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1.
Sensors (Basel) ; 22(13)2022 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-35808197

RESUMO

The inductor was primarily developed on a low-voltage CMOS tunable active inductor (CTAI) for radar applications. Technically, the factors to be considered for VCO design are power consumption, low silicon area, high frequency with reasonable phase noise, an immense quality (Q) factor, and a large frequency tuning range (FTR). We used CMOS tunable active inductor (TAI) topology relying on cascode methodology for 24 GHz frequency operation. The newly configured TAI adopts the additive capacitor (Cad) with the cascode approach, and in the subthreshold region, one of the transistors functions as the TAI. The study, simulations, and measurements were performed using 65nm CMOS technology. The assembled circuit yields a spectrum from 21.79 to 29.92 GHz output frequency that enables sustainable platforms for K-band and Ka-band operations. The proposed design of TAI demonstrates a maximum Q-factor of 6825, and desirable phase noise variations of -112.43 and -133.27 dBc/Hz at 1 and 10 MHz offset frequencies for the VCO, respectively. Further, it includes enhanced power consumption that varies from 12.61 to 23.12 mW and a noise figure (NF) of 3.28 dB for a 24 GHz radar application under a low supply voltage of 0.9 V.

2.
Sensors (Basel) ; 22(2)2022 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-35062561

RESUMO

A 24 GHz highly-linear upconversion mixer, based on a duplex transconductance path (DTP), is proposed for automotive short-range radar sensor applications using the 65-nm CMOS process. A mixer with an enhanced transconductance stage consisting of a DTP is presented to improve linearity. The main transconductance path (MTP) of the DTP includes a common source (CS) amplifier, while the secondary transconductance path (STP) of the DTP is implemented as an improved cross-quad transconductor (ICQT). Two inductors with a bypass capacitor are connected at the common nodes of the transconductance stage and switching stage of the mixer, which acts as a resonator and helps to improve the gain and isolation of the designed mixer. According to the measured results, at 24 GHz the proposed mixer shows that the linearity of output 1-dB compression point (OP1dB) is 3.9 dBm. And the input 1-dB compression point (IP1dB) is 0.9 dBm. Moreover, a maximum conversion gain (CG) of 2.49 dB and a noise figure (NF) of 3.9 dB is achieved in the designed mixer. When the supply voltage is 1.2 V, the power dissipation of the mixer is 3.24 mW. The mixer chip occupies an area of 0.42 mm2.

3.
Sensors (Basel) ; 22(22)2022 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-36433289

RESUMO

With the recent growth of the Internet of Things (IoT) and the demand for faster computation, quantized neural networks (QNNs) or QNN-enabled IoT can offer better performance than conventional convolution neural networks (CNNs). With the aim of reducing memory access costs and increasing the computation efficiency, QNN-enabled devices are expected to transform numerous industrial applications with lower processing latency and power consumption. Another form of QNN is the binarized neural network (BNN), which has 2 bits of quantized levels. In this paper, CNN-, QNN-, and BNN-based pattern recognition techniques are implemented and analyzed on an FPGA. The FPGA hardware acts as an IoT device due to connectivity with the cloud, and QNN and BNN are considered to offer better performance in terms of low power and low resource use on hardware platforms. The CNN and QNN implementation and their comparative analysis are analyzed based on their accuracy, weight bit error, RoC curve, and execution speed. The paper also discusses various approaches that can be deployed for optimizing various CNN and QNN models with additionally available tools. The work is performed on the Xilinx Zynq 7020 series Pynq Z2 board, which serves as our FPGA-based low-power IoT device. The MNIST and CIFAR-10 databases are considered for simulation and experimentation. The work shows that the accuracy is 95.5% and 79.22% for the MNIST and CIFAR-10 databases, respectively, for full precision (32-bit), and the execution time is 5.8 ms and 18 ms for the MNIST and CIFAR-10 databases, respectively, for full precision (32-bit).


