The most rewarding field in biomedical engineering is the one that allows you to make the biggest impact on people's lives. This could be developing new medical devices, improving existing treatments, or finding new ways to diagnose and treat diseases.

Here are a few of the most rewarding fields in biomedical engineering:
* Tissue engineering: Tissue engineers develop new ways to repair or replace damaged tissues and organs. This work has the potential to improve the lives of millions of people with chronic diseases and injuries.

* Biomedical imaging: Biomedical imaging engineers develop new imaging technologies, such as MRI and ultrasound, to help doctors diagnose and treat diseases. This work is essential for early detection and treatment of many diseases.
* Biomedical robotics: Biomedical robotics engineers develop robotic devices for use in surgery, rehabilitation, and other medical applications. These devices can help doctors to perform more complex and precise surgeries, and they can also help patients to recover from injuries more quickly.

* Drug discovery and delivery: Drug discovery and delivery engineers develop new drugs and drug delivery systems to more effectively treat diseases. This work is essential for the development of new and more effective treatments for many diseases.
* Clinical engineering: Clinical engineers work with doctors and other medical professionals to develop, implement, and maintain medical devices and systems. This work is essential for ensuring the safe and effective use of medical technology.

No matter what field of biomedical engineering you choose, you can be confident that you are making a real difference in the lives of others