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Mazon EE, Villa-Martínez E, Hernández-Sámano A, Córdova-Fraga T, Ibarra-Sánchez JJ, Calleja HA, Leyva Cruz JA, Barrera A, Estrada JC, Paz JA, Quintero LH, Cano ME. A high-resolution frequency variable experimental setup for studying ferrofluids used in magnetic hyperthermia. Rev Sci Instrum 2017; 88:084705. [PMID: 28863641 DOI: 10.1063/1.4998975] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A scanning system for specific absorption rate of ferrofluids with superparamagnetic nanoparticles is presented in this study. The system contains an induction heating device designed and built with a resonant inverter in order to generate magnetic field amplitudes up to 38 mT, over the frequency band 180-525 kHz. Its resonant circuit involves a variable capacitor with 1 nF of capacitance steps to easily select the desired frequency, reaching from 0.3 kHz/nF up to 5 kHz/nF of resolution. The device performance is characterized in order to compare with the theoretical predictions of frequency and amplitude, showing a good agreement with the resonant inverters theory. Additionally, the setup is tested using a synthetic iron oxide with 10 ± 1 nm diameter suspended in liquid glycerol, with concentrations at 1%. Meanwhile, the temperature rise is measured to determine the specific absorption rate and calculate the dissipated power density for each f. This device is a suitable alternative to studying ferrofluids and analyzes the dependence of the power absorption density with the magnetic field intensity and frequency.
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Affiliation(s)
- E E Mazon
- Centro Universitario de la Ciénega, Universidad de Guadalajara, Av. Universidad 1115, Col. Linda Vista, Ocotlán, Jalisco C.P. 47820, Mexico
| | - E Villa-Martínez
- Departamento de Física, División de Ciencias e Ingenierías Campus León, Universidad de Guanajuato, Loma de Bosque 103, Col. Lomas del Campestre, C.P. 37150 Guanajuato, Mexico
| | - A Hernández-Sámano
- Centro Universitario de la Ciénega, Universidad de Guadalajara, Av. Universidad 1115, Col. Linda Vista, Ocotlán, Jalisco C.P. 47820, Mexico
| | - T Córdova-Fraga
- Departamento de Física, División de Ciencias e Ingenierías Campus León, Universidad de Guanajuato, Loma de Bosque 103, Col. Lomas del Campestre, C.P. 37150 Guanajuato, Mexico
| | - J J Ibarra-Sánchez
- Departamento de Ingeniería Química, División de Ciencias Naturales y Exactas, Campus Guanajuato, Universidad de Guanajuato, Noria Alta S/N, Noria Alta, 36050 Guanajuato, Gto., Mexico
| | - H A Calleja
- Centro Nacional de Investigación y Desarrollo Tecnológico, Interior Internado Palmira S/N, Palmira, 62490 Cuernavaca, Mor., Mexico
| | - J A Leyva Cruz
- Centro Universitario de la Ciénega, Universidad de Guadalajara, Av. Universidad 1115, Col. Linda Vista, Ocotlán, Jalisco C.P. 47820, Mexico
| | - A Barrera
- Centro Universitario de la Ciénega, Universidad de Guadalajara, Av. Universidad 1115, Col. Linda Vista, Ocotlán, Jalisco C.P. 47820, Mexico
| | - J C Estrada
- Centro Universitario de la Ciénega, Universidad de Guadalajara, Av. Universidad 1115, Col. Linda Vista, Ocotlán, Jalisco C.P. 47820, Mexico
| | - J A Paz
- Centro Universitario de la Ciénega, Universidad de Guadalajara, Av. Universidad 1115, Col. Linda Vista, Ocotlán, Jalisco C.P. 47820, Mexico
| | - L H Quintero
- Centro Universitario de la Ciénega, Universidad de Guadalajara, Av. Universidad 1115, Col. Linda Vista, Ocotlán, Jalisco C.P. 47820, Mexico
| | - M E Cano
- Centro Universitario de la Ciénega, Universidad de Guadalajara, Av. Universidad 1115, Col. Linda Vista, Ocotlán, Jalisco C.P. 47820, Mexico
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2
