I like to think of myself as a calm, relaxed person, someone rarely ruffled by the little things in life. But a recent stint spent testing self-proclaimed stress-eradicating portable biofeedback devices has taught me that I am far, far away from Zen. In fact, according to these gizmos, I'm a stress machine—or at least I become one when confronted with machines designed (I use the term lightly) to alleviate my stress.

Perhaps I'm a slight technophobe and such gadgets plain freak me out. Or did trying so hard to attain inner peace only ratchet up my tension? In the end—while I probably could have achieved the same effect by simply going somewhere quiet and taking a few deep breaths—some of the devices worked just fine, while others did not. In the least.

In fact, two out of four were wholly irritating, and even sick-making.

Here, then, is a quick look at how I fared in my well-meaning attempts to chill out—attempts that generated results ranging from not too bad to now-I-need-a-vacation.

The StressEraser, $299; stresseraser.com

For my first foray, I logically went with the StressEraser, whose brushed chrome-and-white-plastic housing—as well as its size and heft—recalls a first-generation iPod. I opened its owner's manual and found a very cheery letter from Michael Wood, Chief Science Officer of Helicor and "the proud inventor" of the product, congratulating me, in bold type no less, on my decision to live stress-free.

"Gee. Thanks, Michael," I muttered, to no one in particular, and continued with my reading.

I learned that the device measures your pulse rate and then helps you lower it—and thus your stress levels—through synchronized breathing. You stick your left index finger into a slot, and after a short time, waves representing the beats of your own heart appear on its black-and-white screen. The idea is to breathe nice and slow, so that the jagged peaks and valleys of a stressed body become, onscreen, the digital equivalent of rolling countryside. The StressEraser will even store your sessions, assigning points for how quickly you can induce calm and how long you stayed there.

I had some difficulty at first, getting frustrated when a distracted thought would pop into my head, ruining the arcing, gentle slopes—and solid scores—that I'd worked so hard to attain. But soon enough, I got the hang of it and even fell asleep once in the middle of a session—the only situation I can think of, really, where dozing off on something or someone can be taken as a compliment.

EmWave Personal Stress Reliever, $199; emwave.com

If the StressEraser resembles a first generation iPod, then the emWave, which comes in a nifty teal blue and is roughly a third smaller in size, is its "mini" equivalent. Operating on the same principles as the larger machine, the emWave also measures your heart rhythms and administers breathing techniques to induce calm, just with fewer features (either a good or a bad thing, depending on your perspective and your tolerance for bells and whistles).

The device does not have a monitor that shows you the beating of your heart, but rather a simple light strip along its top. The user places his or her finger on a red sensor and inhales and exhales as a blue illumination runs the length of the strip, the biofeedback equivalent of following a bouncing ball. At the end of the strip is a separate light, which starts out red, but as you relax gradually glows blue and then green. The emWave worked nearly as well as the StressEraser and couldn't have been simpler—a gift in and of itself.

GSR/Temp 2X, $149.95, biof.com

Stress manifests itself in less obvious ways than a rapid heart rate, which is why the GSR Temp measures "galvanic skin resistance" and other signals intricately linked to the minute shifts in your nervous system.

The technique: Grasp what looks like a computer mouse on steroids in your left hand, being sure to rest your index and middle finger lightly on its two stainless steel sensing plates. As soon as you are situated, the device is supposed to release a pleasant tonal frequency, which tells you where your galvanic skin resistance is (the lower the tone, the better). Once you hear the tone, the idea is to relax, take deep breaths, and then passively observe as the tone lowers itself.

All of this sounds great—relaxing, even—until you actually try the thing. The problem is that the GSR Temp's tonal frequency is not pleasant, as advertised, but rather sounds, at best, like a computer that's been left on too long and, at worst, like the mewling death throes of a spoiled lap dog. Either way, it's hard not to tense up when you hear it, which is unfortunate as increased agitation translates into a tone that is even higher pitched and, thus, more agitating than the one that you started with. (Imagine Fluffy being slowly run over in the driveway instead of just quickly kicking the bucket on the living room rug.)

I should note that there is an attachable meter that restricts the device's portability but, thankfully, also bypasses the auditory assault. Alas, once heard, the tone is not easy to forget. Before long, I'd had my fill of the GSR 2's particular brand of tranquility.

The Mind Spa, $249.95; avstim.com

And finally, the MindSpa, a "Personal Development System" that came in its own nylon carrying case and included a small computer, headphones, and démodé black wraparound glasses—the sort that Boca Raton retirees might don post-cataract surgery. This crime against fashion should have indicated to me that further assaults would be forthcoming, but the amusing Ahnold-ness of the shades briefly distracted me.

Wading through The MindSpa's meandering instruction manual required some serious effort, but I managed to glean that the device employed light and sound to tap into specific brainwaves, activating them to lower the user's stress in some cases, and to help increase productivity in others. Based on the manual's recommendations, I selected Program 3: Deep Alpha Relaxation I; plugged my glasses and headphones into the computer; and reclined on my bed, ready to get my unwind on.

For a few seconds, I was completely at peace.

But then the program began. Strobe lights in the frames of the glasses started flashing and a terrible, oscillating, thumping noise (An underwater rave, without the drugs? The soundtrack from an alien womb?) burst forth from the headphones. I felt disoriented and nauseous, trapped in an epileptic's worst nightmare, and was tempted to dash the whole system against the wall. Instead, I persevered for the program's entire 23 minutes. At its end, I did not feel relaxed but sweaty, exhausted, and queasy. I tried other programs and reread the manual, but the result was always the same. After a few days of testing, I simply gave up. Unlike Ahnold, I would not be back.

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