COMPARISON OF THREE MOTION ANALYSIS PROGRAMS BASED ON THE SHOT PUT PERFORMANCE

The aim of the study was to compare the results obtained using the three programs: Vicon, OpenSim and AnyBody. The feasibility of the application and of the selection of one of the programs for further analysis of the sport technique was checked. In the experiment herewith, the torque and power as function of time in the joints of the lower limb during the last phase of shot put was computed. Examinations of the kinematic and kinetic parameters of analyzed movement were carried out using Vicon system and Kistler force plates. Three top level national competitors took part in the study. The differences between the torques and power were checked with a modified RMS index. The results obtained indicate that OpenSim program may be useful for further studies, and in particular in controlling and analyzing the neuromusculaskeletal system

Chamber stapes prosthesis with an improved fastening of the membrane

Stapes prostheses are dedicated to assisting patients with otosclerosis. Currently used stapes prostheses have the form of a piston and are called piston prostheses. However, the perilymph excitation by piston prosthesis is not perfect so a new chamber stapes prosthesis (ChSP) has been proposed. The ChSP allows for a more effective stimulation of the cochlea than the piston. A crucial element of the ChSP is a flexible membrane. The membrane transmits vibrations from the plate to the fluid that fills the chamber and then to the inner ear. In the first prototype, the membrane was glued to the chamber, which is an unacceptable solution in a real medical device because of a risk to patient's health. Therefore, there is a need to improve the membrane fastening. In this study, we present a new improved method for attaching the membrane to the chamber. A modified 3D model of the ChSP was build and an additional fastening element was designed. The design process of the fastening element was based on the analysis of deformation conducted for elements made of different materials. As a result the optimal geometry of the element was determined. The new fastening has been experimentally tested using the 3D printed model. Fastening the membrane to the prosthesis was a success and assessed as efficient. The results of the experimental tests confirmed that presented modification can be used in the ChSPs intended for clinical trials

Chamber stapes prosthesis with an improved fastening of the membrane

Stapes prostheses are dedicated to assisting patients with otosclerosis. Currently used stapes prostheses have the form of a piston and are called piston prostheses. However, the perilymph excitation by piston prosthesis is not perfect so a new chamber stapes prosthesis (ChSP) has been proposed. The ChSP allows for a more effective stimulation of the cochlea than the piston. A crucial element of the ChSP is a flexible membrane. The membrane transmits vibrations from the plate to the fluid that fills the chamber and then to the inner ear. In the first prototype, the membrane was glued to the chamber, which is an unacceptable solution in a real medical device because of a risk to patient's health. Therefore, there is a need to improve the membrane fastening. In this study, we present a new improved method for attaching the membrane to the chamber. A modified 3D model of the ChSP was build and an additional fastening element was designed. The design process of the fastening element was based on the analysis of deformation conducted for elements made of different materials. As a result the optimal geometry of the element was determined. The new fastening has been experimentally tested using the 3D printed model. Fastening the membrane to the prosthesis was a success and assessed as efficient. The results of the experimental tests confirmed that presented modification can be used in the ChSPs intended for clinical trials

A three-dimensional finite element model of round window membrane vibration before and after stapedotomy surgery

Piston stapes prostheses are implanted in patients with refractory conductive or mixed hearing loss due to stapes otosclerosis to stimulate the perilymph with varying degrees of success. The overclosure effect described by the majority of researchers affects mainly low and medium frequencies, and a large number of patients report a lack of satisfactory results for frequencies above 2 kHz. The mechanics of perilymph stimulation with the piston have not been studied in a systematic manner. The objective of this study was to assess the influence of stapedotomy surgery on round window membrane vibration and to estimate the postoperative outcomes using the finite element (FE) method. The study hypothesis is that the three-dimensional FE model developed of the human inner ear, which simulates the round window (RW) membrane vibration, can be used to assess the influence of stapedotomy on auditory outcomes achieved after the surgical procedure. An additional objective of the study was to enable the simulation of RW membrane vibration after stapedotomy using a new type of stapes prosthesis currently under investigation at Warsaw University of Technology. A three-dimensional finite element (FE) model of the human inner ear was developed and validated using experimental data. The model was then used to simulate the round window membrane vibration before and after stapedotomy surgery. Functional alterations of the RW membrane vibration were derived from the model and compared with the results of experimental measurements from temporal bones of a human cadaver. Piston stapes prosthesis implantation causes an approximately fivefold (14 dB) lower amplitude of the RW membrane vibrations compared with normal anatomical conditions. A satisfactory agreement between the FE model and the experimental data was found. The new prosthesis caused an increase of 20–30 dB in the RW displacement amplitude compared with the 0.4-mm piston prosthesis. In all frequencies, the FE model predicted a RW displacement curve that was above the experimental curves for the normal ear. The stapedotomy can be well simulated by the FE model to predict the auditory outcomes achieved following this otosurgery procedure. The 3D FE model developed in this study may be used to optimize the geometry of a new type of stapes prosthesis in order to achieve a similar sound transmission through the inner ear as for a normal middle ear. This should provide better auditory outcomes for patients with stapedial otosclerosis

