Scheduled System Maintenance:
On May 6th, single article purchases and IEEE account management will be unavailable from 8:00 AM - 5:00 PM ET (12:00 - 21:00 UTC). We apologize for the inconvenience.
By Topic

Biomedical Circuits and Systems, IEEE Transactions on

Issue 3 • Date June 2012

Filter Results

Displaying Results 1 - 16 of 16
  • Table of contents

    Publication Year: 2012 , Page(s): C1
    Save to Project icon | Request Permissions | PDF file iconPDF (158 KB)  
    Freely Available from IEEE
  • IEEE Transactions on Biomedical Circuits and Systems publication information

    Publication Year: 2012 , Page(s): C2
    Save to Project icon | Request Permissions | PDF file iconPDF (41 KB)  
    Freely Available from IEEE
  • Label-Free CMOS Bio Sensor With On-Chip Noise Reduction Scheme for Real-Time Quantitative Monitoring of Biomolecules

    Publication Year: 2012 , Page(s): 189 - 196
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1160 KB) |  | HTML iconHTML  

    We present a label-free CMOS field-effect transistor sensing array to detect the surface potential change affected by the negative charge in DNA molecules for real-time monitoring and quantification. The proposed CMOS bio sensor includes a new sensing pixel architecture implemented with correlated double sampling for reducing offset fixed pattern noise and 1/f noise of the sensing devices. We incorporated non-surface binding detection which allows real-time continuous monitoring of DNA concentrations without immobilizing them on the sensing surface. Various concentrations of 19-bp oligonucleotides solution can be discriminated using the prototype device fabricated in 1- μm double-poly double-metal standard CMOS process. The detection limit was measured as 1.1 ng/μl with a dynamic range of 40 dB and the transient response time was measured less than 20 seconds. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Tripolar Current-Steering Stimulator ASIC for Field Shaping in Deep Brain Stimulation

    Publication Year: 2012 , Page(s): 197 - 207
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1211 KB) |  | HTML iconHTML  

    A significant problem with clinical deep brain stimulation (DBS) is the high variability of its efficacy and the frequency of side effects, related to the spreading of current beyond the anatomical target area. This is the result of the lack of control that current DBS systems offer on the shaping of the electric potential distribution around the electrode. This paper presents a stimulator ASIC with a tripolar current-steering output stage, aiming at achieving more selectivity and field shaping than current DBS systems. The ASIC was fabricated in a 0.35-μ m CMOS technology occupying a core area of 0.71 mm2. It consists of three current sourcing/sinking channels. It is capable of generating square and exponential-decay biphasic current pulses with five different time constants up to 28 ms and delivering up to 1.85 mA of cathodic current, in steps of 4 μA, from a 12 V power supply. Field shaping was validated by mapping the potential distribution when injecting current pulses through a multicontact DBS electrode in saline. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Analysis of Dual Band Power and Data Telemetry for Biomedical Implants

    Publication Year: 2012 , Page(s): 208 - 215
    Cited by:  Papers (9)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (762 KB) |  | HTML iconHTML  

    Inductive coupling is commonly used for wireless power and data transfer in biomedical telemetry systems. To increase data bandwidth while maintaining power transfer efficiency, a multiband telemetry system transmitting power and data using different frequencies has been adopted. However, the power link and data link interact with each other, complicating the operation of both power and data transmission. In this paper, we demonstrate that to achieve high performance data transmission, the cross-coupling between the power coils and data coils have to be taken into consideration. Design equations have been derived and shown that the signal to noise (interference) ratio could be significantly reduced and the resulting data transmission could fail if only the data link coupling is optimized without considering the cross-coupling between the power link and the data link. Design examples have been constructed to demonstrate that there could be more than 30 dB difference in the signal to noise ratio. The analysis has been verified with simulation and measurement results. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Active Books: The Design of an Implantable Stimulator That Minimizes Cable Count Using Integrated Circuits Very Close to Electrodes

    Publication Year: 2012 , Page(s): 216 - 227
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1830 KB) |  | HTML iconHTML  

