172 results about "Mechanical impedance" patented technology

A physiological sensing stethoscope suitable for use in high-noise environments is disclosed. The stethoscope is designed to be substantially matched to the mechanical impedance of monitored physiological activity and substantially mismatched to the mechanical impedance of air-coupled acoustic activity. One embodiment of the stethoscope utilizes a passive acoustic system. Another embodiment utilizes an active Doppler system. The passive and active systems can be combined in one stethoscope enabling switching from a passive mode to an active mode suitable for use in very high-noise environments. The stethoscope is suitable for use in environments having an ambient background noise of 100 dBA and higher. The passive includes a head having a housing, a flexural disc mounted with the housing, and an electromechanical stack positioned between the housing and the flexural disc in contact with the skin of a patient. The active system detects Doppler shifts using a high-frequency transmitter and receiver.

In a robot arm controlling device, a mechanical impedance set value of the arm is set by an object property-concordant impedance setting device based on information of an object property database in which information associated with properties of an object being gripped by the arm is recorded, and a mechanical impedance value of the arm is controlled to the set mechanical impedance set value by an impedance controlling device.

A control device for a robot arm is designed such that, based on information on a transportation state database in which information on a transportation state of a person operating the arm is recorded, an impedance setting unit sets a mechanical impedance set value of the arm, and an impedance control unit controls a mechanical impedance value of the arm to the mechanical impedance set value thus set.

In one aspect, the invention provides methods and apparatus facilitating an adjustable-stiffness prosthesis or orthosis (including approximations to arbitrarily definable non-linear spring functions). Spring rates may be varied under no-load conditions during a walking gate cycle to minimize power consumption. In another aspect, the invention provides methods and apparatus for outputting positive power from a prosthesis or orthosis, facilitating high-performance artificial limbs. In one embodiment of the invention, the positive power is transferred from a functioning muscle to the prosthesis or orthosis, which mimics or assists a non-functioning or impaired muscle. In another embodiment of the invention, the positive power comes from an on-board power source in the prosthesis or orthosis.

A hand-held massager capable of self-excited, impedance-matched vibration for optimal massaging of each particular body part of each particular individual. The massager includes a hollow, open-ended contact piece to which is coupled a vibrator and which is to be held against a desired body part. A pressure sensor is mounted to the contact piece for sensing pressure variations in the cavity in the contact piece while the open end thereof is held against the body part, in order to ascertain the mechanical impedance of that body part. A closed-loop, electropneumatic vibration control system makes it possible for the mechanical impedance to be fed back to the vibrator, causing the latter to make self-induced vibration. Thus the desired body part is optimally massaged at its resonance frequency.

A segmented, electro-mechanical, remotely controlled programmable impedance tuner for the frequency range between 10 and 200 MHz uses a cascade of three continuously variable mechanical capacitors interconnected by a set of two low loss flexible or semi-rigid cables; the electrical length of the interconnecting cables between the capacitors determines the frequency at which tuning coverage of the entire area of the Smith chart is optimum; for maximum impedance coverage the length is to be chosen such as to generate a transmission phase shift of 60 degrees at the center frequency between each capacitor stage. Remote tuning is possible by changing the value of the capacitors using electrical stepper motors. The tuner is calibrated using a vector network analyzer and the data are saved in the memory of the control computer, which then allows tuning to any user defined impedance within the tuning range. Reflection factor values between 0 and higher than 0.9 can be obtained using this tuner.

Disclosed is an apparatus and methodology for structural health monitoring (SHM) in which smart devices interrogate structural components to predict failure, expedite needed repairs, and thus increase the useful life of those components. Piezoelectric wafer active sensors (PWAS) are applied to or integrated with structural components and various data collected there from provide the ability to detect and locate cracking, corrosion, and disbanding through use of pitch-catch, pulse-echo, electro/mechanical impedance, and phased array technology. Stand alone hardware and an associated software program are provided that allow selection of multiple types of SHM investigations as well as multiple types of data analysis to perform a wholesome investigation of a structure.

