Physicians use pain expressions shown in a patient’s
face to regulate their palpation methods during physical examination.
Training to interpret patients’ facial expressions with
different genders and ethnicities still remains a challenge, taking
novices a long time to learn through experience. This paper
presents MorphFace: a controllable 3D physical-virtual hybrid
face to represent pain expressions of patients from different
ethnicity-gender backgrounds. It is also an intermediate step
to expose trainee physicians to the gender and ethnic diversity
of patients. We extracted four principal components from the
Chicago Face Database to design a four degrees of freedom
(DoF) physical face controlled via tendons to span 85% of
facial variations among gender and ethnicity. Details such as skin
colour, skin texture, and facial expressions are synthesized by a
virtual model and projected onto the 3D physical face via a frontmounted
LED projector to obtain a hybrid controllable patient
face simulator. A user study revealed that certain differences in
ethnicity between the observer and the MorphFace lead to different
perceived pain intensity for the same pain level rendered by
the MorphFace. This highlights the value of having MorphFace as
a controllable hybrid simulator to quantify perceptual differences
during physician training.