Mobile Robot Driven by
Miniature Onboard Motors
for Cardiac Intervention
Apaper presented at the 34th Annual Northeast
Bioengineering Conference written by P. Allen, N. Patronik,
and C. Riviere of The Robotics Institute at Carnegie Mellon
University, and M. Zenati of the Division of Cardiac Surgery
at the University of Pittsburgh describes the development and
construction of a mobile robot driven by miniature ultrasonic
piezoelectric motors (SQUIGGLE motors) for minimally
invasive cardiac therapy. The robot design extends upon previous
prototypes of the HeartLander miniature mobile robot that moves
in an inchworm-like fashion.
The HeartLander OMNI (Onboard Motor Navigational
Instrument) has been developed to reduce tether stiffness by
utilizing small onboard SQUIGGLE motors which would result in
more efficient turning capability by eliminating the drive-wire
mechanism from the tether of the robot. The development of the
robot allows for increased turning capability and higher traction
during locomotion, and represents the first step in designing a
wireless mobile robot for cardiac therapy. The lifetime
specification for the SQL-1.8 SQUIGGLE motor has been
increased to >1 million cycles.
The robotic design was developed as a proof of concept to
demonstrate mobility on the cardiac surface. Construction of the
system included motor selection, body design, and development of
the control system. The paper presents the design of the robotic
platform and preliminary testing results in vitro.
A copy of the paper is available for download (with
permission from CMU) at www.newscaletech.com/doc_
downloads/CMU-Heartlander-NEbioengConf2008.pdf.
Robotic Grape Vine Pruner
Just recently, in the agriculturally rich central valley of California,
Vision Robotics planned to test a prototype robotic device
for the pruning of grape vines. “It’s a highly skilled job,” says CEO
Derek Morikawa. “The manner in which you prune the vines
affects the quantity and quality of the grapes you get in the
coming season.”
Vision Robotics already builds a number of robots that
harvest apples and oranges, but this is its first foray into an area
that requires significantly more precision and mechatronic
expertise. The $150,000 robot combines computer software,
machine vision, and robotics to perform the work.
The two-ton prototype is 15 ft long, 10 ft tall, and 9 ft wide. It
covers the length of a six foot vine in about 45 seconds (Morikawa
estimates the production version will move three times as fast).
Its cameras take pictures of the vine and (in real time) an
on-board computer converts that information into a graphical
representation of it. The computer model then transmits
instructions to the robotic pruners. “We developed an engine
that incorporates different rules about pruning the vine,” says
Morikawa. “Different growers have different rules based on age
of the vines and the varietal of grape.”
The prototype has to be as tall as it is because some trellis
methods and stakes can be as high as eight feet tall, Morikawa
explains. The time it takes to do the imaging dictates the length
of the prototype. “The cameras are six feet ahead of the robotic
arms,” says Morikawa, “so we can see an entire vine before we
make a decision about pruning.” The size is typical for agricultural
equipment, he says.
Tests are scheduled to take place in Lodi, CA in a number of
vineyards with flat ground. Morikawa says his company will work
on a version for pruning grape vines on steep hills such as those
in Tuscany in the future.
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