Good health is a person's greatest wealth. It is a very happy thing that your husband has just recovered from a serious illness. If he can have your careful care and company, I believe he will be equally happy no matter what kind of gift he receives.
Go to the travel agency in advance to book a short trip, and then give your husband a lightweight SLR camera. Wear the SLR and go on a trip together. Your husband has just recovered from a serious illness and can take this opportunity to have a close contact with nature and breathe fresh air, which is very beneficial to the recovery of the body.
You can choose sports equipment or outdoor sports equipment suitable for your husband. Proper exercise after recovering from a serious illness can help your husband recover faster and better to his previous state. You can choose a badminton racket, and you can interact well with your husband.
Give your husband a box of creative chocolates, which can be customized to look like mahjong tiles. Seeing such a creative gift, your husband will definitely smile with teeth showing.