Six-rod type wrist disjunction artificial limb and design method

Abstract

The invention relates to the technical field of bionic prostheses, and discloses a six-rod type wrist disengagement prosthesis and a design method, the six-rod type wrist disengagement prosthesis comprises an upper arm sleeve, a forearm sleeve, a first rod piece, a second rod piece, a third rod piece, a fourth rod piece and an execution piece; one side of the upper arm sleeve is rotationally connected with the front arm sleeve, one end of the first rod piece is connected with the upper arm sleeve, and the other end of the first rod piece is rotationally connected with the second rod piece. The middle part of the second rod piece is connected with the forearm sleeve, and the other end is rotationally connected with the third rod piece; the fourth rod piece is installed on the front arm sleeve, one end of the fourth rod piece is rotationally connected with the free end of the third rod piece, and the end, away from the third rod piece, of the fourth rod piece is connected with the execution piece. According to the six-rod type wrist disconnect artificial limb and the design method, the partial buckling movement of the elbow joint of a patient in daily life is utilized to realize the buckling movement of the wrist disconnect artificial limb execution part, so that the buckling movement of the wrist joint is simulated; the device assists patients with wrist joint dysfunction such as wrist disengagement to easily realize daily life activities such as feeding and fetching for self-care.

Description

Technical Field

[0001] The invention relates to the technical field of bionic prostheses, and in particular to a six-rod wrist amputation prosthesis and a design method thereof. Background Art

[0002] The number of patients with upper limb amputation is increasing year by year due to traffic accidents, physical illness, natural disasters, accidental work injuries and other reasons. Upper limb paraplegia patients face many difficulties such as difficulty in eating, difficulty in dressing, weakened body balance and support function, and limited employment, which even bring heavy psychological and physiological burdens to patients and even their families and society.

[0003] Currently, most common wrist disarticulation prostheses are decorative prostheses or powered prostheses. Among them, the wrist joint of decorative wrist disarticulation prostheses cannot move, which is of little help in daily life activities. Powered wrist disarticulation prostheses need to be equipped with power devices such as motors, which are complex in structure and heavy in weight.

[0004] At the same time, many patients with wrist dislocation prostheses also have functional disorders such as elbow flexion. Currently, few wrist dislocation prostheses have the function of simultaneously coupling elbow and wrist joint dysfunction to assist patients in their daily activities. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention proposes a six-rod wrist amputation prosthesis and a design method to solve the above technical problems.

[0006] In a first aspect, a six-rod wrist amputation prosthesis is provided, comprising: an upper arm sleeve, a forearm sleeve, a first rod, a second rod, a third rod, a fourth rod and an actuator;

[0007] One side of the upper arm sleeve is rotatably connected to the forearm sleeve, one end of the first rod is connected to the upper arm sleeve, and the other end is rotatably connected to the second rod;

[0008] The middle part of the second rod is connected to the forearm sleeve, and the other end is rotatably connected to the third rod;

[0009] The fourth rod is mounted on the forearm sleeve, and one end of the fourth rod is rotatably connected to the free end of the third rod, and one end of the fourth rod away from the third rod is connected to the actuator.

[0010] Furthermore, a first adjustment hole is opened on the outer side of the upper arm sleeve and the forearm sleeve, and a first installation shaft is installed on one side of the first rod and the second rod, and the first installation shaft is connected to the first adjustment hole.

[0011] Furthermore, a plurality of the first adjustment holes are arranged at equal intervals.

[0012] Furthermore, a second adjustment hole is formed on the outer side of the forearm sleeve close to the fourth rod, a second installation shaft is installed on one side of the fourth rod, and the second installation shaft is connected to the second adjustment hole.

[0013] Furthermore, a slot is formed at one end of the fourth rod away from the third rod, and one end of the actuator is installed in the slot.

[0014] Furthermore, the actuator may be any one of a spoon, a fork or a hook.

