# of deaths in the hospital carries over on new cycles/playthroughs, so the only way to reset it is through a fresh new game. You can bypass resurrecting in the hospital by equipping a weight on a dead character and going through a map, they'll be brought back with 1 HP. Characters also get resurrected/fully healed at the start of a chapter, so that's also an option if you don't want to use weights.

With that said, there's not really much point to it, there's even the in-game rewards for resurrecting your chars at the hospital.