IEEE Transactions on Biomedical Circuits and Systems This is an RSS file. You can use it to subscribe to this data in your favourite RSS reader or to display this data on your own website or blog.

Large-Scale Bio-Inspired FPGA Models for Path Planning
The hippocampus provides significant inspiration for spatial navigation and memory in both humans and animals. Constructing large-scale spiking neural network (SNN) models based on the biological neural systems is an important approach to comprehend the computational principles and cognitive function of the hippocampus. Such models are usually implemented on neuromorphic computing platforms, which often have limited computing resources that constrain the achievable scale of the network. This work introduces a series of digital design methods to realize a Field-Programmable Gate Array (FPGA) friendly SNN model. The methods ...
Source: IEEE Transactions on Biomedical Circuits and Systems - August 7, 2023 Category: Biomedical Engineering Source Type: research

A Self-Adaptive Dual-ILRO Clock-Recovery Technique for Two-Tone Battery-Free Crystal-Free Neural-Recording SoC
Wireless implantable devices are widely used in medical treatment, which should meet clinical constraints such as longevity, miniaturization, and reliable communication. Wireless power transfer (WPT) can eliminate the battery to reduce system size and prolong device life, while it's challenging to generate a reliable clock without a crystal. In this work, we propose a self-adaptive dual-injection-locked-ring-oscillator (dual-ILRO) clock-recovery technique based on two-tone WPT and integrate it into a battery-free neural-recording SoC. The 2$\text{nd}$-order inter-modulation (IM2) component of the two WPT tones is extracted...
Source: IEEE Transactions on Biomedical Circuits and Systems - August 7, 2023 Category: Biomedical Engineering Source Type: research

Low-Noise Low-Power Ultrasound AFE With Continuous TGC Built in Both TIA and Beamformer
This article presents a low-noise high-power-efficiency analog front-end (AFE) for capacitive-micromachined-ultrasonic transducers (CMUT). Implemented in 28-nm CMOS technology, the proposed AFE features three-stage continuous time-gain compensation (TGC) embedded in both trans-impedance amplifiers (TIAs) and an analog beamformer to provide a large compensation range with no extra power-consumption cost. The use of noise cancellation and capacitive feedback optimizes the noise performance of TIAs. The first stage of the TGC is built in the TIA by adjusting the positive and negative resistance loads, which are composed of vo...
Source: IEEE Transactions on Biomedical Circuits and Systems - August 7, 2023 Category: Biomedical Engineering Source Type: research

A 0.67 $\mu$V-IIRN super-T$\Omega$-Z$_{IN}$ 17.5 $\mu$W/Ch Active Electrode With In-Channel Boosted CMRR for Distributed EEG Monitoring
We present the design, development, and experimental characterization of an active electrode (AE) IC for wearable ambulatory EEG recording. The proposed architecture features in-AE double common-mode (CM) rejection, making the recording's CMRR independent of typically-significant AE-to-AE gain variations. Thanks to being DC coupled and needless of chopper stabilization for flicker noise suppression, the architecture yields a super-T$\Omega$ input impedance. Such a large input impedance makes the AE's CMRR practically immune to electrode-skin interface impedance variations across different recording channels, a critical fea...
Source: IEEE Transactions on Biomedical Circuits and Systems - August 3, 2023 Category: Biomedical Engineering Source Type: research

A 1.5 mm2 4-Channel EEG/BIOZ Acquisition ASIC With 15.2-Bit 3-Step ADC Based on a Signal-Dependent Low-Power Strategy
This article presents a multichannel EEG/BIOZ acquisition application specific integrated circuit (ASIC) with 4 EEG channels and a BIOZ channel, a switch resistor low-pass filter (SR-LPF). Each EEG channel includes a frontend, and a 4-channel multiplexed analog-to-digital converter (ADC), while the BIOZ channel features a pseudo sine current generator and a pair of readout paths with multiplexed SR-LPF and ADC. The ASIC is designed for size and power minimization, utilizing a 3-step ADC with a novel signal-dependent low power strategy. The proposed ADC operates at a sampling rate of 1600 S/s with a resolution of 15.2 bits,...
Source: IEEE Transactions on Biomedical Circuits and Systems - August 3, 2023 Category: Biomedical Engineering Source Type: research

