What causes amputation

Patients with upper limb amputation patients are mostly caused by work-related injuries, traffic accidents, battle wound and other injuries. Especially in urban areas there are many mechanical injuries leading to hand tissue necrosis and amputation.In rural areas it is mostly due to agricultural machinery and other machinery injuries leading to upper limb amputation.

MEDI-REHATEK has learned about the datum for amputation as below:

Referring to the causes of lower limb amputation, work-related injuries and traffic accidents mainly accounted for about 30 percent of the trauma, arteriosclerosis, diabetes, vasculitis and other blood circulation disorders leading to amputation accounted for about 40% of the illness case.

According to the survey of authority, in recent years the proportion of amputation caused by work-related injuries andtraffic accidents caused by traffic accidents was significantly reduced.And the case of blood circulationdysfunction leading to amputation accounts for 80% of the total number,which is about 7 times more than the data of1990s. And blood circulation disorders cause amputation, arteriosclerosis obliterans and diabetes have increased significantly.  

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Lightweight Thigh Prosthesis for the elderly

The elderly are amputated with the main cause of atherosclerosis and diabetes on thigh.They are more passive in the spirit and lack a certain ability to judge in theirspirit Their emotions are more unstable. Also due to physical failure,the stump muscle strength and trunk and upper limb muscle strength will decline. The healthy leg can not have a good grasp of balance, there will be limb shrinkage.

Traditional thigh prosthesis is very heavy, the prosthetic knee is unstable, and the wearing is cumbersome. There are many difficulties in adapting the prosthetic socket according to the weight change of the user and the swelling of the residual limb.Therefore the elderly with thigh amputation loses knee function and has to use a wheelchair instead.


Especially in Europe and the United States,the system demands amputees with shorter hospital stay.So that amputees can not have fully prosthesis gait training, a lot of patients rely on wheelchair life after coming out of the hospital. Earlier years, there are internal bone bars with knee-locking structures,they soften the upper edge of polypropylene socket, so that the circumference of the prosthetic socket could be adjusted according to the circumference of the stump.

In recent years, according to the research of safety and light weight of the thigh prosthesis, there has been a large variety of prosthetic knee and socket. One representative of MEDI-REBATEK develops a variety of prosthetic socket that are suitable for human body, there are all kinds of hydraulic, pneumatic prosthetic kneewith high safety. There are a special prosthetic knee for Asian people,that is more suitable for Asian people use and installation. 

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How to choose fit below knee prosthesis

Some prosthetic patients are not satisfied with the leg prostheses from prosthetic company, they would like to match their own satisfaction with the below knee prostheses. Then what should we pay attention to choose prostheses?

Referred to information from MEDI-REHATEK, we suggest that the disabled friends  should consider the following factors for choosing proper below knee prosthesis:

1, The length of the stump:

Amputee with long residual limb is easy to feel cold in winter, should not choose aluminum below knee prosthesis but optional leather below knee prosthesis or modern below knee prosthesis with suspension belt above knee (called Patellar Tendon Bearing below-knee prosthesis,referred to as PTB prosthesis); 

Amputee with medium or short stump can choose to prosthetic socket that contains the widest part of knee at the widest point type (known as the Kondylen Bettung Münster below knee prosthesis, referred to as KBM prosthesis); or choose the prosthetic socket that can contain the patella (called the prosthese-tibiale-emboitage-supracondylienne below prosthesis, referred to as PTES prosthesis).

2,The load capacity of residual limb and knee stability: 

When amputees with short stumps have unstable knee, and skin scar in large size, poor weight-bearing function,  they should use shank prostheses with metal knee joint hinge and tube-shaped parts on upper thigh.

3, Age: 

The elderly should choose lightweight prostheses; young people like sports who should choose dynamic feet or prosthetic feet with energy storage; The length of children's lower limb easily increases every year,so they should choose the prosthetic socket which allows to be replaced easily. 

(The special problems of children's prostheses:as the growth of healthy limbs, prosthetic sockets need replacing one time from six months to 1 year replacement time; prostheses need replacing one time from 1 year  to 2 years).

4, The surrounding environment, occupation, economic capacity, maintenance conditions: 

If the amputees live in rural areas, are engaged in agricultural labor.That is appropriate to use traditional prostheses such as practical, inexpensive and universal below knee prosthesis. These prostheses are cheap,also easy to repair by themselves. 

