feedback. The corresponding user models were based
on interviews using the Repertory Grid Technique
(George A. Kelly, 2001).
The further structure of this paper first shows the
related works and then the stroke therapy considered
here and then presents a model of when feedback
from the robot is appropriate. This is followed by a
discussion and a summary.
2 RELATED WORKS
Winkle researched in (Katie Winkle, 2020) how a
SAR can be used as a treadmill running instructor and
how participants would accept it. She uses an input
space of 20 features with different dimensions to
monitor a runner approach. It includes features like
heart rate, speed, activity level and also psychological
traits combined in the Big 5 model.
This is one of the commonly used model to assess
the personality of patients as shown by Dwan et al.
(Toni Dwan and Tamara Ownsworth, 2019). Coming
from the field of psychology, the five personality
factors are “Neuroticism”, “Extraversion”,”
Openness to experience”, “Agreeableness”,
“Conscientiousness”. A person’s factors will be
determined through questionnaires.
The Robot has many different actions as a coach
for a treadmill like reminding about time or how to
correct the pose of the runner. Winkle uses an
interactive machine learning approach, whereby a
trainer enters during a live-session with a runner new
state-action pairs into the system. The robot then
improves his next autonomous action from the
previously gathered examples from the trainer.
Casas et al. (Jonathan A. Casas, et al., 2019) use a
NAO Robot in a therapy setup to increase cardiac
function. Patients run on a treadmill and the nearby a
robot provides verbal and gestural feedback. Inside
their patient-robot interaction they monitor the level
of exertion with the “Borg scale” (Bahar Irfan, et al.,
2020) and the patient’s heart rate. The Borg scale is a
method to quantify perceived exertion and aims to
make it comparable between individuals. Even with
its subjective nature, this method proved to have a
good correlation with the level of more measurable
effort metrics in diverse application.
Additionally, they watch several cases with these
two metrics and switch between different interaction
modes. Depending on a “high” or “low” exertion
and/or heart rate they ask the patient if he is feeling
alright. For cases whereby, the exceeds the heart rate
exceeds for too long the normal values, the robot will
e.g. be saying: “Doctor, the patient needs help.”. This
interaction mode then can only be switched off, when
the medical staff touches the head of the robot.
A lately, different approach has been done by
Irfan et al. (Bahar Irfan, et al., 2020) by measurements
with an ECG, Borg Scale entered thorugh the patient
via a tablet, a laser range finder and an inertial
measurement unit and a tablet camera. Next to
predefined phrases at certain points in the session, and
alerting the patient and medical staff about a high
exertion or Heart rate, the robot will provide prompts
if the patient should improve his cervical posture.
A rather different perspective to look on the
provision of feedback to the patients comes directly
from medical literature. Bachelor et al. (Alexandra
Bachelor, 1991) state, that the success of the therapy
outcome and the “alliance” between patient and
therapist is that the patients perception yields a better
prediction of the success than the therapist
perception. Furthermore, from a patient’s perspective
therapist-provided aid, warmth, caring, emotional
involvement are factors which truly helped in
therapies.
Duncan et al. (Barry L. Duncan, et al., 1994) adds
to these findings and states, that in the “alliance”
literature, the therapy progresses the most, if the
therapist talks about what the patients see as
important for them. Additionally the therapist should
have chosen methods, that the patient will think, that
it helps him to reach the goal specified by the patient.
Because of these finding, we would primarily
target the patient’s needs and we later present robot
actions, which we try to tailor to the findings of
Bachelor and Duncan et al.
3 ARM BASIS TRAINING (ABT)
3.1 Classic ABT with a Therapist
ABT has been designed for severe arm impairment.
The focus lies on improving the patient’s capabilities
for selected movements of the patients’ arms as
displayed in figure 1. The ABT will be done in a
structured repetitive training manner with each
session to complete a set of arm and hand exercises
(Thomas Platz, Bernhard Elsner, and Jan Mehrholz.
2015). The therapy’s’ movements are starting with
joint movements “without” the factor of gravity (step
1), meaning that the therapist is holding the extremity
of the patient up and manually assists the movement
of the patients arm, hand or finger during the exercise.
The next step -after the patient acquires the full range
of motion of the movement- is to let the patient do the
exercises with gravity (step 2), whereby the patient is