    This paper presents an integrated stimulator that can be embedded in implantable electrode books for interfacing with nerve roots at the cauda equina. The Active Book overcomes the limitation of conventional nerve root stimulators which can only support a small number of stimulating electrodes due to cable count restriction through the dura. Instead, a distributed stimulation system with many tripole electrodes can be configured using several Active Books which are addressed sequentially. The stimulator was fabricated in a 0.6-μm high-voltage CMOS process and occupies a silicon area of 4.2 × 6.5 mm2. The circuit was designed to deliver up to 8 mA stimulus current to tripole electrodes from an 18 V power supply. Input pad count is limited to five (two power and three control lines) hence requiring a specific procedure for downloading stimulation commands to the chip and extracting information from it. Supported commands include adjusting the amplitude of stimulus current, varying the current ratio at the two anodes in each channel, and measuring relative humidity inside the chip package. In addition to stimulation mode, the chip supports quiescent mode, dissipating less than 100 nA current from the power supply. The performance of the stimulator chip was verified with bench tests including measurements using tripoles in saline. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Maximum Achievable Efficiency in Near-Field Coupled Power-Transfer Systems

    Publication Year: 2012 , Page(s): 228 - 245
    Cited by:  Papers (25)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1267 KB) |  | HTML iconHTML  

    Wireless power transfer is commonly realized by means of near-field inductive coupling and is critical to many existing and emerging applications in biomedical engineering. This paper presents a closed form analytical solution for the optimum load that achieves the maximum possible power efficiency under arbitrary input impedance conditions based on the general two-port parameters of the network. The two-port approach allows one to predict the power transfer efficiency at any frequency, any type of coil geometry and through any type of media surrounding the coils. Moreover, the results are applicable to any form of passive power transfer such as provided by inductive or capacitive coupling. Our results generalize several well-known special cases. The formulation allows the design of an optimized wireless power transfer link through biological media using readily available EM simulation software. The proposed method effectively decouples the design of the inductive coupling two-port from the problem of loading and power amplifier design. Several case studies are provided for typical applications. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Energy-Efficient Neuron, Synapse and STDP Integrated Circuits

    Publication Year: 2012 , Page(s): 246 - 256
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1427 KB) |  | HTML iconHTML  

    Ultra-low energy biologically-inspired neuron and synapse integrated circuits are presented. The synapse includes a spike timing dependent plasticity (STDP) learning rule circuit. These circuits have been designed, fabricated and tested using a 90 nm CMOS process. Experimental measurements demonstrate proper operation. The neuron and the synapse with STDP circuits have an energy consumption of around 0.4 pJ per spike and synaptic operation respectively. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • BioThreads: A Novel VLIW-Based Chip Multiprocessor for Accelerating Biomedical Image Processing Applications

    Publication Year: 2012 , Page(s): 257 - 268
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2028 KB) |  | HTML iconHTML  

    We discuss BioThreads, a novel, configurable, extensible system-on-chip multiprocessor and its use in accelerating biomedical signal processing applications such as imaging photoplethysmography (IPPG). BioThreads is derived from the LE1 open-source VLIW chip multiprocessor and efficiently handles instruction, data and thread-level parallelism. In addition, it supports a novel mechanism for the dynamic creation, and allocation of software threads to uncommitted processor cores by implementing key POSIX Threads primitives directly in hardware, as custom instructions. In this study, the BioThreads core is used to accelerate the calculation of the oxygen saturation map of living tissue in an experimental setup consisting of a high speed image acquisition system, connected to an FPGA board and to a host system. Results demonstrate near-linear acceleration of the core kernels of the target blood perfusion assessment with increasing number of hardware threads. The BioThreads processor was implemented on both standard-cell and FPGA technologies; in the first case and for an issue width of two, full real-time performance is achieved with 4 cores whereas on a mid-range Xilinx Virtex6 device this is achieved with 10 dual-issue cores. An 8-core LE1 VLIW FPGA prototype of the system achieved 240 times faster execution time than the scalar Microblaze processor demonstrating the scalability of the proposed solution to a state-of-the-art FPGA vendor provided soft CPU core. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Wireless Reflectance Pulse Oximeter With Digital Baseline Control for Unfiltered Photoplethysmograms