[0015] In a second aspect, a method for designing a six-bar wrist amputation prosthesis is provided, based on a six-bar wrist amputation prosthesis as described in any one of the preceding paragraphs, comprising the following steps:

[0016] Step S01, constructing a six-bar mechanism motion diagram, calculating the degrees of freedom, and establishing a six-bar mechanism mathematical model;

[0017] Step S02, disassembling the six-bar mechanism into two sets of four-bar mechanisms, and analyzing them;

[0018] Step S03, establishing a mathematical relationship between the patient's elbow flexion angle change value, the length of each component of the six-bar mechanism, and the wrist flexion angle simulated by the actuator;

[0019] Step S04, analyzing the mathematical relationship between the position change of the first adjustment hole of the upper arm sleeve and the forearm sleeve and the rod length of the six-bar mechanism and the wrist joint flexion angle simulated by the actuator.

[0020] Furthermore, the calculation formula of degrees of freedom includes:

[0021] F=3n-2p L -p H

[0022] Where F is the degree of freedom, n is the number of active components, and p is L For low pair number, p H It is a high pair number.

[0023] Furthermore, the mathematical relationship in step S03 includes:

[0024]

[0025] ∠DCB=∠ACB+∠ACD

[0026]

[0027] θ(t)=∠CEG-∠FEG

[0028] Among them, AB, BC, CD, AD, EC, EF, GF, and CG are the lengths of the rods in the schematic diagrams 1 and 2 of the disassembled four-bar mechanism of the six-bar mechanism of the wrist amputation prosthesis. is the elbow flexion angle, θ is the wrist flexion angle of the wrist disarticulation prosthesis, ∠ACB, ∠ACD, ∠CEG, ∠FEG and ∠DCB are the structural angles for calculating the transition in the disassembly of the four-bar mechanism of the six-bar mechanism of the wrist disarticulation prosthesis, Given the initial flexion angle of the elbow joint, ω is the angular velocity of the elbow joint flexion, and t is the elapsed time.

[0029] Furthermore, the mathematical relationship in step S04 includes:

[0030]

[0031] ∠DCB=∠ACB+∠ACD

[0032]

[0033] θ(t)=∠CEG-∠FEG

[0034] Wherein, Δx is the parameter of the first adjustment hole in the upper arm cuff, and Δy is the parameter of the first adjustment hole in the forearm cuff.

[0035] The invention adopting the above technical solution has the following advantages:

[0036] The present invention is particularly aimed at patients with limited elbow flexion and wrist dislocation dysfunction. It can be personalized and adapted in real time according to the elbow flexion of patients with wrist dislocation, coupled with the residual flexion movement of the patient's elbow joint, and realize the prosthesis simulating the wrist flexion movement. In terms of design and analysis methods, the six-bar mechanism is split into two sets of four-bar mechanism combinations, and the mutual coupling relationship of the two sets of four-bar mechanisms is analyzed to establish the patient's elbow flexion angle.

[0037] The mathematical relationship between the rod lengths of each component of the six-bar mechanism and the wrist flexion angle simulated by the actuator is analyzed, and on this basis, the influence of the position change of the first adjustment hole in the upper arm sleeve and the forearm sleeve on the change of the rod length of the six-bar mechanism in the wrist amputation prosthesis and the wrist flexion angle simulated by the actuator is analyzed. Finally, the design and analysis of the coupling relationship between the wrist joint movement of the six-bar wrist amputation prosthesis and the residual elbow flexion movement of the patient is realized, thereby improving the convenience and practicality of patients using prostheses in daily life activities. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the specific implementation of the present invention, the following will briefly introduce the drawings required for use in the specific implementation. In all the drawings, each element or part is not necessarily drawn according to the actual scale.