Assuntos
Computadores , Redes Neurais de Computação , Simulação por Computador , Bases de Dados Factuais
4.
Sensors (Basel) ; 21(18)2021 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-34577325

RESUMO

A 24 GHz high linear, high-gain up-conversion mixer is realized for fifth-generation (5G) applications in the 65 nm CMOS process. The mixer's linearity is increased by applying an Improved Derivative Super-Position (I-DS) technique cascaded between the mixer's transconductance and switching stage. The high gain and stability of amplifiers in the transconductance stage of the mixer are achieved using novel tunable capacitive cross-coupled common source (TCC-CS) transistors. Using the I-DS, the third-order non-linear coefficient of current is closed to zero, enhancing the linearity. Additionally, a TCC-CS, which is realized by varactors, neutralizes the gate-to-drain parasitic capacitance (Cgd) of transistors in the transconductance stage of the mixer and contributes to the improvement of the gain and stability of the mixer. The measured 1 dB compression point OP1dB of the designed mixer is 4.1 dBm and IP1dB is 0.67 dBm at 24 GHz. The conversion gain of 4.1 dB at 24 GHz and 3.2 ± 0.9 dB, from 20 to 30 GHz is achieved in the designed mixer. Furthermore, a noise figure of 3.8 dB is noted at 24 GHz. The power consumption of the mixer is 4.9 mW at 1.2 V, while the chip area of the designed mixer is 0.4 mm2.

5.
Int Orthop ; 39(6): 1121-7, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25631686

RESUMO

PURPOSE: Paediatric femur neck fractures are exceedingly rare owing to dense bone surrounded by a strong periosteum; they account for 1 % of paediatric fractures and are usually associated with high energy trauma. METHODS: This was a prospective multicenter therapeutic study on pediatric femoral neck fractures from June 2004 to September 2013 at three centres in Odisha, India. Children with femoral neck fractures (Delbet type 2 and 3) who were operated and completed a minimum one-year follow-up were included. We divided the neck of femur (100 %) into four zones (25 % each), with zone I being highly unstable and zone IV being most stable. Implants for fixation, as suggested by pre-operative zone distribution, were used. RESULTS: Twenty-eight children were studied with mean two- to seven-year follow-up. In 23 children cancellous screws were used. In zone I Smooth Moore's pins that crossed the epiphysis were the implant of choice. Causes were avascular necrosis (14.2 %), nonunion (7.14 %) and one case of implant failure, while coxa vara was encountered in two instances. Functional results (Ratliff's criteria) were good in 82.1 %, fair in 7.1 % and poor in 10.7 % of patients; the mean IOWA hip scores were 96, 94 and 98, respectively. CONCLUSION: Early surgical intervention hastens recovery, rehabilitation and return to school and decreases the risk of developing avascular necrosis. We suggest Smooth Pins fixation in zones I and II (nearer to zone I) and cancellous screw fixation in zones II, III and IV. Decompression of hip joint by capsulotomy releases the tamponade effect and should be performed in all cases of paediatric femoral neck fractures.


Assuntos
Fraturas do Colo Femoral/cirurgia , Fixação Interna de Fraturas/métodos , Adolescente , Criança , Pré-Escolar , Descompressão Cirúrgica , Feminino , Fraturas do Colo Femoral/diagnóstico por imagem , Necrose da Cabeça do Fêmur/classificação , Necrose da Cabeça do Fêmur/prevenção & controle , Humanos , Índia , Liberação da Cápsula Articular , Masculino , Estudos Prospectivos , Radiografia , Resultado do Tratamento
6.
Arch Trauma Res ; 5(4): e36406, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28144606

