Offset Point Research Articles

Characterization of accurate 3D collimator-detector response function for single- and multi-lofthole collimated SPECT cameras.

Collimator-detector response function (CDRF) of a SPECT scanner refers to the image generated from a point source of activity. This research aims to characterize the CDRF of a breast-dedicated SPECT imager equipped with a lofthole collimator using GATE Monte Carlo simulation. To do so, a cylindrical multi-lofthole collimation system with lofthole apertures dedicated to breast imaging was modeled using the GATE Monte Carlo simulator. The dependency of the CDRF on the source-to-collimator distance of a single-lofthole as well as 8-lofthole collimations was assessed and then compared. In addition, the 3D-sensitivity map of the 8-lofthole collimation was derived. Finally, fair comparisons were conducted between the response of the 8-lofthole collimator and that of an 8-pinhole and also existing analytical derivations. In all cases, a data acquisition period of 5.0 min with an in-air 99mTc point source was considered. For the single-lofthole collimator, 4.5 times increasing the magnification factor leads to a 16- and twofold improvement in the sensitivity and spatial resolution, respectively. In the single-lofthole collimator, the resolution and sensitivity are degraded as the source-to-aperture distance increases. For the cylindrical 8-lofthole collimator, the findings confirm that CDRF strongly depends on source-to-aperture distance and angle of photon incidence. For a 30 mm in-plane offset point, a 25% increase in sensitivity is observed compared to that of the center of the FOV. Increasing the angle from 0 to 34 results in a 50% reduction in sensitivity. Furthermore, the findings illustrate that spatial resolution follows a quadratic function as where d is an offset along the x-, y-, and z-axis, and R0 is the spatial resolution at the center of the FOV. In conclusion, both spatial resolution and sensitivity of the lofthole collimation are considerably angle- and offset-dependent within the FOV of single- and multi-lofthole collimated SPECT imagers.

Real Gas Corrections Based on the Interaction of One-Dimensional Unsteady Waves in a Shock Tube

There are multiple unsteady wave system interactions such as shock waves, expansion waves, and reflection, transmission, and intersection of the contact surface inside a shock tube. Studying the law of unsteady wave system interaction has important guiding significance for the design of gas wave equipment. This paper proposes a solution method for the interaction law of unsteady wave systems based on real gas equation of state (EoS) and applies it to shock tubes. The results show that the temperature maximum error between the code based on ideal gas EoS and simulation results is 3.64%, and the error of wave velocity results is between 2.99% and 18.27%. While the error of temperature results between code based on real gas EoS and simulation is not exceed 3%. More importantly, the wave velocity calculated by the code based on real gas EoS is pretty consistent with the simulation results. The code based on the real gas model can help to solve the problem of offset design point. Research has also shown that as pressure and temperature gradually increase, the deviation between ideal and real gases increases, which also proves that the influence of real gas effects is becoming increasingly significant.

Flexspline Pitch Deviation Rapid Measurement Method Using Offset Point Laser Sensors

Flexsplines in harmonic gear reducers are usually characterized by a large number of teeth, small modulus, and poor stiffness, which makes them difficult to measure using conventional gear measuring centers. In order to efficiently evaluate the quality of flexsplines in harmonic gear reducers, a rapid measurement method for flexspline pitch using offset point laser sensors (PLS) is proposed. This paper investigates the principle of measuring the tooth flank of the flexspline under the offset of the PLS, establishes a model for collecting and analyzing gear surface data, builds an experimental system, calibrates the six pose parameters of the sensor using the geometric features of the flexspline’s outer circular surface, and completes the reconstruction of the left and right gear surfaces of the flexspline based on the measured data. In the experiment, the gear surface obtained by the proposed method is largely consistent with that measured by the video imaging method, and the repeatability of both single pitch deviation and cumulative pitch deviation is within ±3 µm.

