WO2020005182A2

WO2020005182A2 - Six-axis hydraulic foot prosthesis

Info

Publication number: WO2020005182A2
Application number: PCT/TR2019/050206
Authority: WO
Inventors: Turhan Alcelik
Original assignee: Individual
Current assignee: Individual
Priority date: 2018-06-27
Filing date: 2019-03-29
Publication date: 2020-01-02
Anticipated expiration: 2020-12-27
Also published as: TR201809076A2; WO2020005182A3

Abstract

The 6 (six) axis hydraulic foot prosthesis with active vacuum system (A) of the invention is an artificial foot prosthesis which consists of a fixed upper body (1), a lower body / leg part (2) connected to the upper body and connection elements, and is capable of moving the ankle forward-backward, inward-outward and upward-downward directions.

Description

SIX-AXIS HYDRAULIC FOOT PROSTHESIS

Field of Invention

The 6 (six) axis hydraulic foot prosthesis within the scope of the present invention is related to an artificial foot prosthesis with mechanical properties which can simulate natural physiological movements of human foot, store energy and reduce ground reactions occurring while walking.

Background Art

Some prior patent documents on below-knee, ankle and foot prostheses using the current techniques with regard to 6 (six) axis hydraulic foot prosthesis are given below:

US Patent Numbers: 53931; 56983; 975489; 1001641; 1002774; 1102774; 1198399; 1400042; 2066599; 2183076; 2215525; 2357893; 2368917; 2390920; 2438581; 2416817; 2470480; 2644165; 2692990; 2731645; 292800; 2996295; 3196463; 3551914; 3754286; 3874004; 4007497; 4089072; 4196903; 4306320; 4364128; 4370761; 4395783; 4442554; 4605417; 4718913; 5482513; 487697; 5030239; 5196630; 5405411; 5458656; 5545234; 5766264; 5695526; 5800566; 5957981; 5984972; 6080197; 6187052; 6206934; 6478826; 6488717; 6572659; 06692533; 06855170; 6887279; 06929614; 7052519; 07063727; 7112227; 7169190; 7347877; 7581454; 07846213; 809876; 8118879; 8480760; 8574312; 8628585; 8641780; 8721737;8740991 ; 20040236435; 20050060045; 20040064195; 20040236435; 20060173555; 20130073056 and 20140088729; DE Patents No: 19642719; 327494 and EP Patent No: 1302183.

Hydraulic dampers and coil spring mechanisms applied in foot prostheses described in the patent documents given above and commonly used today decrease ground reactions occurring while walking but they can only use a part of the stored energy and cannot meet the energy need required to move the body forward.

Therefore, users of such prostheses consume more energy than normal individuals and get tired more quickly.

Today, researches made in the field of foot prostheses have brought up active / bionic foot prostheses with microprocessors in order to meet the energy need required to move the body forward and ensure balance while walking. However, such prosthetic applications increase the costs and bring along some difficulties in use and maintenance problems for patients.

The 6 (six) axis hydraulic foot prosthesis system within the scope of the described invention minimizes ground reactions occurring while walking and running, allows to use the energy generated on the ankle with the weight of the legs and the body for walking and running at an optimum level, creates a hydraulic foot prosthesis system having mechanical properties, and restricts involuntary joint movements in case of any strain.

Objective of the Invention

6 (six) axis hydraulic foot prosthesis has been developed in order to reform the foot anatomy damaged or lost for any reason in a way which is most suitable for the physiological structure, and make the foot functional again artificially. Advantages and usage objectives of the invention are outlined below.

The main objective of the 6 (six) axis hydraulic foot prosthesis of the invention is to develop a new foot prosthesis which can simulate natural physiological functions of ankle joint in a way to minimize disadvantages of the prior art as much as possible.

One of main objectives of the invention is to create a mechanical foot prosthesis with hydraulic damper and coil spring support in order to develop impact absorber / shock absorber properties of artificial prostheses.

Another objective of the invention is to create an ankle joint which has the optimum form for the natural foot structure of the patient and can simulate physiological functions of the ankle in the most compatible way, thereby to obtain a natural walking and running function.

