719 results about "Length change" patented technology

A heat exchanger with a plurality of stacked flat tubes and a collecting tank having a wall extending around the entire periphery of, and connected to, the end of the stacked flat tubes. A first medium may be distributed through the collecting tank and flat tubes. Internal inserts are in the flat tubes, with the inserts being bonded between the broad sides of the tubes and, in the region of connection of the tubes to the collecting tank, being configured to compensate for length changes in the stacking direction caused by temperature changes, as by recesses in connectors such as wave flanks or by corrugated wave flanks. The flat tubes with inserts such as described may be separately provided for use in manufacture of heat exchangers.

A method for 3D reconstruction of the positions of a catheter as it is moved within a region of the human body, comprising: (a) ascertaining the 3D position of a point on a catheter for insertion in the body region; (b) acquiring a fixed angle, single-plane fluoroscopic image of the body region and of the catheter; (c) transferring the image data and catheter-point position to a computer; (d) determining the 2D image coordinates of the point on the catheter; (e) changing the length of catheter insertion by a measured amount; (f) thereafter acquiring a further single-plane fluoroscopic image of the body region and the catheter from the same angle, transferring the length change and additional image data to the computer, and determining the 2D image coordinates of the point on the catheter; (g) computing the 3D position of the catheter point; and (h) repeating steps e-g plural times. A 3D model is constructed by assembling the plural 3D positions of the point within the body region into a 3D model of the region.

Broadband energy incident on a transducer having partially or fully reflective surfaces separated by a gap which is greater than the coherence length of the broadband energy but smaller than one-half a coherence length of a band of energy within said broadband energy causes a portion of the spectral content of the broadband energy corresponding to a coherence length greater than twice the gap length to exhibit interference effects while the average power of the broadband energy remains unaffected. Splitting energy reflected from the transducer into two beams which are filtered at preferably similar center frequencies but with different pass bands yields beams which are radically different in sensitivity to changes in gap length. Analyzing the beams to derive a ratio of powers (since source intensity and fiber attenuation in a common fiber are thus self-cancelling) allows high accuracy and high resolution absolute measurement of temperature, pressure or strain. Effects of any of these physical parameters which are not of interest in a measurement can be fully compensated or made arbitrarily insignificant in a simple transducer structure of extremely small size. Use of broadband energy permits measurement over greater lengths of optical fiber.

The invention discloses a rope-driven waist rehabilitation robot. The robot comprises a frame, a gravity balance unit, rope winding and unwinding units, a rope-driven rehabilitation exercise unit and a control unit, wherein the rope-driven rehabilitation exercise unit comprises a rehabilitation waist belt, pulling ropes and a guide pulley; the rehabilitation waist belt is at least connected with six pulling ropes; each pulling rope corresponds to one rope winding and unwinding unit; and the control unit controls the length change of the corresponding pulling rope by controlling each rope winding and unwinding unit so as to drive the waist of a rehabilitation patient to move along a pelvic movement track of a normal person during walking. Therefore, aiming at the problem of a coordination control mode of controlling the pelvic movement track of the rehabilitation patient in the rehabilitation training process, the rehabilitation patient can move along the pelvic movement track of the normal person under standing and walking conditions through the coordinated action of a set of gravity balance unit and a plurality of pulling ropes so as to achieve an effective waist rehabilitation training effect; and the robot can perform configuration change and rehabilitation training amplitude and strength adjustment according to the disease condition and individual difference of the rehabilitation patient.

A system and method for generating an optical laser pulse train of constant ultrashort pulse duration and low timing jitter in a fiber ring laser system (resonator) while keeping the laser resonator resilient to environmental conditions like temperature, humidity and pressure. The laser resonator may be actively mode-locked with a periodic electrically driven modulation at a specific frequency that corresponds to the inverse of the transit time inside the resonator. The optical pulse train quality may be monitored in real time, and the frequency of the modulation may be dynamically tuned in real time to compensate for resonator length changes due to changes in the environmental conditions.

The invention provides a vapor-liquid two-phase flow tube shell type heat exchanger. The heat exchanger comprises a shell, wherein sealing heads are arranged at two ends of the shell respectively; tube plates are arranged in connection positions between the sealing heads and the shell; heat exchange tubes are connected with the tube plates at two ends; vapor phase in vapor-liquid two-phase flow can be condensed into liquid phase in the heat exchange process; the vapor-liquid two-phase flow flows in a tube process; separation devices used for decreasing vibration and reducing noise are arranged in the heat exchange tubes; a plurality of separation devices are arranged in the same heat exchange tube; the length of the separation devices is gradually reduced along the flowing direction of flow in the heat exchange tubes. According to the vapor-liquid two-phase flow tube shell type heat exchanger, the vibration of the tubes can be decreased to a maximum extent due to the length change of the separation devices when the vapor-liquid two-phase flow flows in the tubes; the noise level is reduced; meanwhile, the flowing resistance is reduced; the heat exchange uniformity is improved.