A new method for interpreting well-to-well interference tests and quantifying the magnitude of production impact: theory and applications in a multi-basin case study

Interference tests are used in shale reservoirs to evaluate the strength of connectivity between wells. The results inform engineering decisions about well spacing. In this paper, we propose a new procedure for interpreting interference tests. We fit the initial interference response with the solution to the 1D diffusivity equation at an offset observation point. It is advantageous to use the initial interference response, rather than the subsequent trend, because the initial response is less affected by nonlinearities, time-varying boundary conditions, and uncertainties about flow geometry and flow regime. From the curve fit, we estimate the hydraulic diffusivity and the conductivity of the fractures connecting the wells. For engineering purposes, it would be useful to quantify the impact of interference on well production. Thus, we seek a relationship between the ‘degree of production interference’ (DPI) and an appropriate dimensionless quantity that can be derived from the estimate of fracture conductivity. Using simulations run under a wide range of conditions, we find that the classical definition for dimensionless fracture conductivity does not achieve a consistent prediction of DPI. This occurs because the dimensionless fracture conductivity was derived assuming radial flow geometry, but the dominant flow geometry during shale production is linear. We also find that the Chow Pressure Group metric does not yield consistently accurate predictions of DPI. As an alternative, we derive a dimensionless quantity similar to the classical ‘dimensionless fracture conductivity,’ but which is derived for linear, not radial, flow geometry. Using this approach, we calculate a ‘dimensionless interference length’ that collapses all cases onto a single curve that predicts DPI as a function of fracture conductivity, well spacing, and formation properties. We conclude by applying the new method to field cases from the Anadarko and Delaware Basins.

The influence of different offset modes on the drainage characteristics of a double stack drainage system in a high-rise building

To meet the functional requirements of high-rise buildings, drainage stacks usually employ an offset pipe in the structural transfer floor. At the offset point, the flow direction changes and the air pressure fluctuates, which significantly influences the drainage system capacity and water seal effectiveness. Different offset modes have different degrees of influence on drainage characteristics. To better understand the influence of different offset modes on drainage characteristics, five different test conditions in double stack building drainage systems were established and investigated. DS1 was a standard double-stack drainage system with anti-reflux H-tube joints for every two floor levels. The remaining four systems were developed from DS1 by adopting various offset pipes (or pipe joints) on the fourth floor. DS2 adopted an S-shape offset pipe joint at the offset point. DS3 adopted double S-shape offset pipe joints. DS4 adopted a 1.0-m-long horizontal offset pipe. DS5 adopted a 1.5-m-long horizontal offset pipe. The pressure fluctuations and water seal losses were chosen as the experimental parameters to determine the maximum discharge capacity according to the Standard for Capacity Test of Vertical Pipe of the Domestic Residential Drainage System CJJ/T 245. The experimental results demonstrated that the installation of offset pipes (or pipe joints) contributed to the abrupt positive pressure and severe water seal losses at the position where flow direction shifted. As the length of the offset pipe increased, the positive pressure was more severe, and maximum discharge capacity was minor. The relationships among the maximum discharge rate, pressure fluctuation limits, and water seal losses are discussed. Lastly, a nondimensional analysis was adopted to understand the relationship between water seal losses and pressure limit values under different discharge rates for current test facilities. Practical application: Pipe offset has the potential to influence a drainage system discharge capacity. As the length of the horizontal offset pipe increases, the discharge capacity will decrease. In the actual design, the length of the offset pipe section should be reduced and this study demonstrates that the application of S-shape offset pipe joints is an efficient solution.

Towards Intricate Stand Structure: A Novel Individual Tree Segmentation Method for ALS Point Cloud Based on Extreme Offset Deep Learning

Due to the complex structure of high-canopy-density forests, the traditional individual tree segmentation (ITS) algorithms based on ALS point cloud, which set segmentation threshold manually, is difficult to adequately cover a variety of complex situations, so the ITS accuracy is unsatisfactory. In this paper, a top-down segmentation strategy is adopted to propose an adaptive segmentation method based on extreme offset deep learning, and the ITS set aggregation strategy based on gradient change criterion is designed for the over-segmentation generated by random offset, and the precise ITS is realized. Firstly, the segmentation sub-plot is set as 25 m × 25 m, the regional point cloud and its treetop are marked, and the offset network is trained. Secondly, the extreme offset network is designed to carry out spatial transformation of the original point cloud, and each point is offset to the position near the treetop to obtain the offset point cloud with a high density at the treetop, which enhances the discrimination among individual trees. Thirdly, the self-adaptive mean shift algorithm based on average neighboring distance is designed to divide and mark the offset point cloud. Fourthly, the offset point cloud, after clustering, is mapped back to the original space to complete the preliminary segmentation. Finally, according to the gradient change among different canopies, the ITS aggregation method is designed to aggregate adjacent canopies with a gentle gradient change. In order to investigate the universality of the proposed method on different stand structures, two coniferous forest plots (U1, U2) in the Blue Ridge area of Washington, USA, and two mixed forest plots (G1, G2) in Bretten, Germany, are selected in the experiment. The learning rate of the deep network is set as 0.001, the sampled point number of the sub-plot is 900, the transformer dimension is 512 × 512, the neighboring search number of points is 16, and the number of up-sampling blocks is 3. Experimental results show that in mixed forests (G1, G2) with complex structures, the F-score of the proposed method reaches 0.89, which is about 4% and 7% higher than the classical SHDR and improved DK, respectively. In high-canopy-density areas (U2, G2), the F-score of the proposed method reaches 0.89, which is about 3% and 4% higher than the SHDR and improved DK, respectively. The results show that the proposed method has high universality and accuracy, even in a complex stand environment with high canopy density.

