Researcher Lisa Helen is working on a ‘parking sensor’ for needles to help accurately deliver anaesthetic before surgery and in other procedures.
If you have parking sensors on your car, then you will know they are like extra eyes that tell you more about a hard-to-see place.
Similarly, Lisa Helen at the Tyndall National Institute in Cork is working on a sensor to help anaesthetists guide needles close to peripheral nerves in the body and avoid administering unwanted dings.
“We are creating a smart needle,” said Helen, a third-year PhD researcher in Tyndall’s sensing and separation and life sciences interface groups, and in University College Cork’s chemistry department.
“We are taking a needle that is already being used in the clinic and putting a small sensor on the tip of it. That sensor is there to identify the tissue type that the needle is touching in the body, so we can identify exactly where the needle is and what it is touching.”
Not getting on your nerves
She is specifically looking at how the smart needle could be used to deliver a peripheral nerve block, a procedure where the anaesthetist uses ultrasound to monitor where a needle is going in the body before injecting anaesthetic close to a peripheral nerve, thereby blocking sensation from the limb extremities.
“They watch the needle as it is going through the tissue towards that nerve in real time,” explained Helen. “They cannot tell though whether the needle tip is just outside the nerve, at the nerve covering, or whether it has gone into the nerve.”
While ‘dings’ are rare, they can cause pain and even paralysis for the patient, and one of the aims of the smart needle is to use the sensor as well as the ultrasound to get more information about the needle-tip’s environment, explained Helen, who said she hopes that making the peripheral block easier to do will help reduce the need for general anaesthetics.
“The main point of developing this technology is to make the block safer and more effective but it [would also] be useful for training, and, by making the technique easier to perform, more people will be able to be trained to do it,” she said.
Impedance clues
Lisa Helen with Damien English TD (l) and SFI head Mark Ferguson (r) after she won the TIDA pitch-off last year. Picture: Jason Clarke
So how does the sensor ‘know’ what is around it? The trick is to measure the ‘impedance’ of the tissue, explained Helen.
“If you introduce a tiny electrical current, each tissue type will have a different electrical property,” she said. “Muscle would conduct electrical current quite easily and quite quickly, and you have a low impedance of electrical current. But if you put an electrical current through fat it is highly insulating, it will impede the current. That bio-impedance is what we use to distinguish between different tissue types.”
The Irish Research Council-funded project is looking to move from lab-bench to in-vivo studies, and, ultimately, Helen hopes it will be used in the clinic.
“[The smart needle] is still going to be used with the ultrasound,” she explained, adding that consultant anaesthetist Dr Brian O’Donnell from Cork University Hospital is a co-supervisor on the project. “It will still be the same procedure to them but they are getting extra, valuable information. It is like putting a parking sensor on the back of a car – they don’t change the car in any way, they just put the sensor on it.”
The Tyndall group is developing similar technology to detect breast cancer, and last year Helen won the Science Foundation Ireland TIDA ‘pitch-off’ speaking about the smart needle.
Lab life
Working in a research lab was not on her radar when she was in school, although she knew she wanted to study biology.
“I am from a farming background and I would have seen a lot of scientific farming and genetics in the breeding there, and my mum is a nurse,” she said. “In secondary school, I really just loved biology and I wanted to pursue something in that.”
Visits to open days in college introduced her to options. “I realised I had been looking for biomedical science but I didn’t know it existed,” she said.
Helen studied biomedical science in a joint degree between UCC and Cork Institute of Technology, and started out sure she would work in a hospital lab afterwards, but her final year project introduced her to research and she opted to do a PhD in Tyndall.
“I didn’t necessarily have the engineering background [when starting the project], but coming into a place like Tyndall you get to learn a lot from the colleagues and teammates, so it was the ideal place to come for this type of project,” she said.
“And I have developed a lot of the fabrication process [for the smart needle] with the expertise of the staff in Tyndall.”
Her advice for students with an interest in science and technology is to visit open days, find a suitable course and make sure it is well accredited. “Look into the different aspects and ask lots of questions about it,” she said. “Also, keep in mind your path can change too.”
