US-20260124049-A1 - ARTIFICIAL KNEE JOINT, ADJUSTMENT SUPPORT APPARATUS FOR ARTIFICIAL KNEE JOINT, METHOD OF CONTROLLING ARTIFICIAL KNEE JOINT, AND PROGRAM TO CONTROL ARTIFICIAL KNEE JOINT

Abstract

A prosthetic limb includes: a socket as a thigh part; a thigh joint part provided on a side of the socket; a lower leg part coupled to the thigh joint part and provided to be rotatable around a knee shaft; a thigh part inclination angle acquisition unit that acquires an inclination angle Ψ formed by the socket relative to a vertical line passing through the knee shaft; and a rotational resistance control unit that weakens a rotational resistance of the knee shaft in accordance with a transition from a positive inclination angle formed when the socket is inclined rearward relative to the vertical line to a negative inclination angle formed when the socket is inclined forward relative to the vertical line.

Inventors

• Hiroaki Hashimoto

Assignees

• NABTESCO CORPORATION

Dates

Publication Date

20260507

Application Date

20260105

Priority Date

20240614

Claims (2)

1. 1 . An artificial knee joint provided with a thigh joint part provided on a side of a thigh part and with a lower leg part coupled to the thigh joint part and provided to be rotatable around a knee shaft, including: a forward movement amount sensing unit that senses a forward movement amount of a user wearing the artificial knee joint; and a rotational resistance control unit that strengthens a rotational resistance of the knee shaft when the forward movement amount sensed makes a transition from a state in which the forward movement amount is equal to or larger than a predetermined forward movement amount threshold value to a state in which forward movement amount is smaller than the forward movement amount threshold value, or, a rotational resistance control unit that enables controlling a rotational resistance of the knee shaft to be weaker when the forward movement amount sensed is equal to or greater than a predetermined forward movement amount threshold value.
2. 2 . The artificial knee joint according to claim 1 , further including: a thigh part inclination angle acquisition unit that acquires an inclination angle formed by the thigh part relative to a vertical line passing through the knee shaft, wherein the forward movement amount sensing unit senses the forward movement amount from the inclination angle of the thigh part.

Description

CROSS REFERENCES TO RELATED APPLICATIONS The present application is a divisional application of U.S. patent application Ser. No. 17/839,588, filed on Jun. 14, 2022, the entire contents of which are incorporated herein by reference and priority to which is hereby claimed. U.S. application Ser. No. 17/839,588 claimed the benefit of the date of the earlier filed Japanese Patent Application No. 2021-098688, filed Jun. 14, 2021, priority to which is also claimed herein, and the contents of which are also incorporated by reference herein. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an artificial knee joint. 2. Description of the Related Art An artificial knee joint or a prosthetic limb worn by a person who has lost a leg due to an injury or a disease, in which the rotational resistance of the knee shaft is controlled in accordance with the phase of walking of the wearer, is known. In the Stance phase in which the prosthetic limb is in contact with the ground and is under load, the rotational resistance of the knee shaft is increased to prevent the knee from being bent under load. In the Swing phase in which the prosthetic limb leaves the ground and is swung, the rotational resistance of the knee shaft is decreased to bend the knee and prevent the prosthetic limb from touching the ground. [Patent literature 1] JP2011-101807 We have studied multiple aspects of control of the rotational resistance of a knee shaft for the purpose of further improving the convenience of an artificial knee joint or a prosthetic limb. SUMMARY OF THE INVENTION The present invention addresses the above-described issue, and a purpose thereof is to provide a highly convenient artificial knee joint or prosthetic limb. An artificial knee joint according to an embodiment of the present invention includes: a thigh joint part provided on a side of a thigh part; a lower leg part coupled to the thigh joint part and provided to be rotatable around a knee shaft; a thigh part inclination angle acquisition unit that acquires an inclination angle formed by the thigh part relative to a vertical line passing through the knee shaft; and a rotational resistance control unit that weakens a rotational resistance of the knee shaft in accordance with a transition from a positive inclination angle formed when the thigh part is inclined rearward relative to the vertical line to a negative inclination angle formed when the thigh part is inclined forward relative to the vertical line. Another embodiment of the present invention also relates to an artificial knee joint. The artificial knee joint is provided with a thigh joint part provided on a side of a thigh part and with a lower leg part coupled to the thigh joint part and provided to be rotatable around a knee shaft, and includes: a forward movement amount sensing unit that senses a forward movement amount of a user wearing the artificial knee joint; and a rotational resistance control unit that strengthens a rotational resistance of the knee shaft when the forward movement amount sensed makes a transition from a state in which the forward movement amount is equal to or larger than a predetermined forward movement amount threshold value to a state in which forward movement amount is smaller than the forward movement amount threshold value. Another embodiment of the present invention also relates to an artificial knee joint. The artificial knee joint is provided with a thigh joint part provided on a side of a thigh part and with a lower leg part coupled to the thigh joint part and provided to be rotatable around a knee shaft, and includes: a forward movement amount sensing unit that senses a forward movement amount of a user wearing the artificial knee joint; and a rotational resistance control unit that enables controlling a rotational resistance of the knee shaft to be weaker when the forward movement amount sensed is equal to or greater than a predetermined forward movement amount threshold value. Another embodiment of the present invention also relates to an artificial knee joint. The artificial knee joint is provided with a thigh joint part provided on a side of a thigh part and with a lower leg part coupled to the thigh joint part and provided to be rotatable around a knee shaft, and includes: a rotational resistance control unit that weakens a rotational resistance of the knee shaft in accordance with a transition of a user walking and wearing the artificial knee joint from a Stance phase to a Swing phase; a walk information acquisition unit that acquires walk information indicating a state of walk of the user; and a control timing determination unit that determines a timing according to which the rotational resistance control unit weakens the rotational resistance of the knee shaft, based on the walk information. Another embodiment of the present invention relates to an adjustment support apparatus for an artificial knee joint. The apparatus is an adjustment sup