blush grade and ST-segment resolution were also higher in the 80-mg atorvastatin arm (2.2 +/- 0.8 vs. 1.9 +/- 0.8, p = 0.02 and 61.8 +/- 26.2 vs. 50.6 +/- 25.8%, p = 0.01). CONCLUSIONS: High-dose atorvastatin pre-treatment before PCI did not show a significant reduction of MACEs compared with low-dose atorvastatin but did show improved immediate coronary flow after primary PCI. High-dose atorvastatin may produce an optimal result for STEMI patients undergoing PCI by improving microvascular myocardial perfusion. (Efficacy of High-Dose AtorvaSTATIN Loading Before Primary Percutaneous Coronary Intervention in ST-Elevation Myocardial Infarction [STATIN STEMI]; NCT00808717).