    Publication Year: 2012 , Page(s): 269 - 278
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1996 KB) |  | HTML iconHTML  

    Pulse oximeters are central to the move toward wearable health monitoring devices and medical electronics either hosted by, e.g., smart phones or physically embedded in their design. This paper presents a small, low-cost pulse oximeter design appropriate for wearable and surface-based applications that also produces quality, unfiltered photo-plethysmograms (PPGs) ideal for emerging diagnostic algorithms. The design's “filter-free” embodiment, which employs only digital baseline subtraction as a signal compensation mechanism, distinguishes it from conventional pulse oximeters that incorporate filters for signal extraction and noise reduction. This results in high-fidelity PPGs with thousands of peak-to-peak digitization levels that are sampled at 240 Hz to avoid noise aliasing. Electronic feedback controls make these PPGs more resilient in the face of environmental changes (e.g., the device can operate in full room light), and data stream in real time across either a ZigBee wireless link or a wired USB connection to a host. On-board flash memory is available for store-and-forward applications. This sensor has demonstrated an ability to gather high-integrity data at fingertip, wrist, earlobe, palm, and temple locations from a group of 48 subjects (20 to 64 years old). View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Power Flow Control Based Solely on Slow Feedback Loop for Heart Pump Applications

    Publication Year: 2012 , Page(s): 279 - 286
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1313 KB) |  | HTML iconHTML  

    This paper proposes a new control method for regulating power flow via transcutaneous energy transfer (TET) for implantable heart pumps. Previous work on power flow controller requires a fast feedback loop that needs additional switching devices and resonant capacitors to be added to the primary converter. The proposed power flow controller eliminates these additional components, and it relies solely on a slow feedback loop to directly drive the primary converter to meet the heart pump power demand and ensure zero voltage switching. A controlled change in switching frequency varies the resonant tank shorting period of a current-fed push-pull resonant converter, thus changing the magnitude of the primary resonant voltage, as well as the tuning between primary and secondary resonant tanks. The proposed controller has been implemented successfully using an analogue circuit and has reached an end-to-end power efficiency of 79.6% at 10 W with a switching frequency regulation range of 149.3 kHz to 182.2 kHz. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Linear Parametric Approach for Analysis of Mouse Respiratory Impedance

    Publication Year: 2012 , Page(s): 287 - 294
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (952 KB) |  | HTML iconHTML  

    Assessment of the lung mechanics is crucial in lung function studies. Commonly lung mechanics is achieved through measurement of the input impedance of the lung where the experimental data is ideal for the application of system identification techniques. This study proposes a new approach for investigating the severity of lung conditions and also evaluating the treatment progression. The proposed method is established based on linear parametric identification of lung input impedance in mice and is applied to normal and asthmatic models (including acute, tolerant and chronic asthma) as well as a pharmacological intervention model. Experimental findings confirm the effectiveness of the analysis technique applied here. We discuss the potential application of this method to analyses of human lung mechanics. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • IEEE Xplore Digital Library [advertisement]

    Publication Year: 2012 , Page(s): 295
    Save to Project icon | Request Permissions | PDF file iconPDF (1347 KB)  
    Freely Available from IEEE
  • IEEE Transactions on Biomedical Circuits and Systems information for authors

    Publication Year: 2012 , Page(s): 296
    Save to Project icon | Request Permissions | PDF file iconPDF (35 KB)  
    Freely Available from IEEE
  • IEEE Transactions on Biomedical Circuits and Systems society information

    Publication Year: 2012 , Page(s): C3
    Save to Project icon | Request Permissions | PDF file iconPDF (25 KB)  
    Freely Available from IEEE
  • [Blank page]

    Publication Year: 2012 , Page(s): C4
    Save to Project icon | Request Permissions | PDF file iconPDF (5 KB)  
    Freely Available from IEEE

Aims & Scope

IEEE Transactions on Biomedical Circuits and Systems (TBioCAS) publishes peer-reviewed manuscripts reporting original and transformative research at the intersection between the life sciences and circuits and systems engineering principles.

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Gert Cauwenberghs
University of California at San Diego