Another objective is to create a durable and secure ankle joint structure which restricts ankle movements in a way optimized for the physiological structure, allows the user to have a very good command and prevents falling down by inhibiting uncontrolled ankle movements.

Yet another objective of the invention is to enable prosthesis users to use their prostheses in all movement directions and even under bad road conditions without having any balance problems.

Still another objective and advantage is that the installation, use and when necessary, repair of the prosthesis are very easy thanks to the current functional design and the time for the adaptation of the user to the prosthesis is very short.

Finally, since it is possible to choose the hydraulic system, active vacuum system and coil springs included in the prosthesis structure in accordance with the weight and age of the user, it is possible to choose the prosthesis fitting the needs best, and the ease of replacement of prosthesis elements facilitates clinic applications. Figures To Help To Clarify The Invention

Figure 1 : General perspective view of installed six-axis hydraulic foot prosthesis with active vacuum system of the invention,

Figure 2: Perspective view of ball joint mechanism of the six-axis hydraulic foot prosthesis with active vacuum system,

Figure 3: Top cross-sectional view of six-axis hydraulic foot prosthesis with active vacuum system, Figure 4: A-A cross-section of six-axis hydraulic foot prosthesis with active vacuum system,

Figure 5: B-B cross-section of six-axis hydraulic foot prosthesis with active vacuum system,

Figure 6: C-C cross-section view of six-axis hydraulic foot prosthesis with active vacuum system.

Part Numbers

A- Hydraulic foot prosthesis

1 - Prosthesis upper body

2- Prosthesis lower body

3- Prosthesis base

4- Hydraulic damper

5- Active vacuum unit

6- Ball joint unit

6.1 Ball joint seat

7- Front pusher elements

7.1 Front and rear pusher seat

8- Rear pusher elements

9- Central pusher element

9.1 Central pusher seat

10- Main connection shaft

1 1- Main connection shaft seat

12- Main connection shaft cap

13- Hydraulic damper connection shafts

14- Active vacuum unit connection shaft

15- Vacuum part

16- Discharge part 17- Ball joint knob

18- Ball joint handle

18.1 Ball joint handle seat

19- Prosthesis connection head

Detailed Description of the Invention

Properties and advantages of the invention will be better understood with the detailed description of drawings shown on the following Figures. In Figure 1 , the perspective view of installed form of the preferred first structure of 6 (six) axis hydraulic foot prosthesis with active vacuum system; in Figure 2, top view of cross-sectional axes of six-axis hydraulic foot prosthesis with active vacuum system (A); in Figure 3, the A- A cross-sectional view of six-axis hydraulic foot prosthesis with active vacuum system (A); in Figure 4, B-B cross-sectional view of six-axis hydraulic foot prosthesis with active vacuum system; in Figure 5, C-C cross- sectional view of six-axis hydraulic foot prosthesis with active vacuum system, and in Figure 6, the ball joint unit (6) is shown.

The preferred structure of the six-axis hydraulic foot prosthesis (A) shown in Figure 1 -6 consists of two main parts: The fixed upper prosthesis body (1) and movable lower prosthesis body (2).

Upper prosthesis body (1 ) is mounted below the knee or on the tibia (over the stump part) by means of a pipe system in order to complete the missing lower part of amputated leg by means of a prosthesis connection head (19). (Figures do not show the legs of the user and the pipe system).

The lower prosthesis body (2) is mounted on the upper body (1 ) by means of a hydraulic damper (4), an active vacuum unit (5), a main connection shaft (10) and a ball joint unit (6).

In the preferred hydraulic foot prosthesis (A) structure, there is one hydraulic damper (4) located in the front part, and mounted in the seats (1 , 2) in the upper and lower prosthesis bodies by means of hydraulic damper connection shafts (13). The number of hydraulic damper (4) may be more.

Hydraulic damper connection shafts (13) are stopped with at least one fastening element on their both ends.

