25 research outputs found
Design Considerations of a Sub-50 {\mu}W Receiver Front-end for Implantable Devices in MedRadio Band
Emerging health-monitor applications, such as information transmission
through multi-channel neural implants, image and video communication from
inside the body etc., calls for ultra-low active power (<50W) high
data-rate, energy-scalable, highly energy-efficient (pJ/bit) radios. Previous
literature has strongly focused on low average power duty-cycled radios or low
power but low-date radios. In this paper, we investigate power performance
trade-off of each front-end component in a conventional radio including active
matching, down-conversion and RF/IF amplification and prioritize them based on
highest performance/energy metric. The analysis reveals 50 active
matching and RF gain is prohibitive for 50W power-budget. A mixer-first
architecture with an N-path mixer and a self-biased inverter based baseband
LNA, designed in TSMC 65nm technology show that sub 50W performance can
be achieved up to 10Mbps (< 5pJ/b) with OOK modulation.Comment: Accepted to appear on International Conference on VLSI Design 2018
(VLSID
Bioelectronic Sensor Nodes for Internet of Bodies
Energy-efficient sensing with Physically-secure communication for bio-sensors
on, around and within the Human Body is a major area of research today for
development of low-cost healthcare, enabling continuous monitoring and/or
secure, perpetual operation. These devices, when used as a network of nodes
form the Internet of Bodies (IoB), which poses certain challenges including
stringent resource constraints (power/area/computation/memory), simultaneous
sensing and communication, and security vulnerabilities as evidenced by the DHS
and FDA advisories. One other major challenge is to find an efficient on-body
energy harvesting method to support the sensing, communication, and security
sub-modules. Due to the limitations in the harvested amount of energy, we
require reduction of energy consumed per unit information, making the use of
in-sensor analytics/processing imperative. In this paper, we review the
challenges and opportunities in low-power sensing, processing and
communication, with possible powering modalities for future bio-sensor nodes.
Specifically, we analyze, compare and contrast (a) different sensing mechanisms
such as voltage/current domain vs time-domain, (b) low-power, secure
communication modalities including wireless techniques and human-body
communication, and (c) different powering techniques for both wearable devices
and implants.Comment: 30 pages, 5 Figures. This is a pre-print version of the article which
has been accepted for Publication in Volume 25 of the Annual Review of
Biomedical Engineering (2023). Only Personal Use is Permitte
Human Body–Electrode Interfaces for Wide-Frequency Sensing and Communication: A Review
Several on-body sensing and communication applications use electrodes in contact with the human body. Body–electrode interfaces in these cases act as a transducer, converting ionic current in the body to electronic current in the sensing and communication circuits and vice versa. An ideal body–electrode interface should have the characteristics of an electrical short, i.e., the transfer of ionic currents and electronic currents across the interface should happen without any hindrance. However, practical body–electrode interfaces often have definite impedances and potentials that hinder the free flow of currents, affecting the application’s performance. Minimizing the impact of body–electrode interfaces on the application’s performance requires one to understand the physics of such interfaces, how it distorts the signals passing through it, and how the interface-induced signal degradations affect the applications. Our work deals with reviewing these elements in the context of biopotential sensing and human body communication