A loudspeaker comprising a panel-form acoustic member adapted for operation as a bending wave radiator and an electrodynamic moving coil transducer having a voice coil mounted to the acoustic member to excite bending wave vibration in the acoustic member. The junction between the voice coil and the acoustic member is of sufficient length in relation to the size of the acoustic member to represent a line drive such that the acoustic member has a mechanical impedance which has a rising trend with bending wave frequency.

A polymer interlayer having improved sound insulation is disclosed. The polymer interlayer comprises at least one soft layer wherein the soft layer comprises: a first poly(vinyl butyral) resin having a first residual hydroxyl content and a first glass transition temperature (T_g); a second poly(vinyl butyral) resin having a second residual hydroxyl content and a second glass transition temperature (T_g), wherein the difference between the first residual hydroxyl content and the second residual hydroxyl content is at least 1.0 weight percent; wherein the difference between the first glass transition temperature (T_g) the second glass transition temperature (T_g) is at least 1.5° C.; and a plasticizer; at least one stiffer layer comprising a third poly(vinyl butyral resin) having a third residual hydroxyl content; and a plasticizer, wherein the polymer interlayer has a damping loss factor (q) (as measured by Mechanical Impedance Measurement according to ISO 16940) of at least about 0.16 measured at two or more different temperatures selected from 10° C., 20° C. and 30° C.

The invention relates to a wideband sound absorption structure combing mechanical impedance of composite resonance cavities with micropunch plates, and belongs to the technical field of environmental noise control. The wideband sound absorption structure comprises one or more layers of micropunch plates in the front of the structure and a mechanical impedance plate at the rear part of the structure, wherein the micropunch plates and the mechanical impedance plate are all fixed on a bracket; the mechanical impedance plate is formed by an elastically supported thin plate; Helmholtz resonance cavities are compositely arranged on the mechanical impedance plate; each Helmholtz resonance cavity consists of a cavity body and an insertion tube. According to the wideband sound absorption structure, Helmholtz resonance units are designed on the mechanical impedance plate, and the thicknesses of the resonance cavities are smaller, thus the whole structural thickness does not change too much. The micropunch plates can have good sound absorption effect for middle-frequency and high-frequency noises, and a plurality of absorption peaks can be generated at low frequency through a mechanical impedance unit and the Helmholtz resonance units, so that the whole structure can ensure good middle-frequency and high-frequency sound absorption performance and also has good sound absorption effect at low frequency.

A low cost eccentric mass motor vibrotactile transducer provides a point-like vibrational stimulus to the body of a user in response to an electrical input. Preferably the eccentric mass and motor form part of the transducer actuator moving mass. The actuator moving mass is constrained into vertical motion by a spring between the actuator housing and moving mass. The actuator moving mass is in contact with a skin (body) load. The actuator housing is in simultaneous contact with the body load. The mass of the motor/contactor assembly, mass and area of the housing, and the compliance of the spring are chosen so that the electromechanical resonance of the motional masses, when loaded by the typical mechanical impedance of the skin (body), are in a frequency band where the human body is most sensitive to vibrational stimuli 150-300 Hz.

An acoustic device comprising a diaphragm (10) having an area and having an operating frequency range and the diaphragm (10) being such that it has resonant modes in the operating frequency range, an electromechanical transducer having a drive part coupled to the diaphragm (10) and adapted to exchange energy with the diaphragm, and at least one mechanical impedance means (20,22,24) coupled to or integral with the diaphragm, the positioning and mass of the drive part (26) of the transducer and of the at least one mechanical impedance means (20,22,24) being such that the net transverse modal velocity over the area of the diaphragm (10) tends to zero. A method of making an acoustic device having a diaphragm having an area and having an operating frequency range which includes the piston-to-modal transition, comprising choosing the diaphragm parameters such that it has resonant modes in the operating frequency range, coupling a drive part of an electro-mechanical transducer to the diaphragm to exchange energy with the diaphragm, adding at least one mechanical impedance means to the diaphragm, and selecting the positioning and mass of the drive part of the transducer and the positioning and parameters of the at least one mechanical impedance means so that the net transverse modal velocity over the area tends to zero.

