Great question! It's very common for students to want to get different experiences while still in school. Don't be afraid to have an open and honest conversation with your current employer about this. Let your manager know that while you have enjoyed your time with the company, you would like to be able to spend next semester gaining additional experience to diversify your resume. As long as you approach the situation respectfully, and as long as you performed well throughout your internship, your manager will likely have no issue serving as a reference for you. He/she could also be a great resource to help you find another opportunity. If you want to work within the same industry, it is likely that your manager or other members of your company have external contacts they could pass your resume along to. In addition, I would also search job boards (Indeed, LinkedIn, your school job board, etc.). If you have healthcare companies already in mind, check out their website directly.
Best of luck!