Technology Gives Paraplegics New Freedom

你是否相信,一个四肢瘫痪的病人也可以灵活自如地玩游戏?科技的进步将很多不可能变成了可能。本文便讲述了一位四肢瘫痪多年的病人全凭大脑的力量,移动一支假手控制电脑屏幕上的光标来玩游戏。他是如何做到的呢?不妨阅读此文,了解个中秘密。

Dynamical Measurement Method of Handle Reaction Vector for FES-Assisted Paraplegic Walking

To analyze the use of upper limb support during paraplegic walking assisted by functional electrical stimulation ( FES), a new dynamical measurement for handle reaction vector (HRV) ap- plied by patient to walker was proposed. To avoid the discomfort of direct monitoring, the dyna- mometer system was designed based on 12 string-gauge bridges instrumented on a standard walker frame. The detailed positions of these bridges were determined according to the deformation distri- butions of the walker frame under different directional components of HRV. To adapt the system to quantitative and reliable measurement, a redundant-optimized technique was developed in calibra- tion. The measurement accuracy, nonlinearity. and crosstalk of the designed system were investi- gated, which were better than 1.01%. 2.91%, and 3.19% respectively. Clinical trials were done with 6 paraplegic subjects using the system and one case was given as the example of actual mea- surement. All experiment and clinical trial results show that this method is reliable and practicable.

Quantifying of Paraplegic Patient Facial Agitation Based on Fuzzy k-NN

A non-specific symptom of one or more physical, or psychological processes in which screaming, shouting, complaining, moaning, cursing, pacing, fidgeting or wandering pose risk or discomfort, become disruptive or unsafe or interfere with the delivery of care are called agitation. Individuals in agitation manifest their condition through ＂pain behavior＂, which includes facial expressions. Clinicians regard the patient＇s facial expression as a valid indicator for pain and pain intensity. Hence, correct interpretation of the facial agitation of the patient and its correlation with pain is a fundamental step in designing an automated pain assessment system. Computer vision techniques can be used to quantify agitation in sedated patients in Intensive Care Unit （ICU）. In particular, such techniques can be used to develop objective agitation measurements from patient motion. In the case of paraplegic patients, whole body movement is not available, and hence, monitoring the whole body motion is not a viable solution. Hence in this case, the author measured head motion and facial grimacing for quantifying facial patient agitation in critical care based on Fuzzy k-NN.

Minimum-Time and Minimum-Jerk Gait Planning in Joint Space for Assistive Lower Limb Exoskeleton

Assistive lower limb exoskeleton robot has been developed to help paraplegic patients walk again.A gait planning method of this robot must be able to plan a gait based on gait parameters,which can be changed during the stride according to human intention or walking conditions.The gait is usually planned in cartesian space,which has shortcomings such as singularities that may occur in inverse kinematics equations,and the angular velocity of the joints cannot be entered into the calculations.Therefore,it is vital to have a gait planning method in the joint space.In this paper,a minimum-time and minimum-jerk planner is proposed for the robot joints.To do so,a third-order system is defined,and the cost function is introduced to minimize the jerk of the joints throughout the stride.The minimum time required is calculated to keep the angular velocity trajectory within the range specified by the motor’s maximum speed.Boundary conditions of the joints are determined to secure backward balance and fulfill gait parameters.Finally,the proposed gait planning method is tested by its implementation on the Exoped®exoskeleton.

Parametric Gait Online Generation of a Lower-limb Exoskeleton for Individuals with Paraplegia

Lower-limb exoskeletons can provide paraplegics with the ability to restore gait function. In the community ambulation, the user would frequently meet different floors, doorsills, and other obstacles. Therefore, parametric gait generation is a significant issue for this kind of exoskeletons. In this paper, a parametric gait online generation approach is proposed, which combines a parametric gait control method with a torque compensation control strategy, based on the state machine. In the torque compensation control, the reference tra- jectories of joint positions are obtained through compensating gravity, inertia, and friction, which is intent on the natural and well-directed source data. Based on the reference trajectories, the parametric gait control method is established, in which the gait can be controlled via three parameters： velocity, step-length, and step-height. Two test cases are performed on three healthy subjects. The results demonstrate that the parametric gait can be online generated smoothly and correctly, meanwhile every variable step can be triggered as users expect. The effectiveness and practicability of the gait generation approach proposed in this paper are validated. In addition, this research is the foundation of autonomous gait planning.

DOUBLE CORTICAL LINE IN THE ACETABULAR ROOF OF PARAPLEGIC PATIENTS

The pelvic radiographs of 60 patients with paraplegia or quadriplegia were reviewed and double cortical line in the acetabular roofs on both sides was found in 35 patients. It was concluded that the double cortical line was a radiologic sign of disuse osteoporosis after spinal cord injury. It was noticed that the acetabular double cortical line in incomplete paralysis was not so prominent as that in complete paralysis (P<0.05), suggesting that the degree of acetabular osteoporosis may be related to the severity of spinal cord injuries. The etiology of double cortical line and related factors were discussed.