The active vacuum unit (5) is located at the rear side of the prosthesis and placed in the seat allocated to it on the lower prosthesis body, and mounted in its seat on the upper prosthesis body (1 ) by means of the active vacuum unit connection shaft (14).

There is a total of four front and rear pusher elements (7, 8) between upper and lower prosthesis bodies (1 , 2) as two elements on the front part and two elements on the rear part. These pusher elements preferably include a coil spring. The function of coil springs is to carry the body weight and ensure the prosthesis movements.

The ball joint unit (6) between upper and lower prosthesis bodies (1 , 2) which makes centering in the middle part is the main part ensuring the six-directional joint movements mechanism.

The ball joint unit (6) consists of a ball joint unit knob (17) in a mushroom shape, a ball joint handle (18) in a rectangular shape and a central pusher element (9). The ball joint knob (17) is placed in its specific ball seat located on the lower surface of the upper prosthesis body (1 ).

In a preferred structure, the ball joint handle (18) part has a rectangular shape and fits into the specific ball joint handle seat which is located on the lower prosthesis body and allows the ball joint handle (18) part to move easily inside. There is a cylindrical spring seat on the lower part of the ball joint seat. The central pusher elements (9) placed in this seat provides the vertical joint movement of the prosthesis in up and down directions. When load is applied on the central pusher elements (9) pushing the ball joint unit (6) upwards while walking and running, energy is stored on the contracted spring. When the load on the prosthesis is removed, the ball joint unit moves vertically upwards as a whole and comes to normal tonus (half stretched position) position with the driving force of the central pusher element (9). The energy stored during this time contributes to walking and running. Central pusher elements (9) also act as shock absorbers and impact absorbers. The ball joint unit (6) allows forward-backward, inward-outward and upward-downward movement of the prosthesis and it is designed in a way to prevent uncontrolled ankle joint movements during any strain and impact. In the preferred structure, the hydraulic foot prosthesis (A) include at least one prosthesis base (3) made of carbon material connected to the lower prosthesis body (2). In the preferred structure, the prosthesis base (3) has two parts, and mounted on the lower surface of the lower prosthesis body (2). The prosthesis base (3) provides a firm contact to the ground, and contributes to six-axis joint movements. In hydraulic foot prostheses with active vacuum system; the active vacuum system connection shaft (14) ensuring the mounting of active vacuum unit (5) to the upper prosthesis body is stopped by at least one fastening element from both sides. There are front and rear pusher elements (7, 8), two on the front part and two on the rear part of upper and lower bodies of the prosthesis (a total of four pusher elements), and there is a central pusher element (9) on the central joint part. The main function of the hydraulic damper (4), active vacuum unit (5) and front, rear and central pusher elements (7, 8, 9) in the preferred 6 (six) axis hydraulic foot prosthesis with active vacuum system (A) is to connect the upper and lower bodies of the prosthesis to each other, store energy while walking and running, and provide impact absorption and shock absorption against impacts that may occur. There is one protrusion on each of two sides of the lower prosthesis body (2) to restrict inwards and outwards joint movements. There are holes on these protrusions which belong to the main connection shaft seat (11 ) allowing the passage of the main connection shaft (10) and such holes are closed with at least one main connection shaft cap (12). Main connection shaft caps (12) are connected to the lower body (2) strongly in the preferred structure of the 6 (six) axis hydraulic foot prosthesis with active vacuum system (A), the ankle joint surfaces are designed so that the lower surface of the upper prosthesis body (1) is a single flat surface while there are four flat joint surfaces with different angles on the upper surface of the lower prosthesis body (2). The purpose of these four different joint surfaces is to form a secure ankle joint structure by providing the widest contact surface for each movement direction, and ensure balance for the user by restricting uncontrolled joint movements.

In the preferred structure, the hydraulic damper (4) and front pusher elements (7) located on the front part of the hydraulic foot prosthesis (A), the active vacuum unit (5) and rear pusher elements (8) on the rear part and the ball joint unit (6) on the central part constitute support mechanisms of the prosthesis during the normal standing position, i.e., normal pressing position.

