If you’re anything like me, you probably dread getting the flu shot or your blood drawn at the doctor’s office. In fact, about one in 10 people develop “needle phobia” as children, a time when they may receive multiple vaccinations every year. Needle phobia can have damaging health effects if, as adults, we’re less likely to get our flu shot, give blood, or go for timely visits to the dentist or doctor.
That’s why researchers are looking into harnessing a decades-old theory of how pain works in order to build a device that makes injections far less painful or “close the gate” to neural traffic up the spinal cord.
“All of that stuff has been known for a long time, so what we’ve done is quantify it,” says William McKay, a professor of anesthesiology at the University of Saskatchewan.
McKay, with colleagues and students, created a device to apply pressure and vibration to the upper arm site of an injection just before a needle jab was made (they used fake plastic needles that still caused a similar sensation). They asked the 21 subjects, healthy adult volunteers, to say at what point they reached a 3/10 on the pain scale, and measured the force on the needle required to get to that point.
The result? They learned the optimal pressure and vibration frequency that allowed the subjects to withstand the most pressure on the needle before reaching a 3/10 pain point, which they figured was about the right level for a typical injection (where 0 is no pain at all, and 10 is the worst pain imaginable).
For the last five years, there’s already been a device on the market, called the Buzzy, that performs a similar task, though McKay doesn’t believe it’s widely used by doctors yet. He hope their data informs the improvement and wider adoption of a similar device, though he has no plans to commercialize a product himself. The research team’s next step is to do a randomized clinical trial in a flu vaccine clinic on adults, and then test it on children.
An interesting side effect of the study was learning about people’s varying thresholds for pain. It varied not only person to person, but by the situation. For example, at first male subjects who did the study while women were in the room would show a higher pain threshold than they would normally.
The lesson? “We need a better, more objective way to measure pain,” McKay says.