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Meet the final fantasy of each thigh amputee II

The hydraulic cylinder cooperates with other parts to imitate the healthy limb movement. According to the instruction of the magnitude of damping issued by the servomotor, the hydraulic cylinder adjusts the swing speed of the knee joint.Itensures its movement that can be dynamically controlled according to stride lengthand stride frequency. 

Meanwhile the data collected by the torque sensor in the connection tube,which ensures that the damping adjustment can be adapted to the state of the joint at all times.It ensures the maximum stability and safety of the artificial limb during the whole walking and standing process.

The whole system of intelligent prosthesis is always processing information whetherit is fast or slow walking, or active or static. Intelligent bionic prosthesis will monitor every step of walking and take into account all aspects of measurement data to adapt to any one situation, and then continuously respond to the needs of users. 

This means that no matter if you go up the stairs, up and down the slope, or deal with different road conditions, users do not have to concentrate on controlling the prosthesis, and can save energy and effort to do what they want to do.

MEDI-REHATEK also learns that the long-term lithium battery power of intelligentcan be repeatedly charged full, the way of charging is also very convenient. After intelligent prostheses has a full charge,it can guarantee about 40 to 45 hours of normal use.

If the user temporarily forgets the charge, the battery is about to run out, the intelligent bionic prosthetic will alert to the user in way of vibration or buzzing.And if the power is turned off, the joint automatically switches to safe mode until it is recharged. 

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Meet the final fantasy of each thigh amputee

Each thigh amputee has their own final fantasy, most fantasy is like living a normal life.The emergence of intelligent prostheses has a great help to improve the quality of life of thigh amputee.Let's take a look at how intelligent the current prosthesis is.

Prosthetic experts of MEDI-REHATEK informs that it takes 0.05 seconds to see the outline of the object once the object suddenly appears in front of human eye.The sensors collect walk information for 50 times per second and guard the walk.Knee angle sensor and ankle torque sensor are the sensory system of intelligent bionic prosthetic knee joint.They have the equivalent as every 0.02 seconds to collect a message. 

The central microprocessor of intelligent prosthesis is equivalent to the human brain and receives the gathered information at such a rate in real time and judges the swing speed and position of lower leg of prosthesis and the torque and support status from prosthetic heel touching the ground to forefoot with load-bearing leaving the ground. It will have automatic analysis of the response of joints, and convey the command to the internal servo motor of intelligent prosthesis.

Servo motor is like the human nervous system.Fluid cylinder as the important extension device of adjustable knee joint has hydraulic valve that provides appropriate damping at the appropriate time.It changes the swing speed of prosthetic leg and provides strong protection to fixation and security of knee whenstanding and walking.

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Advantages and disadvantages of intelligent lower limb prostheses

The development of artificial limbs has always followed the three main principles, namely "security, functionality, practicality." Safety is a good understanding,prosthesis needs to ensure the safety of the product itself.

The prosthesis provides a certain degree of security when users are in the process of use in order to avoid the injury to the user caused by product failure; 

functionality refers to the materials and assistive device as compensatory features to the physiological function of the defect site so that the user can achieve living a life as close as possible to the normal state of life; 

practicality consideration is whether assembly of  artificial limbs causes any additional burden for users,which includes the physiological burden,psychological Burden, economic burden.

Currently Medi-Rehatek intelligent lower limb prosthesis develops very fast in the international development,the actual number of users substantially increase each year, because itachieves a relative balance among "security, functionality, practicality". 

The intelligent prosthesis provides protection at abnormal state of support phase, andautomatic gait analysis and control at sway phase,so that prosthetic users have a closer to the normal state of life. It can be said that the intelligent lower limb prosthetic system is an important milestone in the development of modern prosthetic technology.

But we should also clearly understand that, due to the high cost of intelligent prosthetic limbs, its corresponding use cost is also much higher than other types of prostheses.it is not suitable for a wide range of promotion and use. However, in recent years, China's development of intelligent prostheses is also very serious.

The key project of "Eleventh Five-Year" National Science and Technology Support Programof "Aids to the Disabled Aids Research" has the establishment of the intellectual limb prosthesis research topic.Its goal is to promote intellectual Intelligent prosthetic knee joint so that knee amputees can use lower limb prostheses with lower price isand excellent performance. 

Relative blog:Simple classification of below-knee prosthesis II