3D modeling

I have an idea for a grasp assist piece of medical equipment for people with disabilities and weakened hands. It would essentially look like a hand grip as you see in gyms, or it could be operated using wrist actions. When you barely squeeze it, or simply move your wrist, a three-inch, right-angled attachment that comes off of the top closes. The two tips of these attachments would be rubber coated and about the size of fingertips. You could grab and adjust things small and petite with hands that you might have thought would never be able to do such tasks again. I need a 3D model.