Design of Lower Prosthetic Limb Using Additive Manufacturing Processes

This paper presents an approach for designing a prosthetic limb using SolidWorks. The process of stereolithography helped manufacture the prosthetic limb due to the flexibility in the provided parameters. The designed leg weighs 4kg approx. The entire weight acts on the sole of the leg. The sole again underwent a SolidWorks simulation with the application of a 1200N load. The preferred material - TPU - was selected after considering all the factors. The manuscript proceeds with a financial analysis to get a price estimate for the manufacturing of each part of the limb, which is a crucial factor.

Finite Element Analysis of Transhumeral and Transtibial Percutaneous Osseointegrated Endoprosthesis Implantation

Cadaveric mechanical testing of a percutaneous osseointegration docking system (PODS) for osseointegration (OI) prosthetic limb attachment revealed that translation of the exact system from the humerus to the tibia may not be suitable. The PODS, designed specifically for the humerus achieved 1.4–4.8 times greater mechanical stability in the humerus than in the tibia despite morphology that indicated translational feasibility. To better understand this discrepancy, finite element analyses (FEAs) modeled the implantation of the PODS into the bones. Models from cadaveric humeri (n = 3) and tibia (n = 3) were constructed from CT scans, and virtual implantation preparation of an array of endoprosthesis sizes that made contact with the endosteal surface but did not penetrate the outer cortex was performed. Final impaction of the endoprosthesis was simulated using a displacement ramp function to press the endoprosthesis model into the bone. Impaction force and maximum first principal (circumferential) stress were recorded to estimate stability and assess fracture risk of the system. We hypothesized that the humerus and tibia would have different optimal PODS sizing criteria that maximized impaction force and minimized first principal stress. The optimal sizing for the humerus corresponded to implantation instructions, whereas for the tibia optimal sizing was three times larger than the guidelines indicated. This FEA examination of impaction force and stress distribution lead us to believe that the same endoprosthesis strategy for the humerus is not suitable for the tibia because of thin medial and lateral cortices that compromise implantation.

Evaluation of Electromyogram Signals in the Control of Prosthetic Limb: A Review

: Electromyogram (EMG) signals are produced by the human body and are used in prosthetic design due to its significant functionality with human biomechanics. Engineers are capable of developing a variety of prosthetic limbs with the advancement of technology in the domain of biomedical signal processing, as limb amputees can restore their lives with the help of prosthetic limbs. This current review paper looks at the signals that are used to monitor the device, explaining the various steps and techniques involved (such as data acquisition, feature vector conversion after noise, and redundant data removal) and reviewing previously developed electromyogram-based prosthetic controls. Furthermore, this research also focuses on a variety of electromyogram controlled applications.

Enhance embodiment of a virtual prosthesis through a training protocol using an EMG-based human-machine interface: a case series

Background: The embodiment of a prosthesis can bring a series of benefits during the rehabilitation of people with amputation, such as improvement of motor control and sense of agency, in addition to optimizing the training process with the prosthetic limb. New therapeutic strategies capable of enhancing prosthesis embodiment are, therefore, a key point for better adaptation to and acceptance of prosthesis use. In this study, we developed a system and a new rehabilitation protocol using an EMG-based human-machine interface (HMI) to induce and enhance the embodiment of a virtual prosthesis.Methods: This is a case series with seven people of both sexes with unilateral transfemoral traumatic amputation without previous use of prostheses. Participants performed a training protocol with the EMG-based HMI during the preprosthetic rehabilitation phase, composed of six sessions held twice a week, each lasting thirty minutes. This system was composed of myoelectric control of the movements of a virtual prosthesis immersed in a 3D virtual environment. Additionally, vibrotactile stimuli were provided on the participant’s back corresponding to the movements performed. The objectives were to evaluate the virtual prosthesis embodiment, to investigate motor learning during training with EMG-based HMI, and to determine whether vibrotactile stimuli could facilitate the perception of virtual limb movements. The embodiment was investigated from a set of physiological and behavioral measurements and reports before and after the training. Motor learning was assessed through performance analysis. To investigate the use of vibrotactile stimulation to guide virtual prosthesis movements, the performance was assessed during the virtual prosthesis control test without adding vision.Results and conclusions: The different features evaluated throughout the protocol training consistently showed the induction and enhancement of virtual prosthesis embodiment and increased motor control. Therefore, this protocol using EMG-based HMI was shown to be a viable option to achieve the embodiment of a virtual prosthetic limb and to train motor control. Furthermore, the participants were able to guide the prosthesis based on vibrotactile stimuli, showing that this method can be used as an alternative sensorial path to be implemented in new therapeutic strategies and neuroprostheses to facilitate the movement perception of a prosthetic limb.

