Staying current with insomnia-related technologies

Table 1: Examples of wearable devices and sleep interventions provided

Mobile apps

Basic sleep apps offer sleep tracking and may also claim to improve insomnia, anxiety, or stress. See Table 2. While there are many available digital CBT-I (dCBT-I) apps, the only FDA-cleared apps for insomnia are Somryst and SleepioRx. With a few exceptions (e.g., Headspace, Calm, Sleep Easy, doze, others), most apps lack studies demonstrating feasibility or performance efficacy. Insomnia apps may integrate information from mattresses, wearables, nearables or other health apps.

Simple sleep apps function as sleep diaries, helping users become aware of their sleep habits, and some offer standardized or customized suggestions to make improvements. Other apps include features such as soothing or appealing sounds, stories, guided imagery, meditation, or breathwork. SleepScore, Pillow, and Sleep Cycle are examples of apps that use a smartphone’s microphone and speaker to monitor breathing and movement and also to track sleep. Other apps interface with mattresses to track sleep (e.g., Sleeptracker-AI, SleepIQ). A few apps, such as Sleep as Android, include an alarm feature to awaken users during light or optimal sleep stages, while others have added features for children, teens and young adults (e.g., Calm). There are several apps for shift workers or to prevent jet lag. For those with disruptive dreams, DreamApp claims to provide interpretation and feedback based on published studies and more than 3 million collected dreams.

Table 2: Examples of mobile applications to improve quality and duration of sleep

Nearables

Sleep nearables are devices designed to monitor sleep without needing to be worn. Nearables can be considered in two categories: those incorporated into a bed and those by the bedside or in the room, which often use sound or radar to provide sleep metrics. Both primarily focus on tracking sleep metrics such as sleep times, sleep duration, sleep stages, and sleep disturbances. See Table 3.

Table 3: Examples of nearable devices | Abbreviations: electroencephalogram (EEG); ballistocardiography (BCG)

Bedside nearables often incorporate features that aim to improve the sleep environment, such as alternating light intensity or providing soothing white noise (e.g., Hatch Restore). Sound+SLEEP SE is a nearable sound machine with 64 distinct sound profiles engineered to potentially promote deeper sleep, relaxation, and renewal. While these features can contribute to improved sleep quality, they may fall short in addressing specific sleep disorders, particularly insomnia. Among the numerous sleep nearables, one device is notable for including CBT-I based interventions by integrating sleep therapist access directly into their services: Full Sleep by Koko Labs.

A critical issue with most sleep nearables is the lack of peer-reviewed studies validating their performance efficacy. Few published studies focus on a device’s ability to track sleep, and scientific evidence supporting claims to enhance sleep is generally lacking.

The other type of nearables are products in bed that monitor movement or other physiology to determine sleep metrics or to provide interventions.

The Dreampad uses a vibrational sound system inside a pillow that is activated by a head resting on it; music is vibrationally conducted so it is only audible to the person touching the Dreampad. The Aurras under-pillow speaker and Puretone Sound Pillow use embedded stereos to play sound, music, and audiobooks. Clinical studies have shown promising results, indicating that acoustic sleep technology can significantly reduce the time it takes to fall asleep, increase total sleep duration, and improve overall sleep efficiency.

Sleep metrics can be approximated using BCG by measuring body movement, heart rate, respiratory rate, and calculating heart rate variability. Such technologies offer easy long-term monitoring but are subject to significant motion artifact. This technology is incorporated in under-the-mattress or pillow products like Fibion, EMFIT bed sensors, Withings sleep pad, and Cubo AI sleep sensor pad for crib mattresses. BCG sensors can also be built into mattress bases, as seen in Fullpower Technologies’ Sleeptracker (available in some Simmons, Tempur-Pedic, and Sealy beds), Sleep Number beds, and Dawn House Bed systems. The Toch Sleepsense pad monitors sleep when placed under a single bed leg.

BCG sensors can be coupled with other technologies to improve sleep, such as mattress cooling as offered with Eightsleep pod or Rezet mattress topper. Other technologies improve sleep or comfort through temperature, pressure, or sound/vibration modulation. Notable temperature-regulating products include BedJet, Chilipad, or moisture wicking sheets. Weighted blankets may significantly improve insomnia severity in those with mood disorders, with many options available based on weight and material.

Some products use calming vibrations with various frequencies to relax or comfort users. The Snoo bassinet slowly rocks infants while playing white noise when crying is detected. Similar rocking motions for adults are being explored by Somnomat. Some adjustable beds by Ergomotion vibrate to provide a massage. The Hapbee Smart Sleep Pad claims to create an electromagnetic field to promote deep sleep.

Transcranial Electrical Stimulation Devices

Explored since the early 1900s, brain electrical stimulation therapies are categorized as invasive deep brain stimulation or noninvasive brain stimulation (NIBS). NIBS includes transcranial magnetic, ultrasound, and electrical stimulation (TES). TES is further divided into transcranial direct current, alternating current (tACS), random noise stimulation, and vagal nerve stimulation.

Clinically, most devices have been studied for psychiatric and neurological disorders. For insomnia, tACS is the most studied and available. tACS involves alternating sinusoidal current and polarity between two electrodes to modulate brain waves and potentially affect neurotransmitter or hormonal production. Devices differ in how tASC is delivered: electrical output (frequency, strength, duration, and timing), wave shape (symmetric or asymmetric square or sinusoidal shape variations), location (e.g., earclips, templar, mastoid, maxilla-occiput, or supraorbital headbands), potential brain target, and electrode type (saline, sponges, or gel). In addition to the heterogenicity of device deliveries, most studies are poorly designed with mixed results.

The first cranial electrical stimulation device was FDA cleared in 1978. In 2014, these devices were reclassified by the FDA as Class II (moderate risk) for treatment of insomnia or anxiety, and Class III (highest safety risk) for depression. Among these devices, Alpha-Stim devices stand out in terms of number of publications, clinical trials, and publicly available information for insomnia. However, most studies focus on anxiety, depression, and/or pain using several Alpha-Stim device versions in clinical trials. While adverse events are generally localized and mild, there is an active FDA recall for the Fisher Wallace Stimulator due to more serious adverse effects. See Table 4.