[0039] Figure 1It is a schematic structural diagram of a six-rod wrist amputation prosthesis of the present invention;

[0040] Figure 2 It is a schematic structural diagram of a six-rod wrist amputation prosthesis of the present invention before the elbow joint is flexed;

[0041] Figure 3 It is a schematic structural diagram of a six-rod wrist amputation prosthesis of the present invention after the elbow joint is flexed;

[0042] Figure 4 A schematic diagram of the kinematics of a six-bar mechanism of a six-bar wrist amputation prosthesis according to the present invention;

[0043] Figure 5 Disassembling the four-bar mechanism of the six-bar mechanism of the six-bar wrist amputation prosthesis of the present invention Figure 1 ;

[0044] Figure 6 Disassembling the four-bar mechanism of the six-bar mechanism of the six-bar wrist amputation prosthesis of the present invention Figure 2 ;

[0045] Figure 7 A curve diagram showing the relationship between the elbow flexion angle and the wrist flexion angle of a six-bar wrist amputation prosthesis of the present invention;

[0046] Figure 8 It is a structural schematic diagram of a first adjustment hole in a six-rod upper arm sleeve of a wrist amputation prosthesis according to the present invention;

[0047] Fig. 9 It is a schematic structural diagram of a first adjustment hole in a six-rod forearm sleeve of a wrist amputation prosthesis according to the present invention;

[0048] Fig.10 A curve diagram showing the relationship between the first adjustment hole parameters of the upper arm sleeve of a six-bar wrist amputation prosthesis and the flexion angle of the prosthesis elbow and wrist joint;

[0049] Fig.11 A curve diagram showing the relationship between the first adjustment hole parameters of a six-rod wrist amputation prosthesis forearm sleeve and the flexion angle of the prosthesis elbow and wrist joint;

[0050] Reference numerals:

[0051] Upper arm sleeve 1, forearm sleeve 2, first rod 3, second rod 4, third rod 5, fourth rod 6, slot 7, actuator 8,

[0052] The first adjustment hole 91 and the second adjustment hole 92 . DETAILED DESCRIPTION

[0053] The following embodiments of the technical solution of the present invention are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and are therefore only used as examples, and cannot be used to limit the protection scope of the present invention.

[0054] like Figures 1 to 11 As shown, a six-rod wrist amputation prosthesis of the present invention comprises: an upper arm sleeve 1, a forearm sleeve 2, a first rod 3, a second rod 4, a third rod 5, a fourth rod 6 and an actuator 8;

[0055] The left side of the upper arm sleeve 1 is rotatably connected to the forearm sleeve 2, the right end of the first rod 3 is connected to the upper arm sleeve 1, and the left end of the first rod 3 is rotatably connected to the second rod 4;

[0056] The middle part of the second rod 4 is connected to the forearm sleeve 2, and the left end of the second rod 4 is rotatably connected to the third rod 5;

[0057] The fourth rod 6 is mounted on the forearm sleeve 2 , and the right end of the fourth rod 6 is rotatably connected to the free end of the third rod 5 , and one end of the fourth rod 6 away from the third rod 5 is connected to the actuator 8 .

[0058] Specifically, the partial flexion movement of the patient's elbow joint during daily activities is used to form the angle change between the upper arm sleeve 1 and the forearm sleeve 2 as the power input of the wrist amputation prosthesis, and the residual flexion movement of the elbow joint is used in conjunction with the six-bar structure composed of the upper arm sleeve 1, the forearm sleeve 2, the first rod 3, the second rod 4, the third rod 5, and the fourth rod 6 to realize the actuator 8 to simulate the flexion movement of the wrist joint. The realization process is as follows Figure 2 and Figure 3 shown.

[0059] The upper arm sleeve 1, the forearm sleeve 2, the first rod 3, the second rod 4, the third rod 5 and the fourth rod 6 form a six-rod mechanism with one degree of freedom.

[0060] In some embodiments, a first adjustment hole 91 is opened on the outer side of the upper arm sleeve 1 and the forearm sleeve 2, and a first mounting shaft (not shown in the figure) is installed on one side of the first rod 3 and the second rod 4, and the first mounting shaft is connected to the first adjustment hole 91.

[0061] In some embodiments, four first adjustment holes 91 are arranged at equal intervals.

