1. Department of Bioengineering, Stanford University School of Medicine and School of Engineering, Stanford, California 94305, USA
2. Department of Mechanical Engineering, Stanford University School of Engineering, Stanford, California 94305, USA
3. Department of Applied Physics, Stanford University School of Humanities and Sciences, Stanford, California 94305, USA
4. Department of Materials Science and Engineering, Stanford University School of Engineering, Stanford, California 94305, USA
5. Department of Electrical Engineering, Stanford University School of Engineering, Stanford, California 94305, USA
6. Department of Surgery, Stanford University School of Medicine, Stanford, California 94305, USA
7. Department of Engineering Mathematics and Physics, Faculty of Engineering, Cairo University, Giza 12613, Egypt
8. Department of Radiology, Molecular Imaging Program at Stanford (MIPS), Stanford University School of Medicine, Stanford, California 94305, USA