Wednesday, 5/14/97 Student creates device with host of
possibilities for heart research TECHNOLOGY: Invention may be used
to monitor individual human cells
By Gregory Mena Daily Bruin Contributor A device as small as the
width of a human hair might someday signal early signs of heart
disease. Gisela Lin, a UCLA graduate student in electrical
engineering, has invented microelectromechanical systems (MEMS)
that have improved heart research and may eventually be used to
monitor human cells. Lin’s devices may one day be implanted in the
body to monitor heart cells. The MEMS would then be able to alert
medical attention of unhealthy cells through a wireless
communication system. But before inventing a communication system,
researchers must first understand the properties of diseased heart
cells. In current heart research, scientists use "force
transducers" to differentiate the cell activity of a healthy heart
cell from a diseased one. Specifically, experimenters measure the
amount of force that a heart cell exerts as it contracts and
expands. Because of their similarity to human heart cells,
researchers use cells from rabbits or rats as a model for
understanding human heart disease. Constructing MEMS is a delicate
and careful process. First, researchers design detailed blue-prints
of the micro machines and send them to a fabrication facility. The
fabrication process combines oxides, metals and glass in the MEMS.
When they return to the laboratory, they are etched and shaped with
different chemicals. Engineers then manually assemble the MEMS with
tiny tools, or micro-manipulators. Researchers fold the aluminum
parts and glue other parts in place. The force transducers that Lin
has created are more than miniature sculptures; they are actually
functional devices. Lin’s MEMS include glass arms which extend from
the body of machine. Individual heart cells are manually placed
between the delicate projections. The arms bend and move as the
cell contracts. The relative force of these contractions sends a
voltage response which can be analyzed and displayed by a computer.
The device has so far been successful in heart disease research,
said Roy Palmer, a UCLA post-doctoral researcher from the
Cardiovascular Research Laboratory. "In heart failure, contractions
are different. Our systems enable us to look at the cells and how
they change," Palmer said. "We have already made a lot of progress.
We have had a number of advances in differences in (heart cell)
forces ." Before the invention of micro machine transducers,
researchers used a larger, less accurate device, according to Ken
Roos, coordinator of the Cardiovascular Research Laboratory. "The
large transducer was subject to the noise from the building
environment and the wind current from the air conditioning," Roos
said. In contrast, the new transducers have an increased
sensitivity and the potential to make quality measurement, Roos
explained. "It’s a hundred times better. We already know that," he
said. "This technology allows us to do things that we couldn’t do
before. The mechanical devices are on the same time scale and the
same size scale of what we are measuring." MEMS technology, which
has contributed to heart research from about 20 years ago, has
steadily grown and matured, according to Patrick Chu, a fifth-year
graduate student in electrical engineering. "In the past 10 to 15
years, the development has been the fastest," said Chu. Lin
explained that her project is still in the early stages. She
studied electrical engineering at UC Berkeley as an undergraduate
before building MEMS at UCLA. "There is a good lifetime’s work in
this project," she said. In the future, Lin plans to work in
research and development. A microscopic transducer measures the
force exerted by individual cells. The micro machine holds one
heart cell with arm-like structures. GENEVIEVE LIANG/Daily Bruin
Fourth year graduate student, Gisela Lin, from the school of
Engineering and Applied sciences in her laboratory. Lin uses a
microscope to examine her microelectromechanical system (MEMS).
GENEVIEVE LIANG/Daily Bruin Fourth-year electrical engineering
graduate student Gisela Lin may have made an important medical
breakthrough in heart disease. Previous Daily Bruin stories:
Pediatric cardiologist;s work recognized