Radiation Patterns of RF Wireless Devices Implanted in Small Animals: Unexpected Deformations Due to Body Resonance
One challenge in designing RF wireless bioelectronic devices is the impact of the interaction between electromagnetic waves and host body tissues on far-field wireless performance. In this article, we investigate a peculiar phenomenon of implantable RF wireless devices within a small-scale host body related to the deformation of the directivity pattern. Radiation measurements of subcutaneously implanted antennas within rodent cadavers show that the direction of maximum radiation is not always identical with the direction to the closest body–air interface, as one would expect in larger-scale host bodies. For an implanted ...
Source: IEEE Transactions on Biomedical Circuits and Systems - August 1, 2023 Category: Biomedical Engineering Source Type: research

Scalable Multi-Hierarchy Embedded Platform for Neural Population Simulations
Brain-inspired structured neural circuits are the cornerstones of both computational and perceived intelligence. Real-time simulations of large-scale high-dimensional neural populations with complex nonlinearities pose a significant challenge. Taking advantage of distributed computations using embedded multi-cores, we propose an ARM-based scalable multi-hierarchy parallel computing platform (EmPaas) for neural population simulations. EmPaas is constructed using 340 ARM Cortex-M4 microprocessors to achieve high-speed and high-accuracy parallel computing. The tree-two-dimensional grid-like hybrid topology completes the overa...
Source: IEEE Transactions on Biomedical Circuits and Systems - August 1, 2023 Category: Biomedical Engineering Source Type: research

A Review of Ultrasound Neuromodulation Technologies
This article first provides some fundamental knowledge in ultrasound, and then reviews various examples of successful tFUS experiments in animals and humans using different stimulation patterns, as well as available tFUS technologies for generating, focusing, and steering ultrasound beams in neural tissues. In particular, phased array technologies for the ultrasound stimulation application are discussed with an emphasis on the design, fabrication, and integration of ultrasound transducer arrays as well as the design and development of phased array electronics with beamformer and high-voltage driver circuitry. The challenge...
Source: IEEE Transactions on Biomedical Circuits and Systems - July 28, 2023 Category: Biomedical Engineering Source Type: research

SkinAid: A Wirelessly Powered Smart Dressing Solution for Continuous Wound-Tracking Using Textile-Based Frequency Modulation
In this article, SkinAid, a battery-free, low-cost, robust, and user-friendly smart bandage for electrochemical monitoring and sensing of chronic wounds is proposed. The working principle of the bandage is based on direct frequency modulation of a tri-electrode electrochemical sensing of wound data. The electronics and biotelemetry links were realized using low-cost manufacturing process of textile embroidery onto fabric substrate. The transmitter was represented by a bedsheet with novel corrugated crossed-dipole made of Elektrisola-7 embroidered onto gauze fabric. An input RF signal of 1 W was transmitted at 462 MHz from ...
Source: IEEE Transactions on Biomedical Circuits and Systems - July 13, 2023 Category: Biomedical Engineering Source Type: research

A 4.5 $\mu$W Miniaturized 3-Channel Wireless Intra-Cardiac Acquisition System
This article presents a chip designed for wireless intra-cardiac monitoring systems. The design consists of a three-channel analog front-end, a pulse-width modulator featuring output-frequency offset and temperature calibration, and inductive data telemetry. By employing a resistance boosting technique in the instrumentation amplifier feedback, the pseudo-resistor exhibits lower non-linearity, leading to a total harmonic distortion of below 0.1%. Furthermore, the boosting technique enhances the feedback resistance, leading to a reduction in the size of the feedback capacitor and, consequently, the overall size. To make the...
Source: IEEE Transactions on Biomedical Circuits and Systems - July 12, 2023 Category: Biomedical Engineering Source Type: research