RESUMO

BACKGROUND: Scapula fractures occur in approximately 1% of all fractures and constitute about 3% - 5% of all injuries of the shoulder joint. OBJECTIVES: This study aimed to evaluate the clinical outcomes of 20 surgically treated patients with displaced glenoid fractures after stabilization with distal radius plate. METHODS: Between 2012 and 2015, at 2 centers (HMCH & SHCE) of Bhubaneswar Odisha, we stabilized 20 scapular intra-articular fractures surgically with distal radius locking plate and studied the outcome of the surgeries. The outcome of the 20 fractures was determined using the Constant and Murley score. Both shoulders were assessed and the score on the injured side was given as a percentage of that on the uninjured side. RESULTS: The median score was 88% (mean 65%, range 30 to 100). The median score for strength was 21/25 (mean 19, range 0 to 25) and that for pain 11/15 (mean 11, range 5 to 15). The median functional score was 16/20 (mean 15, range 0 to 20). The mean range of active abduction of the shoulder was 135° (20 to 180), the mean range of flexion 138° (20 to 180) and the mean range of external rotation 38° (0 to 100). Five patients showed excellent result; 11 patients showed good result; three patients showed fair result and one patient had poor outcome according to the Constant-Murley score. A superficial infection settled with antibiotics after operation in one patient whose score at final follow-up was 96%. In one patient, delayed healing was reported because of infection. One patient with stiffness of the shoulder at six weeks underwent manipulation under anesthesia with a follow-up score of 81%. CONCLUSIONS: Various fixation modalities have been described in the literature, however fixation of intra-articular fracture of glenoid with distal radius locking plate for articular reconstruction in the presented series provides good functional outcome with early restoration of the range of motion of the shoulder.

7.
J Orthop Case Rep ; 5(3): 29-31, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-27299062

RESUMO

INTRODUCTION: Isolated trapezium fractures accounts for 3-5% of all carpal fractures, are often missed on initial presentation. Trapezial fractures should be treated early given its importance in grip and pinch. We report a rare isolated coronal fracture of trapezium, following fall on an outstretched hand. CASE REPORT: A 40-year-old right lady presented with pain in right hand due to fall on out stretched hand. The radial half of wrist and lower forearm were swollen. Tenderness over trapezium and 1st metacarpal base with terminal thumb movements restricted. X-Ray revealed undisplaced incomplete coronal fracture of the trapezium. CT scan confirmed coronal split fracture of the trapezium with a major volar fragment and a dorsal fragment without articular involvement. The patient refused operative intervention. Fracture was treated conservatively. The follow-up radiographs showed normal articular relationship of the trapezium with the base of first metacarpal and scaphoid. The fracture healed with no complications. CONCLUSION: Carpal fracture diagnosis requires high clinical suspicion. X-Rays and CT scans define pattern orientation and understanding.

8.
Geriatr Orthop Surg Rehabil ; 6(4): 269-75, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26623161

RESUMO

INTRODUCTION: Osteoarthritis (OA) is the most common age-related joint disease affecting >80% people beyond 55 years of age. It is a leading cause of elderly visit to outpatient departments and accounts for almost half of all nonsteroidal anti-inflammatory drug prescriptions. The burden and impact of knee OA in Indian population and extent of public health services usage by people with OA are not known. METHODS: We performed a prospective blinded multicenter screening and therapeutic study from June 2013 to June 2014 at 3 centers to screen patients >55 years with knee OA to assess quality of life, functional disability, and limitation of functions and to compare the effectiveness of hip and leg strengthening exercise programs in these patients. Functional disability was assessed by Western Ontario and McMaster's Universities OA index (WOMAC), Friedman, and Wyman Scores; locomotor function was assessed by walking status, Visual Analog Scale (VAS), and 30-second timed chair stand tests; and quality of life was assessed by Short Form-36 (SF-36). RESULTS: Of 2854 patients screened, 2054 (72%) patients had OA (male:female-1.9:1) with mean age of 63 years and standard deviation of 8. Of 2054 patients, 226 patients were randomly selected for therapeutic study. In remaining 1828 patients, baseline 10-meter walk test (10MWT) was 0.3 m/s, mean SF-36 Physical Component Score (PCS) was 31.3, and Mental Component Score (MCS) was 34.2. At 3 months, 79% patients were comfortable with significant VAS, WOMAC, Friedman-Wyman Scores, 10MWT, and timed chair test improvements in patients who performed lifestyle modifications and exercises (P = .04). Short Form-36 improved, mean PCS was 43.6, and MCS was 54.2. At 3 months, 274 (15%) patients were unsatisfied among whom 26% and 74% were treated with arthroscopic procedures and arthroplasty, respectively. Isolated hip and leg strengthening exercise programs similarly improved knee pain, function, and quality of life. CONCLUSION: Motivation and counseling with hip and leg strengthening exercises should be incorporated with pharmacotherapy in each OA prescription. Physical fitness and weight reduction should be promoted as first-line management of OA.

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