Understanding will struggle, how do these products ensure the stability of the human body?

Kingii Wearable Safety Device:

Kingii, one of the first life-saving wristbands, activates a CO2 tank by manually pulling a lever to quickly inflate it to create buoyancy.

BlueProtect Child Safety Bracelet:

Designed for children, the bracelet will emit a high-decibel alarm and send a distress signal when a child accidentally falls into the water.

Bidcom Safety Bracelet:

The bracelet, which sounds an alarm when submerged in water, is suitable for children and pets.

FLOATTOP:

This is a manual inflator designed for water activities, providing buoyancy support for rapid inflation.

WETSUIT O 'Neil:

Although primarily wetsuits, some styles may include life-saving features that provide an extra layer of safety.

Pilot Plastimo (EN399) :

This is a professional life jacket with automatic and manual inflation options, suitable for use at sea.

Neoprene Lifejacket:

Made of neoprene and soft nylon, it provides buoyancy support and is suitable for a variety of water activities.

Amperemeter:

Although primarily used to measure electrical current, it can also be designed as a wearable device for monitoring the user's physiological response.

Bone Conduction Headphones:

Delivering sound via bone conduction technology, while not a life-saving device, can be used in water, providing additional communication and entertainment features.

CO2 Capsule:

These tanks are commonly used in life jackets and other life-saving equipment to provide buoyancy for rapid inflation.

Semi-Rigid Inflatable Life Raft:

These rafts can be inflated automatically or manually in an emergency to provide greater buoyancy support.

Automatic Inflatable Lifejackets:

These lifejackets automatically inflate when they detect a user falling into the water, providing immediate buoyancy support.

 

These companies are worthy of consideration in any discussion of aquatic safety.

Stormy Lifejackets® - Worn not stowed® https://www.stormylifejackets.com.au/

Portable Seawater Desalination Device https://www.quenchsea.world/

 

‘Ensure the stability of human body”
As in inert /unconscious?
Swimmer or sinker?
In the pool, the bathtub, lake or ocean?
Cold water or warm?
What about rescue location devices?
The list of devices above is quite a variety, you need to propose a specific scenario in order to open up any meaningful discussion.

 

A discussion on contemporary personal location devices would be handy actually @kapnD, things have changed a bit since I was regularly at sea.

 

There are many theoretical papers studying smart life jackets, focusing on detecting whether the wearer is deep enough in the water, inflation control, the wearer's posture and acceleration, but there is no mention of how to make different people face up.