5 research outputs found
Extending The Lossy Spring-Loaded Inverted Pendulum Model with a Slider-Crank Mechanism
Spring Loaded Inverted Pendulum (SLIP) model has a long history in describing
running behavior in animals and humans as well as has been used as a design
basis for robots capable of dynamic locomotion. Anchoring the SLIP for lossy
physical systems resulted in newer models which are extended versions of
original SLIP with viscous damping in the leg. However, such lossy models
require an additional mechanism for pumping energy to the system to control the
locomotion and to reach a limit-cycle. Some studies solved this problem by
adding an actively controllable torque actuation at the hip joint and this
actuation has been successively used in many robotic platforms, such as the
popular RHex robot. However, hip torque actuation produces forces on the COM
dominantly at forward direction with respect to ground, making height control
challenging especially at slow speeds. The situation becomes more severe when
the horizontal speed of the robot reaches zero, i.e. steady hoping without
moving in horizontal direction, and the system reaches to singularity in which
vertical degrees of freedom is completely lost. To this end, we propose an
extension of the lossy SLIP model with a slider-crank mechanism, SLIP- SCM,
that can generate a stable limit-cycle when the body is constrained to vertical
direction. We propose an approximate analytical solution to the nonlinear
system dynamics of SLIP- SCM model to characterize its behavior during the
locomotion. Finally, we perform a fixed-point stability analysis on SLIP-SCM
model using our approximate analytical solution and show that proposed model
exhibits stable behavior in our range of interest.Comment: To appear in The 17th International Conference on Advanced Robotic
Epidemiological features of primary glomerular disease in Turkey: a multicenter study by the Turkish Society of Nephrology Glomerular Diseases Working Group
Background The largest data on the epidemiology of primary glomerular diseases (PGDs) are obtained from the databases of countries or centers. Here, we present the extended results of the Primary Glomerular Diseases Study of the Turkish Society of Nephrology Glomerular Diseases (TSN-GOLD) Working Group. Methods Data of patients who underwent renal biopsy and received the diagnosis of PGD were recorded in the database prepared for the study. A total of 4399 patients from 47 centers were evaluated between May 2009 and May 2019. The data obtained at the time of kidney biopsy were analyzed. After the exclusion of patients without light microscopy and immunofluorescence microscopy findings, a total of 3875 patients were included in the study. Results The mean age was 41.5 +/- 14.9 years. 1690 patients were female (43.6%) and 2185 (56.3%) were male. Nephrotic syndrome was the most common biopsy indication (51.7%). This was followed by asymptomatic urinary abnormalities (18.3%) and nephritic syndrome (17.8%). The most common PGD was IgA nephropathy (25.7%) followed by membranous nephropathy (25.6%) and focal segmental glomerulosclerosis (21.9%). The mean total number of glomeruli per biopsy was 17 +/- 10. The mean baseline systolic blood pressure was 130 +/- 20 mmHg and diastolic blood pressure was 81 +/- 12 mmHg. The median proteinuria, serum creatinine, estimated GFR, and mean albumin values were 3300 (IQR: 1467-6307) mg/day, 1.0 (IQR: 0.7-1.6) mg/dL, 82.9 (IQR: 47.0-113.0) mL/min and 3.2 +/- 0.9 g/dL, respectively. Conclusions The distribution of PGDs in Turkey has become similar to that in other European countries. IgA nephropathy diagnosed via renal biopsy has become more prevalent compared to membranous nephropathy
Epidemiological features of primary glomerular disease in Turkey: a multicenter study by the Turkish Society of Nephrology Glomerular Diseases Working Group
Background The largest data on the epidemiology of primary glomerular
diseases (PGDs) are obtained from the databases of countries or centers.
Here, we present the extended results of the Primary Glomerular Diseases
Study of the Turkish Society of Nephrology Glomerular Diseases
(TSN-GOLD) Working Group. Methods Data of patients who underwent renal
biopsy and received the diagnosis of PGD were recorded in the database
prepared for the study. A total of 4399 patients from 47 centers were
evaluated between May 2009 and May 2019. The data obtained at the time
of kidney biopsy were analyzed. After the exclusion of patients without
light microscopy and immunofluorescence microscopy findings, a total of
3875 patients were included in the study. Results The mean age was 41.5
+/- 14.9 years. 1690 patients were female (43.6\%) and 2185 (56.3\%)
were male. Nephrotic syndrome was the most common biopsy indication
(51.7\%). This was followed by asymptomatic urinary abnormalities
(18.3\%) and nephritic syndrome (17.8\%). The most common PGD was IgA
nephropathy (25.7\%) followed by membranous nephropathy (25.6\%) and
focal segmental glomerulosclerosis (21.9\%). The mean total number of
glomeruli per biopsy was 17 +/- 10. The mean baseline systolic blood
pressure was 130 +/- 20 mmHg and diastolic blood pressure was 81 +/- 12
mmHg. The median proteinuria, serum creatinine, estimated GFR, and mean
albumin values were 3300 (IQR: 1467-6307) mg/day, 1.0 (IQR: 0.7-1.6)
mg/dL, 82.9 (IQR: 47.0-113.0) mL/min and 3.2 +/- 0.9 g/dL, respectively.
Conclusions The distribution of PGDs in Turkey has become similar to
that in other European countries. IgA nephropathy diagnosed via renal
biopsy has become more prevalent compared to membranous nephropathy