Physics Doesn't Bite - A Simple Experiment for Introducing Biomechanical Operational Principles of the Temporomandibular Joint

2021 ◽  
Author(s):  
Daniel Dziob ◽  
Marcin Mlynarczyk ◽  
Tomasz Rok ◽  
Grzegorz Taton ◽  
Bartosz Lisowski
Keyword(s):  
Temporomandibular Joint ◽  
Force Measurement ◽  
Wheatstone Bridge ◽  
Mathematical Concept ◽  
Electrical Circuit ◽  
Bite Force ◽  
Physical Models ◽  
Fundamental Properties ◽  
Physical Background ◽  
Beam Bending

Abstract Biophysics is rarely mentioned as one of the most useful parts of dental and medical students' curricula. However, with growing complexity of tools and methods used in diagnostics and therapy, the knowledge of their physical foundations becomes important and helps with choosing the optimal solutions for both, a patient and a doctor. The aim of the proposed activity is to develop students' intuition about simple physical models that help with understanding fundamental properties of temporomandibular joint (TMJ). A simple device, which allows for bite force measurement, is proposed. It is based on beam bending and a strain gauge Wheatstone bridge circuit, mounted on two connected arms: the stiff one and the more elastic one. Linear regression is the only mathematical concept needed for understanding the physical background of the proposed activity. During the proposed activity - measuring of bite force for incisors, premolars and molars - students are confronted with basic concepts, such as lever, torque, electrical circuit, calibration curve. By utilizing a simple idea, instead of a commercially available device, students can understand where the data come from. Proposed system delivers physiologically reasonable results.

scholarly journals The Jaw Adductor Resultant and Estimated Bite Force in Primates

2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
Jonathan M. G. Perry ◽  
Adam Hartstone-Rose ◽  
Rachel L. Logan
Keyword(s):  
Temporomandibular Joint ◽  
Body Mass ◽  
Bite Force ◽  
Cross Sectional Area ◽  
Primate Species ◽  
Sectional Area ◽  
Cross Sectional ◽  
Joint Distraction ◽  
Jaw Adductors

We reconstructed the jaw adductor resultant in 34 primate species using new data on muscle physiological cross-sectional area (PCSA) and data on skull landmarks. Based on predictions by Greaves, the resultant should (1) cross the jaw at 30% of its length, (2) lie directly posterior to the last molar, and (3) incline more anteriorly in primates that need not resist large anteriorly-directed forces. We found that the resultant lies significantly posterior to its predicted location, is significantly posterior to the last molar, and is significantly more anteriorly inclined in folivores than in frugivores. Perhaps primates emphasize avoiding temporomandibular joint distraction and/or wide gapes at the expense of bite force. Our exploration of trends in the data revealed that estimated bite force varies with body mass (but not diet) and is significantly greater in strepsirrhines than in anthropoids. This might be related to greater contribution from the balancing-side jaw adductors in anthropoids.

scholarly journals Pressure Sensor with New Electrical Circuit Utilizing Bipolar Junction Transistor

2021 ◽  
Author(s):  
Mikhail
Keyword(s):  
Theoretical Model ◽  
Pressure Sensor ◽  
High Sensitivity ◽  
Wheatstone Bridge ◽  
Electrical Circuit ◽  
Sensor Chip ◽  
Chip Size ◽  
Junction Transistor ◽  
Developed Pressure ◽  
P Type

High sensitivity MEMS pressure sensor chip for different ranges (1 to 60 kPa) utilizing the novel electrical circuit of piezosensitive differential amplifier with negative feedback loop (PDA-NFL) is developed. Pressure sensor chip PDA-NFL utilizes two bipolar-junction transistors (BJT) with vertical n-p-n type structure (V-NPN) and eight piezoresistors (p-type). Both theoretical model of sensor response to pressure and temperature and experimental data are presented. Data confirms the applicability of theoretical model. Introduction of the amplifier allows for decreasing chip size while keeping the same sensitivity as a chip with classic Wheatstone bridge circuit.

