US 11,774,246 B2
Correction of heading errors of inertial measurement units of a motion tracking system
Pedro Henrique Oliveira Santos, Oporto (PT); Luís Ungaro Pinto Coelho, Oporto (PT); Marta Maria Ramalho Ferreira, Oporto (PT); Ana Clara Ferreira Matos, Oporto (PT); Pablo Peñas, Oporto (PT); and Virgílio António Ferro Bento, Oporto (PT)
Assigned to SWORD HEALTH, S.A., Oporto (PT)
Filed by SWORD HEALTH, S.A., Oporto (PT)
Filed on Sep. 9, 2022, as Appl. No. 17/941,764.
Application 17/941,764 is a continuation of application No. PCT/EP2021/056233, filed on Mar. 11, 2021.
Claims priority of application No. 20398002 (EP), filed on Mar. 11, 2020.
Prior Publication US 2023/0003528 A1, Jan. 5, 2023
Int. Cl. A61B 5/11 (2006.01); G01C 21/16 (2006.01); A61B 5/00 (2006.01); G01C 25/00 (2006.01); G01P 13/00 (2006.01)
CPC G01C 21/16 (2013.01) [A61B 5/1126 (2013.01); A61B 5/6828 (2013.01); G01C 25/005 (2013.01); G01P 13/00 (2013.01); A61B 2505/09 (2013.01); A61B 2560/0223 (2013.01); A61B 2562/0219 (2013.01); A61B 2562/0223 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method of compensating for heading errors of a plurality of inertial measurement units, the method comprising:
providing first and second inertial measurement units each comprising an accelerometer and a gyroscope;
arranging the first and second inertial measurement units on first and second body members of a person, the first and second body members being connected by a joint;
obtaining a first orientation measurement of the first unit;
computing a heading rotation value for containing the first orientation measurement within an
axis plane of the joint based on a second orientation measurement of the second
measurement unit; and
modifying the first orientation measurement or the second orientation measurement by applying a rotation based on the heading rotation value computed.