We draw a certain analogy between the classical information–theoretic problem of lossy data compression (source coding) of memoryless information sources and the statistical mechanical behavior of a certain model of a chain of connected particles (e.g., a polymer) that is subjected to a contracting force. The free energy difference pertaining to such a contraction turns out to be proportional t...

BACKGROUND A lack of consistent guidelines regarding mammographic compression has led to wide variation in its technical execution. Breast compression is accomplished by means of a compression paddle, resulting in a certain contact area between the paddle and the breast. This procedure is associated with varying levels of discomfort or pain. On current mammography systems, the only mechanical p...

Headless screws are favored for internal fixation in the treatment of displaced or unstable small bone (e.g., Scaphoid) fractures, because they are embedded below the articular surface of the bone, reducing tissue irritation and immobilization. Compression plays an important role in fracture stability, maintaining gap reduction and also accelerating the healing of cancellous bone [1]. There are...

Injuries involving the midtarsal joint, which are frequently misdiagnosed, have been studied to clarify the mechanism, classification and treatment. The necessity for routine antero-posterior, lateral and oblique radiographs is emphasised. Seventy-one injuries have been classified according to the direction of the deforming force:medial, longitudinal compression, lateral, plantar and crush type...

We draw a certain analogy between the classical information–theoretic problem of lossy data compression (source coding) of memoryless information sources and the statistical mechanical behavior of a certain model of a chain of connected particles (e.g., a polymer) that is subjected to a contracting force. The free energy difference pertaining to such a contraction turns out to be proportional t...

QUESTION What is the relationship between vibration of the chest wall and the resulting chest wall force, chest wall circumference,intrapleural pressure, and expiratory flow rate? Is the change in intrapleural pressure during vibration the sum of the intrapleural pressure due to recoil of the lung, chest wall compression, and chest wall oscillation? DESIGN Randomised, within-subject,experimen...

PURPOSE The purpose of this study was to compare the interfragmentary compression force across a simulated scaphoid fracture by two commonly used compression screw systems; the Acutrak 2 Standard and the 3.0 mm Synthes headless compression screw. METHODS Sixteen (8 pairs; 6 female, 2 male) cadaver scaphoids were randomly assigned to receive either the Acutrak 2 or Synthes screw with the contr...

Background: With respect to physical relations in force and pressure, we hypothesized that the prevalence of traumatic tympanic membrane perforation in patients with a patulous Eustachian tube is greater than normal, because in Eustachian tube patency, the internal air pressure of the middle ear will not increase after compression, subsequent to trauma. Therefore the force upon the tympanic...

OBJECTIVE To determine the effect of visual feedback on rate of chest compressions, secondarily relating the forces used. DESIGN Randomised crossover trial. SETTING Tertiary teaching hospital. SUBJECTS Fifty trained hospital staff. INTERVENTIONS A thin sensor-mat placed over the manikin's chest measured rate and force. Rescuers applied compressions to the same paediatric manikin for two...

Metal forming processes, compared with machining ones, reduce production steps and increase manufacturing speed in addition to saving raw material. In this paper, forming process of column of a steering mechanism is investigated by finite element analyses and experimental tests; and optimum die design parameters are found. Forming process parameters including die opening angle, bearing length, ...