Evolutionary algorithm-based model predictive control for a reactive distillation column in biodiesel production

Biodiesel is touted to be an alternative to the fossil fuels as it is conducive to the environment. This investigation proposes a control framework to produce biodiesel in a reactive distillation column via a transesterification process. To extract quality product, the temperature profile must be maintained along the column as per the requirements. However, constant interactions among the products inside the column disturb the temperature profile and consequently the product quality. Therefore, this investigation treats the process as a single input and single output system, where in the process interactions are modelled as disturbances. A model predictive controller (MPC) is designed for the proposed system to ensure product quality. The MPC parameters must be selected appropriately to ensure optimal performance. In this regard, to tune the MPC parameters optimally, we use two evolutionary algorithms namely, the real coded genetic algorithm (RGA) and the bio-geography based optimization algorithm (BBO). The results indicate the proposed control strategy provides offset free set point tracking when compared to the multivariable control strategy employed using the MPC algorithm. Among the two evolutionary controllers used for tuning the MPC parameters, the RGA MPC controller provides a satisfactory performance.

Modeling individual differences in the timing of change onset and offset.

Individual differences in the timing of developmental processes are often of interest in longitudinal studies, yet common statistical approaches to modeling change cannot directly estimate the timing of when change occurs. The time-to-criterion framework was recently developed to incorporate the timing of a prespecified criterion value; however, this framework has difficulty accommodating contexts where the criterion value differs across people or when the criterion value is not known a priori, such as when the interest is in individual differences in when change starts or stops. This article combines aspects of reparameterized quadratic models and multiphase models to provide information on the timing of change. We first consider the more common situation of modeling decelerating change to an offset point, defined as the point in time at which change ceases. For increasing trajectories, the offset occurs when the criterion attains its maximum ("inverted J-shaped" trajectories). For decreasing trajectories, offset instead occurs at the minimum. Our model allows for individual differences in both the timing of offset and ultimate level of the outcome. The same model, reparameterized slightly, captures accelerating change from a point of onset ("J-shaped" trajectories). We then extend the framework to accommodate "S-shaped" curves where both the onset and offset of change are within the observation window. We provide demonstrations that span neuroscience, educational psychology, developmental psychology, and cognitive science, illustrating the applicability of the modeling framework to a variety of research questions about individual differences in the timing of change. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Spatially Offset Raman Spectroscopy Combined with Attention-Based LSTM for Freshness Evaluation of Shrimp

Optical detection of the freshness of intact in-shell shrimps is a well-known difficult task due to shell occlusion and its signal interference. The spatially offset Raman spectroscopy (SORS) is a workable technical solution for identifying and extracting subsurface shrimp meat information by collecting Raman scattering images at different distances from the offset laser incidence point. However, the SORS technology still suffers from physical information loss, difficulties in determining the optimum offset distance, and human operational errors. Thus, this paper presents a shrimp freshness detection method using spatially offset Raman spectroscopy combined with a targeted attention-based long short-term memory network (attention-based LSTM). The proposed attention-based LSTM model uses the LSTM module to extract physical and chemical composition information of tissue, weight the output of each module by an attention mechanism, and come together as a fully connected (FC) module for feature fusion and storage dates prediction. Modeling predictions by collecting Raman scattering images of 100 shrimps within 7 days. The R2, RMSE, and RPD of the attention-based LSTM model achieved 0.93, 0.48, and 4.06, respectively, which is superior to the conventional machine learning algorithm with manual selection of the optimal spatially offset distance. This method of automatically extracting information from SORS data by Attention-based LSTM eliminates human error and enables fast and non-destructive quality inspection of in-shell shrimp.

Signal strength and integrated intensity in confocal and image scanning microscopy.

