Lithium-Ion Battery Simulation for Greener Ford Vehicles

mEdiCal
Scientific & Biomedical microSyStemS llc, columBia, md
Laser Vision Patient Unit/
Data Receiver
Wireless Data Transfer
Flash Memory
Storage (SD)
Secure Permament
Patient Record
Patient Product
Capsule System
Patient test
Capsule Endoscope
External Communication
Sensors (disposable)
Figure 2. The new endoscopy system incorporates a smaller, more energy-efficient imaging pill with
scanning imager; a portable data controller with sensors that stick to the abdomen and resemble EKG
pads and leads; and software for data analysis.
“since each fabrication
run of these devices takes
many weeks and thousands
of dollars, the modeling
we’ve been able to do has
been critical in keeping this
project moving forward
aggressively and on budget.”
but RF’s power demands severely limit
the power available for use by miniaturized
devices. They also reduce battery life
and require larger pills than might otherwise
be possible. Energy inefficiency is a
major reason why current imaging pills
feature a resolution of only about 70 kilopixels,
running at two frames/second. The
resulting images are often disjointed and
herky-jerky, especially when the capsule is
being propelled quickly as happens during
a bout of peristalsis.
By contrast, SB Microsystems is helping
Innurvation develop a data channel with a
1 Mb/sec data transmission rate and a longer-life
imaging pill with a 360° radial scanning
imager that together will enable much
sharper, continuous imagery (Figure 3).
The communications channel has been
tested successfully in pigs and is moving to
human trials this year, while the scanning
imager is a later phase of the project.
“The human body is basically a big bag
of salt water and there are many situations
and sets of conditions where transmitting
data via acoustic waves through
this medium is very energy-efficient,”
said Jamieson. “Traditional endoscopes
with a high-resolution CMOS imager at
their tip produce really sharp images.
The goal here is to achieve high-resolution
endoscope-type clarity and coverage
in a imaging pill.”
In the system under development, the
acoustic wave source is a piezoelectric
(PZT) element. SB Microsystems is using
COMSOL’s piezo-acoustic tools for
multiple aspects of this project, from optimizing
the behavior of the PZT acoustic
source, to exploring acoustic interactions
with different tissues, to implementing
multiple receiver network designs in order
to minimize multipath interference
(Figure 4).
“These issues have required us to
develop an understanding of the coupling
between the acoustic, electric and
mechanical domains, and the integrated,
expert physics capabilities of COMSOL
Multiphysics have been absolutely critical
to the success of that effort,” said Jamieson.
“For example, by coupling the
piezoelectric and pressure acoustics user
interfaces we were able to optimize PZT
material choice and sensor geometry to
design a transmitter that is very nearly
omnidirectional, a critical requirement.”
Coupling the pressure acoustics and
mechanical domains, meanwhile, enabled
the design team to analyze the
interactions of acoustic signals with different
tissues, which provided the ability
to understand and to accommodate important
issues such as multipath interference
and signal fade.
Variable Rate Sidewall Scanning
Innurvation Solution
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Figure 3. 360° radial scanning technology produces much sharper and continuous imagery.
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