New chamber stapes prosthesis - A preliminary assessment of the functioning of the prototype.

Piston-stapedotomy is the most common method for hearing restoration in patients with otosclerosis. In this study, we have experimentally examined a prototype of a new chamber stapes prosthesis. The prototype was implanted in a human cadaver temporal bone. The round window vibrations before and after implantation were measured for the acoustic signal (90 dB SPL, 0.8-8 kHz) in the external auditory canal. In comparison with a 0.4-mm piston prosthesis, the chamber prosthesis induced significantly higher vibration of the round window, especially for frequencies above 1.5 kHz. Based on the results, it can be surmised that stapedotomy with a chamber stapes prosthesis could provide better hearing results in comparison with the piston-stapedotomy

Bone conduction stimulation of the otic capsule: a finite element model of the temporal bone

Bone conduction stimulation applied on the otic capsule may be used in a conductive hearing loss treatment as an alternative to the bone conduction implants in clinical practice. A finite element study was used to evaluate the force amplitude and direction needed for the stimulation. Methods: A finite element model of a female temporal bone with a precisely reconstructed cochlea was subjected to a harmonic analysis assuming two types of stimulation. At first, the displacement amplitude in the form of air conduction stimulation was applied on the stapes footplate. Then the force amplitude was applied on the otic capsule in the form of bone conduction stimulation. The two force directions were considered: 1) the primary direction, when a typical opening is performed during mastoidectomy, and was coincident with the axis of an imaginary cone, inscribed in the opening, and 2) the direction perpendicular to the stapes footplate. The force amplitude was set so that the response from the cochlea corresponded to the result of air conduction stimulation applied on the stapes footplate. Results: The amplitude and phase of vibration and the volume displacement on the round window membrane were considered as well as vibrations of the basilar membrane, spiral lamina, and promontory. Conclusions: The cochlear response was comparable for the two types of stimulation. The efficiency of bone conduction stimulation depended on the force direction. For the primary direction, the force was a few times smaller than for the direction perpendicular to the stapes footplate

InputRatio-frequency characteristics.

<p>The ChSP (IR_ChSP, red line) and the 0.4-mm piston (IR_{0.4 piston}, black line).</p

Chamber stapes prosthesis.

<p>(A) Design of the ChSP. 1 –conical chamber filled with fluid, 2 –flexible membrane (mimics the AL), 3 –rigid plate with an attachment (mimics the stapes), 4 –thin capillary tube (connects the chamber with the vestibule and allows fluid to flow). (B) Photo of the ChSP prototype filled with fluid.</p

OutputRatio-frequency characteristics for the ChSP (OR_ChSP, red line) and the 0.4-mm piston (OR_{0.4 piston}, black line).

<p>OutputRatio-frequency characteristics for the ChSP (OR_ChSP, red line) and the 0.4-mm piston (OR_{0.4 piston}, black line).</p

Three-dimensional visualization of displacements at the cochlear input.

<p>Left column–vibration of the ChSP plate, middle column–vibration of the normal stapes [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0178133#pone.0178133.ref033" target="_blank">33</a>], right column–vibration of the 0.4-mm piston prosthesis [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0178133#pone.0178133.ref033" target="_blank">33</a>]. All measurements for 90 dB SPL at the tympanic membrane. 1 –stapes head, 2 –tendon of the stapedial muscle, 3 –lenticular process, 4 –long process of the incus, 5 –piston, 6 –wire loop of the piston prosthesis.</p