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This work presents a compressing-and-expanding, i.e., companding, strategy for spectral enhancement inspired by the operation of the auditory system. The companding strategy simulates the two-tone suppression phenomena of the auditory system and implements a soft local winner-take-all-like enhancement of the input spectrum. It performs multichannel syllabic(More)
We report a programmable analog bionic ear (cochlear implant) processor in a 1.5-microm BiCMOS technology with a power consumption of 211 microW and 77-dB dynamic range of operation. The 9.58 mm x 9.23 mm processor chip runs on a 2.8 V supply and has a power consumption that is lower than state-of-the-art analog-to-digital (A/D)-then-DSP designs by a factor(More)
Pulse oximeters are ubiquitous in modern medicine to noninvasively measure the percentage of oxygenated hemoglobin in a patient's blood by comparing the transmission characteristics of red and infrared light-emitting diode light through the patient's finger with a photoreceptor. We present an analog single-chip pulse oximeter with 4.8-mW total power(More)
Sounds originating from within the inner ear, known as otoacoustic emissions (OAEs), are widely exploited in clinical practice but the mechanisms underlying their generation are not entirely clear. Here we present simulation results and theoretical considerations based on a hydrodynamic model of the human inner ear. Simulations show that, if the cochlear(More)
Deaf patients with more than 70dB-80dB of hearing loss cannot use a hearing aid and require a cochlear implant. The implant stimulates the auditory nerve with electrical current using 8-20 electrodes surgically implanted in the patient's cochlea. The stimulation is coded such that logarithmic spectral-energy outputs of an audio filter bank are(More)
This study tested a time-domain spectral enhancement algorithm that was recently proposed by Turicchia and Sarpeshkar [IEEE Trans. Speech Audio Proc. 13, 243-253 (2005)]. The algorithm uses a filter bank, with each filter channel comprising broadly tuned amplitude compression, followed by more narrowly tuned expansion (companding). Normal-hearing listeners(More)
A new tag for pervasive sensing applications consists of a custom integrated circuit, an antenna for radio frequency energy harvesting, and sensors for monitoring physiological parameters. This paper presents a wearable tag design that can monitor multiple signals. The tag generates an alarm when it suspects a patient emergency. To quickly cover a large(More)
Analogies between (a) molecular flux in chemical reactions and (b) electronic current flow in subthreshold transistors. The mean current flow and stochastics of Poisson flow are similar in both domains [1]. Figure 2. A simplified overview of the processes of induction, transcription, and translation in a bacterial genetic circuit. Abstract—We show that(More)
We present a synchronous time-based dual-threshold imager that experimentally achieves 95.5 dB dynamic range, while consuming 1.79 nJ/pixel/frame, making it one of the most wide-dynamic-range energy-efficient imagers reported. The imager has 150x256 pixels, with a pixel pitch of 12.5µm x 12.5µm and a fill factor of 42.7%. The imager is intended for use in a(More)
The ability to decode neural activity into meaningful control signals for prosthetic devices is critical to the development of clinically useful brain- machine interfaces (BMIs). Such systems require input from tens to hundreds of brain-implanted recording electrodes in order to deliver robust and accurate performance; in serving that primary function they(More)