The properties of signal strength and integrated intensity in a scanned imaging system are reviewed. These properties are especially applied to confocal imaging systems, including image scanning microscopy. The integrated intensity, equal to the image of a uniform planar (sheet) object, rather than the peak of the point spread function, is a measure of the flux in an image. Analytic expressions are presented for the intensity in the detector plane for a uniform volume object, and for the resulting background. The variation in the integrated intensity with defocus for an offset point detector is presented. This axial fingerprint is independent of any pixel reassignment. The intensity in the detector plane is shown to contain the defocus information, and simple processing of the recorded data can improve optical sectioning and background rejection.

A 3D radius compensation method to reduce the influence of probe fluctuation error in blade space curve measurement

In the contact measurement of the coordinate measuring machine, the space curve cannot obtain the third-dimension information of its compensation vector by itself. Moreover, the fluctuation error of the probe will cause the unknown spatial offset of the contact point of the curve, making it more difficult to obtain the third-dimensional information of the compensation vector. A three-dimensional radius compensation method based on iterative third-dimensional information is proposed in this paper. The distance value between the intersection point and the compensation point is used as the convergence condition to approximate the offset contact point. The simulation test results show that the error accuracy of radial parameters is 0.1 μm and the error accuracy of Z-direction parameters is 1 μm when only Z-direction fluctuation error is considered. The real machine test results show that this method is closer to the actual situation than the two-dimensional radius compensation method.

Cricothyroid Dysfunction in Unilateral Vocal Fold Paralysis Females Impairs Lexical Tone Production.

In this cross-sectional study, we compared voice tone and activities relating to the laryngeal muscle between unilateral vocal fold paralysis (UVFP) patients with and without cricothyroid (CT) muscle dysfunction to define how CT dysfunction affects language tone. Eighty-eight female surgery-related UVFP patients were recruited and received acoustic voice analysis and laryngeal electromyography (LEMG) when the patient was producing the four Mandarin tones. The statistical analysis was compared between UVFP patients with (CT+ group, 17 patients) and without CT muscle (CT- group, 71 patients) involvement. When producing Mandarin Tone 2, the voice tone in the CT+ group had smaller rise range (p = 0.007), lower rise rate (p = 0.002), and lower fundamental frequency (F0) at the offset point of the voice (p = 0.023). When producing Mandarin Tone 4, the voice tone in the CT+ group had smaller drop range (p = 0.019), lower drop rate (p = 0.005), and lower F0 at voice onset (p = 0.025). The CT+ group had significantly lower CT muscle activity when producing the four Mandarin tones. In conclusion, CT dysfunction causes a limitation of high-rising tone in Tone 2 and high-falling tone in Tone 4, a property that dramatically limits the tonal characteristics in Mandarin, a tonal language. This limitation could further impair the patient's communication ability.

Local offset point cloud transformer based implicit surface reconstruction

AbstractImplicit neural representations, such as MLP, can well recover the topology of watertight object. However, MLP fails to recover geometric details of watertight object and complicated topology due to dealing with point cloud in a point‐wise manner. In this paper, we propose a point cloud transformer called local offset point cloud transformer (LOPCT) as a feature fusion module. Before using MLP to learn the implicit function, the input point cloud is first fed into the local offset transformer, which adaptively learns the dependency of the local point cloud and obtains the enhanced features of each point. The feature‐enhanced point cloud is then fed into the MLP to recover the geometric details and sharp features of watertight object and complex topology. Extensive reconstruction experiments of watertight object and complex topology demonstrate that our method achieves comparable or better results than others in terms of recovering sharp features and geometric details. In addition, experiments on watertight objects demonstrate the robustness of our method in terms of average result.

Overcoming the influence of a 2 metre long pipe offset on water flow capacity of drainage with secondary ventilation in a high-rise building

