Up to now, there are few original inventions like electric light/telephone, and most of them are improvements on the basis of others' inventions, which are called improved inventions.
First of all, the invention protects the product/method and/or its improvement, so the improvement can be patented.
Secondly, the utility model only protects the structure or construction of the product, and I don't know if your product meets the definition.
Third, whether you can apply for a patent is related to many factors, and you need to consult a formal patent agency.
Zhong Kui talks about patent blog.