Gas pressure, Volume and Flow Measurement

2011 ◽  
Author(s):  
Patrick Magee ◽  
Mark Tooley
Keyword(s):  
Airway Pressure ◽  
Gas Flow ◽  
Intrathoracic Pressure ◽  
Wheatstone Bridge ◽  
External Pressure ◽  
Electrical Circuit ◽  
Gas Pressure ◽  
Positive Pressure ◽  
Electrical Analogy ◽  
Metal Bellows

The physics of pressure, flow and the gas laws have been discussed in Chapter 7 in relation to the behaviour of gas and vapour. This section will focus on the physical principles of the measurement of gas pressure, volume and flow. Unlike a liquid, a gas is compressible and the relationship between pressure, volume and flow depends on the resistance to gas flow (or impedance if there is a frequency dependence between pressure and flow in alternating flow, see Chapter 4 for the electrical analogy of this) in conduits (bronchi, anaesthetic tubing); it also depends on the compliance of structures being filled and emptied (alveoli, reservoir bags, tubing or bellows). Normal breathing occurs by muscular expansion of the thorax, thus lowering the intrathoracic pressure, allowing air or anaesthetic gas to flow towards the alveoli down a pressure gradient from atmospheric pressure. When positive pressure ventilation occurs, gas is ‘pushed’ under pressure into the alveoli. Depending on the exact relationship between the ventilator and the lungs, different relationships exist between airway pressure (rather than alveolar pressure, which cannot easily be measured) and gas flow and volume. Gas pressure measurement devices were traditionally in the form of an aneroid barometer, a hollow metal bellows calibrated for pressure and temperature, which contracts when the external pressure on it increases, and expands when it decreases. The movement is linked to a pointer and indicator dial. It is often more convenient to make the device in the shape of part of a circular section, but the principle is the same. This is what the Bourdon gauge, which commonly measures pressure in gas cylinders, looks like. The detection of movement of the diaphragm of an aneroid barometer can take several forms. The movement can either be linked via a direct mechanical linkage to a pointer, or diaphragm movement can be linked to a capacitative or inductive element in an electrical circuit, such as a Wheatstone bridge. Airway pressure during spontaneous breathing or artificial ventilation is low. The preferred units of measurement are cm H2O and the range of values is between −20 and +20 cmH2O. The aneroid barometer to measure this will therefore be of light construction, using thin copper for the bellows material.

The variability of bite force measurement between sessions, in different positions within the dental arch

1998 ◽  
Vol 25 (9) ◽  
pp. 681-686 ◽  
Author(s):  
D. Tortopidis ◽  
M. F. Lyons ◽  
R. H. Baxendale ◽  
W. H. Gilmour
Keyword(s):  
Force Measurement ◽  
Bite Force ◽  
Dental Arch

Micro Double Pressure Sensor for Measuring the Applying Forces in Balloon Angioplasty

2013 ◽  
Author(s):  
Arman Dabiri
Keyword(s):  
Medical Device ◽  
Circuit Design ◽  
Balloon Angioplasty ◽  
Pressure Sensor ◽  
Wheatstone Bridge ◽  
Vascular Wall ◽  
Electrical Circuit ◽  
Mechanical Behaviors ◽  
Reaction Forces ◽  
Vessel Walls

This paper describes a new catheter based on double pressure sensor for measuring reaction forces of cardiovascular vessel walls in balloon angioplasty. This medical device is based on Wheatstone bridge and a passive transformer module. It assists cardiologists to measure reaction forces exiting between the catheter and the vascular wall. Reaction forces on the catheter can be grouped into two types: 1) reaction forces on the catheter head and 2) reaction forces between the balloon and the vascular wall. Its new proposed transducer module aids doctors decrease cardiology steps leading to the reduction of patients’ pains from inputting consecutive catheters into their bodies. Moreover, its special circuit design reduces needing wires for power supplying of the sensors, and simplifies the fabrication processes. Finally, mechanical behaviors of the sensor have been simulated in SolidWorks and its electrical circuit is modeled in Simulink\electrical. Also, Fabrication processes are projected in the final step of designing.

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