Assistive Robot ARM Research Papers Example

1. Introduction
1.1 Abstract
Contained in this paper is a report on a research conducted on the development of an assistive arm robot for patients with Cerebral Palsy. Presented in the report is a brief description of the disease, a historical perspective of the use of assistive robots and the general description of the research together with the challenges faced during execution of the research and a conclusion which carries recommendations for further research in the same topic.
1.2 Background
Cerebral Palsy is a devastating disease that causes unremitting muscle destruction/impairment. The disease begins at childhood but it impacts on a victim do exacerbate over time. It is occasioned by faulty development of an infant’s brain or destruction of the motor cortex. This disease can be mild or serious depending on the extent of the effects of the disease to the victim. Among the effects of cerebral palsy include impaired muscle movement ,posture and balance problems, problems in verbal enunciation and sometimes mental impediment .Basically, this syndrome compromises a victim’s ability t have a coordinated movement, thinking and speaking. As such patients with this condition face a lot of difficulties in their day to day activities Athetoid Quadriplegia is one of the classes f this syndrome which is characterized by impaired muscle movement .As the term suggests patients with this kind of condition have a compromised limbs and trunk abilities such as ability to have coordinated movements. Profoundly affected patients suffer total effects of this condition with a total impairment of their limbs’ abilities. Profoundly affected patients cannot undertake simple activities such as feeding themselves, washing themselves or even dressing themselves.
As it stands, assistive robots have been used to assist these kinds of patients in living a normal independent life. Assistive robots used to assist handicapped people have recently attracted world attention in countering the challenges faced by this category of people. For instance in Korea alone there are over two million people registered as with disabilities. The number of this class of people is increasing day in day out and the biggest bearers of responsibilities for maintaining these people are the family members (Belfiore, M. P. 2009). This justifies the need for a technological approach in addressing this problem. Very many innovations have been undertaken across the globe to assist people with dysfunctionality of limbs. The upper limbs (hands) are the most important limbs to a human as they assist in personal chores such as washing and feeding.
However ,the robots available for this class of people have been found a bit ineffective in terms of reducing arm effort and movement coordination .Moreover, full effectiveness of the current robots is realized with intensive training which in many times lock out people with this condition. All the assistive robots manufactured currently tend to assume a similar design and does not address unique problems encountered by patients with different degree of impairment. Therefore, my research was prompted by the urge to make improvements to the existing robots. For that reason, this research aimed at seeing how improvements can be made on the assistive robot arm to make their purpose in solving problems for patients suffering this condition realizable. Consequently the research aimed at making improvements to the assistive arm robot and subsequently assessing their effectiveness and hence reliability in solving problems related to patients suffering from Athetoid Quadriplegia. This can be realized through custom making devices to suit the different needs of this class of patients, something that current designs seems not address (Belfiore, M. P. 2009).
1.3 Historical perspective
Many previous similar works have been done in different parts of the world. Although not directly similar they were all aimed at solving problems occasioned by the incapacities caused by muscle impairment .Exact Dynamics (Netherlands) came up with a device that helps people with arm disabilities in undertaking various roles. The device known as Assistive Robotic Manipulator (ARM) compensates for a dysfunctional arm especially among patients with problems with their upper arms (Partridge, K. 2010). Mounted on an electric computer keyboard, the device is capable of receiving a number of inputs from computer devices such as joysticks, switches and switches. The device is not limited only to computing activities but also assists patients in feeding, opening door, brushing teeth and combing air. A 20N clamp that is mounted onto a holder to assist in grasping objects assists it.
In another project by Mississippi Engineering Department a similar project was undertaken to develop an assistive robot for people with Athetoid Quadriplegia. The “Reacher Arm for Quadriplegics” was mounted onto a wheelchair and had the ability to lift objects of up to two pounds .Moreover; the assistive robot had two switches that controlled rotation and the grasping of objects. The device helped patients in a number of activities such as opening doors and feeding (Belfiore, M. P. 2009).
The Clutching and Griping device was another device developed by students from Arizona University and served similar purposes just as the other above-mentioned robots .However, the device is more advanced in terms of controls and strength.
The Winsford feeder is another typical example of a existent mechanical self-feeding system .This robot utilizes a mechanical pusher to fill food on the spoon and a pivoting arm which is movable to allow movement of the spoon from the bowl to the mouth of the user. It also has a pad on which the plate sits. The position at which the plate sits is also adjustable to enable its accessibility by the spoon (Partridge, K. 2010).
These are just but a few illustrations to show the existence and application of assistive arm robots in assisting patients with Athetoid Quadriplegia.