Analysis of Automated Clinical Depression Diagnosis in a Chinese Corpus
This study introduces a new corpus of depression clinical interviews collected directly from a psychiatric hospital, containing 113 recordings with 52 healthy and 61 depressive patients. The subjects were examined using the Montgomery-Asberg Depression Rating Scale (MADRS) in Chinese. Their final diagnosis was based on medical evaluations through a clinical interview conducted by a psychiatry specialist. All interviews were audio-recorded and transcribed verbatim, and annotated by experienced physicians. This dataset is a valuable resource for automated depression detection research and is expected to advance the field of ...
Source: IEEE Transactions on Biomedical Circuits and Systems - July 3, 2023 Category: Biomedical Engineering Source Type: research

A Memristor-Based Learning Engine for Synaptic Trace-Based Online Learning
The memristor has been extensively used to facilitate the synaptic online learning of brain-inspired spiking neural networks (SNNs). However, the current memristor-based work can not support the widely used yet sophisticated trace-based learning rules, including the trace-based Spike-Timing-Dependent Plasticity (STDP) and the Bayesian Confidence Propagation Neural Network (BCPNN) learning rules. This paper proposes a learning engine to implement trace-based online learning, consisting of memristor-based blocks and analog computing blocks. The memristor is used to mimic the synaptic trace dynamics by exploiting the nonlinea...
Source: IEEE Transactions on Biomedical Circuits and Systems - June 30, 2023 Category: Biomedical Engineering Source Type: research

A Re-Configurable Body Channel Transceiver Towards Wearable and Flexible Biomedical Sensor Networks
Body channel communication (BCC) has become a promising candidate in wireless body area networks (WBAN) due to its advantages in energy efficiency and security. However, BCC transceivers face two challenges: diverse application requirements and varying channel conditions. To overcome these challenges, this article proposes a re-configurable architecture for BCC transceivers (TRXs), whose key parameters and communication protocols can be software-defined (SD) according to the requirements. In the proposed TRX, the programmable direct-sampling receiver (RX) is a combination of a programmable low-noise amplifier (LNA) and a f...
Source: IEEE Transactions on Biomedical Circuits and Systems - June 27, 2023 Category: Biomedical Engineering Source Type: research

A Wireless and Wearable Body-Pressure-Monitoring System for the Prevention of Pressure-Induced Skin Injuries
This article presents a wireless and wearable body-pressure-monitoring system for the on-site, real-time prevention of pressure injuries for immobilized patients. For the prevention of pressure-induced skin injuries, a wearable pressure sensor system is designed to monitor the pressure at multiple sites on the skin and to alert the danger of prolonged application of pressure on the skin with a pressure-time integral (PTI) algorithm. The wearable sensor unit is developed using a pressure sensor based on a liquid metal microchannel and integrated with a flexible printed circuit board that includes a thermistor-type temperatu...
Source: IEEE Transactions on Biomedical Circuits and Systems - June 27, 2023 Category: Biomedical Engineering Source Type: research

An 8-Channel Ambulatory EEG Recording IC With In-Channel Fully-Analog Real-Time Motion Artifact Extraction and Removal
Wereport the design, implementation, and experimental characterization of an 8-channel EEG recording IC (0.13 $\mu$m CMOS, 12 mm$^{2}$ total area) with a channel architecture that conducts both the extraction and removal of motion artifacts on-chip and in-channel. The proposed dual-path feed-forward method for artifact extraction and removal is implemented in the analog domain, hence is needless of a DSP unit for artifact estimation, and its associated high-DR ADCs and DACs employed by the state of the art for artifact replica generation. Additionally, the presented architecture improves system's scalability as it enables ...
Source: IEEE Transactions on Biomedical Circuits and Systems - June 26, 2023 Category: Biomedical Engineering Source Type: research