The time-of-flight mass spectrometers which must demonstrate a high constancy of the calibrated mass scale even under changeable ambient temperatures and thermal loads due to pumps or electronics. Time-of-flight mass spectrometers calculate the masses of ions from the measured time of flight in a long flight tube that is normally manufactured of stainless steel. These flight tubes are subject to temperature-related length changes which affect the flight time and therefore the mass determination. The thermal expansion of spectrometer parts between ion source and ion detector, thus keeping the flight path for the ions at a constant length. Length compensation can be produced by design of the spacing system made of materials of different thermal expansion coefficients, the length changes of which balance out in opposite directions.

An isolation assembly for downhole injection use is described that features at least one isolation device mounted on a tubular so that when injection fluid changes the tubular temperature which can cause a length change in the tubular, an anchor for the tubular is provided to resist such a dimension change. The result is that the isolation device such as a packer can be left undamaged and retaining its sealing integrity. The anchor can be an inflatable or telescoping pistons disposed to grab in open hole. When using telescoping pistons, their placement on the liner and their pattern can meet the desired locations where grip is enhanced. Use of cement inflatable anchors is contemplated as an alternative.

The invention provides a wireless communication terminal device and a gap allotting method capable of completing a measuring process at high speed and reducing the number of retransmissions. Upon determining that the average number of retransmissions exceeds the parameter for the average number of retransmissions in gap length change judging unit (115), a gap changing unit (125) changes the currently set gap length using a gap off duration “G_Off_Duration”. A gap pattern setting unit (120) sets a gap pattern based on a gap parameter or the changed gap length, and a measuring unit (130) creates a gap by using the set gap pattern and measures the reference signal in a physical layer input during the gap.

The invention relates to the technical field of a camera, and especially relates to a miniature optical anti-vibration camera module. The module at least is equipped with a lens, an automatic focusing voice coil motor, an image sensor module and a miniature memory alloy optical anti-vibration actuator. The lens is fixed on the automatic focusing voice coil motor. The image sensor module sends an image obtained by the lens. The automatic focusing voice coil motor is fixed on the miniature memory alloy optical anti-vibration actuator. A control chip drives the automatic focusing voice coil motor to move based on length change of a memory alloy wire on the miniature memory alloy optical anti-vibration actuator, thereby realizing vibration compensation of the lens. According to the module, the module structure is simplified, the cost is reduced, the power consumption is low, through novel layout of a flexible circuit board, the relative movement problem of a moving board and a fixed board is solved, multi-line connection is realized, the technology is simple, the structure stability is high, the integrated height of the module will not be increased, and the product structure is light and miniature.

A heart-rate sensor for detecting artery blood-flow volume per unit length change in a human or animal subject, which comprises an antenna for sensing the instantaneous volume of blood in the artery of the subject, to be measured; a RADAR unit for transmitting microwave signals into a subject's body part or limb representing tissue targets. The output of the RADAR unit includes a superposition of signals each of which corresponding to a different tissue target with amplitudes that relate to the target's reflection strength; a sampling circuitry for converting reflected signals to digital; a window function circuitry for suppressing unwanted spectral sidebands originating from the subsequent processor operating on time truncated data; an FFT processor following the window function circuitry, for splitting the superposition according to its relative frequency into a multiplicity of bins, each of which with an amplitude that represents the reflection magnitude of a target at a specific distance from the antenna; a signal processor for filtering out the effect of the sensor movement with respect to the subject body part, or the movement of the body part, and for generating a signal, the amplitude of which is proportional to the artery varying dilatation representing the heart-rate; a heart-rate estimator for measuring the frequency of the artery dilatation variations and for canceling the interference of the amplitude of any signal that does not originate from the artery; a battery for powering the sensor.

The invention provides a steam boiler. The steam boiler comprises an upper boiler barrel, a lower boiler barrel, rising pipes and falling pipes, wherein the rising pipes and the falling pipes are connected between the upper boiler barrel and the lower boiler barrel. The rising pipes are internally provided with flow stabilizers, and the multiple flow stabilizers are arranged in the same rising pipe; and the lengths of the flow stabilizers are constantly increased in the fluid flowing direction of the rising pipes. According to the flow stabilizer steam boiler of a novel structure, through length changing of the flow stabilizers, when steam-liquid two phase flowing exists in the rising pipes, heat transmission is reinforced; and meanwhile, vibration of the rising pipes is weakened, and the noise level is reduced.

Provided is an extreme learning machine based on a length-changing particle swarm optimization algorithm. The method comprises the steps that (1) the position and the speed of a particle swarm are initialized randomly, each particle in the particle swarm represents an ELM classifier; (2) an adaptation value f(p) for an evaluation function of each particle is computed; (3) the magnitude relationship of the row number of particles and the row number of globally optimal solution is compared, different updating formulas are selected to update the speed and the positions of the particles, a next generation of particle swarm is generated; (4) the optimum hidden unit number and corresponding input weight and hidden unit offset are selected; (5) output weight is computed, and the ELM classifier with the highest cross validation accuracy is obtained. The hidden unit number is automatically selected through the length-changing particle swarm optimization algorithm, and meanwhile the corresponding input weight and hidden unit offset are selected, so that the generalization performance of the ELM classifier is maximum, the ELM classifier with a small number of the hidden units can obtain the maximum generalization performance, testing time is short, and efficiency is high.