Design of a 5-bit algorithmic A/D converter for potential use in a wireless neural recorder application

The constant endeavor to measure and record neural signals from the human brain and anticipate the results to figure out the mechanism which governs the functionality of our brain and its true behavior is the major driving force behind this thesis. Neural recording integrated circuits (ICs) are often inserted directly into the brain, with a set of probes for sensing these action potentials (and local field potentials), and appropriate circuitry for amplifying the neural signals (Pre-Amp), sampling and converting the analog signals to digital (ADC) and transmitting the resulting digital signal (Transmitter) to a nearby reader instrument (Receiver). Action potentials are comprised of signals typically looking like spikes having a peak voltage of 1-2mV, whereas local field potentials are continuous signals generally having an amplitude of around 100-200μV often with a dc component of several mV. Fourier analysis of action potentials and local field potentials show frequency components in the range of 0.1 Hz up to 10kHz. This thesis proposes a low-power 5-bit algorithmic A/D converter to feed a 5-stage serial shift register for use in sampling and converting a presumed neuron action potential signal at the rate of 20k samples/sec. In addition to that, a low-power preamp with at least 40dB gain and a low-pass type spectrum having a unity-gain frequency of at least 20MHz is used to amplify the input signal. The algorithmic A/D converter includes a sample-and-hold circuit for sampling the analog action potential spike at a rate of 20kHz. The ADC utilizes an X2 gain circuit based on a capacitive redistribution technique. A less complex circuit in terms of dependency on Capacitor sizing and their non-ideal effects is the key factor for selecting this type of ADC which can be used for neural recording applications. All the circuits are designed based on the IBM/Global Foundries 8HP 130nm BiCMOS technology

Complexation of O-Vanillin with Some First Transition Cations in Aqueous Ethanol (70%) Medium

The present paper summarizes the complexation behaviour of Mn(II), Co(II), Ni(II), Cu(lI) and Zn(II) with 2-hydroxy-3-methoxybenzaldehyde examined by Crow\u27 s me an diffusion coefficient method. Diffusion currents of polarographic waves were used to determine the stability constants of the 1: 1 and 1 : 2 complexes of the respective ions (298 K) which were 4.0, 2.7; 4.7, 3.3; 5.4, 2.5; 5.3, 3.5 and 4.5, 3.5, respectively. Overall stability constants at three temperatures 288, 298 and 308 K yielded the thermodynamic parameters

Review on Interference Cancellation in MIMO Receiver

The signal processing in orthogonal frequency division multiplexing and the effect of channel interference are presented in this paper. We've also talked about different multiplexing techniques like frequency division multiplexing and time division multiplexing. Also, several researchers' work in the field of interference cancellation

Photonic Supercoupling in Silicon Topological Waveguides

Electromagnetic wave coupling between photonic systems relies on the evanescent field typically confined within a single wavelength. Extending evanescent coupling distance requires low refractive index contrast and perfect momentum matching for achieving a large coupling ratio. Here, we report the discovery of photonic supercoupling in a topological valley Hall pair of waveguides, showing a substantial improvement in coupling efficiency across multiple wavelengths. Experimentally, we realize ultra-high coupling ratios between waveguides through valley-conserved vortex flow of electromagnetic energy, attaining 95% coupling efficiency for separations of up to three wavelengths. This demonstration of photonic supercoupling in topological systems significantly extends the coupling distance between on-chip waveguides and components, paving the path for the development of supercoupled photonic integrated devices, optical sensing, and telecommunications.Comment: 8 pages, 4 figure

Discovery of dominant and dormant genes from expression data using a novel generalization of SNR for multi-class problems

