(thanks Zephyros

)
That's interesting Farzon...
I would likely have the cards in reverse to you...(and with ritual I may or may not stick to
meanings, because imagery is more powerful for me, so I play more with the imagery according to the deck I've chosen) so:
1) The desired effect of the spell is healing to health.
4 of Swords for me can be recuperation and repair - particularly in The Gendron Tarot, where the convalescent is depicted as a lady apparently resting after having "a strengthening walk outdoors".
Or - I could have
The Empress from The Tarot of the Night - for instance, because here - she is depicted bringing someone back to life...an exceptionally powerful kind of healing. Lol.
(I'm not at home right now, so I can't look through my ritual decks for more possible options).
2) The place the spell takes place is within the body of the person.
I would use a
Significator of some sort. For myself - the Tarot card itself would depend on which one I decide fits the bill at that specific time, and again, which deck it's from. (I don't really have a "fixed" significator that I stick to).
More likely I'll choose
a photograph or object, that in my minds eye, reminds me of me - or the other person who's the target. This is my usual practice for ritualistic healing.
3) The higher principle behind the spell - Wellness and freedom on all planes.
The Sun (freedom, joy and energy)
The World (all things within reach and at optimum)
Temperance (the perfect balance).
I might get more specific with specific health issues - for example back pain:
1)
10 of Swords Reversed (i.e. no more back pain) with
Ace of Swords crossing it to represent assisted removal of the health obstacle (therapist, doctor).
2)
Significator
3)
Strength a return to full strength.