[0062] Specifically, according to the actual elbow joint mobility of patients with wrist dysfunction such as wrist dislocation, the length of some rods in the six-bar mechanism is changed to achieve the adjustment of the coupling between the simulated wrist flexion movement and the residual elbow flexion movement of the actuator 8.

[0063] In some embodiments, a second adjustment hole 92 is further opened on the outer side of the forearm sleeve 2 near the fourth rod 6 , and a second mounting shaft (not shown) is installed on one side of the fourth rod 6 , and the second mounting shaft is connected to the second adjustment hole 92 .

[0064] In some embodiments, a slot 7 is defined at one end of the fourth rod 6 away from the third rod 5 , and one end of the actuator 8 is installed in the slot 7 .

[0065] In some embodiments, the actuator 8 can be any one of a spoon, a fork or a hook.

[0066] Specifically, in this embodiment, the execution component 8 is represented by a spoon as a daily auxiliary tool to help the patient eat.

[0067] In some other embodiments, a method for designing a six-bar wrist amputation prosthesis is provided, which is based on a six-bar wrist amputation prosthesis as described in any one of the preceding articles, and comprises the following steps:

[0068] Step S01, constructing a six-bar mechanism motion diagram, calculating the degrees of freedom, and establishing a six-bar mechanism mathematical model;

[0069] Step S02, disassembling the six-bar mechanism into two sets of four-bar mechanisms, and analyzing them;

[0070] Step S03, establishing a mathematical relationship between the patient's elbow flexion angle change value, the length of each component of the six-bar mechanism, and the wrist flexion angle simulated by the actuator;

[0071] Step S04, analyzing the mathematical relationship between the position change of the first adjustment hole 901 of the upper arm cuff 1 and the forearm cuff 2 and the rod length of the six-bar mechanism and the wrist joint flexion angle simulated by the actuator.

[0072] In some embodiments, the calculation formula of the degree of freedom includes:

[0073] F=3n-2p L -p H

[0074] Where F is the degree of freedom, n is the number of active components, and p is L For low pair number, p H It is a high pair number.

[0075] In some embodiments, the mathematical relationship in step S02 includes:

[0076]

[0077] ∠DCB=∠ACB+∠ACD

[0078] Let ∠DCB = γ

[0079]

[0080] θ=∠CEG-∠FEG

[0081] In some embodiments, the mathematical relationship in step S03 includes:

[0082]

[0083] ∠DCB=∠ACB+∠ACD

[0084]

[0085] θ(t)=∠CEG-∠FEG

[0086] Among them, AB, BC, CD, AD, EC, EF, GF, and CG are the lengths of the rods in the schematic diagrams 1 and 2 of the disassembled four-bar mechanism of the six-bar mechanism of the wrist amputation prosthesis. is the elbow flexion angle, θ is the wrist flexion angle of the wrist disarticulation prosthesis, ∠ACB, ∠ACD, ∠CEG, ∠FEG and ∠DCB are the structural angles for calculating the transition in the disassembly of the four-bar mechanism of the six-bar mechanism of the wrist disarticulation prosthesis, Given the initial flexion angle of the elbow joint, ω is the angular velocity of the elbow joint flexion, and t is the elapsed time.

[0087] Set AB=51.20mm, BC=83.27mm, CD=100mm, AD=40mm, EC=100.62mm, EF=30mm, GF=40mm, CG=100mm to obtain the relationship diagram between the patient's elbow flexion angle and the wrist flexion angle of the wrist amputation prosthesis.

[0088] In some embodiments, the mathematical relationship in step S04 includes:

[0089]

[0090] ∠DCB=∠ACB+∠ACD

[0091]

[0092] θ(t)=∠CEG-∠FEG

[0093] Wherein, Δx is the parameter of the first adjustment hole in the upper arm sleeve, Δy is the parameter of the first adjustment hole in the forearm sleeve, wherein the relationship curve between the position setting and the change parameters of the first adjustment hole 901 in the upper arm sleeve 1 and the forearm sleeve 2 and the change of the elbow wrist joint flexion angle is as shown in Figure 8-Figure 11 .

