IEEE Robotics & Automation Magazine - September 2022 - 36

parameters; and 3) it carries a cloud-based artificial intelligence
diagnosis platform, which allows doctors and family
members to monitor the patient's progress when he/she is
under home rehabilitation. The integration of the aforementioned
features helps BEAR-H better understand the
patient's condition and then generate a more " intelligent "
gait for rehabilitation. Additionally, an adaptive impedance
control scheme is proposed to drive BEAR-H to track such
a gait, which guarantees a safe interaction and also encourages
the patient to execute voluntary efforts and hence
speed up the recovery. Moreover, compliant actuators are
fully deployed in the hip, knee, and ankle joints of BEAR-H
to further ensure safety at the structural level. BEAR-H has
been successfully implemented in clinical applications, and
comparative studies have been carried out for 30 hemiplegic
patients. The experimental results from different aspects
are presented to validate the effectiveness of BEAR-H.
Overview of BEAR-H
BEAR-H is a lower-limb exoskeleton robot designed to facilitate
smart rehabilitation. Specifically, the robot fully assesses
the body parameters, online status, and history data of the
patient and then customizes the rehabilitation strategy to better
suit his/her condition, thereby improving the rehabilitation
effect. The overall system consists of a backpack (housing
the control module), segments of waist and both legs, and a
touchpad as the interface.
Hardware
The leg length can be adjusted to suit users with different
heights, from 150 cm (i.e., children) to 190 cm (i.e.,
adults). The dimension of the waist joint can also be
adjusted to suit users who weigh up to 85 kg. Each leg has
three active and two passive DoF. Hence, the whole robot
has six active DoF in total. The active DoF are designed as
the flexion/extension around the hip, knee, and ankle
joints, while the passive DoF are designed as the inversion/
eversion of the ankle joint and the adduction and abduction
of the hip joint. Therefore, the whole robot has 10
DoF in total, and such a high-DoF structure supports full
rehabilitation for lower limbs. All of the active joints are
driven with compliant actuators, guaranteeing safety from
the structural aspect. A module in the shape of a shoe is
designed at the end of both legs to support the patient's
feet. The module is displayed in Figure 1.
The central control system is embedded into the
backpack to realize multiple interaction modes and the
algorithm of intelligent rehabilitation. The backpack
also integrates the modules of emergency stop, input/
outputs, and indicators to show the level of assistance and
the ground contact status. The battery inside the backpack
can support BEAR-H's continuous operation for
roughly 8 hr. There are also two handles on the backpack,
which enables therapists to help patients put on the robot
[see Figure 1(b)].
The touchscreen conveys information during rehabilitation,
where therapists specify the training mode and
parameters according to the progress of rehabilitation.
During the patient's development, such an interface is useful
for debugging as well.
A range of sensors is installed in BEAR-H to capture the
change of human limbs and monitor the robot's posture.
Emergency
Stop
Handle
Power
Indicator
Bandages
Assistance
Indicator
Length
Adjustment
Shoe-Shape
Module
(a)
Ground Contact
Indicator
Battery
Intake
Outtake
Power
Button
I/O
(b)
Figure 1. The structure of BEAR-H. (a) Each leg consists of 5 DoF (i.e., three active and two passive degrees of freedom), and the length
can be adjusted for patients with different heights. (b) The backpack carries the battery and the embedded control system and also has
a power indicator, emergency stop, and multiple input/outputs (I/Os) for extension.
36 * IEEE ROBOTICS & AUTOMATION MAGAZINE * SEPTEMBER 2022

IEEE Robotics & Automation Magazine - September 2022

Table of Contents for the Digital Edition of IEEE Robotics & Automation Magazine - September 2022