Give the doctor some staff to improve:
- Driver weight
- Condition
- Endurance
- Mental stuff
etc.
It adds another managing task. If you have more staff for the doctor the driver gets trained more and this maybe stops the atrofy and gives some +++ for the above skills and whatever skills apropiate. Offcourse it has its price, you need to redistribute your staff so your design or assembly will slow down.
Just a suggestion for future development. Don't hurry it cause you guys have your hands full.