The Need to Work Arm in Arm: Calling for Collaboration in Delivering Neuroprosthetic Limb Replacements

Over the last few decades there has been a push to enhance the use of advanced prosthetics within the fields of biomedical engineering, neuroscience, and surgery. Through the development of peripheral neural interfaces and invasive electrodes, an individual's own nervous system can be used to control a prosthesis. With novel improvements in neural recording and signal decoding, this intimate communication has paved the way for bidirectional and intuitive control of prostheses. While various collaborations between engineers and surgeons have led to considerable success with motor control and pain management, it has been significantly more challenging to restore sensation. Many of the existing peripheral neural interfaces have demonstrated success in one of these modalities; however, none are currently able to fully restore limb function. Though this is in part due to the complexity of the human somatosensory system and stability of bioelectronics, the fragmentary and as-yet uncoordinated nature of the neuroprosthetic industry further complicates this advancement. In this review, we provide a comprehensive overview of the current field of neuroprosthetics and explore potential strategies to address its unique challenges. These include exploration of electrodes, surgical techniques, control methods, and prosthetic technology. Additionally, we propose a new approach to optimizing prosthetic limb function and facilitating clinical application by capitalizing on available resources. It is incumbent upon academia and industry to encourage collaboration and utilization of different peripheral neural interfaces in combination with each other to create versatile limbs that not only improve function but quality of life. Despite the rapidly evolving technology, if the field continues to work in divided “silos,” we will delay achieving the critical, valuable outcome: creating a prosthetic limb that is right for the patient and positively affects their life.

The Effect of Product Quality, Price Perception, and Brand Image on Product Purchase Decision at Pt. Ottobock Healthcare Indonesia

Prosthesis is a medical technology that is commonly called prosthetic limb, where the prosthesis marketing strategy has a unique way of marketing so that it needs to be carefully implemented whether the factors that influence the decision to buy prosthesis. The purpose of this study was to determine what factors determine which patients buy Ottobock prostheses from product quality, price perception, and brand image. See which factor is the most powerful. This research was conducted at PT. Ottobock Healthcare Indonesia with a total population and sample of 100 respondents. The analytical method used is multiple regression analysis. This type of research is quantitative research. The data presented in this study were obtained from a questionnaire provided to Ottobock's (amputated) patients. Statistical analysis using SPSS 25 which is used in the model and testing. The results of this study partially indicate that price perceptions and brand image have no effect on purchase decision for Ottobock’s prosthesis, but product quality does influence purchasing decisions. However, simultaneously, product quality, price perception and brand image have a positive effect on purchasing decisions for Ottobock prosthesis.

Comparison of electromyographic activity of quadriceps muscle in persons with unilateral traumatic transtibial amputation using patellar tendon bearing supracondylar endoskeletal prosthesis with the unaffected limb in weight bearing positions.

Purpose: comparison of electromyographic activity of quadriceps muscle in persons with unilateral traumatic transtibial amputation using patellar tendon bearing supracondylar endoskeletal prosthesis with the unaffected limb in weight bearing positions. Method: 30 individuals aged 18-60 years were assessed using surface electromyography with functional level K3 according to K-level functional assessment scale to compare the activity of quadriceps of affected side using patellar tendon bearing supracondylar endoskeletal prosthesis with the unaffected side. The data was analysed using paired t-test. Result: There was a significant difference in the activity of VMO and VLO muscles of the quadriceps in high sitting positions. There was also a significant difference in the activity of VMO muscle in single limb stance and bipedal stance. However, there was no significant difference between the activity of VLO muscle in bipedal stance but there was reduced activity of VLO muscle in the prosthetic limb in single limb stance. Conclusion: The quadriceps activity was reduced in the affected limb in high sitting position, single limb stance and bipedal stance. However, no difference in the muscle activity was noted in VLO muscle in bipedal stance. Keywords: trans tibial amputation, patellar tendon bearing supracondylar prosthetis, surface electromyography.

Joint internal moments in subjects with unilateral transtibial amputation during walking

Background: Subjects with a unilateral transtibial amputation (UTA) that have used prosthesis for over five years have a higher occurrence rate of osteoarthritis at the knee and hip joints of the intact limb. Objective: To research the joint internal moments of the hip, knee, and ankle in the sagittal and frontal planes during gait in persons with UTA. Methods: 25 individuals with UTA (50.26 years ± 13.76) and 25 subjects without amputation (46.71 years ± 13.76) participated in this study. Gait analysis was carried out using a Vicon® Motion System (Oxford Metrics, Oxford, UK) with eight 100 Hz cameras with infrared strobes, two 1000 Hz AMTI® force-plates. Results: People with UTA walk with a greater hip extensor moment in both intact and prosthetic limbs. The hip abductor moment was lower on the prosthetic limb compared to the intact limb and the control group. At the knee joint, the subjects with UTA walked with a reduced knee extensor and valgus moment on their prosthetic limb compared to the control group. At the ankle joint, the statistical analysis showed that the individuals with UTA walked with a reduced plantarflexor moment during the stance period on the intact limb compared to the people without amputation. Conclusions: Subjects with UTA walk with a different joint kinetic pattern in the sagittal and frontal planes compared to non-disabled individuals.