2. Purpose
The purpose of this study is to carry out a detailed state of the art investigation on how scientists can improve the assistive robot arm for people with limited ability caused by Cerebral Palsy. This research will also go a long way in aiding to satisfy the course requirements of EGR3350, Fall 2013.
2.1 Problem
Cerebral Palsy is a disease that causes incapacitation of an individual such that their some of their muscles and especially those on the four limbs have impairments. This condition makes it impossible of the affected individual to perform their daily responsibilities including the most basic such as eating, opening doors and others which are quite essential in the day to day life of an individual. This renders such people dependants on others for survival.
The focus of this research is solely on individual whose upper limbs are impaired by the cerebral palsy condition. The new design being researched on will therefore aim at improving the assistive ability of the device for users with impaired upper limbs.
Apart from this, it is quite important to understand that this is an educational research considered a very important formal report requirement for the course EGR3350.
2.2 Scope
This is a research paper meant to offer extensive investigation into how scientist can help improve the assistive robot arm so that it becomes a more important and easier to use device. This research however had several limitations that in one way or another provided a challenge to the researcher. Some of these limitations are discussed below as feasibilities;
2.2.1 Time feasibility
The time period of 4 weeks between the approval of the proposal for the project and the scheduled time for the completion of this report is very short considering that the researcher in this case is not a full time researcher. The ability to balance the research with other aspects of class work was not easy. Similarly, a lot of travelling was required so as to interact with users and designers of assistive arms and health physicians with special knowledge of cerebral palsy and challenges that these individuals go through. Meeting these groups so much time was consumed to cover a total of 55 miles without mentioning the time required to discuss with these groups about issue that were considered important for his research.
2.2.2 Cost feasibility
Traveling and labor required for the research had a cost associated with it. This cost was catered for by the researcher and without doubt there were limitations associated with this it was not effectively possible to adequately finance all requirements for the research. These financial limitations had a great impact on the quality of information that was collected.
2.2.3 Resource feasibility
The research required personnel resources. Adequate experience in the engineering field was required. Considering that the researcher is a student, leaning and implementing the content at the same time was not an easy task as it may sound. The researcher also did not have enough experience to effectively determine what was required for the research. At times therefore, there was need to review what had been accomplished and perform several changes where it was considered that something had been left out.
On the other hand, resources like computers and printers were supplied by the school. The technicalities involved in acquiring these resources when required proved a challenge. The fact that the researcher did not have some resources such as recorders and cameras that would have been crucial especially when meeting the relevant groups also compromised on the level of information or data collected.
The researcher had to interact with relevant groups to gain as much knowledge about the research as possible. Convincing most of these groups to afford him time was not easy and the researcher was forced to find alternatives; a solution that was neither easier.
2.2.4 Social feasibility
The researcher was dealing conducting research about an equipment or device that is used by a group that is highly stigmatized within the society. Therefore, a major requirement was to balance ethics and the need to acquire information. Sometimes, most important questions were foregone as they seemed to affect the emotions of the respondents especially the users. This limitation meant that important information was overlooked as there was need to maintain a reasonable level of ethics.
3. Discussion
The assistive robot arm will be expected to assist the user to perform various chores that they could have performed using their upper limbs in normal situations. The assistive robot arm will have three joints and a very stable base. These three joints are a model of the normal human arm. It will thus have a base joint, an elbow joint and a wrist joint. Research about this part of the research took a total of 8 working hours.
3.1 The elbow
The elbow is divided into the upper arm and the lower arm. The elbow is immobile. The upper arm of the elbow connects to the shoulder and the lower arm connects to the wrist joint. These two arms will be required to provide a 3600 of rotation so that the user can be able to pick whatever item they need from various positions with little movement from their point of rest. This elbow will provide different types of motion ranging from circumnavigated movements which provide for an all round rotation and back to the original position with total stability, the flexibility motion that will be crucial in activities that require pulling back and forth such as closing the door, extension movements that provide for the ability to reach for something from a static position, opposition movements that will offer a reaction force required for activities where counterforce is necessary, and a rotational movement over a range of 00 to 3600 (Belfiore, M. P. 2009).
At the point where the upper arm connects to the shoulder, the joint will be required to function like a hinge joint so that it provides motion over 1800 rotation. The elbow joint will be always be involved in motion when the assistive robot arm is in use. Therefore the material used to make this joint is one that is able to withstand so much friction and associated wearing out while also being light to ensure easy rotation and movements. In particular, an alloy of aluminum and steel would work quite well on the joints (Partridge, K. 2010). Other parts of the arm are exclusively made of pure steel which should be rust proof to ensure durability of the assistive robot arm. The failure of elbow joints to move withy ease would render the whole equipment obsolete or not effective to support its intended purpose. In this perspective therefore, this research proposes that a material that is highly resistive of rust such as fiberglass be implemented within the joints designing. The joints should be completely waterproof with zero chances of rust (Bajd, T. 2010).
