  Data-driven science requires data to drive it. Being able to make accurate
and precise measurement of biomaterials in the body means that medical
assessments can be more accurate. There are differences between how blood
absorbs and how it reflects light. The Mayo Clinic's Double-Integrating Sphere
Spectrophotometer (MDISS) is an automated measurement device that detects both
scattered and direct energy as it passes through a sample in a holder. It can
make over 1,200 evenly spaced color measurements from the very deep purple
(300-nm) through the visible light spectrum into the near infrared (2800-nm).
The MDISS samples measured have been also measured by commercial laboratory
equipment. The MDISS measurements are as accurate and more precise than those
devices now in use.
  With so many measurements to be made during the time that the sample remains
undegraded, mechanical and data collection automation was required. The MDISS
sample holders include different thicknesses, versions that can operate at high
pressure (such as divers may experience), and versions that can pump and rotate
the measured material to maintain consistency of measurement. Although the data
obtained are preliminary, they have potential to guide the design of new
devices for more accurate assessments. There is an extensive "lessons learned"
section. Please also see the companion report arXiv:2301.00938
