a tissue oximetry probe including a probe surface, which will be placed against a tissue to be measured;

a first structure of a first type formed on the probe surface;

a second structure of the first type formed on the probe surface;

a third structure of a second type formed on the probe surface;

a fourth structure of the second type formed on the probe surface;

a fifth structure of the second type formed on the probe surface; and

a sixth structure of the second type formed on the probe surface, wherein a first distance extends between the first structure and the third structure without touching the second structure or the fifth structure, a second distance extends between the second structure and the fourth structure without touching the first structure or sixth structure, the first distance is different from the second distance,

a third distance extends between the first structure and the fifth structure, a fourth distance extends between the second structure and the sixth structure, and the third distance is different from the fourth distance,

a first line passing through the third and fourth structures,

a second line passing through the fifth and sixth structures,

the first line is not collinear with the second line,

the first type of structure comprises a source and the second type of structure comprises a detector,

the probe surface includes the first structure without an intervening structure of the second type between an edge of the probe surface and the first structure,

there is not an intervening structure of the first type between the third structure and fifth structure, and

there is not an intervening structure of at least one of the first type or second type between the second structure and fourth structure.