Development of a 3D Relative Motion Method for Human-Robot Interaction Assessment.

Exoskeletons have been assessed by qualitative and quantitative features known as performance indicators. Within these, the ergonomic indicators have been isolated, creating a lack of methodologies to analyze and assess physical interfaces. In this sense, this work presents a three-dimensional relative motion assessment method. This method quantifies the difference of orientation between the user's limb and the exoskeleton link, providing a deeper understanding of the Human-Robot interaction. To this end, the AGoRA exoskeleton was configured in a resistive mode and assessed using an optoelectronic system. The interaction quantified a difference of orientation considerably at a maximum value of 41.1 degrees along the sagittal plane. It extended the understanding of the Human-Robot Interaction throughout the three principal human planes. Furthermore, the proposed method establishes a performance indicator of the physical interfaces of an exoskeleton.

[The echocardiography in cardiac remodeling after acute myocardial infarction]. / La ecocardiografía en la remodelación cardíaca después del infarto agudo de miocardio.

OBJECTIVES: The goal of this study was to assess the impact of left ventricular diastolic filling on remodeling and survival after acute myocardial infarction. METHODS: We studied 36 patients with first acute myocardial treated with thrombolytic agents. A Doppler echocardiography was performed at 24 hours, 30 and 90 days after infarction. It measured the relation between E and A waves peak velocities (E/A ratio) and of the E deceleration time (EDT, ms), as well as the flow propagation velocity using color mode M and the E'-wave by tissular Doppler at the lateral mitral ring. RESULTS: Patients were divided into three groups. Group I, restrctive filling (deceleration time < 140 ms, E/FPV > or = 2, E/A> 2 and E/E' > 15). Group II, elevated filling pressure (deceleration time > or = 140 ms, E/FVP > or = 2, E/A 1,2 and E/E' < or = 15). Group III, normal filling pressure (deceleration time > or = 140 ms, E/FVP < 2, E/A < 1 and E/E' < 15). The E/FPV showed a better correlation in the group with restrictive filling and left ventricular filling pressure was significantly greater than in the group with normal filling pressure at 90 days (2.18 +/- 0.90 vs. 1.5 +/- 0.35; r = 0.99; P = .0001). The end diastolic volume (EDV) was similar in the three groups 24 hours after infarction. EDV varied at 90 days after infarction in those patients that underwent successful coronary angioplasty. Group I, 142.48 +/- 32 vs. 112.48 +/- 32, r = 573; P < .0001). CONCLUSIONS: E/FVP, using color M-mode Doppler echocardiography, estimates left ventricular filling pressure and predicts left ventricular dilation after acute myocardial infarction.

[Correlation between left ventricular stroke work loss index and aortic valve area in patients with aortic stenosis]. / Correlación entre el índice de pérdida de trabajo-latido ventricular izquierdo y el área valvular aórtica en pacientes con estenosis aórtica.

UNLABELLED: In echocardiographic evaluation of patients with aortic stenosis (AS), prospective studies have demonstrated that left ventricular stoke work loss index (LVSWLI) provide a more clinical efficacy than calculate of aortic valve area (AVA) by continuity equation to estimate severity of stenosis. The aim of this study was assess in our population of patients with AS the correlation between LVSWLI and AVA in regard to severity. MATERIAL AND METHODS: Forty nine patients with moderate and severe AS were evaluated by transthoracic echocardiography. Grades of AS were assessed by transaortic flow velocity (Vmax) and mean aortic transvalvular gradient (deltaP). AVA and LVSWLI were calculated and Pearson's and Spearman's correlation coefficients between both methods were assessed. Significance level was set at <0.05. RESULTS: The age of the patients was 66 +/- 13 (31-84 years). Thirty four (69%) patients had severe AS and 15 (31%) moderate AS. The Pearson's correlation coefficient between LVSWLI and AVA was 0.79 (p<0.04) and between LVSWLI and deltaP was 0.90 (p<0.03). The Spearman's correlation coefficient between LVSWLI and symptomatic status was 0.70 (rho = 0.70, p < 0.003). CONCLUSIONS: In patients with moderate and severe AS, the correlation between LVSWLI and deltaP is higher than correlation between LVSWLI and AVA. Moreover LVSWLI has a higher correlation with presence of symptoms than AVA.

La ecocardiografía en la remodelación cardíaca después del infarto agudo de miocardio / The echocardiography in cardiac remodeling after acute myocardial infarction

OBJECTIVES: The goal of this study was to assess the impact of left ventricular diastolic filling on remodeling and survival after acute myocardial infarction. METHODS: We studied 36 patients with first acute myocardial treated with thrombolytic agents. A Doppler echocardiography was performed at 24 hours, 30 and 90 days after infarction. It measured the relation between E and A waves peak velocities (E/A ratio) and of the E deceleration time (EDT, ms), as well as the flow propagation velocity using color mode M and the E'-wave by tissular Doppler at the lateral mitral ring. RESULTS: Patients were divided into three groups. Group I, restrctive filling (deceleration time < 140 ms, E/FPV > or = 2, E/A> 2 and E/E' > 15). Group II, elevated filling pressure (deceleration time > or = 140 ms, E/FVP > or = 2, E/A 1,2 and E/E' < or = 15). Group III, normal filling pressure (deceleration time > or = 140 ms, E/FVP < 2, E/A < 1 and E/E' < 15). The E/FPV showed a better correlation in the group with restrictive filling and left ventricular filling pressure was significantly greater than in the group with normal filling pressure at 90 days (2.18 +/- 0.90 vs. 1.5 +/- 0.35; r = 0.99; P = .0001). The end diastolic volume (EDV) was similar in the three groups 24 hours after infarction. EDV varied at 90 days after infarction in those patients that underwent successful coronary angioplasty. Group I, 142.48 +/- 32 vs. 112.48 +/- 32, r = 573; P < .0001). CONCLUSIONS: E/FVP, using color M-mode Doppler echocardiography, estimates left ventricular filling pressure and predicts left ventricular dilation after acute myocardial infarction.

Correlación entre el índice de pérdida de trabajo-latido ventricular izquierdo y el área valvular aórtica en pacientes con estenosis aórtica / Correlation between left ventricular stroke work loss index and aortic valve area in patients with aortic stenosis

In echocardiographic evaluation of patients with aortic stenosis (AS), prospective studies have demonstrated that left ventricular stoke work loss index (LVSWLI) provide a more clinical efficacy than calculate of aortic valve area (AVA) by continuity equation to estimate severity of stenosis. The aim of this study was assess in our population of patients with AS the correlation between LVSWLI and AVA in regard to severity. MATERIAL AND METHODS: Forty nine patients with moderate and severe AS were evaluated by transthoracic echocardiography. Grades of AS were assessed by transaortic flow velocity (Vmax) and mean aortic transvalvular gradient (deltaP). AVA and LVSWLI were calculated and Pearson's and Spearman's correlation coefficients between both methods were assessed. Significance level was set at <0.05. RESULTS: The age of the patients was 66 +/- 13 (31-84 years). Thirty four (69%) patients had severe AS and 15 (31%) moderate AS. The Pearson's correlation coefficient between LVSWLI and AVA was 0.79 (p<0.04) and between LVSWLI and deltaP was 0.90 (p<0.03). The Spearman's correlation coefficient between LVSWLI and symptomatic status was 0.70 (rho = 0.70, p < 0.003). CONCLUSIONS: In patients with moderate and severe AS, the correlation between LVSWLI and deltaP is higher than correlation between LVSWLI and AVA. Moreover LVSWLI has a higher correlation with presence of symptoms than AVA.