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Leyva-Cruz JA, Ferreira ES, Miltão MSR, Andrade-Neto AV, Alves AS, Estrada JC, Cano ME. Reconstruction of magnetic source images using the Wiener filter and a multichannel magnetic imaging system. Rev Sci Instrum 2014; 85:074701. [PMID: 25085156 DOI: 10.1063/1.4884641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
A system for imaging magnetic surfaces using a magnetoresistive sensor array is developed. The experimental setup is composed of a linear array of 12 sensors uniformly spaced, with sensitivity of 150 pT*Hz(-1/2) at 1 Hz, and it is able to scan an area of (16 × 18) cm(2) from a separation of 0.8 cm of the sources with a resolution of 0.3 cm. Moreover, the point spread function of the multi-sensor system is also studied, in order to characterize its transference function and to improve the quality in the restoration of images. Furthermore, the images are generated by mapping the response of the sensors due to the presence of phantoms constructed of iron oxide, which are magnetized by a pulse of 80 mT. The magnetized phantoms are linearly scanned through the sensor array and the remanent magnetic field is acquired and displayed in gray levels using a PC. The images of the magnetic sources are reconstructed using two-dimensional generalized parametric Wiener filtering. Our results exhibit a very good capability to determine the spatial distribution of magnetic field sources, which produce magnetic fields of low intensity.
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Affiliation(s)
- J A Leyva-Cruz
- Instrumentation Physics Lab, Department of Physics, Universidade Estadual de Feira de Santana, 44036-900 Feira de Santana, BA, Brazil
| | - E S Ferreira
- Materials Physics Lab, Department of Physics, Universidade Estadual de Feira de Santana, 44036-900 Feira de Santana, BA, Brazil
| | - M S R Miltão
- Instrumentation Physics Lab, Department of Physics, Universidade Estadual de Feira de Santana, 44036-900 Feira de Santana, BA, Brazil
| | - A V Andrade-Neto
- Instrumentation Physics Lab, Department of Physics, Universidade Estadual de Feira de Santana, 44036-900 Feira de Santana, BA, Brazil
| | - A S Alves
- Materials Physics Lab, Department of Physics, Universidade Estadual de Feira de Santana, 44036-900 Feira de Santana, BA, Brazil
| | - J C Estrada
- Centro Universitario de la Ciénega, Universidad de Guadalajara, Av. Universidad, 1115, Ocotlán, JAL, CP.47810, Mexico
| | - M E Cano
- Centro Universitario de la Ciénega, Universidad de Guadalajara, Av. Universidad, 1115, Ocotlán, JAL, CP.47810, Mexico
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3
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Servin M, Garnica G, Estrada JC, Quiroga A. Coherent digital demodulation of single-camera N-projections for 3D-object shape measurement: co-phased profilometry. Opt Express 2013; 21:24873-24878. [PMID: 24150330 DOI: 10.1364/oe.21.024873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Fringe projection profilometry is a well-known technique to digitize 3-dimensional (3D) objects and it is widely used in robotic vision and industrial inspection. Probably the single most important problem in single-camera, single-projection profilometry are the shadows and specular reflections generated by the 3D object under analysis. Here a single-camera along with N-fringe-projections is (digital) coherent demodulated in a single-step, solving the shadows and specular reflections problem. Co-phased profilometry coherently phase-demodulates a whole set of N-fringe-pattern perspectives in a single demodulation and unwrapping process. The mathematical theory behind digital co-phasing N-fringe-patterns is mathematically similar to co-phasing a segmented N-mirror telescope.
