Quanquan Liu

Inertial Sensor-Based Motion Analysis of Lower Limbs for Rehabilitation Treatments

The hemiplegic rehabilitation state diagnosing performed by therapists can be biased due to their subjective experience, which may deteriorate the rehabilitation effect. In order to improve this situation, a quantitative evaluation is proposed. Though many motion analysis systems are available, they are too complicated for practical application by therapists. In this paper, a method for detecting the motion of human lower limbs including all degrees of freedom (DOFs) via the inertial sensors is proposed, which permits analyzing the patients motion ability. This method is applicable to arbitrary walking directions and tracks of persons under study, and its results are unbiased, as compared to therapist qualitative estimations. Using the simplified mathematical model of a human body, the rotation angles for each lower limb joint are calculated from the input signals acquired by the inertial sensors. Finally, the rotation angle versus joint displacement curves are constructed, and the estimated values of joint motion angle and motion ability are obtained. The experimental verification of the proposed motion detection and analysis method was performed, which proved that it can efficiently detect the differences between motion behaviors of disabled and healthy persons and provide a reliable quantitative evaluation of the rehabilitation state.The hemiplegic rehabilitation state diagnosing performed by therapists can be biased due to their subjective experience, which may deteriorate the rehabilitation effect. In order to improve this situation, a quantitative evaluation is proposed. Though many motion analysis systems are available, they are too complicated for practical application by therapists. In this paper, a method for detecting the motion of human lower limbs including all degrees of freedom (DOFs) via the inertial sensors is proposed, which permits analyzing the patients motion ability. This method is applicable to arbitrary walking directions and tracks of persons under study, and its results are unbiased, as compared to therapist qualitative estimations. Using the simplified mathematical model of a human body, the rotation angles for each lower limb joint are calculated from the input signals acquired by the inertial sensors. Finally, the rotation angle versus joint displacement curves are constructed, and the estimated values of joint motion angle and motion ability are obtained. The experimental verification of the proposed motion detection and analysis method was performed, which proved that it can efficiently detect the differences between motion behaviors of disabled and healthy persons and provide a reliable quantitative evaluation of the rehabilitation state.

Development of a New Robotic Ankle Rehabilitation Platform for Hemiplegic Patients after Stroke

A large amount of hemiplegic survivors are suffering from motor impairment. Ankle rehabilitation exercises act an important role in recovering patients walking ability after stroke. Currently, patients mainly perform ankle exercise to reobtain range of motion (ROM) and strength of the ankle joint under a therapists assistance by manual operation. However, therapists suffer from high work intensity, and most of the existed rehabilitation devices focus on ankle functional training and ignore the importance of neurological rehabilitation in the early hemiplegic stage. In this paper, a new robotic ankle rehabilitation platform (RARP) is proposed to assist patients in executing ankle exercise. The robotic platform consists of two three-DOF symmetric layer-stacking mechanisms, which can execute ankle internal/external rotation, dorsiflexion/plantarflexion, and inversion/eversion exercise while the rotation center of the distal zone of the robotic platform always coincides with patients ankle pivot center. Three exercise modes including constant-speed exercise, constant torque-impedance exercise, and awareness exercise are developed to execute ankle training corresponding to different rehabilitation stages. Experiments corresponding to these three ankle exercise modes are performed, the result demonstrated that the RARP is capable of executing ankle rehabilitation, and the novel awareness exercise mode motivates patients to proactively participate in ankle training.

Study on synthesis and properties of nanoparticles loaded with amaryllidaceous alkaloids

Abstract Alzheimer’s disease (AD) is the most common disease among the elderly people and a major social and medical problem. Amaryllidaceous alkaloids, acting as acetylcholinesterase inhibitors, represent a potential treatment of AD. However, they also have some deficiencies, such as extensive toxicity and widespread side effects. In order to improve the bioavailability and reduce the toxic and side effects, brain targeting of amaryllidaceous alkaloids was enhanced by considering low density lipoprotein (LDL) receptors of blood-brain barrier (BBB) endothelial cells as therapeutic targets. Amaryllidaceous alkaloids were highly selectively and quantitatively riveted to the surface of low density lipoproteins by using a new method - mild click chemistry. The structure of products has been characterized by NMR, FT-IR, and other methods. In addition, drug loading rate, encapsulation rate, and drug release by the nanoparticles were determined to assess the quality of the nanoparticles.

