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Development of Hand Rehabilitation System for Paralysis Patients
L = x 1
2 + h
2
1
h
α = arctan
1
x 1
r + r
β = arccos
1
2
a 1
r r
γ = arccos s
2 + 3
a 2
The geometrical relation yields the following equation:
ϕ π
= −θ 1 +θ 2 − θ 3
(15.4)
The relation between l AB and φ is obtained by removing θ 1 , θ 2 , and θ 3 in
Equations (15.1) to (15.4); that is, the result indicates that the traction distance
of the wire controls the human finger joint.
15.2.2 Coupled Mechanism for the Distal Interphalangeal
and Proximal Interphalangeal Joints
Physiological studies have revealed that the distal interphalangeal (DIP)
and proximal interphalangeal (PIP) joints in a human finger are actuated
with the same muscles, and the movements are coupled. We used a similar
coupled mechanism in our hand rehabilitation machine in order to enhance
its mobility; that is, reducing the number of motors results in a lighter and
smaller machine that is long lasting. The conceptual design of the coupled
mechanism is shown in Figure 15.7: (1) the wire-driven four-link mechanism is set on the DIP and PIP joints; (2) the wire that bends the DIP joint is
connected to the wire that bends the PIP joint; and (3) the wire that extends
the DIP joint is connected to the wire that extends the PIP joint. Thus, both
the DIP and PIP joints are both subjected to the same directional force
through the connected wires, and the movements are coupled.
15.3 Actual Hand Rehabilitation Machine
A computer-aided design (CAD) image and a photograph of the proposed rehabilitation machine are shown in Figures 15.8 and 15.9, respectively. The machine
is designed such that there are three arm structures for the metacarpophalangeal
Development of Hand Rehabilitation System for Paralysis Patients
L = x 1
2 + h
2
1
h
α = arctan
1
x 1
r + r
β = arccos
1
2
a 1
r r
γ = arccos s
2 + 3
a 2
The geometrical relation yields the following equation:
ϕ π
= −θ 1 +θ 2 − θ 3
(15.4)
The relation between l AB and φ is obtained by removing θ 1 , θ 2 , and θ 3 in
Equations (15.1) to (15.4); that is, the result indicates that the traction distance
of the wire controls the human finger joint.
15.2.2 Coupled Mechanism for the Distal Interphalangeal
and Proximal Interphalangeal Joints
Physiological studies have revealed that the distal interphalangeal (DIP)
and proximal interphalangeal (PIP) joints in a human finger are actuated
with the same muscles, and the movements are coupled. We used a similar
coupled mechanism in our hand rehabilitation machine in order to enhance
its mobility; that is, reducing the number of motors results in a lighter and
smaller machine that is long lasting. The conceptual design of the coupled
mechanism is shown in Figure 15.7: (1) the wire-driven four-link mechanism is set on the DIP and PIP joints; (2) the wire that bends the DIP joint is
connected to the wire that bends the PIP joint; and (3) the wire that extends
the DIP joint is connected to the wire that extends the PIP joint. Thus, both
the DIP and PIP joints are both subjected to the same directional force
through the connected wires, and the movements are coupled.
15.3 Actual Hand Rehabilitation Machine
A computer-aided design (CAD) image and a photograph of the proposed rehabilitation machine are shown in Figures 15.8 and 15.9, respectively. The machine
is designed such that there are three arm structures for the metacarpophalangeal