Smart Gun - Engineers Develop Technique For Recognizing Gun Owner's Grip

May 1, 2005 — Researchers have designed, built and tested a handgun that will fire only when its component circuitry and software recognize the grip of an authorized shooter. The technology measures not only the size, strength and structure of a person's hand, but also the reflexive way in which the person acts. For the smart gun, the observed actions are how the person squeezes something to produce a unique and measurable pattern. Embedded sensors in the experimental gun then can read and record the size and force of the user's hand during the first second when the trigger is squeezed.

NEWARK, N.J.--Many Americans keep a gun in the house for safety, but the National Safety Council reports nine children are killed every day from gun violence. Now, a new smart gun technology may help keep guns from going off in the wrong hands. Nancy Vazquez does what she can to keep her kids safe from guns in her home, but she still feels uneasy. "I do have concerns even though the guns are locked up, and the children don't have them. There's always the big what if they get a hold of the key."

Vazquez has a right to be concerned -- guns and kids are a bad mix. But now, engineers have developed a new smart gun. It can't be fired unless it recognizes the owner's hand size and grip.

"The idea is to use the science of biometrics, the ability to identify the individual by some unique attribute in this case literally by the way that you squeeze the gun when you pull the trigger," says engineer Donald Sebastian of New Jersey Institute of Technology in Newark.

Unlike other gun safety mechanisms, the smart gun's grip recognition makes it impossible for another adult or more importantly -- a child -- to duplicate the gun owner's one-of-a-kind hold on a gun.

Sebastian says, "Underneath the different elements of your finger and under your palm there are different amounts of pressure that indicate how hard you are squeezing. Right at the very point-by-point, where you touch the gun, we put sensors."

The ergonomically designed gun has 16 computerized sensors embedded in the handle. The sensors capture the unique pattern and pressure of your grip, plus the size of your hand. If someone else tries to use the gun, the information will not match the stored pattern of the owner's -- and the gun won't fire.

"We need smart gun technology, frankly, because we still have too many incidences of unauthorized access to weapons in the home," Sebastian says.

Experts say smart gun technology might someday help prevent tragedy but can't replace talking to your kids.

Vazquez says, "My hope is that by educating my children they'll know to either walk away from the situation or go get an adult." Which may be the smartest gun lesson of all.

Researchers expect the smart gun grip recognition technology to be available in about three years.

Many people assume that grip strength is primarily determined by the size of a person's forearm, particularly the wrists. But many other factors inside the hand really make a difference. The size, strength and structure of the hand -- including the palm and fingers -- all contribute to grip strength, and can vary widely.

Reflexes can also vary. For instance, how someone squeezes something can produce a unique pattern. The pattern can be detected by sensors, which read and record the size and force of a user's hand during the first second of squeezing.

There are several kinds of grip strength. A firm handshake, for example, is a form of crushing strength, while the ability to exert crushing strength on something and sustain it over time is an example of supporting grip strength. Pinch grip strength is the ability to grasp and lift an object between your thumb and fingers, and relies very heavily on the strength of the thumb.

Scientific studies disagree about what grip strength shows about a person's health. One study conducted by the Boston University Arthritis Center found that men with a strong grip were more likely to develop arthritis in certain joints of their hands and fingers. Another study conducted by the Honolulu Heart Program found that low grip strength could be an indicator for disability later in life.

Note: This story and accompanying video were originally produced for the American Institute of Physics series Discoveries and Breakthroughs in Science by Ivanhoe Broadcast News and are protected by copyright law. All rights reserved.