An automatic multi frequency-range electro-mechanical impedance tuner covers frequencies from a low megahertz to a high gigahertz range, by combining a high frequency with one or two a low frequency tuner modules; the low frequency module is made using either variable phase shifter-capacitor or multi-capacitor-transmission line tuner structures. The high frequency module is a single, double or triple probe slide screw tuner covering up to 1.5 decades in frequency; the low frequency tuner is using cascades of three or more capacitor-coax cable tuning sections or a low frequency phase shifter combined with a variable shunt capacitor; the low frequency tuner can operate as low as a few megahertz whereas the high frequency tuner can operate up to several gigahertz. Depending on the application, low frequency parallel-blade capacitors or high frequency coaxial trimmers are used. Typical cross-over frequencies between low and high frequency modules range from 200 to 800 megahertz, lowest frequencies can reach below 10 megahertz and highest frequencies 26 to 40 gigahertz. Appropriate calibration, control and tuning procedures allow for a fully integrated operation.

The invention provides a thin broadband sound-absorbing structure. The structure comprises a sound-absorbing material, a support and at least two layers of mechanical impedance plates, wherein the sound-absorbing material is installed on the inner side of one end of the support, a supporting plate is arranged on the inner wall of the other end of the support, each of the mechanical impedance plates consists of a back plate and sticky elastic rings at two ends of the back plate, adjacent back plates are not in contact, sticky elastic rings are stuck to the supporting plate through an adhesive, the sticky elastic rings, the support inner wall and the back plates are attached tightly, a hollow is formed among the sound-absorbing material and the mechanical impedance plates, and the back plate on the outermost side is recessed towards the support end face by certain distance. Mechanical impedance is coupled to a traditional sound-absorbing material and a cavity resonance absorption mechanism, a novel thin broadband sound-absorbing mechanism is formed, the structure thickness is not increased basically based on the acoustic performance, the middle/high-frequency sound absorption performance is good, the low-frequency sound absorption effect is improved greatly and the sound-absorbing structure of which the thickness is thin and the sound-absorbing frequency band is wide is produced.

Disclosed herein is a golf ball with a solid core having a PGA compression of 55 or less and an outer cover layer having a Shore D hardness of at least 60, the ball having a PGA compression of 80 or less. In another embodiment of the invention, the ball has a mechanical impedance with a primary minimum value in a frequency range of 3100 Hz or less after the ball has been maintained at 21.1° C., 1 atm. and about 50% relative humidity for at least 15 hours. A further embodiment of the invention is a golf ball having a core, and a cover with a Shore D hardness of at least 58, the ball having a mechanical impedance with a primary minimum value in the frequency range of 2600 Hz after the ball has been maintained at 21.1° C., 1 atm. and about 50% relative humidity for at least 15 hours. The balls of the invention have good distance while providing a soft sound and feel.

The invention discloses a wide band sound absorption structure of film mechanical impedance combined with micropunched plate acoustic impedance, which comprises an upper support and a lower support which are fixedly and perpendicularly connected with a wall. A front micropunched plate and a rear micropunched plate are fixedly and perpendicularly connected between the two supports. A rectangular cavity is formed respectively between the front micropunched plate and the rear micropunched plate and between the rear micropunched plate and the wall. In the rectangular cavity formed by the rear micropunched plate and the wall, the inner side faces of the two supports are respectively and fixedly connected with a groove structure with the front face of a groove mouth facing the rear micropunchedplate in a vertically symmetrical mode. An elastic ring is closely bonded in the groove mouth of the groove structure in an adhesive mode and bonded with a composite film in an adhesive mode, and thecomposite film is formed by evenly pasting an elastic film and a sound insulation film. A mechanical impedance unit formed by films is added in a rear cavity. The micropunched plate is combined with mechanical impedance of films, the micropunched plate structure is utilized to absorb sound energy at middle and high band, and mechanical impedance of films is utilized to absorb sound energy for lowfrequency. The broadband sound absorption structure has the advantage that sound absorption frequency band is wide.