Are vibration devices okay to use in babies bassinet? I have a 4 week old who loves to be rocked I sometimes spend an hour rocking her to sleep and every time I stop she wakes up. I’ve seen a few devices which vibrate the mattress. Are these devices safe to use ? I’m desperate to get some sleep.

Red Nose does not have recommendations/endorsements for bassinets or vibrating devices in bassinets.
The concern about rocking a bassinet, is that baby may be at risk of being rocked into a position, other than on the back, particularly if baby is unsupervised.

There are no mandatory standards for bassinets & rocking cradles in Australia, however, Product Safety (ACCC)  has the following suggestions (buying tips)

Ensure the sides of the bassinette are at least 300 mm higher than the top of the mattress base.
Ensure it has a wide stable base and a sturdy bottom so that it won’t tip over.
Ensure the mattress fits well and is firm, smooth and no more than 75 mm thick.
If the product has folding legs, make sure it cannot accidentally fold during use.
https://www.productsafety.gov.au/products/babies-kids/kids-furniture/bassinettes

Babies can suffer serious injuries if they fall out of a rocking cradle that tilts too far, or if the bottom breaks.
Rocking cradles should have a tilt limiter to limit the angle of tilt to no more than 10 degrees from the cradle’s horizontal position.
Make sure the cradle has a permanent child-resistant lock that stops the cradle from rocking when the baby is unattended.
Regularly check that screws and bolts are tight to avoid accidental collapse.
https://www.productsafety.gov.au/products/babies-kids/kids-furniture/rocking-cradles

Red Nose does not recommend positional products such as anti-roll devices and items that fasten a baby into a sleeping position.
https://rednose.org.au/article/is-it-safe-to-use-products-designed-to-keep-baby-in-a-particular-position

Red Nose also has the following information when buying products for baby’s sleep.
It is important for parents when they are thinking of buying a product for their baby to be able to make the best informed decision based on evidence of product safety. This is crucial for preventing SUDI or other fatal sleeping accidents.

It is often assumed that all nursery products sold in retail stores must be safe, however many products have never been formally tested so it can be difficult to tell what is safe for your child.
https://rednose.org.au/article/baby-safe-sleeping-products