Robotics, virtual worlds meet medicine
Health
Industry Today, Nov, 1992 by Sharyn Rosenbaum
Technology that
combines computer models and images could revolutionize surgical training and
surgical procedures. Manufacturers, especially those that supply laparoscopic
instruments, are likely to begin developing a marketing strategy to capitalize
on the potential medical breakthroughs.
Already being
explored in surgical simulations, motion measurement and patient
rehabilitation, virtual reality and telepresence
offer exciting opportunities in health care.
Virtual reality
is a technology that enables users to interact with three-dimensional computer
worlds that resemble the real world. It combines computers and sensory
mechanisms to create a controlled environment. Users can interact with the
virtual environment through sight, sound or touch. The technology may not only
empower patients by helping them to communicate, but also may help physicians
better diagnose and treat patients in the future.
Telepresence extends sensory apparatus to a
remote location through robotics. The user, from a distant site, could see,
feel and touch objects in the real world.
For example, a
surgeon in one location could have a similar hand control, visualization and
touch as if he were actually at the operation site performing a surgical
procedure. He or she could actually pick up an object from a remote location
and feel its weight and texture. The technology has already found a niche in
pathology diagnosis, whereby a surgical pathologist has immediate access to a
microscope and a slide of a patient's biopsy at a remote site.
Telepresence is being investigated for use in
laparoscopic surgery. Researchers are trying to commercialize the technology so
surgeons performing minimally invasive surgery could have the same freedom of
movement as in open surgery.
The real-time use
virtual reality technology for direct patient care is years away, but telepresence may be used sooner, according to Dr. Eric
Horvitz of Stanford University School of Medicine, Palo Alto, Calif., and
president of Knowledge Industries, a Palo Alto company that produces real-world
reasoning systems for physicians in a variety of medical specialty areas.
"Authentic
or high-fidelity virtual reality is a long way off," he said.
"Current virtual reality projects stimulate the imagination about the
possibilities of using the technology in medicine decades from now.
Telepresence applications are likely to come to
fruition earlier because the technology does not face the inherent
computational problems associated with building rich, artificial worlds.
"For
example, for generating realistic simulations of surgery, computers have great
difficulty at simulating the look and feel of soggy, slippery tissue. But telepresence can make use of the world as it currently
exists."
Horvitz likened
the resolution and functionality of medical virtual reality systems today to
that of video games. "But people are excited today about the possibilities, and today's toy-like demonstrations highlight
the promise of future technology for training and patient care."
Applications
abound
The technology
involved in virtual reality and telepresence, Horvitz
said, has applications in three areas: visualization of complex structures and
anatomy; more efficient access to delicate structures; and visual integration
of diverse information sources.
Through virtual
reality, the user could view a high-definition image on a computer screen that
mimics the actual operating field and specific anatomy. The technology could be
used commercially in both surgical planning and an actual operation when its
resolution is improved.
Wearing virtual
reality head gear, the surgeon could have a view of the operating field that
would closely represent the real thing. The surgeon could then better prepare
for difficult operations and have an easier time navigating instruments during
procedures.
"Virtual
reality is good for the 'three Ps'--planning, performing surgery and predicting
outcomes," said
Investigators at
The prototype
systems enable medical students and surgeons to don virtual reality gloves and
headsets and to manipulate virtual surgical tools along with structures in the
abdomen. But the low resolution of the images and other factors, Horvitz said,
"make the simulation a distant shadow of a real
surgical experience."
The second area
involves using telepresence devices to plan or
perform surgeries on delicate structures. The technology would be particularly
advantageous in laparoscopic surgery, where clear visualization and effective
control of surgical tools are crucial.
Using a version
of telepresence called micropresence, a surgeon
could work on a magnified image of the real anatomy. A micropresence
system electronically amplifies the size of a structure and provides a
different perspective of the anatomy as the physician moves his or her head.
"Micropresence is quite feasible because the essential
components of the technology exist today," Horvitz said.
The technology
involves the positioning of one or more miniature television cameras and
related camera-control systems in hard-to-reach or compact areas of a patient's
anatomy and to identify the exact position of teleoperated
microsurgery tools, Horvitz said. The technology would enable the surgeon to
enter and navigate through difficult anatomical regions.
As mentioned
above, telepresence also could be used to perform
surgery from a remote location or having experts guide a surgeon through a
procedure from another site.
The third area
involves overlaying of radiologic images on a
patient's anatomy. This technique holds great promise for use in such tasks as
surgical planning and radiation therapy. According to Horvitz, some of these
methods are already in use.
At Scripps Research
Institute,
"The future
is rich with the possibilities for applying such anatomically keyed display
technology," Horvitz said.
For example,
computed tomography images could be overlaid onto live anatomy, allowing a
surgeon to "see through" the patient and inspect a tumor, Horvitz
said. "This technology could be used for highlighting the outlines of a
malignancy or of delicate blood vessels during surgery," he added.
A fourth area
involving the use of computational methods in medicine is robotic conducted
surgery. Microcontrolled robotic scalpels are already
being tested at the
"The notion
of a robot cutting tissue may initially frighten patients," Horvitz said.
"However, for many delicate surgeries, a finely controlled robotic scalpel
may be preferred to even the most steady human hand.
Someday, patients may demand robotic precision for such surgeries."
Laparoscopic
surgery aid
A number of
companies displayed and discussed their virtual reality-like systems at the
"Medicine Meets Virtual Reality" conference in
"The surgeon
would sit at a console and look into the patient," he said. "He would
reach into the patient with his instruments and perform complex surgical
procedures. This is widely heralded as the coming thing in laparoscopic
surgery."
Telepresence could be used in open surgery and
microsurgery as well, along with surgical planning and training. The technology
also would eliminate direct contact between the surgeon's hand, instruments and
patient, therapy eliminating the risk of disease transmission.
"By the
middle of the decade, surgeries will routinely be performed this way. I believe
it to be very cost effective,"
Hands-on virtual
reality
Greenleaf Medical
Systems,
The patient with
Parkinson's disease puts on the DataGlove, which has
fiber optic cables along its surface. When the joints in the hand bend, the
fibers bend, and sensors record the movement. The recordings are then digitized
and forwarded to a computer, which calculates the angle at which each joint is
bent. This can be done for 10 joints simultaneously.
An image of a
hand can move on the screen that represents the actual hand motion of the
patient.
Another
application of the DataGlove at
The system was
used to treat a patient who had come out of a coma with brainstem encephalitis.
She could not open her eyes or make facial expressions. The DataGlove
was put on her hand, and she was told to make specific gestures--move her index
finger for yes, her pinky finger for no. Then she was asked questions such as,
"Are you feeling any pain?" When she gestured, the computer emitted
sounds that indicated that she was responding. This kind of situation,
New markets
targeted
Greenleaf is
aiming to expand its customer base to include medical and non-medical markets.
Along with
contacting key investigators for the DataGlove and
other motion enhancement products, the company also will target the
disabilities market, according to
Greenleaf will
target therapists who work with people who are motion and/or temporarily
vocally impaired. A sales force of about 40 reps will initially call on
physical therapists at research labs.
Another market
for the products is the workplace, where upper extremity injuries frequently
occur.
The system adapts
the DataGlove's fiber optics and links it with new
software to quantitatively assess upper extremity function. Potential customers
include orthopedic surgeons, physical therapists, occupational therapists and
research clinics.
The system costs
$12,000, compared to competing video systems that cost up to three times as
much,