I was helping a friend spruce up her house. She and her wife are upgrading and had closed on a new place, so they needed to get their current home into prime selling shape fast. I painted doors and floorboards. Another guy with more construction experience worked a table saw. He accidentally stuck his hand in it. He didnt scream. He shut the saw off and briskly walked away, his other hand gripping the one spurting blood.

Are you okay? I asked. (In retrospect: stupid question.) No, no, no, he said. I called 911 as he sat in the living room, next to the homeowner, the end of his middle finger growing grey. Paramedics arrived and crowded out the room. I moved to the back and saw the blood splatter, igniting my squeamishness. Fight-or-slight chemicals were flooding my nervous system.

(He will be fine, after surgery. He said the lesson is dont allow your familiarity with the saw to diminish your vigilance.)

Returning to my car, I saw the Apollo in my laptop bag. I planned to start the week-long trial, for which to write this review, the following day, but it seemed like an ideal time for the chemical-free come-down its makers promised. I strapped it to my wrist and chose rebuild and recovery from the seven settings on the corresponding app. Slow throbs reverberated on my wrist, like I had an extra external pulse. As I drove home through the rain, the device helped center my mind.

While the electronics market is increasingly flush with wearables to measure your mood , Apollo (priced at $349) is one of the first to promise to do something about it. Its developers tout research showing that inaudible vibrations can increase heart rate variability (HRV), unlocking an anxious or burnt-out person from a state of overextended alertness.

David Rabin, M.D., Ph.D., the devices main developer and the companys co-founder, told me that the Apollo offers a handy solution for when you're too anxious to lower the mental noise enough to think of a pacifying strategy or you cant logistically take yourself out of a moment to go into a corner and deep breathe. With Apollo, we wanted something we take out of the lab and would not monopolize the users ears or hands or sense of touch, Rabin said.

The Apollo Stress-Reduction Tool: Tested
The Apollo Stress-Reduction Tool: Tested
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Rabin hopes the Apollo will one day succeed antidepressants as a first option for depression. We should start with what has the least amount of side effects and that isnt Zoloft, he said. Ultimately, we have to bring the locus of control back to users and away from medications and things that are used to self-medicate.

The impetus for the device stems from research Rabin says he completed at a psychiatric hospital on severely depressed patients. But when his team put this idea into a matchbox-sized black device that could be strapped to a wrist or ankle and sent out a few hundred units for various people to beta-test, they discovered it had a receptive audience in athletes, military personnel, executives, and self-optimizers. Once we put it out into the wild, it was used for energy and focus, he said.

I might fit into both categories of Apollo user: I am a self-optimizer, in that I am a freelance writer for whom productivity equates directly to rent and foodand I am also often a nervous wreck, for mostly the same reason. I spend too much time in front of a laptop, am frightened by blank Microsoft Word documents, and student loans cause me to wake up at 4 a.m.

The Apollo Stress-Reduction Tool: Tested
The Apollo Stress-Reduction Tool: Tested
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I was sold on the Apollos effectives for extreme stress after my first experience; it succeed in Rabins aim of releasing one from a mental resource-depleted stupor. As for its impact on everyday life? The Apollo has seven settings and allows the user to vary the intensity and the duration of the vibes.

On my first full day using the Apollo, I woke up, strapped the device to my wrist and started with the energy and wakeup setting. It sent big, quick pulsations, as if it was trying to do CPR on my wrist. It, uh, succeeded in stirring my alertness and I understood why the standard duration is five minutes.

I was much fonder of the clear and focused mode, which sets off a series of long, steady throbs. The productivity pitfalls for a freelance writer are multifold. Theres spending too long on any one email or task, the distraction of thinking about taxes or bills or some other work-unrelated worry, and the allure of scouring the internet for something like memes of Bernie Sanders tormenting Chris Matthews . Clear and focused is slow, steady, non-evasive reminder that Im supposed to be working, and at a steady pace.

Stressed Man at Desk
Stressed Man at Desk
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My second favorite setting was social and open, another one that utilized slow waves. It was like having a small electronic cat purring at your feet (and I found that having it on the ankle was less cumbersome than the wrist). I took the Apollo with me grocery shopping a few times on this setting and the extra rhythm added a little pep for monotonous tasks.

One big drawback: The Apollo looks like a monitor for parole or probation. I suppose that cant be helped. Still, for that reason, my girlfriend requested I not wear it when we were socializing. (She also, while cleaning up the bedroom and picking it from the floor, nonchalantly called it your vibrator.)

The rebuild and recover mode (the one I used after witnessing the accident) is popular with athletes, Rabin told me, and I understand why. After a gym workout, I usually feel a crash, typical as the body tries to replenish muscles. In R&R mode, the Apollo provided some bodily stableness that made it so I didnt feel off-kilter until I got my usual hardboiled egg or handful of trail mix or other protein-rich remedy.

Italy, mountain running man sitting on rock looking at sunset
Italy, mountain running man sitting on rock looking at sunset
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There are three settingsmeditation and mindfulness, relax and unwind and sleep and renewalthat I didnt notice, literally. All these were so low-impact, they blended into the sensory backdrop.

Meditation and mindfulness offers these big waves I forgot about after the first few pulses. I tried it for some mindful activities, like writing and cooking, but preferred the old standby of clear and focused.

Relax and unwind has this slow motoring vibration, like the silent, gentle engine of a Prius shrunken and pressed against your foot. Sleep and renewal was barely noticeable, even when I jacked up the vibration strength. I got to sleep every night that I used it, so no complaints. (I also take a lot of sleep-related pills.)

Tired woman yawning while using mobile phone on bed at night
Tired woman yawning while using mobile phone on bed at night
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The Apollo was not world-changing for me but I enjoyed having the extra measure of emotional self-manipulation. I punched into an app what mood I wanted to be in and this little companion on my ankle collaborated.

Perhaps it was partially placebo; by ordering around the Apollo I was also telling myself I needed to be clear and focused or social and open for as long as the vibrations lasted.

I think I was more stable and productive during my week with the Apollo than I was schlepping through an ordinary week. By the end of it, I wasnt expecting specific results, but was just glad the Apollo was there help me contain whatever mood may come or adjust my mind to the task the day offered.

To paraphrase Rabin, it brought back the locus of control.