Background
Motor neuron disease can lead to a loss of motor hand and arm function. In this constellation, assistance with all everyday activities is required from family members, care staff, or other assistants. Dependence on third parties can be experienced as a loss of autonomy. Since 2017, arm robots have been available that can take over certain actions (instead of the patient’s own arm)
Arm robots are approved assistive technology devices that can be provided based on a doctor’s decision and following an application for cost coverage by health insurance.
Assistive robots are gripper arms that are mounted on the wheelchair and equipped with gripper fingers. Various options allow the patient to control the robotic arm independently. The type and frequency of use are very individual and can also be changed as the disease progresses.
Function and structure
The robotic arm has a complex and versatile motor system that mimics the movements of a human arm from the shoulder and elbow to the fingertips. Complex movement sequences with a large radius of action can be carried out safely and in a controlled manner by the user.
A robotic arm can be used to independently carry out basic manual actions such as reaching for a glass, opening doors, and handling oneself, moving (in the sense of “repositioning”) one’s own arms, straightening glasses, or scratching one’s head.
Attached to a wheelchair, a bed, or a table, the robotic arm increases independence in activities of daily living and motor self-determination.
Control is still via the existing control element, which can be a joystick, a head control, an eye control, or another control variant, depending on the individual situation.
A scientific study shows the expectations of a robotic arm in people with ALS. The study analyzed 58 patients with ALS (men: 69%, n=40; women: 31%, n=18) who received a medical prescription for a robotic arm. The ALS Functional Rating Scale (ALS-FRS) showed a high motor impairment of the arms in these people.
The majority of patients (93%) would use the robotic arm both during the day and at night. 7% of patients would not use it during the day. Fixation of the robotic arm is planned on the wheelchair (98%, n=57), on the table (52%, n=30) or on the bed (35%, n=20).
Figure: Importance of the fixation options of the robot arm. n=58
More than 90% of patients use the robotic arm for movements close to the body (e.g., scratching or putting on glasses), for handing out drinks, handling objects, opening doors or cupboards, and pressing buttons (e.g., light switches or elevators). Further expectations of use are shown in the following illustration.
Figure: Patient expectations of a robotic arm. n=58
Almost all patients rated the possibility of being fitted with a robotic arm as very important (95%). At the same time, 85% of the ALS patients surveyed showed a severe restriction of the upper extremities. The option of being fixed to a wheelchair is desired by almost all patients (98%). The greatest patient expectation is to be able to pass drinks, make movements close to the body, such as scratching, handling objects, opening doors, and pressing buttons.
Users of a robotic arm may have the following conditions:
Users must be able to operate the robotic arm safely. The following criteria must be observed for the supply: