A Dual Piezoelectric Element Force Pedal for Kinetic Analysis of Cycling

In light of substantial interest in the measurement of rider-induced loads, a new bicycle pedal instrumentation system is presented. The system employs dual piezoelectric transducers and permits the measurement of three components of a uniaxial load, moments about the pedal’s vertical axis, and the point of application of the applied load. Force and moment patterns derived from pedal output agree with previously reported data. Unique to this design, however, is the determination of center of pressure—and these data indicate that the applied load location varies during the pedaling cycle, with a significant effect on the calculated pedal moment.

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A Dual Piezoelectric Bicycle Pedal with Multiple Shoe/Pedal Interface Compatibility

International Journal of Sport Biomechanics ◽

10.1123/ijsb.8.3.251 ◽

1992 ◽

Vol 8 (3) ◽

pp. 251-258 ◽

Cited By ~ 12

Author(s):

Jeffrey B. Wheeler ◽

Robert J. Gregor ◽

Jeffrey P. Broker

Keyword(s):

Lower Extremity ◽

Applied Load ◽

Knee Injuries ◽

Knee Kinematics ◽

Piezoelectric Element ◽

Overuse Injuries ◽

Load Location ◽

The Moment ◽

Kinetics Of ◽

Kinematics And Kinetics

In response to the popularity of clipless bicycle pedals with float designs, an instrumented force pedal system with multicompatibility for different shoe/pedal interfaces is presented. A dual piezoelectric element pedal has been modified for use with popular clipless pedal interfaces. The dual transducer arrangement permits measurement of three components of uniaxial load, location of the applied load, and calculation of the moment Mz about an axis through the position of the applied load and orthogonal to the pedal surface. Quantification of lower extremity kinetics using float feature pedals and the investigation of the pathomechanics of lower extremity cycling overuse injuries, especially knee injuries, is warranted. Qualitative descriptions of lower extremity pathomechanics related to overuse injuries have suggested that foot constraint may induce undesirable knee kinematics and kinetics. The instrumented force pedal system described here permits a comparison between pedal kinematics and kinetics of popular shoe/pedal interfaces with varying degrees of float allowance.

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Calculating the aerodynamics of vertical axis wind turbines

Vietnam Journal of Mechanics ◽

10.15625/0866-7136/34/3/2358 ◽

2012 ◽

Vol 34 (3) ◽

pp. 169-184 ◽

Cited By ~ 1

Author(s):

Hoang Thi Bich Ngoc

Keyword(s):

Wind Turbine ◽

Incidence Angle ◽

Vertical Axis ◽

Rotor Blades ◽

Vertical Axis Wind Turbine ◽

Horizontal Axis Wind Turbine ◽

Velocity Triangle ◽

Relationship Of ◽

The Relationship

Vertical axis wind turbine technology has been applied last years, very long after horizontal axis wind turbine technology. Aerodynamic problems of vertical axis wind machines are discussible. An important problem is the determination of the incidence law in the interaction between wind and rotor blades. The focus of the work is to establish equations of the incidence depending on the blade azimuth, and to solve them. From these results, aerodynamic torques and power can be calculated. The incidence angle is a parameter of velocity triangle, and both the factors depend not only on the blade azimuth but also on the ratio of rotational speed and horizontal speed. The built computational program allows theoretically selecting the relationship of geometric parameters of wind turbine in accordance with requirements on power, wind speed and installation conditions.

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Determination of bulk density of the source of heat in the analysis of thermodynamic processes in the quartz piezoelectric element

2014 24th International Crimean Conference Microwave & Telecommunication Technology ◽

10.1109/crmico.2014.6959599 ◽

2014 ◽

Cited By ~ 9

Author(s):

A. A. Taranchuk ◽

S. K. Pidchenko ◽

R.P. Khoptinskiy

Keyword(s):

Bulk Density ◽

Piezoelectric Element ◽

Thermodynamic Processes

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EVALUATION OF MONITORING HYPERTENSION CASE BASED ON NINE SURVEILLANCE ATTRIBUTES IN JOMBANG DISTRICT HEALTH OFFICE IN 2018

The Indonesian Journal of Public Health ◽

10.20473/ijph.v16i1.2021.89-100 ◽

2021 ◽

Vol 16 (1) ◽

pp. 89

Author(s):

Dewi Lestari

Keyword(s):

Evaluation Method ◽

Qualitative Evaluation ◽

Noncommunicable Diseases ◽

Research Subject ◽

District Health Office ◽

District Health ◽

Data Collection Technique ◽

Reported Data ◽

Primary Healthcare Centers

Hypertension is still a global problem, therefore, even affecting the citizens of Indonesia. Among 10 most common diseases in Jombang regency, hypertension was ranked second in 2017. One of the efforts in overcoming hypertension was by monitoring hypertension cases through Noncommunicable Diseases (NCD) surveillance system strengthening. However, the completeness of the MSS hypertension reports in Jombang region was low.The purpose of this study was to evaluate the monitoring of hypertension cases based on surveillance attributes in the Jombang District Health Office throughout 2018. This study was conducted using the qualitative evaluation method. The research subject was NCD surveillance, specifically in monitoring hypertension cases in the Jombang District Health Office. The determination of the informants used purposive sampling. The research informants consist of NCD officers in Jombang District Health Office, and NCD officers in 2 selected primary healthcare centers. The data collection technique used interview guidelines and document observation where data analysis was performed descriptively. The results show in the assessment of surveillance attributes of simplicity, acceptability, positive predictive value, data quality, and stability the results were low. While, flexibility, sensitivity, representativeness, and timeliness cannot be assessed. The conclusion was that the assessment of the surveillance attributes was quite good, but there are still obstacles in its implementation, namely incomplete reports, no attendance records, and so on. This study suggests to implement attendance records in each unit allowing the reported data to be used for planning in preventing hypertension.Keywords: evaluation, hypertention, surveillance attribute.

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Experimental determination of the reflective index of ultrasound waves from homogenous mediums by means of piezoelectric transducers

6th International Conference on Telecommunications in Modern Satellite, Cable and Broadcasting Service, 2003. TELSIKS 2003. ◽

10.1109/telsks.2003.1246351 ◽

2004 ◽

Author(s):

I.S. Simeonov

Keyword(s):

Experimental Determination ◽

Piezoelectric Transducers ◽

Ultrasound Waves ◽

Reflective Index

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Rheometer enabled study of cartilage frequency-dependent properties

Scientific Reports ◽

10.1038/s41598-020-77758-9 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Stefano Perni ◽

Polina Prokopovich

Keyword(s):

Applied Load ◽

Cost Effective ◽

Constant Load ◽

Hydraulic Permeability ◽

Frequency Dependent ◽

Shear Moduli ◽

Tissue Replacement ◽

Cost Effective Approach ◽

The Impact

AbstractDespite the well-established dependence of cartilage mechanical properties on the frequency of the applied load, most research in the field is carried out in either load-free or constant load conditions because of the complexity of the equipment required for the determination of time-dependent properties. These simpler analyses provide a limited representation of cartilage properties thus greatly reducing the impact of the information gathered hindering the understanding of the mechanisms involved in this tissue replacement, development and pathology. More complex techniques could represent better investigative methods, but their uptake in cartilage research is limited by the highly specialised training required and cost of the equipment. There is, therefore, a clear need for alternative experimental approaches to cartilage testing to be deployed in research and clinical settings using more user-friendly and financial accessible devices. Frequency dependent material properties can be determined through rheometry that is an easy to use requiring a relatively inexpensive device; we present how a commercial rheometer can be adapted to determine the viscoelastic properties of articular cartilage. Frequency-sweep tests were run at various applied normal loads on immature, mature and trypsinased (as model of osteoarthritis) cartilage samples to determine the dynamic shear moduli (G*, G′ G″) of the tissues. Moduli increased with increasing frequency and applied load; mature cartilage had generally the highest moduli and GAG depleted samples the lowest. Hydraulic permeability (KH) was estimated from the rheological data and decreased with applied load; GAG depleted cartilage exhibited higher hydraulic permeability than either immature or mature tissues. The rheometer-based methodology developed was validated by the close comparison of the rheometer-obtained cartilage characteristics (G*, G′, G″, KH) with results obtained with more complex testing techniques available in literature. Rheometry is relatively simpler and does not require highly capital intensive machinery and staff training is more accessible; thus the use of a rheometer would represent a cost-effective approach for the determination of frequency-dependent properties of cartilage for more comprehensive and impactful results for both healthcare professional and R&D.

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Experimental Evaluation of Sensing and Energy Harvesting Behavior of Implanted Piezoelectric Transducers in Total Knee Replacement

Volume 1: Development and Characterization of Multifunctional Materials; Mechanics and Behavior of Active Materials; Bioinspired Smart Materials and Systems; Energy Harvesting; Emerging Technologies ◽

10.1115/smasis2017-3881 ◽

2017 ◽

Cited By ~ 1

Author(s):

Mohsen Safaei ◽

Steven R. Anton

Keyword(s):

Energy Harvesting ◽

Total Knee Replacement ◽

Knee Replacement ◽

Center Of Pressure ◽

Experimental Testing ◽

Surgical Techniques ◽

Piezoelectric Transducers ◽

Computer Assisted ◽

Total Knee ◽

Self Powered

Total knee replacement has been utilized to restore the functionality of diseased knee joints for more than four decades. Today, despite the relatively high level of patient satisfaction, still about 20% of patients are not fulfilled with their surgical outcomes in terms of function and reduction in pain. There is still an ongoing discussion on correlating the postoperative functionality of the joint to intraoperative alignment, which suffers from lack of in vivo data from the knee after surgery. However, it is necessary to mention that using computer assisted surgical techniques, the outcomes of knee replacement procedures have been remarkably improved. In order to obtain information about the knee function after the operation, the design of a self-powered instrumented knee implant is proposed in this study. The design is a total knee replacement ultra high molecular weight polyethylene insert equipped with four piezoelectric transducers distributed in the medial and lateral compartments of the bearing. The piezoelectric elements are employed to measure the axial force applied on the tibial insert through the femoral component of the joint as well as to track the movement in the center of pressure. In addition, generated voltage from the piezoelectrics is harvested and stored to power embedded electronics for further signal conditioning and data transmitting purposes. The performance of the instrumented implant is investigated via experimental testing on a fabricated prototype in terms of sensing and power harvesting capacity. Piezoelectric force and center of pressure measurements are compared to the actual quantities recorded from the load frame and pressure sensitive films in order to evaluate the performance of the sensing system. The output voltage of the piezoelectric transducers is rectified and stored in a capacitor to evaluate the energy harvesting ability of the system. The results show only a small level of error in sensing the force and the location of center of pressure. Additionally, a 4.9 V constant voltage is stored in a 3.3 mF capacitor after 3333 loading cycles. The sensing and energy harvesting results present the promising potential of this system to be used as an integrated self-powered instrumented knee implant.

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