While the front, rear and central pusher elements (7, 8, 9), hydraulic damper (4) and active vacuum unit (5) mechanisms in the 6 (six) axis hydraulic foot prosthesis (A) structure constitute a hydraulic foot prosthesis system which can simulate natural movements of the ankle and has mechanical properties; it also ensures optimum use of the energy generated on the ankle joint with the weight of the legs and the body, minimizes ground reactions occurring while walking and running, and ensures the balance of the prosthesis user by restricting involuntary joint movements in case of any strain.

The active vacuum unit (5) has a vacuum part (15) and a discharge part (16).

Stroke / course of the hydraulic damper and active unit have distances allowing securing ankle movements comfortably.

The main connection shaft (10), located between the upper and lower bodies of the prosthesis (1 , 2), ensures joint movements and balance in all directions (forward-backward-inward-outward-upward- downward).

The main connection shaft (10) is located in the main connection shaft seats (1 1 ) in the oval cylindrical structure which is located on the internal-external protrusions on the lower prosthesis body (2) and inside the ball joint knob (17), and these shaft seats are closed with main connection shaft caps (12).

The main connection shaft seats (11 ) have a form and dimensions allowing free movement of the main connection shaft (10) while walking or running.

The positions of the hydraulic damper (4), active vacuum unit (5), front and rear pusher elements (7, 8), central pusher element (9) and ball joint unit (6) included in the structure of the prosthesis are designed so that a secure, safe and balanced walking and running movement will be possible. In the preferred structure, the hydraulic foot prosthesis (A) has a total of 5 coil springs; two on the front part, two on the rear part and one on the central part. These front, rear and central pusher elements (7, 8, 9) are placed in their cylindrical seats in the upper and lower bodies of the prosthesis, and they are in a half stretched position (tonus position) when they are mounted. The stretch / tonus and pushing force of these front, rear and central pusher elements (7, 8, 9) and the hydraulic damper (4) keep the prosthesis in balance in the normal flat standing position. The number of front, rear and central pusher elements (7, 8, 9) may be less or more.

During normal walking, one presses on the heels first, and then on toes (plantar). Energy is stored on the rear pusher elements (8) and active vacuum unit (5) when the heel part of the prosthesis contacts the ground, and on the front pusher elements (7) and on the ankle joint as a result of the contraction of the hydraulic damper (4) when the toe part contacts the ground, and a pushing force (torque) is provided. The stored energy contributes to the forward movement of the body while the prosthesis is taking its flat position. Thereby, a walking function close to natural physiological walking is achieved.

The function of the active vacuum unit (5) included in the structure of the 6 (six) axis hydraulic foot prosthesis with active vacuum system of the presented invention is to ensure secure attachment of the prosthesis to the stump by creating a negative pressure between the hydraulic/pneumatic foot prosthesis (A) and the stump, and provides the prosthesis user with a secure and comfortable prosthesis use. This, in turn, makes the user feel the prosthesis as the continuance of his/her own leg, and provides a natural walking feeling.

Prosthesis bodies (1 , 2) and ball joint unit (6) elements are preferably made of aluminum, steel or plastic material resistant to any impact.

The prosthesis base (3) is made of a durable and lightweight plastic or carbon material, and mounted on the lower prosthesis body (2).

The prosthesis outer body may be applied an aesthetic external housing which is compatible with the foot form and accommodates prosthesis internal structures.

Support plates and bearings may be used between contact surfaces in order to improve prosthesis movements and increase the lifetime of the prosthesis by decreasing friction.

Front, rear and central pusher elements (7, 8, 9), hydraulic damper (4) and ball joint unit used in the 6 (six) axis hydraulic foot prosthesis (A) developed according to foot prostheses movement mechanisms commonly used in the market are designed so that the prosthesis can return to its normal standing position very quickly whenever the load on the pusher elements and the damper is removed, and it is possible to use the prosthesis comfortably and securely without any delay while walking and running. In 6 (six) axis hydraulic foot prosthesis (A) applications, it is possible to use different pusher elements with a pneumatic and hydro-pneumatic structure instead of hydraulic dampers, whereas it is possible to use rubber, gum elastic, plastic or similar elastic durable materials instead of coil springs. The hydraulic foot prosthesis (A) may be supported with active vacuum system, sensors, microprocessors (microchip) and electronic equipment.

