UBC Reports | Vol. 50 | No. 2 | Feb. 5, 2004

New Invention Saves Pain for Patients and Doctors

Making needles easier to give and easier to take

By Michelle Cook

(with files from ErinRose Handy, Applied Science)

Joanne Driscoll (not her real name) has a deteriorating disc in her spine. To slow the deterioration down, doctors must insert a long needle filled with a steroid into her back every three months.

It's an experience marked with fear and anxiety and sometimes, when the needle misses its mark, excruciating pain.

"I have heard others scream when this happens and I've wanted to scream myself. One time it felt like molten lava coursing down my leg," Driscoll says. "It is also very stressful for the person inserting the needle. Once after many painful failed attempts, a resident actually asked my supervising doctor to put on his gloves and take over my treatment."

Needle insertion is one of the most common medical procedures. It can also be one of the most nerve-racking for both medical practitioners and patients -- especially when it involves the 15-cm-long needles used to reach regions deep inside the human body.

Now, a group of UBC engineers has developed a steerable needle to help doctors hit their target on the first try -- and save their patients the stress and pain of multiple insertions.

"What's interesting about this needle is that instead of putting a straight needle into the body and hoping it goes towards its target, we have a needle that can steer itself from the tip. It can guide itself. It's a very smart needle," says Prof. Robert Rohling, a professor jointly appointed to the departments of mechanical engineering and electrical and computer engineering and one of the needle's inventors.

The steerable needle prototype looks like a stainless-steel barbeque lighter with a 15-cm hypodermic needle attached to it. What makes it unique is that within its barrel, there is a second, flexible needle with a curved tip. The second needle can be steered by a joystick on the needle's handle, giving doctors greater accuracy in locating their target, and make corrections along the way.

Rohling says the steerable needle won't change the basic aspects of the biopsy procedure. Like a conventional needle, it is inserted into the body by puncturing the skin at the best access point, and pushed in until the tip reaches the desired target. The big difference is that, once inserted, the doctor can use the thumb-controlled joystick to steer it along straight or curved paths.

He envisions doctors using the device in conjunction with ultrasound -- another medical technique he is working to improve.

"The steerable needle will give doctors an extra degree of control," Rohling says. "We expect the first applications will be the more difficult, deeper insertions [but] it is also possible that the steerable needle will help a novice reach their target on the first attempt -- without trial and error."

As the director of Surgical Techniques Training Programs for UBC's medical undergraduates, Karim Qayumi has guided many residents through the needle insertion procedure. He's also performed countless needle insertions himself. He says it's not an easy experience.

He says the main challenge for doctors is having to imagine where to direct the needle, without actually being able to see where it's going. It's a skill that comes only with experience. The potential dangers are numerous: a misplaced needle can cause bleeding, pain, or seed healthy cells with cancerous ones.

"There's a certain anxiety when you insert a big needle into someone and you don't know whether you're going to get results or not," Qayumi says. "If the biopsy is in a remote place, even experienced doctors can have difficulties. They've got to get to the target area without damaging tissue or causing complications."

Although he has not used the steerable needle, Qayumi welcomes Rohling's research, with fellow inventors Tim Salcudean, an engineering professor, and master's engineering students Richelle Ebrahimi and Stephen Okazawa, to improve the technique of needle insertion.

Okazawa says the biggest hurdle in designing the steerable needle prototype was getting the mechanical and electrical parts to work together with the computer software designed to run the needle. But the result is a one-of-a-kind device that the research team hopes will take some of the discomfort out of a painful procedure, and cut down on the time needed to perform it.

Rohling adds that while the cost of the system is still more than a regular, disposable needle, the health-care savings will be in the reduction of time it takes doctors to perform a procedure.

The researchers' next step is to prepare the prototype for clinical trials.

The steerable needle hasn't been used on humans -- yet. Instead, researchers have been trying it out on tissue phantoms -- simulated pieces of tissue that Okazawa cooked up in his own kitchen using agar, a gelatinous substance obtained from seaweed, and then embedded with peas and grapes for target practice.

Even before doctors get their hands on the first prototype, its inventors are already thinking about how to improve the steerable needle's capabilities.

"We look at these types of applications and think ahead to even more advanced systems where we have computer-aided control," Rohling says. "The first iteration has a little joystick and the control is all in the operator's [doctor's] hand. The second may be to let the computer handle the joystick and monitor the needle's progress and provide the corrections. Eventually, a robotics system may take care of both pushing the needle and steering the tip."