Biosensors
and bioanalytical devices that are able to provide accurate detection
of target analytes have always been important in the fields of medical
diagnostics, food testing and environmental monitoring. Many of the
available diagnostic and detection platform technologies require the
operation of bulky instruments by well-trained staff and it often takes
days to complete a single testing. Over the years, there are increasing
needs for the development of portable, integrated biosensors that can
be operated outside the laboratory by untrained personnel. These
devices, once developed, will have a major impact on the applications
of personal care, health, food, and environment monitoring.
Until
now, other than glucose sensors and pregnancy testing strips, very few
biosensors have demonstrated their success in large scale and long term
operations. Encouragingly, in recent years, because of the improved
understanding in genomics and proteomics and the advances in techniques
of microfabrication and instrumentation, many interesting and
innovative concepts and prototypes for integrated and automated
bioanalytical systems have been reported.
This special issue
entitled "Biosensors for Point of Care Applications" is intended to be
a timely and comprehensive report on new emerging technologies that are
currently being developed by research laboratories world-wide on
biosensors and biomicrodevices (e.g. DNA sensor, protein sensor,
glucose sensor, immunosensor, biochip, bioMEMS) with emphasis on,
but limited to, point of care and point of use applications. Research
papers, short communications and reviews are all welcome. In case the
author is interested in submitting a review, it would be helpful to
discuss with the guest-editor before your submission.
KeywordsBiosensors, Biomicrosystem, Biochip, Biodetection, Point of Care, DNA, Protein
Submitted Papers
Title: Implantable Biosensors for Real-time Strain and Pressure MonitoringAuthors: Ee Lim Tan
1, Brandon D. Pereles
1, Brock Horton
1, Ranyuan Shao
2, Mohammed Zourob
3 and
Keat Ghee Ong
1,*1 Department of Biomedical Engineering, Michigan Technological University, Houghton, MI 49931, USA.
2 Norinse Technologies LLC, Houghton, MI 49931, USA.
3 Biophage Pharma Inc, 6100 Royalmount, Montreal, QC, H4P 2R2, Canada.
* Author to whom correspondence should be addressed; Tel.: +1-906-487-2749; Fax: +1-906-487-1717
Abstract:
Abstract: Implantable biosensors were developed for real-time
monitoring of pressure and strain in the human body. The sensor, which
was wireless and passive, consisted of a soft magnetic material and a
permanent magnet. When exposed to a low frequency AC magnetic field,
the soft magnetic material generated secondary magnetic fields that
also included the higher-order harmonic modes. Parameters of interest
were determined by measuring the changes in the pattern of these
higher-order harmonic fields, which was achieved by changing the
intensity of a DC magnetic field generated by a permanent magnet. The
DC magnetic field, or the biasing field, was altered by changing the
separation distance between the soft magnetic material and the
permanent magnet. For pressure monitoring, the permanent magnet was
placed on the membrane of an airtight chamber. Changes in the ambient
pressure deflected the membrane, altering the separation distance
between the two magnetic elements and thus the higher-order harmonic
fields. Similarly, the soft magnetic material and the permanent magnet
were separated by a flexible substrate in the stress/strain sensor.
Compressive and tensile forces flexed the substrate, changing the
separation distance between the two elements and the higher-order
harmonic fields. In the current study, both stress/strain and pressure
sensors were fabricated and characterized. Good stability, linearity
and repeatability of the sensors were demonstrated. This passive and
wireless sensor technology may be useful for long term detection of
physical quantities within the human body as a part of treatment
assessment, disease diagnosis, or detection of biomedical implant
failures.
Keywords: magnetic harmonic fields, wireless sensors, passive detection, stress, pressure
Title: NeuroMEMS: Neural Probe MicrotechnologiesAuthors: Mohamad HajjHassan 1, Vamsy Chodavarapu 1,* and Sam Musallam 1, 2
1 Department of Electrical and Computer Engineering, McGill University, 3480 University Street, Montreal, Canada H3A 2A7
2 Department of Physiology, McGill University, 3655 Promenade Osler, Montreal, Canada H3G 1Y6
E-Mails:
[email protected];
[email protected];
[email protected]* Author to whom correspondence should be addressed; Tel.: +1-514-398-3118; Fax: +1-514-398-4470
Abstract:
Neural probe technologies have already had a significant positive
effect on our understanding of the brain by revealing the functioning
of networks of biological neurons. Probes are implanted in different
areas of the brain to record and/or stimulate specific sites
in the
brain. Neural probes are currently used in many clinical settings for
diagnosis of brain diseases such as seizers, epilepsy, migraine,
Alzheimer’s, and dementia. We find these devices assisting paralyzed
patients by allowing them to operate computers or robots using
their
neural activity. In recent years, the probe technologies are assisted
by rapid advancements in microfabrication and microelectronic
technologies and thus are enabling highly functional and robust neural
probes which are opening new and exciting avenues in
neural sciences
and brain machine interfaces. With a wide variety of probes that have
been designed, fabricated, and tested to date, this review aims to
provide an overview of the advances and recent progress in the
microfabrication techniques of neural probes. In
addition, we aim to
highlight the challenges faced in developing and implementing ultralong
multi-site recording probes that are needed to monitor neural activity
from deeper regions in the brain. Finally, we review techniques that
can improve the biocompatibility of
the neural probes to minimize
the immune response and encourage neural growth around the electrodes
for long term implantation studies.
Keywords:
Neural probes, Microfabrication, Biocompatibility, Microelectrodes,
Brain machine interfaces, Neural prosthesis, NeuroMEMS, BioMEMS.
Mr. Matthias Burkhalter and
Ms. Laura SimonManaging Editor
MDPI Center - Sensors Office
Kandererstrasse 25 - CH-4057 Basel / Switzerland
E-mail:
[email protected]Tel +41 61 683 7734, Fax +41 61 302 8918
http://www.mdpi.org/sensorsMDPI - Matthias Burkhalter - 25 September 2008