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1.
Sensors (Basel) ; 21(12)2021 Jun 17.
Article in English | MEDLINE | ID: mdl-34204487

ABSTRACT

The chest organ, which gained popularity at the beginning of the 17th century, is a small pipe organ the size of a large box. Several years ago, while compiling an inventory, a previously unidentified chest organ was discovered at St. John the Baptist's Co-Cathedral in Kamien Pomorski. Regrettably, the instrument did not possess any of its original pipes. What remained, however, was an image of the front pipes preserved on the chest door. The main issue involved in the reconstruction of a historic instrument is the restoration of its original tuning (temperament). Additionally, it is important to establish the frequency of A4, as this sound serves as a standard pitch reference in instrument tuning. The study presents a new method that aims to address the above-mentioned problems. To this end, techniques to search for the most probable temperament and establish the correct A4 frequency were developed. The solution is based on the modeling of sound generation in flue pipes, as well as statistical analysis to help match a model to the parameters preserved in the chest organ drawing. Additionally, differentalues of the A4 sound values were defined for temperatures ranging from 10 ∘C to 20 ∘C. The tuning system proposed in 1523 by Pietro Aaron proved to be the most probable temperament. In the process of testing the developed flue pipe model, the maximum tuning temperature was established as 15.8 ∘C.


Subject(s)
Music , Sound
2.
Sensors (Basel) ; 22(1)2021 Dec 21.
Article in English | MEDLINE | ID: mdl-35009552

ABSTRACT

This paper describes the influence of the presence of an obstacle near the flue pipe's mouth on the air jet, which directly affects the parameters of the sound generated by the flue pipe. Labial pipes of the most common types of mouth were tested. The method of interval calculus was used instead of invasive measuring instruments. The obtained results prove that the proximity of an obstacle affects the sound's fundamental frequency, as the airflow speed coming out of the flue pipe's mouth changes. The relationship between the airflow speed, the value of the Reynolds number, and the Strouhal number was also established. The thesis of the influence of the proximity of an obstacle on the fundamental frequency of the sound of a flue pipe was generalized, and formulas for calculating the untuning of the sound of the pipe were presented for various types of mouth.


Subject(s)
Mouth , Sound
3.
Australas Phys Eng Sci Med ; 42(3): 701-710, 2019 Sep.
Article in English | MEDLINE | ID: mdl-31201609

ABSTRACT

Electromyography (EMG) is a diagnostic technique allowing for the detection of signals generated by changes in electrical potentials of striated muscles. The application of this technology is becoming an increasingly popular subject of scientific research. With the appearance of new devices retrieving EMG data, novel methods of its processing for various purposes are being developed. One such device is the Myo movement controller, produced by Thalmic Labs (now North). The device has been used for the analysis of muscle activation levels in patients with "tennis elbow" and "golfer's elbow"-conditions of upper limbs which usually result from occupational injuries. The process of their rehabilitation is complex and requires a continuous monitoring of its progress. The data obtained by means of the Myo controller was used for pattern recognition of an injured hand with relation to the healthy one. The study involved examining ten subjects, including five controls. The results indicate that the muscle activation force is considerably lower in injured individuals. The arithmetic mean for the 6 analyzed motions in the injured group is 38.54% lower. The SmartEMG application ( https://www.smartemg.com ) enables the implementation of procedures performed during an examination as well as those involved in the management of the collected recordings. The study produced satisfactory results, which indicates the possibility of using the Myo controller in the treatment of elbow enthesopathy.


Subject(s)
Elbow/physiopathology , Electromyography/methods , Enthesopathy/physiopathology , Enthesopathy/therapy , Motion , Algorithms , Case-Control Studies , Female , Humans , Male
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