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Resistance Exercise Machine within Lower Body Negative Pressure for Counteracting Effects of Microgravity

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18. Jan. 2022

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Figure 1.

3-D model of the multi-platform.
3-D model of the multi-platform.

Figure 2.

The multi-platform paired with an existing environmentally controlled LBNP Box.
The multi-platform paired with an existing environmentally controlled LBNP Box.

Figure 3.

2-D sketch of a four-bar parallelogram paired with a sliding crank mechanism. The sliding crank is a spring and damping system that offers a variable resistance.
2-D sketch of a four-bar parallelogram paired with a sliding crank mechanism. The sliding crank is a spring and damping system that offers a variable resistance.

Figure 4.

Kinematic diagram of the mechanism.
Kinematic diagram of the mechanism.

Figure 5.

The left photo shows final integration of the multi-platform to the existing LBNP Box. The right photo displays a close up of the multi-platform outside of the LBNP Box.
The left photo shows final integration of the multi-platform to the existing LBNP Box. The right photo displays a close up of the multi-platform outside of the LBNP Box.

Figure 6.

A 3-D CAD model, left, of the upright device that will support the multi-platform in a vertical position. The right photograph is the final integration of the multi-platform and the upright device.
A 3-D CAD model, left, of the upright device that will support the multi-platform in a vertical position. The right photograph is the final integration of the multi-platform and the upright device.

Figure 7.

Theoretical static resistance curve on the outward stroke for the multi-platform considering only spring resistance.
Theoretical static resistance curve on the outward stroke for the multi-platform considering only spring resistance.

Figure 8.

Theoretical resistance curve assuming a motion profile with a constant angular acceleration to start and end the motion cycle and a period of constant velocity in between. The pressure differential set at the recommended 50mmHg.
Theoretical resistance curve assuming a motion profile with a constant angular acceleration to start and end the motion cycle and a period of constant velocity in between. The pressure differential set at the recommended 50mmHg.

Figure 9.

Theoretical resistance curve assuming a motion profile with positive and negative constant acceleration without a period of constant velocity. The pressure differential is set at -50mmHg.
Theoretical resistance curve assuming a motion profile with positive and negative constant acceleration without a period of constant velocity. The pressure differential is set at -50mmHg.

Figure 10.

Variation in the user’s force as the spring preload increases through a change in dimension lo.
Variation in the user’s force as the spring preload increases through a change in dimension lo.

Specifications for the contributing links in the Moments of Inertia (MOI) equations discussed in section Kinematics_

Specifications
Link Height (in) Weigh (in) Depth (in) Mass (lbs) Moment of Inertia
2.48 2.06 1.97 0.87 3.13
16.50 2.06 1.97 13.2 1727.93
16.50 2.06 1.97 13.2 1727.93
Sum of MOI (kg*sq.in) 3459

UT1

BW Body weight
G Gravity
GRF Ground reaction force
HR Heart rate
LBNP Lower body negative pressure
γ The angle between the horizontal and the ground pivot on the right side of the mechanism
θ Input position
θ̇ Velocity
θ̈ Acceleration
s Position of the spring
ṡ Velocity of the spring
I* Equivalent inertia of the system
I mass of inertia
m mass
Fspring Resistance provided by the spring
Fuser Resistive force
lo Link length of the member between the horizontal and the ground pivot on the right side of the mechanism
l1 Link length of the member between lo and the rotational pivot
l2 Link length of the member below the rotational pivot
l3 Link length of the member above the rotational pivot
ΔP Pressure differential force- the difference between the pressures inside the Box vs. outside the Box
Axy Cross sectional area of the seal which is placed around the subject’s waist
β The angle between vector Fuser and the arm l3

Spring specifications used in the resistance equations discussed in section Kinematics_

Spring Properties
Stroke length (in) 3
Eye to eye length (in) 12.51
Spring rate (k) 650
Sprache:
Englisch
Zeitrahmen der Veröffentlichung:
2 Hefte pro Jahr
Fachgebiete der Zeitschrift:
Biologie, Biologie, andere, Materialwissenschaft, Materialwissenschaft, andere, Physik, Physik, andere