This is posted in the waiting room of an Irish hospital. Interesting glimpse into their culture.
The full text of the poster
This symbol has been developed by the Hospice Friendly Hospitals Programme to respectfully identify the End of Life.
This symbol is inspired by ancient Irish history; it is not associated with any one religion or denomination.
The white spiral represents the interconnected cycle of life, birth, life and death.
The white outer circle represents continuity, infinity and completion.
Purple has been chosen as the background colour as it is associated with nobility, solemnity and spirituality.
In this hospital the symbol may be displayed on a ward to add respect and solemnity during end of life or following the death of one of our patients.
It has been in general use across loads of areas of Europe - not just Celtic ones, even accounting for how widespread Celtic cultures used to be - and also since thousands of years before Celtic cultures emerged as a distinguishable group. I don't think it'd be reasonable for any one group to claim ownership of it at this point
As far as I remember, it represents the grandma, the mother and the daughter. Some type of cult to woman and generations. It was associated with Celtics and reprieved by Christian religions, specially because introduces importance to matriarchs.