A potential consequence of installing a 2 m long pipe offset on a ventilated drainage system in a high-rise buildings is that the water seal could be damaged when the flowrate exceeds the maximum discharge capacity of a drainage system, thereby threatening the indoor health safety. Some high-rise buildings are designed for commercial and residential use to achieve economic and social benefits, so the whole building use and layout changes in the vertical direction. The drainage stack may be designed with an offset between floors to avoid structural obstacles inside the building. The flow direction change could destroy the water seal of sanitary appliances and threaten the health of residents. To better understand the influence of the form of a pipe offset on the drainage capacity, a full-scale experiment was conducted to study the secondary ventilated system with an antireflux H-tube pipe, which was equipped with two guide plates inside to improve the air-water flow pattern and prevent backflow, installed between floor. This study also considered a kind of offset where the offset distance was 2.0 m rather than the S-shaped offset joint, which is more common in commercial and residential complexes. The influence on the discharge capacity of installing an extra antireflux H-tube pipe was compared with normal 90-degree elbow and only one antireflux H-tube pipe above the offset point. The pressure fluctuation and water seal losses under constant discharge rates were adopted as experimental parameters to determine the maximum discharge capacity according to Standard for Capacity Test of Vertical Pipe of the Domestic Residential Drainage System. Results show that the installation of an extra antireflux H-tube pipe can release the air accumulation caused by pipe offset, and the combined installation of a large curvature elbow and an extra antireflux H-tube pipe can effectively improve the discharge capacity.Practical Application: 2 metre long offsets are not unusual in ventilated drainage systems in high-rise buildings, however, designers and builders do not pay sufficient attention to the adverse consequences of the pipe offset. An extra antireflux H-tube pipe can be installed above the offset joint to optimise the drainage system to perform as it would without the offset. In a system with 2 m long pipe offset, installing a large curvature elbow together with an extra antireflux H-tube pipe together provides a better effect.

FDTD Analysis on WPT Efficiency Between Circuit-Shape Leaky Waveguide and 𝝀/2 Dipole Antenna for Snow Melting Application

The wireless transfer characteristics between a circuit-shape leaky waveguide and a /2 dipole antenna were analyzed with scattering parameters obtained with the FDTD method. The circuit-shaped leaky waveguide was composed of two pairs of straight slotted waveguides and two semicircular waveguides. The circuit-shape leaky waveguide was designed to achieve uniform electromagnetic field distribution with a source for snow melting with microwave radiations by microwave heating. The electromagnetic field of the circuit-shape leaky waveguide was firstly simulated with the FDTD method. Although the electromagnetic distribution exhibited the point symmetry with an off-set feeding point and a slot spacing 𝝀𝒈, it was nearly uniform. The wireless transfer efficiency and the maximum transfer efficiency for four locations at 2.45 GHz revealed that the farthest location from the feeding point had the largest WPT efficiency among four locations. This ensures the circuit-shape leaky waveguide’s uniqueness. The circuit-shape leaky waveguide has favorable characteristics to provide WPT energy at any location above it.

Adjustment Method of “FAST” Active Reflector Based on Optimal Fitting Strategy

The adjustment method of the fast active reflector of “Chinese heavenly eye” is studied. Firstly, this paper studies the offset characteristics of fast main cable node position, combined with the position of the celestial body to be measured, the follow-up coordinate system is established, and the optimal fitting model of active reflector adjustment based on discrete main cable node is established by using the idea of optimal fitting of the ideal surface. Secondly, the genetic algorithm is used to solve the minimum root mean square error (RMSE). The offset of the triangular reflector is driven by the offset of the main cable node, so that the working area is closer to the ideal paraboloid, and the maximum electromagnetic wave signal receiving ratio is achieved. Finally, rotate the coordinate data of each main cable node according to the known celestial body angle and use the Lagrange operator method to obtain the shortest distance from the actual offset point to the ideal paraboloid as the objective function, with the radial expansion range of the actuator and the variation range of the distance between adjacent points as constraints, and the size of the electromagnetic wave contact area is the basis for judging the amount of information, and a reflector adjustment model for the optimal displacement strategy of discrete main cable nodes is established. Through the test, concluded that the optimal fitting strategy is ideal, the model can accurately obtain the fast active reflector adjustment method under the constraint conditions. Through the test, the conclusion that the optimal fitting strategy is ideal is obtained, and the fast active reflector adjustment method that the model can accurately obtain under the constraints is verified.

Interactive Multimedia Data Coscattering Point Imaging for Low Signal-to-Noise Ratio 3D Seismic Data Processing