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4
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Estrada JC, Torres Y, Benguría A, Dopazo A, Roche E, Carrera-Quintanar L, Pérez RA, Enríquez JA, Torres R, Ramírez JC, Samper E, Bernad A. Human mesenchymal stem cell-replicative senescence and oxidative stress are closely linked to aneuploidy. Cell Death Dis 2013; 4:e691. [PMID: 23807220 PMCID: PMC3702285 DOI: 10.1038/cddis.2013.211] [Citation(s) in RCA: 165] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
In most clinical trials, human mesenchymal stem cells (hMSCs) are expanded in vitro before implantation. The genetic stability of human stem cells is critical for their clinical use. However, the relationship between stem-cell expansion and genetic stability is poorly understood. Here, we demonstrate that within the normal expansion period, hMSC cultures show a high percentage of aneuploid cells that progressively increases until senescence. Despite this accumulation, we show that in a heterogeneous culture the senescence-prone hMSC subpopulation has a lower proliferation potential and a higher incidence of aneuploidy than the non-senescent subpopulation. We further show that senescence is linked to a novel transcriptional signature that includes a set of genes implicated in ploidy control. Overexpression of the telomerase catalytic subunit (human telomerase reverse transcriptase, hTERT) inhibited senescence, markedly reducing the levels of aneuploidy and preventing the dysregulation of ploidy-controlling genes. hMSC-replicative senescence was accompanied by an increase in oxygen consumption rate (OCR) and oxidative stress, but in long-term cultures that overexpress hTERT, these parameters were maintained at basal levels, comparable to unmodified hMSCs at initial passages. We therefore propose that hTERT contributes to genetic stability through its classical telomere maintenance function and also by reducing the levels of oxidative stress, possibly, by controlling mitochondrial physiology. Finally, we propose that aneuploidy is a relevant factor in the induction of senescence and should be assessed in hMSCs before their clinical use.
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Affiliation(s)
- J C Estrada
- Department of Cardiovascular Development and Repair, Fundación Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Melchor Fernández Almagro 3, Madrid, Spain
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5
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Vargas J, Restrepo R, Estrada JC, Sorzano COS, Du YZ, Carazo JM. Shack-Hartmann centroid detection using the spiral phase transform. Appl Opt 2012; 51:7362-7367. [PMID: 23089793 DOI: 10.1364/ao.51.007362] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Accepted: 09/10/2012] [Indexed: 06/01/2023]
Abstract
We present a Shack-Hartmann (SH) centroid detection algorithm capable to measure in presence of strong noise, background illumination and spot modulating signals, which are typical limiting factors of traditional centroid detection algorithms. The proposed method is based on performing a normalization of the SH pattern using the spiral phase transform method and Fourier filtering. The spot centroids are then obtained using global thresholding and weighted average methods. We have tested the algorithm with simulations and experimental data obtaining satisfactory results. A complete MATLAB package that can reproduce all the results can be downloaded from [http://goo.gl/o2JhD].
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Affiliation(s)
- J Vargas
- Biocomputing Unit, Centro Nacional de Biotecnología-CSIC, Madrid, Spain.
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6
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Vargas J, Quiroga JA, Sorzano COS, Estrada JC, Servín M. Multiplicative phase-shifting interferometry using optical flow. Appl Opt 2012; 51:5903-5908. [PMID: 22907020 DOI: 10.1364/ao.51.005903] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Accepted: 07/28/2012] [Indexed: 06/01/2023]
Abstract
Fringe patterns with a multiplicative phase shift among them appear in experimental techniques as photoelasticity and RGB shadow moiré, among others. These patterns cannot be processed using standard phase-shifting demodulation techniques. In this work, we propose to use a multiframe regularized optical flow algorithm to obtain the interesting modulating phase. The proposed technique has been applied to simulated and experimental interferograms obtaining satisfactory results.
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Affiliation(s)
- J Vargas
- Biocomputing Unit, Centro Nacional de Biotecnología-CSIC, C/ Darwin 3, 28049, Cantoblanco (Madrid), Spain.