The elbow joint that controls the upper and lower arm will be controlled using that are placed close to the user’s seat or rest point of the complete equipment. These keypads will send the signals produced by the user to the computer system which on the other hand sends back synchronized signals that control the elbow on real-time. There should be no delay of the signal between the time it is produced at the keypad and when the elbow causes movement of the arms. Thus sensitivity of the keypads is crucial.
The upper arm will be controlled using a joystick that is attached to the equipment and the mode of operation between the joystick and shoulder joint is controlled through synchronized signals from the computer (Tsui, K. M., &Yanco, H., 2008).
3.2 The Wrist
A gripping device will be connected to the wrist. This device has removable accessories that correspond to the particular activity of the client. The accessories in question have the ability to snap in and out of the attachment that is situated at the wrist. The attachments include things like a spoon, a drinking glass, a spoon as well as other items such as gardening tools and a default gripper. There are independent switches that correspond to the different motions of each particular joint (Bajd, T. 2010).
The function of the wrist joint will be to connect the lower arm and the upper arm. This wrist joint has the capability of rotating at an angle of 360 degrees from its base. However, the connection between that is between device’s lower arm and gripper is stationary. The stationary state is so as to enhance the stability of the device and it is for no other reason. Finally, the gripper is capable of a couple of several functions that include the grasping motion, opposition, reposition as well as the releasing movement of an object. The grippers are capable of grasping an object with an estimated force of about 3 Newton. The griper’s motions are obtainable by simple pressing or pushing of joy sticks and buttons that are located at the arm’s base.
Glass material are usually very slippery and can lead to injuries when is broken or dropped. As such, the material utilized in the construction of this part of the assistive robot arm is rubber. This rubber material not only provides a grip that is more secure, but also one that averts the grippers from scraping the item being grasped.
3.3 The base joint
The base joint provides the first point of movement. Since the assistive robot arm will be connected to the wheel chair, it will have both mounting equipment and a stability device. This stability device offers is responsible for rotation at the shoulder point of the assistive robot arm.
3.4 The power source
The assistive robot arm will be powered by powerful microprocessors. These microprocessors will be located at the base of the complete equipment. These microprocessors will be powered by deep cycle batteries which have the ability to withstand long periods of time without external power source connected to them (Payne, J. C. 2008).
3.5 The functional block diagram of the assistive robot arm
4. Conclusion
The function of this assistive robot arm is to enable the user to perform actions they would have otherwise performed using their upper limbs were it not for the physical impairment. It has therefore been designed in the form of the upper limb model to give the user the capabilities of performing activities like eating food using the robot arm, opening and closing doors and collecting objects from the ground and many others. The design has three major parts which include the wrist with grippers for holding onto an object, the elbow which forms the most crucial part as it controls the most essential movements of the assisitive robot arm and the base that acts as the connection between the wheel chair and the assistive robot arm. The base also offers a great deal of stability and thus it should be heavy enough to support the whole robot arm and also light enough to ensure the user is not overburdened by the moving load.
The whole system is powered by microprocessors that are powered by deep cycle batteries. The operation of the robot by the user is limited to the keypads and the joysticks. The underlying software that controls the whole system is hidden form the user operations therefore no chances of failure resulting from user operations. It is my hope that the intended users will be satisfied with the final product.
5. Recommendations
The assistive arm robot as seen in the research offers solution to people with the impairment of upper limbs. The robot allows room for customization to suit different needs of patients. Deep cycle batteries that can sustain the system for a long time additionally power it. Since the operations of the robot is limited to the keypads and joysticks it requires little training and skill on the side of the user.
I recommend further research to further enhance the robots technology is offering real solutions to people with disabilities. It is through this that this group of people can lead normal and dignified lives just like other normal humans.
6. References
Bajd, T. (2010). Robotics. Dordrecht: Springer.
Belfiore, M. P. (2009). The department of mad scientists: how DARPA is remaking our world, from the internet to artificial limbs. Washington, D.C.: Smithsonian Books,
Partridge, K. (2010). Robotics. New York: H.W. Wilson Co.
Payne, J. C. (2008). Understanding boat AC power systems: (generators, inverters, shore power). Dobbs Ferry, NY: Sheridan House.
Tsui, K. M., &Yanco, H. (2008). Design and evaluation of a visual control interface of a wheelchair mounted robotic arm for users with cognitive impairment. New York : New York Publishers.