Types of Self Control Wheelchairs
Self-control wheelchairs are used by many people with disabilities to move around. These chairs are great for everyday mobility and can easily climb hills and other obstacles. The chairs also come with large rear shock-absorbing nylon tires which are flat-free.
The translation velocity of a wheelchair was determined by using a local field-potential approach. Each feature vector was fed to a Gaussian decoder, which output a discrete probability distribution. The evidence that was accumulated was used to drive visual feedback, and a command delivered when the threshold had been attained.
Wheelchairs with hand-rims
The kind of wheels a wheelchair has can impact its maneuverability and ability to traverse different terrains. Wheels with hand-rims are able to reduce wrist strain and improve comfort for the user. Wheel rims for wheelchairs can be found in steel, aluminum plastic, or other materials. They are also available in various sizes. They can also be coated with vinyl or rubber to provide better grip. Some are equipped with ergonomic features like being designed to accommodate the user's natural closed grip and wide surfaces for all-hand contact. This allows them to distribute pressure more evenly and avoid the pressure of the fingers from being too much.
Recent research has shown that flexible hand rims can reduce impact forces as well as wrist and finger flexor actions during wheelchair propulsion. They also provide a larger gripping surface than tubular rims that are standard, which allows users to use less force while still retaining the stability and control of the push rim. These rims are available at most online retailers and DME suppliers.
The results of the study showed that 90% of the respondents who used the rims were pleased with the rims. It is important to keep in mind that this was an email survey of those who purchased hand rims from Three Rivers Holdings, and not all wheelchair users with SCI. The survey did not assess any actual changes in the severity of pain or symptoms. It simply measured the extent to which people noticed a difference.
The rims are available in four different styles, including the light, big, medium and prime. The light is a small round rim, and the medium and big are oval-shaped. The rims that are prime are a little bigger in diameter and have an ergonomically-shaped gripping surface. All of these rims are placed on the front of the wheelchair and are purchased in different colors, ranging from natural- a light tan color -to flashy blue red, green or jet black. These rims can be released quickly and can be removed easily to clean or maintain. In addition the rims are encased with a vinyl or rubber coating that helps protect hands from slipping onto the rims and causing discomfort.
Wheelchairs that have a tongue drive
Researchers at Georgia Tech have developed a new system that lets users maneuver a wheelchair and control other digital devices by moving their tongues. It is comprised of a tiny tongue stud and magnetic strips that transmit movement signals from the headset to the mobile phone. The smartphone converts the signals into commands that can control a wheelchair or other device. The prototype was tested on physically able individuals and in clinical trials with patients who suffer from spinal cord injuries.
To assess the effectiveness of this system it was tested by a group of able-bodied people utilized it to perform tasks that tested accuracy and speed of input. Fittslaw was employed to complete tasks, such as keyboard and mouse usage, and maze navigation using both the TDS joystick and standard joystick. The prototype was equipped with a red emergency override button and a person was with the participants to press it if necessary. The TDS worked as well as a normal joystick.
Another test compared the TDS to the sip-and puff system, which allows those with tetraplegia to control their electric wheelchairs by blowing air into a straw. The TDS was able of performing tasks three times faster and with greater accuracy than the sip-and puff system. The TDS is able to operate wheelchairs more precisely than a person suffering from Tetraplegia who controls their chair with a joystick.
The TDS could track tongue position with an accuracy of less than 1 millimeter. It also had cameras that recorded a person's eye movements to identify and interpret their motions. Software safety features were also integrated, which checked the validity of inputs from users twenty times per second. If a valid user signal for UI direction control was not received for a period of 100 milliseconds, the interface module automatically stopped the wheelchair.
The team's next steps include testing the TDS for people with severe disabilities. To conduct these tests, they are partnering with The Shepherd Center, a catastrophic care hospital in Atlanta as well as the Christopher and Dana Reeve Foundation. They intend to improve their system's sensitivity to ambient lighting conditions, to add additional camera systems and to enable repositioning of seats.
Wheelchairs with joysticks
A power wheelchair that has a joystick allows users to control their mobility device without having to rely on their arms. It can be placed in the middle of the drive unit, or on either side. It is also available with a display to show information to the user. Some of these screens have a large screen and are backlit to provide better visibility. Some screens are small, and some may include images or symbols that could help the user. The joystick can be adjusted to fit different hand sizes and grips as well as the distance of the buttons from the center.
As technology for power wheelchairs has evolved and improved, doctors have been able to create and customize alternative driver controls to enable clients to reach their potential for functional improvement. These advances also allow them to do this in a manner that is comfortable for the end user.
A typical joystick, as an example is a proportional device that uses the amount deflection of its gimble to give an output that increases when you push it. This is similar to how accelerator pedals or video game controllers function. However how to self propel a wheelchair requires motor control, proprioception and finger strength in order to use it effectively.
Another type of control is the tongue drive system, which utilizes the position of the user's tongue to determine the direction to steer. A tongue stud with magnetic properties transmits this information to the headset which can carry out up to six commands. It can be used by those with tetraplegia or quadriplegia.
In comparison to the standard joysticks, some alternative controls require less force and deflection in order to operate, which is particularly helpful for users who have limited strength or finger movement. Some can even be operated using just one finger, making them ideal for those who can't use their hands at all or have limited movement.
Some control systems have multiple profiles that can be modified to meet the requirements of each client. This is important for those who are new to the system and may need to adjust the settings regularly when they feel tired or experience a flare-up in a disease. It is also useful for an experienced user who wants to change the parameters set up for a specific environment or activity.
Wheelchairs with steering wheels
Self-propelled wheelchairs can be used by those who have to move themselves on flat surfaces or up small hills. They come with large wheels at the rear for the user's grip to propel themselves. They also come with hand rims that allow the user to use their upper body strength and mobility to move the wheelchair in either a forward or reverse direction. Self-propelled chairs can be fitted with a variety of accessories, including seatbelts and armrests that drop down. They can also have legrests that swing away. Certain models can be converted into Attendant Controlled Wheelchairs that allow family members and caregivers to drive and control wheelchairs for users who require assistance.
Three wearable sensors were connected to the wheelchairs of participants to determine the kinematic parameters. These sensors tracked the movement of the wheelchair for one week. The wheeled distances were measured with the gyroscopic sensors that was mounted on the frame as well as the one mounted on the wheels. To differentiate between straight forward motions and turns, the amount of time during which the velocity differs between the left and right wheels were less than 0.05m/s was considered straight. The remaining segments were analyzed for turns and the reconstructed paths of the wheel were used to calculate turning angles and radius.
This study involved 14 participants. They were evaluated for their navigation accuracy and command latency. They were required to steer the wheelchair through four different ways on an ecological experimental field. During the navigation trials, the sensors tracked the trajectory of the wheelchair over the entire distance. Each trial was repeated twice. After each trial, the participants were asked to select the direction that the wheelchair was to move in.
The results showed that a majority of participants were able complete the tasks of navigation even though they did not always follow the correct direction. In average 47% of turns were correctly completed. The remaining 23% either stopped right after the turn, or redirected into a second turning, or replaced with another straight motion. These results are similar to the results of previous studies.