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7
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Padilla JM, Servin M, Estrada JC. Synchronous phase-demodulation and harmonic rejection of 9-step pixelated dynamic interferograms. Opt Express 2012; 20:11734-11739. [PMID: 22714161 DOI: 10.1364/oe.20.011734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We propose a novel synchronous phase-demodulation of pixelated interferograms using squared 3x3 phase-shifted unit-cells. This 3x3 unit-cell is tiled over the CCD image sensor to create a two-dimensional (2D) pixelated carrier. Our synchronous phase-demodulation uses this 2D carrier to demodulate the pixelated interferogram as in the standard 2x2 unit-cell case. The main motivation behind the use of a 3x3 pixelated carrier (instead of the usual 2x2) is its higher harmonic robustness, allowing one to demodulate intensity-distorted fringe patterns. The harmonic rejection robustness of our spatial 3x3 configuration equals the robustness of the temporal least-squares 9-step phase-shifting algorithm (PSA). In other words, extending from the usual 2x2 phase-shifting unit-cell to 3x3 unit-cells, one extends the harmonic rejection of the demodulation algorithm. Finally we also prove that our proposed 9-step, 3x3 pixelated carrier uses the 2D available spectral space more efficiently than using these 9-steps in a linear spatial-carrier configuration.
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Affiliation(s)
- J M Padilla
- Centro de Investigaciones en Optica AC Loma del Bosque 115, Lomas del Campestre, CP 37150 Leon,Guanajuato, Mexico
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8
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Vargas J, Quiroga JA, Sorzano COS, Estrada JC, Carazo JM. Two-step demodulation based on the Gram-Schmidt orthonormalization method. Opt Lett 2012; 37:443-5. [PMID: 22297380 DOI: 10.1364/ol.37.000443] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
This Letter presents an efficient, fast, and straightforward two-step demodulating method based on a Gram-Schmidt (GS) orthonormalization approach. The phase-shift value has not to be known and can take any value inside the range (0,2π), excluding the singular case, where it corresponds to π. The proposed method is based on determining an orthonormalized interferogram basis from the two supplied interferograms using the GS method. We have applied the proposed method to simulated and experimental interferograms, obtaining satisfactory results. A complete MATLAB software package is provided at http://goo.gl/IZKF3.
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Affiliation(s)
- J Vargas
- Biocomputing Unit, Centro Nacional de Biotecnología-CSIC, Cantoblanco (Madrid), Spain.
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9
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Cano ME, Barrera A, Estrada JC, Hernandez A, Cordova T. An induction heater device for studies of magnetic hyperthermia and specific absorption ratio measurements. Rev Sci Instrum 2011; 82:114904. [PMID: 22129001 DOI: 10.1063/1.3658818] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The development of a device for generating ac magnetic fields based on a resonant inverter is presented, which has been specially designed to carry out experiments of magnetic hyperthermia. By determining the electric current in the LC resonant circuit, a maximum intensity of magnetic field around of 15 mT is calculated, with a frequency around of 206 kHz. This ac magnetic field is able to heat powdered magnetic materials embedded in biological systems to be used in biomedical applications. Indeed, in order to evaluate the sensitivity of the device we also present the measurements of the specific absorption rate in phantoms performed with commercially prepared Fe(3)O(4) and distilled water at different concentrations.
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Affiliation(s)
- M E Cano
- Centro Universitario de la Ciénega, Universidad de Guadalajara, 47810 Ocotlán, JAL, Mexico.