<p>Abstract</p> <p>Background</p> <p>The Signal-to-Noise-Ratio (SNR) is often used for identification of biomarkers for two-class problems and no formal and useful generalization of SNR is available for multiclass problems. We propose innovative generalizations of SNR for multiclass cancer discrimination through introduction of two indices, Gene Dominant Index and Gene Dormant Index (GDIs). These two indices lead to the concepts of dominant and dormant genes with biological significance. We use these indices to develop methodologies for discovery of dominant and dormant biomarkers with interesting biological significance. The dominancy and dormancy of the identified biomarkers and their excellent discriminating power are also demonstrated pictorially using the scatterplot of individual gene and 2-D Sammon's projection of the selected set of genes. Using information from the literature we have shown that the GDI based method can identify dominant and dormant genes that play significant roles in cancer biology. These biomarkers are also used to design diagnostic prediction systems.</p> <p>Results and discussion</p> <p>To evaluate the effectiveness of the GDIs, we have used four multiclass cancer data sets (Small Round Blue Cell Tumors, Leukemia, Central Nervous System Tumors, and Lung Cancer). For each data set we demonstrate that the new indices can find biologically meaningful genes that can act as biomarkers. We then use six machine learning tools, Nearest Neighbor Classifier (NNC), Nearest Mean Classifier (NMC), Support Vector Machine (SVM) classifier with linear kernel, and SVM classifier with Gaussian kernel, where both SVMs are used in conjunction with one-vs-all (OVA) and one-vs-one (OVO) strategies. We found GDIs to be very effective in identifying biomarkers with strong class specific signatures. With all six tools and for all data sets we could achieve better or comparable prediction accuracies usually with fewer marker genes than results reported in the literature using the same computational protocols. The dominant genes are usually easy to find while good dormant genes may not always be available as dormant genes require stronger constraints to be satisfied; but when they are available, they can be used for authentication of diagnosis.</p> <p>Conclusion</p> <p>Since GDI based schemes can find a small set of dominant/dormant biomarkers that is adequate to design diagnostic prediction systems, it opens up the possibility of using real-time qPCR assays or antibody based methods such as ELISA for an easy and low cost diagnosis of diseases. The dominant and dormant genes found by GDIs can be used in different ways to design more reliable diagnostic prediction systems.</p

Modeling of Chip Tool Interface Temperature in Machining Steel- An Artificial Intelligence (AI) Approach

Abstract Chip tool interface temperature control is one of the critical factors during machining because it influences substantially the chip formation mode, cutting forces, tool life, surface finish and product quality. In this paper an artificial neural network (ANN) model has been developed as a function of cutting parameters in turning steel for predicting chip tool interface temperature. The cutting parameters used include cutting speed, feed rate and depth of cut. A feed-forward back propagation network with ten hidden neurons has been selected as the optimum network by trial and error method. The co-efficient of determination (R 2 ) between model prediction and experimental value is found 0.9965. The result implies that, the model can be successfully used to forecast chip tool interface temperature in response to the cutting parameters for which the model has been constructed

Major urological cancer surgery for patients is safe and surgical training should be encouraged during the COVID-19 pandemic : A multi-centre analysis of 30-day outcomes

Funding Information: Funding/Support and role of the sponsor: Wei Shen Tan is funded by the Urology Foundation . Publisher Copyright: © 2021 The Author(s) Copyright: Copyright 2021 Elsevier B.V., All rights reserved.COVID-19 has resulted in the deferral of major surgery for genitourinary (GU) cancers with the exception of cancers with a high risk of progression. We report outcomes for major GU cancer operations, namely radical prostatectomy (RP), radical cystectomy (RC), radical nephrectomy (RN), partial nephrectomy (PN), and nephroureterectomy performed at 13 major GU cancer centres across the UK between March 1 and May 5, 2020. A total of 598 such operations were performed. Four patients (0.7%) developed COVID-19 postoperatively. There was no COVID-19–related mortality at 30 d. A minimally invasive approach was used in 499 cases (83.4%). A total of 228 cases (38.1%) were described as training procedures. Training case status was not associated with a higher American Society of Anesthesiologists (ASA) score (p = 0.194) or hospital length of stay (LOS; p > 0.05 for all operation types). The risk of contracting COVID-19 was not associated with longer hospital LOS (p = 0.146), training case status (p = 0.588), higher ASA score (p = 0.295), or type of hospital site (p = 0.303). Our results suggest that major surgery for urological cancers remains safe and training should be encouraged during the ongoing COVID-19 pandemic provided appropriate countermeasures are taken. These real-life data are important for policy-makers and clinicians when counselling patients during the current pandemic. Patient summary: We collected outcome data for major operations for prostate, bladder, and kidney cancers during the COVID-19 pandemic. These surgeries remain safe and training should be encouraged during the ongoing pandemic provided appropriate countermeasures are taken. Our real-life results are important for policy-makers and clinicians when counselling patients during the COVID-19 pandemic.Peer reviewe

Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy

Effects of antiplatelet therapy after stroke due to intracerebral haemorrhage (RESTART): a randomised, open-label trial

