ABSTRACT
Introduction Modern transfemoral knee prostheses are designed to offer comfort and self-confidence to amputees. These prostheses are mainly based upon either a passive concept, with a damping system, or an active computational intelligent design to control knee motion during the swing phase. In Brazil, most lower extremity amputees are unable to afford modern prostheses due to their high cost. In this work, we present the conception, design and development of a low-cost intelligent prosthesis for one-sided transfemoral amputees. Methods The concept of the prosthesis is based on a control system with sensors for loads, which are installed on the amputee’s preserved leg and used as a mirror for the movement of the prosthesis. Mechanical strength analysis, using the Finite Element Method, electromechanical tests for the sensors and actuators and verification of data acquisition, signal conditioning and data transferring to the knee prosthesis were performed. Results The laboratory tests performed showed the feasibility of the proposed design. The electromechanical concept that was used enabled a controlled activation of the knee prosthesis by the two load cells located on the shoe sole of the preserved leg. Conclusions The electromechanical design concept and the resulting knee prosthesis show promising results concerning prosthesis activation during walking tests, thereby showing the feasibility of a reduced manufacturing cost compared to the modern prostheses available on the market.
ABSTRACT
@#Objective To investigate the characteristics of walking ability of the amputees with unilateral transfemoral prosthesis. Methods 16 unilateral transfemoral amputees (patients) and 16 healthy adults (controls) were tested with 6-minute walking test indoor, 1000 m walking outdoor on various terrain, balance test and energy expenditure test. Results The speed, frequency and stride length were significantly less in the patients than in the controls (P<0.05) in the indoor 6-minute walking test, and the cycle of gait and energy expenditure were significantly more (P<0.05); single support time, double and single/double support time were different (P<0.05). In balance tests, there was no significant difference in the total track length, confidence ellipse area, maximum horizontal deviation and maximum vertical deviation between the patients and the controls (P>0.05). There were significant differences in time and energy expenditure of outdoor 1000 m walk test between two groups (P<0.05). There were significant differences in time of outdoor 1000 m walk test and distance of indoor walking test between amputees wearing mechanical four-link prosthetic knee joint and fluid control prosthetic knee joint (P<0.05), but not in energy expenditure of indoor and outdoor walking test. Conclusion The amputees with unilateral transfemoral prosthesis appear the inefficient in gait, and expend more energy. Their balance remains well. The transfemoral prosthesis the amputees wore may impact their walking ability.
ABSTRACT
Objective To investigate the characteristics of walking ability of the amputees with unilateral transfemoral prosthesis. Meth-ods 16 unilateral transfemoral amputees (patients) and 16 healthy adults (controls) were tested with 6-minute walking test indoor, 1000 m walking outdoor on various terrain, balance test and energy expenditure test. Results The speed, frequency and stride length were significant-ly less in the patients than in the controls (P0.05). There were significant differences in time and energy expenditure of outdoor 1000 m walk test between two groups (P<0.05). There were significant differences in time of outdoor 1000 m walk test and distance of indoor walking test be-tween amputees wearing mechanical four-link prosthetic knee joint and fluid control prosthetic knee joint (P<0.05), but not in energy expen-diture of indoor and outdoor walking test. Conclusion The amputees with unilateral transfemoral prosthesis appear the inefficient in gait, and expend more energy. Their balance remains well. The transfemoral prosthesis the amputees wore may impact their walking ability.
ABSTRACT
Objective: To determine the changes in health-related quality of life (HRQOL)in the osseointegrated transfemoral amputee patients treated in the Hospital del Trabajador of Santiago (HTS) during 2009-2010. Patients and Methods: Quasiexperimental design study with a unique cohort. The study included 10 transfemoral amputee patients who were beneficiaries of the 16,744 Law and treated in the HTS. They had undergone osseointegration treatment between August 2009 and March2010 and they had completed the rehabilitation process and protocol described in OPRA (Osseointegrated Prostheses for Rehabilitation of Amputees). HRQOL was assessed using the SF-36 questionnaire before and after surgery. Results: All patients were men with a mean age at the time of amputation of 35 years. 9 of10 subjects had unilateral amputation (4 right and 5 left) and one had a bilateral amputation. Trauma was the cause of amputation in all patients. 6 of 10 suffered traffic accidents and 3 of 10 had other associated injuries. Their age at the time of the first surgery was 42 +/- 8 years. Regarding HRQOL, there was a statistically significant difference in the 8 dimensions of the SF-36 questionnaire and in the physical component summary measure between pre and post surgery in relationship to the perceived quality of life (p < 0.05). Conclusions: This is the first study of osseointegration patients in Chile with encouraging results in relation to the improvement in HRQOL for patients who use osseointegraded prosthesis.
Objetivo: Determinar cambios en la calidad de vida relacionada a salud(CVRS) de los pacientes amputados transfemorales osteointegrados tratados en el Hospital del Trabajador de Santiago (HTS) durante 2009-2010. Pacientes y Método: Estudio de diseño cuasi experimental de cohorte única. Se incluyeron 10 pacientes amputados transfemorales beneficiarios de la Ley 16.744 y atendidos en el HTS, que fueron sometidos a la técnica de osteointegración entre agosto de 2009 y marzo de 2010 y quienes completaron el proceso de rehabilitación y seguimiento descrito en el protocolo OPRA (Osseointegrated Prostheses for Rehabilitation of Amputees). La CVRS se evaluó mediante encuesta SF-36 pre y post cirugía. Resultados: Todos los pacientes son hombres; edad promedio al momento de la amputación de 35 años. 9/10 sujetos tenían amputación unilateral (4 derechos y 5 izquierdos) y uno bilateral. La causa de amputación fue traumática en todos los pacientes; de ellos 6/10, sufrieron lesiones de trayecto (traumas de tránsito y atropello) y 3/10 presentaban otras lesiones asociadas. Edad al momento de la primera cirugía de 42 +/- 8 años. Respecto a CVRS, se registró diferencia estadísticamente significativa en las 8 dimensiones de la encuesta SF-36 y en componente sumario físico entre el pre y post operatorio (p < 0,05). Conclusiones: Este estudio es el primero que se realiza en pacientes osteointegrados en Chile, donde los resultados son alentadores en relación a la mejoría en CVRS de los pacientes usuarios de prótesis osteointegradas.