RU2086212C1 - Knee unit of lower extremity prosthesis - Google Patents

Abstract

FIELD: medical equipment applicable in manufacture of prostheses. SUBSTANCE: the offered knee unit has upper link with fastening unit of femur bush, rear, lower and front links, stop, crus-hinging device. The unit additionally has carrying body with stop for lower link and shock-absorbing device, and unit for fastening of crus tube and predeformed flexible link. Carrying body rear part is hinged with lower link. Flexible link is connected by its ends with lower link and carrying body and rests with its middle part of shock-absorbing device. EFFECT: higher efficiency. 2 dwg

Description

 The invention relates to medical equipment, in particular, to the designs of the knee nodes of lower limb prostheses.

 Known uniaxial knee assembly that provides a bending function, comprising a main hinge for complete bending, an additional hinge for sprung bending, an intermediate link mounted on a common axis, a spring bending shock absorber, a mechanism for fixing the main knee hinge, including a latch and a return spring and a mechanism for unlocking the main hinge including a movable pilot and a flexible cable / 1 /.

 The disadvantages of this design are its complexity, high weight, material and laboriousness of manufacture.

 The closest analogue is the knee assembly containing the upper, lower, front and rear links pivotally, an emphasis, an ankle-folding device / 2 /.

 The disadvantage of the closest analogue is the lack of bending function, which determines the reduced anthropomorphism of walking on the prosthesis, increased energy consumption.

 The objective of the invention is to increase the anthropomorphism of walking on the prosthesis and lower energy consumption.

 This task is achieved due to the fact that in the knee assembly containing the upper with the thigh sleeve attachment unit, the back, lower, front links, emphasis, ankle-folding device, a distinctive feature is that it additionally contains a supporting body with emphasis for the lower link and shock absorbing the device, as well as the attachment of the lower leg tube and a previously deformed flexible link, while the supporting body in its rear part is pivotally connected to the lower link, the flexible link is connected at its ends with the lower link and carried conductive housing and rests in its central portion to a damping device.

 In FIG. 1 is a side view of the knee assembly, and in FIG. 2 its front view.

 The knee assembly of the lower limb prosthesis comprises upper 1, rear 2, lower 3, front 4, links the supporting body 5 with a shock-absorbing device 6, a flexible link 7, an emphasis 8, 9, an ankle-folding device 10.

 The knee node of the prosthesis of the lower limb operates as follows.

 In the transfer phase, the preliminary tightening force of the shock-absorbing device 6 creates the tension of the flexible link 7, causing the lower link 3 to be pressed against the supporting body 5, sufficient to ensure their mutual immobility. The kinematics of the movements of the lower leg relative to the hip in this case is ensured by the angular movements of the links 2, 3, 4 relative to the link 1 in the same way as in the closest analogue.

 At the beginning of the support reaction phase, the support reaction presses link 2 to the stop 8, turning the four-link mechanism (1, 2, 3, 4) into a rigid frame structure with preservation of the closure resistance of the closest analogue. At the same time, under the action of the moment created in the sagittal plane by the reaction of the support passing behind the hinge joint between the bearing housing 5 and the lower link 3, which is detached from the stop 9 located on the bearing housing 5, and makes angular movement around the hinge between the bearing housing 5 and the lower link 3 relative to the bearing body 5, moving the upper branch of the flexible link 7 and changing the length of its span. This causes a decrease in the arrow of its deflection, i.e. compression of the shock absorber 6.

 In accordance with the rule of the thread, the relatively small force of the shock-absorbing device 6 causes, with a small arrow, the deflection of the flexible link 7, a significant reactive moment relative to the hinge of the elements 3 and 5, thereby ensuring the bending of the prosthesis. The stiffness of the elastic characteristics, providing the function of bending the prosthesis, is regulated by the magnitude of the deflection of the flexible link 7 and the stiffness and tightening of the shock-absorbing device.

 In the process of rolling, the reaction of the support changes the place of application on the foot and the angle of inclination to the horizontal, moving forward and deviating from the position “behind the knee node” to the position “in front of the knee shaft”, thereby changing the sign of the moment acting on the node in the sagittal plane and causing stable the pressing of the link 3 to the stop 9 of the housing 5 and the readiness of the knee assembly for further operation.

 The design has the advantage that it provides the function of bending the prosthesis in the support phase, increasing the anthropomorphism of the gait and reducing the energy spent on walking.

Claims (1)

 The knee node of the lower limb prosthesis, comprising an upper with a thigh sleeve attachment unit, a back, lower, front link, an abutment, an ankle-folding device, characterized in that it further comprises a supporting body with an abutment for the lower link and a shock absorber, as well as an ankle mount and a pre-deformed flexible link, while the bearing body in its rear part is pivotally connected to the lower link, the flexible link is connected at its ends to the lower link and the bearing housing and rests in its middle hour ty on a shock absorber.

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