In this paper, low signal-to-noise ratio 3D seismic data are processed by the method of coscattered point imaging, and the imaging method is analyzed in combination with interactive multimedia for 3D seismic data. The reconstruction is carried out using a convex set projection algorithm based on the curvilinear wave transform. The track set is extracted from the 3D data body and transformed into the common offset distance-center point tract set to achieve the reconstruction of seismic data in the common offset distance track set domain and through comparison. It is concluded that the reconstruction effect is better in the common. The reconstruction results are better in the common offset distance track set domain. To shorten the processing time and obtain better reconstruction results, this paper proposes the idea of direct reconstruction of frequency slices. Experiments on the actual seismic three-component wavefield based on velocity-type and acceleration-type three-component geophones are carried out to reveal the signal characteristics of the actual seismic wavefield under the mining space. Due to the limitation of the construction observation space and the particularity of the actual needs of mine detection, the application of the scattered wave imaging method in the mine must be based on the corresponding detection space and detection purpose. The implementation of this thesis improves the signal-to-noise ratio, resolution, and fidelity of the 3D seismic data of the Shawan Formation, which is more conducive to the search for lithological traps. Combined with the seismic geological data, several traps were finally found and implemented, indicating that the fidelity of the resultant information is good and can meet the needs of interpretation and comprehensive research. The multiwave scattering imaging method in this paper can complete multiwave field imaging of longitudinal, transverse, and slot waves, which has the advantages of data redundancy, high superposition number, and more accurate imaging than conventional reflection wave imaging and provides field application value for ensuring mine safety production.

Statistical shape modeling-based reconstruction eliminates the need for full scapular computed tomography scan data in preoperative total shoulder arthroplasty planning

BackgroundPreoperative total shoulder arthroplasty (TSA) planning tools use a three-dimensional (3D) model of the full scapula based on computed tomography (CT) images with a scan length covering the complete scapula with a given radiation exposure for patients. The aim of this study is to investigate whether full scapular models can be reconstructed from partial CT data. MethodsIn this retrospective cohort study, bone models representing 5 scan lengths with decreasing levels of scapular coverage (level 1-5) were created. All the models were reconstructed with a validated statistical shape model (SSM) allowing automatic 3D measurements of glenoid version, inclination, scapular offset, and center point position. Radiation exposure between 2 patient groups (group 1 = corresponding to L1, group 2 = complete scapula) was compared. ResultsIn terms of inclination and version, we found a mean absolute difference between the complete model and the different partial scan models of 0.5° (SD 0.4°). The maximum difference was 3° for inclination and 2° for version. For scapular offset and center point position, the mean difference was 0 mm (max 1 mm). The mean radiation exposure was 4 mSv (SD 2 mSv) for group 1 and 13 mSv (SD 6 mSv) for group 2 (P = .009). ConclusionAn SSM-based reconstruction technique can accurately reconstruct complete scapular bone models based on partial CT scan data. Incorporation of an SSM-based reconstruction technique in software tools for preoperative TSA planning would lead to decreased radiation exposure (9 mSv) for patients without influencing its accuracy.

A second-order scheme with nonuniform time grids for Caputo–Hadamard fractional sub-diffusion equations

In this paper, a second-order scheme with nonuniform time meshes for Caputo–Hadamard fractional sub-diffusion equations with initial singularity is investigated. Firstly, a Taylor-like formula with integral remainder is proposed, which is crucial to studying the discrete convolution kernels and error estimate. Secondly, we come up with an error convolution structure (ECS) analysis for Llog,2−1σ interpolation approximation to the Caputo–Hadamard fractional derivative. The core result in this paper is an ECS bound and a global consistency analysis established at an offset point. By virtue of this result, we obtain a sharp L2-norm error estimate of a second-order Crank–Nicolson-like scheme for Caputo–Hadamard fractional differential equations. Ultimately, an example is presented to show the sharpness of our analysis.

A packaged food internal Raman signal separation method based on spatially offset Raman spectroscopy combined with FastICA

Raman spectroscopy attempts to reflect food quality by characterizing molecular vibration and rotation. However, the blocking of optical signals by packaging materials and the interference of the optical signal generated by the packaging itself make the detection of internal food quality without destroying packaging highly difficult. In this regard, this paper proposes a novel packaged food internal signal separation based on spatially offset Raman spectroscopy (SORS) coupled with improved fast independent component analysis (FastICA). Firstly, the Raman scattering image of the packaged food with offset laser incident point was obtained. Then, the movable quadratic mean of information entropy was used to select the observation feature region of the image. Thirdly, the main independents decomposed by the optimized FastICA method were identified by spectral attenuation characteristics of the SORS peak signal. Finally, the non-negativity of the separated signal was ensured by baseline recognition and correction. The effectiveness of this method was verified by refactoring the similarity between the signal and the reference signal by testing three different packaging and four internal materials under standard experimental conditions. The applicability of the method was proved by the internal signal separation of three packaged foods on sale. The experimental results indicate that the proposed method can separate the Raman signal of packaged food and can be used as a pretreatment method and auxiliary analysis means for the detection of packaged food.