**4.2 Electrically powered prostheses**

Unlike the body-powered prostheses, electrically powered prostheses have actuators to perform the opening and closing of the terminal device. The electrically

**15**

*Impact of Medical Advancement: Prostheses DOI: http://dx.doi.org/10.5772/intechopen.86602*

*4.2.1 Mind-controlled prostheses*

*4.2.2 Myoelectric prostheses*

classify the desired movement of the prostheses.

the contraction of the muscle changes [14].

*4.2.2.1 i-Limb by Touch Bionics, UK*

from the user's muscle.

grip on the i-Limb quantum.

open source 3D printing counter prostheses [16].

four sizes of i-Limb Quantum are shown in **Figure 6** [17].

switching between the states of the FSM.

The new i-Limb Quantum has four different modes of control:

powered prostheses are more delicate and versatile that enhance or mimic the

These types of prostheses usually consist of motors (as an actuator), which is used to drive a mechanism to achieve the movements of the terminal device. These motors receive control signals from the main controller which, after the analysis of the input signal, instructs the motor to achieve desired movements. The electrically powered prostheses are further divided into two types on the bases of the sensing or input signals [6].

The mind-controlled prostheses (also called brain-controlled prostheses) sense the signal from brain, i.e., electroencephalogram (EEG) [13]. The controller extracts the information from the EEG signals after amplification and filtration in the form of features. These features are then used by the pretrained classifier to

The myoelectric prostheses use the same mechanism as of mind-controlled prostheses. The only difference is the sensing or input signal. In myoelectric prostheses, the signal is sensed from the muscle level instead of the brain. These signals are named as electromyogram (EMG). The EMG signal is usually sensed at the residual muscle of the amputated limb. Therefore, the EMG signals are easy to predict the intentions of the user as compared with the EEG signals. On the other hand, EMG signals are likely to be dissimilar if the position of the sensor is slightly changed or

The myoelectric prostheses are the most commonly used prostheses due to onsite EMG signal acquisition and relatively simpler control scheme. The state-ofthe-art prostheses [15] for the upper limb will be discussed in this section with the

Touch Bionics is one of the top companies in producing prostheses for transradial, wrist disarticulation, and finger amputees. A finger of i-Limb consists of four-bar mechanism driven by a DC motor via worm gears. The latest model i-Limb Quantum weighs 470 g for the ultrasmall model and 630 g for the large model. The

1.Trigger muscle control: this is the default control scheme based on a finite state machine (FSM). The user contracts his/her muscle to control the prosthesis by

2.Quick grip app control: the Touch Bionics has introduced a mobile app that can communicate with the i-Limb quantum. This app can be used to control the prostheses and perform the desired operation without sensing the EMG signals

3.Intelligent motion gesture control (i-mo): i-mo makes use of the internal sensors to detect the movement of the prostheses and activate a pre-programmed

functionality and appearance of the missing limb of the body.

**Figure 5.** *A typical body-powered upper limb prosthesis.*

#### *Impact of Medical Advancement: Prostheses DOI: http://dx.doi.org/10.5772/intechopen.86602*

*Computer Architecture in Industrial, Biomechanical and Biomedical Engineering*

The powered prostheses are further divided into the following:

The body-powered prostheses aid the disable person in achieving the functionality lost due to the loss of the limb. The body-powered prostheses also increase the quality of the subject's life by allowing them to perform the activities of daily living

These types of prostheses consist of a tendon or a cable that is attached with the person's body and by pulling that cable, the body-powered prosthesis performs the desired operation [10]. A typical body-powered upper limb prosthesis consists of socket, wrist, control cable, harness, and terminal device as shown in **Figure 5** [11]. The socket is worn on the residual limb, while the harness is worn on the opposite shoulder. To open or close the terminal device, the subject moves his/her shoulder, which results in the movement of harness, which in turn pulls the control cable. Most of the terminal devices in the body-powered prostheses are metal hooks due to the fact that it can withstand high loading and easy to control with a single cable-

Unlike the body-powered prostheses, electrically powered prostheses have actuators to perform the opening and closing of the terminal device. The electrically

**4. Powered prostheses**

1.Body-powered prostheses

**4.1 Body-powered prostheses**

spring mechanism [12].

**4.2 Electrically powered prostheses**

2.Electrically powered prostheses

(ADL) without the assistance of another human being.

**14**

**Figure 5.**

*A typical body-powered upper limb prosthesis.*

powered prostheses are more delicate and versatile that enhance or mimic the functionality and appearance of the missing limb of the body.

These types of prostheses usually consist of motors (as an actuator), which is used to drive a mechanism to achieve the movements of the terminal device. These motors receive control signals from the main controller which, after the analysis of the input signal, instructs the motor to achieve desired movements. The electrically powered prostheses are further divided into two types on the bases of the sensing or input signals [6].
