by David Geer
Contact the author at geercom@windstream.net
Miniature Surgeons Travel
Inside the Human Body
Microbots — wireless
miniature surgical robots
— traverse veins and
ventricles performing lifesaving procedures inside
the human body. Atop a
foundation of benefits of
minimally invasive surgery,
scientists are sampling
the efficacy of sending
mechanical physicians of
only a few millimeters into
orifices, organs, and blood
vessels to administer
treatments with little or
no disruption.
A microbot on a chorioallantoic
membrane of a chicken embryo
(a vascular membrane used to
model retinal veins).
Current mini-medical robots perform capsule colonoscopies and work in the GI tract. By shrinking the
robots to a few millimeters, researchers and clinicians can
start to think about working inside the urinary system, the
circulatory system, and even the central nervous system, as
well as blood vessels in the eyeball (Microbots for Minimally
Invasive Medicine, Nelson, et. al., April 2010,
AnnualReviews.org).
Procedures include therapeutic drug delivery, highly
localized radiation therapy for tumors, delivering stem cells,
opening blood vessels, taking minute biopsies, and inserting
scaffoldings, stints, and implants to name a subset of
theorized and as yet unknown possibilities; some are
already successful in animal trials.
Using wireless technology, the medical robots would
transmit areas of interest such as cancers discovered using
sensors, as well as the bot’s location in the given human
system. With the bot’s location at the time of discovery,
physicians could pinpoint the cancers, internal bleeding, and
other matters of concern. The robots are highly applicable
to microsurgery of the retina, which is currently difficult to
10 SERVO 07.2011
approach. The robots could use the low level force and
reach the heights of precision necessary, neither of which is
possible with the human hand. A robot is theorized that
could be observed through the eye and manipulated using
magnetic wireless technology.
Microbots could also perform operations on the inner
ear, where the bots could install cochlear implants with
increases in sound quality. Similar procedures using current
surgical technologies can lead to damage and infection.
Microbots could be used in a number of fetal surgeries
where existing surgical tools lose their degrees of freedom
due to the number of layers (mother’s abdomen, uterus)
the tools must pass through.
Power Up and Go
Potential power supplies for microbots include onboard
power such as thin film batteries, MEMS-based generators,
and “scavenged” power in which the robot pulls energy
from chemicals in the environment, i.e., inside the human
body where the pH is neutral (cited in Nelson, et. al.).