The scope of the invention described herein is not limited to the terms and expressions used while describing the prosthesis. Other than the preferred applications, any change and modification to be made in different fields of use and any change or variation to be made on the form of the prosthesis may be considered within the scope of this invention provided not to deviate from the main working mechanism of the invention.

Claims

1. A 6 (six) axis hydraulic foot prosthesis (A), wherein this prosthesis includes: a fixed upper prosthesis body (1 ) to complete the lower part of the amputated leg, and a movable lower prosthesis body (2) connected to this upper prosthesis body (1 ), at least one hydraulic damper (4), at least one main connection shaft (10) and a plurality of front and rear pusher elements (7, 8) providing the connection between the said upper prosthesis body (1 ) and lower prosthesis body (2), a ball joint unit (6) providing centering and connection between upper and lower bodies of the prosthesis (1 , 2). at least one central pusher element (9) located on the lower part of the said ball joint unit (6), at least one prosthesis base (3) mounted on the said lower prosthesis body (2).

2. Hydraulic foot prosthesis (A) according to Claim 1 , wherein it includes at least one active vacuum unit (5) mounted in its seat in the upper prosthesis body (1 ) by means of a connection shaft (14).

3. Hydraulic foot prosthesis (A) according to Claim 1 , wherein it includes at least one main connection shaft (10) which connects upper and lower bodies of the prosthesis to each other along an internal-external axis and ensures the movement.

4. Hydraulic foot prosthesis (A) according to Claim 1 , wherein it includes at least one central pusher element (9) which moves the ball joint unit (6) vertically.

5. Hydraulic foot prosthesis (A) according to Claim 1 , wherein it includes a ball joint seat (6.1) in a spherical shape which is compatible with the ball joint unit knob (17) on the lower surface of the upper prosthesis body (1 ).

6. Hydraulic foot prosthesis (A) according to Claim 1 , wherein it includes a ball joint seat (18.1) which is compatible with the ball joint handle (18) inside the lower prosthesis body (2).

7. Hydraulic foot prosthesis (A) according to Claim 1 , wherein it includes a central pusher seat (9.1 ) which will accommodate the central pusher element (9) inside the lower prosthesis body (2) and on the lower part of the ball joint unit (6) in order to ensure vertical movement.

8. Hydraulic foot prosthesis (A) according to Claim 1 , wherein it includes a main connection shaft seat (1 1 ) passing through the ball joint knob (17) along an internal-external axis.

9. Hydraulic foot prosthesis (A) according to Claim 1 , wherein hydraulic damper (4) connection seats included in the upper and lower bodies of the prosthesis have angles surfaces which can provide prosthesis joint movements in six directions.

10. Hydraulic foot prosthesis (A) according to Claim 1 , wherein each of front, rear and central pusher elements (7, 8, 9) include cylindrical seats (7.1 ) in the upper and lower bodies of the prosthesis.

11. Hydraulic foot prosthesis (A) according to Claim 1 , wherein it includes at least one prosthesis base (3) which is made of elastic and durable plastic or carbon material and mounted in the lower prosthesis body (2).

12. Hydraulic foot prosthesis (A) according to Claim 1 , wherein it includes at least one stopper cap (12) which is mounted on both sides of the lower prosthesis body (2) and blocks uncontrolled prosthesis joint movements by stopping main connection shafts (10).

13. Hydraulic foot prosthesis (A) according to Claim 1 , wherein it includes pneumatic or hydro- pneumatic dampers instead of a hydraulic damper (4).

14. Hydraulic foot prosthesis (A) according to Claim 1 , wherein the said pusher elements (7, 8, 9) include springs preferably with a coiled structure.

15. Hydraulic foot prosthesis (A) according to Claim 1 , wherein it includes flexible and durable rubber, gum elastic or plastic materials instead of front, rear and central pusher elements (7, 8, 9) made of coil springs.