Jo and Marcel have developed a new tissue mimicking phantom including highly controlled blood flow and independent measurements of pH, pO2 and optical spectroscopy that can be implemented for advanced validation of photoacoustic imaging systems. You can find out more here:
https://www.spiedigitallibrary.org/journals/journal-of-biomedical-optics/volume-24/issue-12/121908/Development-of-a-blood-oxygenation-phantom-for-photoacoustic-tomography-combined/10.1117/1.JBO.24.12.121908.full?SSO=1