Development of a Novel Multi-Functional Rehabilitation Robot

With the development of aging society, the number of hemiplegia patients grows rapidly and over 75% of survivors suffering hemiplegia need rehabilitation training. Traditional training methods need one or more physical therapists to server one patient at the same time. In order to reduce the workload of the physical therapist and to improve patient rehabilitation performance, this paper presents a novel multi-functional rehabilitation robot, which can assist hemiplegic patient for stand up/squatting training, Gravity shifting training and Walking training. The robot system consists of two Support manipulator, Screw lift mechanism, Weight balance device and a Treadmill. Different from the existing rehabilitation robot, the design philosophy of the multi-functional support robot is to mimic hand movement of physical therapist. It is flexible to fit in patients with individual differences. The design of the detailed mechanical components is illustrated. The proposed robot system can be used in multi-function exercise for hemiplegic patient. Introduction China in the 21st century will be fully into the aging society, according to the record of Chinese National Bureau of Statistics, As of 2015the population over 60 years old Chinas elderly population has reached 220 million, the level of aging is 15%. And from 2030 to 2050, the aging rate will show a linear increase in the situation. It is expected that in 2050, the total number of elderly people in China will reach 450 million, accounting for more than 30% of the total population [1]. As the aging population is growing, the aging society caused the disease situation more and more severe. Stroke is a high incidence of disease among elderly people. About 75% of survivors after stroke 392 This is an open access article under the CC BY-NC license (http://creativecommons.org/licenses/by-nc/4.0/). Copyright

Development of a FES System for Hemiplegic Rehabilitation Based on Patient Healthy Limb's EMG Signal

This paper presents a functional electrical stimulation system to mimic the EMG characterization of patient healthy limb to exercise his/her affected limb. Firstly, the existing problems of functional electrical stimulation system are analyzed. Generally, the existing electrical stimulation systems suffer from fixed waveform, large volume and low portability, which make the effect of treatment difficult to improve. Secondly, the hardware platform of the proposed system is constructed, such as EMG acquisition module, FES module, to realize the acquisition of EMG signal and the generation of electrical stimulation pulse. The characterization of the healthy limb is extracted, and then it is used to exercise the affected limb via FES stimulus. Finally, the wireless communication is build, to realize the wireless communication between modules. The system has the advantage of small volume and high portable. The system can effectively collect EMG signals and generate FES pulses. Introduction Functional electrical stimulation (FES) plays an important role in rehabilitation of stroke patients as an important means of rehabilitation training for stroke patients[1]. Currently, the stimulus pulses used by FES are still specific synthetic pulses, such as single-phase, biphasic rectangular wave, triangular wave, sine wave, etc. These synthetic pulses do not accurately simulate the potential transfer of human muscle movement, affecting the treatment to further improve[2]. EMG signal is a more ideal source of stimulation to produce biological signals[3]. It is a good choice to use the normal EMG signal of the sound side as the stimulation source of the functional electrical stimulation ofaffectedside. Because of the large volume and the cable connection, the existing electric stimulation system has the disadvantages of inconvenient, poor comfort and difficult 398 This is an open access article under the CC BY-NC license (http://creativecommons.org/licenses/by-nc/4.0/). Copyright

Development of parallel mechanism with six degrees of freedom for ankle rehabilitation

With the aging population problem getting more and more aggravated, the number of hemiplegia patients increases rapidly, which results in the increasing requirement of rehabilitation training for regaining the body movement function. Taking advantages of rehabilitation robots makes the rehabilitation training more scientific and efficient compared to traditional rehabilitation measures such as manual training. By now, many types of rehabilitation robots have been proposed by researchers. However, from the view of the physiological structure, many of them cant well fit the motion characteristics. Ankle plays an important role in standing, walking and so on. As the motion of these robots is different from the motion characteristics of ankles, it would make an undesired influence on the training effect. Rehabilitation robots have many structures, and they are mainly serial mechanism and parallel mechanism. However, serial mechanism is inconvenient to package. In this paper, a new type of parallel mechanism with six degrees of freedom is proposed. The basic principle structure of the ankle rehabilitation robot in this paper would be done according to the medical requirement and engineering requirement. After determine the programmer of the mechanism, the degrees of freedom of the mechanism would be calculated by the screw theory, and the Solid works software would be used to simulate and analyze the movement of the mechanism so that the torque and power calculation of key positions of the mechanism would be done with the simulation data. At last, the specific design of the mechanism would be finished with the obtained feasible basic principle structure. The function of different components would be introduced and this paper would check the key components to ensure the reliability of the mechanism.

Lower limb motion analysis based on inertial sensor

Up to now, with the increasing of the elderly population, more and more patients are suffering from hemiplegia. The need for hemiplegic rehabilitation is increasing quickly. As traditional rehabilitation, each patient must be treated by therapist, one by one. However, because of the different levels of therapists, the rehabilitation cannot be performed as the as the same. Normally, the rehabilitation status diagnosing is still be performed by therapists with the subjective experience. It caused the inhomogeneity on rehabilitation evaluation. It also sometimes causes negative influence on the rehabilitation effect. To solve these problems, many researches focusing on assessing the status of the hemiplegic patients quantitatively are proposed rehabilitation evaluation systems. Rehabilitation motion detection is the basis of the evaluation system, and it requires the participation of therapist. In this paper, a method is presented to detect lower limb motion of hemiplegic patients based on inertial sensor technology. The gesture quaternion of lower limb can be obtained through LPMS. With the matrix and Euler angle changing algorithm, combining with the simplified lower limb motion model, the rotation angle of joint can be computed. Finally, the curve of rotation angle of knee is established.