Good news for all those parents on the look-out for new gadgets to keep their beloved infants safe. We have come a long way from the radio baby monitors of the past.

The first baby monitor, called the “radio nurse,” was invented in 1937 and worked using radio waves. You may have been just as likely to pick up sounds from nextdoor’s baby. Today, there are many ways to keep your baby under supervision when you aren’t in the nursery. With the rise of “extreme baby monitoring,” parents can keep a closer eye on their children than ever before, tracking breathing, heartbeat, and a child’s movement through many mediums.

Devices don’t have to use video or audio recording to monitor a child’s every movement. Raybaby ($269) says it’s a “non-contact” baby monitor that uses ultrasound-like technology to monitor a child’s breathing. The company claims to offer an accuracy rate of 98% while not requiring a child to wear any devices. While the app allows parents to take photos and videos of the baby, the alerts come largely from the ultrasound technology.

One review said the device could lead to “needless panic” because of the level of detail it collects. “It’s worth remembering that babies have their own built-in technology for telling you they’re awake or need need your attention — it’s called screaming,” wrote Mashable. (Raybaby did not respond immediately to a request for comment.)

Here are some of the newest technologies to track and care for your infant:

Video and audio monitors

The classic audio-based baby monitor has been upgraded through enhanced sound quality and range. The Motorola audio baby monitor ($99) works in a range of up to 50 meters and uses sound to activate alerts that light up based on what sound is being heard when a child awakes. The baby’s device comes with a night light feature and the signal transmitted between units is secured through encryption, eliminating the risk of picking up on other nearby radio frequencies, which was a problem in earlier monitors.

Video-based baby monitors have gotten an upgrade, too. Cocoon Cam ($150) claims to monitor breathing in real time without the use of wearables — that is, a device that needs to be worn by your child. It works by focusing a camera that can detect breath movement on a child and the company says it can send an alert if the child stops breathing. Parents can also access the live feed of a child through the accompanying app.

“While I initially thought this was going a bit overboard in the ‘paranoid parent’ department, I found I actually did feel reassured by the breathing graph as I checked on my baby in the middle of the night,” wrote a reviewer on the parenting product review site Lucie’s List. That reviewer noted that the Cocoon Cam was “initially a little buggy,” but that the company’s customer service department was very helpful in resolving the issue. Cocoon Cam did not respond immediately to a request for comment.

Other video-based monitors, though they do not track breathing, work in a similar way. Parents can use classic “home monitor” cameras (not specific to babies) to monitor a child. The motion-activated HawkCam Pro Home Security Camera ($129) follows a child’s activity and can be watched through the accompanying app. It was named a top 10 nanny camera by independent review site SafeWise.

Infant wearables

Some monitors have wearable options so a parent can move around the house while still keeping an ear on their child. The Summer Infant Babble Band Wearable Audio Monitor ($25) has a range of 800 feet. MadeForMums, a parenting review site, gave it four out of five stars.

A new generation of baby devices connects directly to a child’s body for close monitoring. Owlet, a $300 “smart sock” that wraps around a child’s foot, claims it can monitor the infant’s heart rate and oxygen levels while they sleep. Parents can use the accompanying app for sleep data on their child and sounds and lights alert them if anything is out of the ordinary with a child’s vitals, according to the list of uses on the device. A review on parenting site What To Expect noted that the sock isn’t a medical device that’s been approved by the FDA, but that it could be useful for parents of premature infants. However, it’s one of the most expensive monitors out there.

The Owlet device wraps around a child’s foot. Courtesy of Owlet

Another device, Snuza Hero, attaches to a child’s diaper and monitors the baby’s abdominal movements to track breathing. If a child does not move for 15 seconds, the company says the device will vibrate in an effort to rouse the baby. If movement has stopped for 15 seconds on three occasions, the parent will be alerted through an alarm, according to the company.

The device retails for $110 and, according to the manufacturer, aims to help prevent Sudden Infant Death Syndrome — which happens when babies suddenly stop breathing without warning — and give parents peace of mind. It has, however, not been proven to prevent SIDS and has no medical use for that purpose.

Mimo ($144), a baby onesie fitted with a sleep tracker, says it monitors a child’s breathing through subtle rises and falls in the infant’s chest. Parents can access data collected from the baby using the accompanying app on iPhone AAPL, -3.17% and Android.

Wearables don’t come without some complications. Sproutling ($250), a Fisher-Price MAT, -1.68% monitor, can be strapped to a baby’s leg. Reviewing the product on Engadget, Terrence O’Brien alleged that the gadget left his baby with an outbreak of eczema, despite washing the monitor and trying it on alternate legs. He said his son was prone to eczema, but wrote that it kept happening when the gadget was attached. (The company did not respond to request for comment on O’Brien’s review.)

The reviewer added, “Arguably the most important feature of the Sproutling is its ability to alert you when your child falls asleep, wakes up, stirs or rolls over. None of these alerts ever went off with any predictability. Often notifications that my son fell asleep came in 15 minutes or more after the fact. And notifications that he woke up would arrive long after he was out of his bassinet and already getting his morning feeding.

Make sure you always change the password

Like all “smart home” devices, oarents should proceed with caution when using these monitors. For any brand or variety of baby monitor, security should be a priority. Because of the intimate nature of the devices, hacks can be particularly violating. In June, one woman in South Carolina claimed her Wi-Fi connected baby monitor had been hacked. (The manufacturer did not respond to request for comment).

In worst-case scenarios, such connected devices can also be co-opted and turned into “botnets,” giant networks of devices used to power major hacks on different service providers by flooding them with traffic. Most connected devices off the shelf can be hacked within 30 minutes, a 2018 study from Ben-Gurion University in Israel claimed.

“We’ve already seen multiple examples of cameras, including baby monitors, hacked to display their feeds on the internet, or re-purposed for botnets,” said David Ginsburg, vice president of marketing at Cavirin, a Santa Clara, Calif.-based provider of cybersecurity. “As more devices are cloud-connected, the potential for compromise only increases.”

Other tips before choosing a baby monitor: Be sure to research the brand of your monitor online to find out if it has ever been the subject of a hack or a breach in the past, Ginsburg added. Avoid products that are ridiculously cheap, and only buy from established brands, particularly those based in the U.S., and never use the default password on your baby monitor or Wi-Fi router, he added.