[0094] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A six-bar wrist amputation prosthesis, characterized in that: include: An upper arm sleeve, a forearm sleeve, a first rod, a second rod, a third rod, a fourth rod and an actuator; One side of the upper arm sleeve is rotatably connected to the forearm sleeve, one end of the first rod is connected to the upper arm sleeve, and the other end is rotatably connected to the second rod; The middle part of the second rod is connected to the forearm sleeve, and the other end is rotatably connected to the third rod; The fourth rod is mounted on the forearm sleeve, and one end of the fourth rod is rotatably connected to the free end of the third rod, and one end of the fourth rod away from the third rod is connected to the actuator.

2. A six-bar wrist amputation prosthesis according to claim 1, characterized in that: The outer sides of the upper arm sleeve and the forearm sleeve are both provided with a first adjustment hole, and one side of the first rod and the second rod is both provided with a first installation shaft, and the first installation shaft is connected to the first adjustment hole.

3. A six-bar wrist amputation prosthesis according to claim 2, characterized in that: A plurality of the first adjustment holes are arranged at equal intervals.

4. The six-bar wrist amputation prosthesis according to claim 2, characterized in that: A second adjustment hole is further provided on the outer side of the forearm sleeve close to the fourth rod, a second installation shaft is installed on one side of the fourth rod, and the second installation shaft is connected to the second adjustment hole.

5. The six-bar wrist amputation prosthesis according to claim 1, characterized in that: A slot is formed at one end of the fourth rod away from the third rod, and one end of the actuator is installed in the slot.

6. The six-bar wrist amputation prosthesis according to claim 5, characterized in that: The actuator may be any one of a spoon, a fork or a hook.

7. A six-bar wrist amputation prosthesis design method, characterized in that: A six-bar wrist amputation prosthesis according to any one of claims 1 to 6, comprising the following steps: Step S01, constructing a six-bar mechanism motion diagram, calculating the degrees of freedom, and establishing a six-bar mechanism mathematical model; Step S02, disassembling the six-bar mechanism into two sets of four-bar mechanisms, and analyzing them; Step S03, establishing a mathematical relationship between the patient's elbow flexion angle change value, the length of each component of the six-bar mechanism, and the wrist flexion angle simulated by the actuator; Step S04, analyzing the mathematical relationship between the position change of the first adjustment hole of the upper arm sleeve and the forearm sleeve and the rod length of the six-bar mechanism and the wrist joint flexion angle simulated by the actuator.

8. The method for designing a six-bar wrist amputation prosthesis according to claim 7, characterized in that: The calculation formula of degrees of freedom includes: F=3n-2p L -p H Where F is the degree of freedom, n is the number of active components, and p is L For low pair number, p H It is a high pair number.

9. The method for designing a six-bar wrist amputation prosthesis according to claim 8, characterized in that: The mathematical relationship in step S03 includes: ∠DCB=∠ACB+∠ACD θ(t)=∠CEG-∠FEG Among them, AB, BC, CD, AD, EC, EF, GF, and CG are the lengths of each bar in the schematic diagrams 1 and 2 of the disassembled four-bar mechanism of the six-bar mechanism of the wrist-disconnection prosthesis, φ is the flexion angle of the elbow joint, θ is the flexion angle of the wrist joint of the wrist-disconnection prosthesis, ∠ACB, ∠ACD, ∠CEG, ∠FEG, and ∠DCB are the structural angles for calculating the transition in the disassembled four-bar mechanism of the six-bar mechanism of the wrist-disconnection prosthesis, φ0 is the given initial flexion angle of the elbow joint, ω is the angular velocity of the elbow joint flexion, and t is the elapsed time.

10. The method for designing a six-bar wrist amputation prosthesis according to claim 9, characterized in that: The mathematical relationship in step S04 includes: ∠DCB=∠ACB+∠ACD θ(t)=∠CEG-∠FEG Wherein, Δx is the parameter of the first adjustment hole in the upper arm cuff, and Δy is the parameter of the first adjustment hole in the forearm cuff.

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