Background: Antiplatelet therapy reduces the risk of major vascular events for people with occlusive vascular disease, although it might increase the risk of intracranial haemorrhage. Patients surviving the commonest subtype of intracranial haemorrhage, intracerebral haemorrhage, are at risk of both haemorrhagic and occlusive vascular events, but whether antiplatelet therapy can be used safely is unclear. We aimed to estimate the relative and absolute effects of antiplatelet therapy on recurrent intracerebral haemorrhage and whether this risk might exceed any reduction of occlusive vascular events. Methods: The REstart or STop Antithrombotics Randomised Trial (RESTART) was a prospective, randomised, open-label, blinded endpoint, parallel-group trial at 122 hospitals in the UK. We recruited adults (≥18 years) who were taking antithrombotic (antiplatelet or anticoagulant) therapy for the prevention of occlusive vascular disease when they developed intracerebral haemorrhage, discontinued antithrombotic therapy, and survived for 24 h. Computerised randomisation incorporating minimisation allocated participants (1:1) to start or avoid antiplatelet therapy. We followed participants for the primary outcome (recurrent symptomatic intracerebral haemorrhage) for up to 5 years. We analysed data from all randomised participants using Cox proportional hazards regression, adjusted for minimisation covariates. This trial is registered with ISRCTN (number ISRCTN71907627). Findings: Between May 22, 2013, and May 31, 2018, 537 participants were recruited a median of 76 days (IQR 29–146) after intracerebral haemorrhage onset: 268 were assigned to start and 269 (one withdrew) to avoid antiplatelet therapy. Participants were followed for a median of 2·0 years (IQR [1·0– 3·0]; completeness 99·3%). 12 (4%) of 268 participants allocated to antiplatelet therapy had recurrence of intracerebral haemorrhage compared with 23 (9%) of 268 participants allocated to avoid antiplatelet therapy (adjusted hazard ratio 0·51 [95% CI 0·25–1·03]; p=0·060). 18 (7%) participants allocated to antiplatelet therapy experienced major haemorrhagic events compared with 25 (9%) participants allocated to avoid antiplatelet therapy (0·71 [0·39–1·30]; p=0·27), and 39 [15%] participants allocated to antiplatelet therapy had major occlusive vascular events compared with 38 [14%] allocated to avoid antiplatelet therapy (1·02 [0·65–1·60]; p=0·92). Interpretation: These results exclude all but a very modest increase in the risk of recurrent intracerebral haemorrhage with antiplatelet therapy for patients on antithrombotic therapy for the prevention of occlusive vascular disease when they developed intracerebral haemorrhage. The risk of recurrent intracerebral haemorrhage is probably too small to exceed the established benefits of antiplatelet therapy for secondary prevention

Effects of antiplatelet therapy after stroke due to intracerebral haemorrhage (RESTART): a randomised, open-label trial

Background: Antiplatelet therapy reduces the risk of major vascular events for people with occlusive vascular disease, although it might increase the risk of intracranial haemorrhage. Patients surviving the commonest subtype of intracranial haemorrhage, intracerebral haemorrhage, are at risk of both haemorrhagic and occlusive vascular events, but whether antiplatelet therapy can be used safely is unclear. We aimed to estimate the relative and absolute effects of antiplatelet therapy on recurrent intracerebral haemorrhage and whether this risk might exceed any reduction of occlusive vascular events. Methods: The REstart or STop Antithrombotics Randomised Trial (RESTART) was a prospective, randomised, open-label, blinded endpoint, parallel-group trial at 122 hospitals in the UK. We recruited adults (≥18 years) who were taking antithrombotic (antiplatelet or anticoagulant) therapy for the prevention of occlusive vascular disease when they developed intracerebral haemorrhage, discontinued antithrombotic therapy, and survived for 24 h. Computerised randomisation incorporating minimisation allocated participants (1:1) to start or avoid antiplatelet therapy. We followed participants for the primary outcome (recurrent symptomatic intracerebral haemorrhage) for up to 5 years. We analysed data from all randomised participants using Cox proportional hazards regression, adjusted for minimisation covariates. This trial is registered with ISRCTN (number ISRCTN71907627). Findings: Between May 22, 2013, and May 31, 2018, 537 participants were recruited a median of 76 days (IQR 29–146) after intracerebral haemorrhage onset: 268 were assigned to start and 269 (one withdrew) to avoid antiplatelet therapy. Participants were followed for a median of 2·0 years (IQR [1·0– 3·0]; completeness 99·3%). 12 (4%) of 268 participants allocated to antiplatelet therapy had recurrence of intracerebral haemorrhage compared with 23 (9%) of 268 participants allocated to avoid antiplatelet therapy (adjusted hazard ratio 0·51 [95% CI 0·25–1·03]; p=0·060). 18 (7%) participants allocated to antiplatelet therapy experienced major haemorrhagic events compared with 25 (9%) participants allocated to avoid antiplatelet therapy (0·71 [0·39–1·30]; p=0·27), and 39 [15%] participants allocated to antiplatelet therapy had major occlusive vascular events compared with 38 [14%] allocated to avoid antiplatelet therapy (1·02 [0·65–1·60]; p=0·92). Interpretation: These results exclude all but a very modest increase in the risk of recurrent intracerebral haemorrhage with antiplatelet therapy for patients on antithrombotic therapy for the prevention of occlusive vascular disease when they developed intracerebral haemorrhage. The risk of recurrent intracerebral haemorrhage is probably too small to exceed the established benefits of antiplatelet therapy for secondary prevention