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10
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Padilla JM, Servin M, Estrada JC. Harmonics rejection in pixelated interferograms using spatio-temporal demodulation. Opt Express 2011; 19:19508-19513. [PMID: 21996891 DOI: 10.1364/oe.19.019508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Pixelated phase-mask interferograms have become an industry standard in spatial phase-shifting interferometry. These pixelated interferograms allow full wavefront encoding using a single interferogram. This allows the study of fast dynamic events in hostile mechanical environments. Recently an error-free demodulation method for ideal pixelated interferograms was proposed. However, non-ideal conditions in interferometry may arise due to non-linear response of the CCD camera, multiple light paths in the interferometer, etc. These conditions generate non-sinusoidal fringes containing harmonics which degrade the phase estimation. Here we show that two-dimensional Fourier demodulation of pixelated interferograms rejects most harmonics except the complex ones at {-3(rd), +5(th), -7(th), +9(th), -11(th),…}. We propose temporal phase-shifting to remove these remaining harmonics. In particular, a 2-step phase-shifting algorithm is used to eliminate the -3(rd) and +5(th) complex harmonics, while a 3-step one is used to remove the -3(rd), +5<(th), -7(th) and +9(th) complex harmonics.
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Affiliation(s)
- J M Padilla
- Centro de Investigaciones en Óptica A. C. Loma del Bosque 115, Lomas del Campestre C.P.37150. León, Guanajuato, México
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11
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Abstract
A two-step phase-shifting method, that can demodulate open- and closed-fringed patterns without local sign ambiguity is presented. The proposed method only requires a constant phase-shift between the two interferograms. This phase-shift does not need to be known and can take any value inside the range (0, 2π), excluding the singular case where it corresponds to π. The proposed method is based on determining first the fringe direction map by a regularized optical flow algorithm. After that, we apply the spiral phase transform (SPT) to one of the fringe patterns and we determine its quadrature signal using the previously determined direction. The proposed technique has been applied to simulated and experimental interferograms obtaining satisfactory results. A complete MATLAB software package is provided in [http://goo.gl/Snnz7].
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Affiliation(s)
- J Vargas
- Biocomputing Unit, Centro Nacional de Biotecnología-CSIC, Madrid, Spain.
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12
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Gonzalez A, Servin M, Estrada JC, Quiroga JA. Design of phase-shifting algorithms by fine-tuning spectral shaping. Opt Express 2011; 19:10692-10697. [PMID: 21643325 DOI: 10.1364/oe.19.010692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
To estimate the modulating wavefront of an interferogram in Phase Shifting Interferometry (PSI) one frequently uses a Phase Shifting Algorithm (PSA). All PSAs take as input N phase-shifted interferometric measures, and give an estimation of their modulating phase. The first and best known PSA designed explicitly to reduce a systematic error source (detuning) was the 5-steps, Schwider-Hariharan (SH-PSA) PSA. Since then, dozens of PSAs have been published, designed to reduce specific data error sources on the demodulated phase. In Electrical Engineering the Frequency Transfer Function (FTF) of their linear filters is their standard design tool. Recently the FTF is also being used to design PSAs. In this paper we propose a technique for designing PSAs by fine-tuning the few spectral zeroes of a PSA to approximate a template FTF spectrum. The PSA's spectral zeroes are moved (tuned) while gauging the plot changes on the resulting FTF's magnitude.
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Affiliation(s)
- A Gonzalez
- Centro de Investigaciones en Optica A.C., Loma del bosque 115, Col Lomas del Campestre, Leon Guanajuato, 37150 Mexico
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13
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Abstract
The standard tool to estimate the phase of a sequence of phase-shifted interferograms is the Phase Shifting Algorithm (PSA). The performance of PSAs to a sequence of interferograms corrupted by non-white additive noise has not been reported before. In this paper we use the Frequency Transfer Function (FTF) of a PSA to generalize previous white additive noise analysis to non-white additive noisy interferograms. That is, we find the ensemble average and the variance of the estimated phase in a general PSA when interferograms corrupted by non-white additive noise are available. Moreover, for the special case of additive white-noise, and using the Parseval's theorem, we show (for the first time in the PSA literature) a useful relationship of the PSA's noise robustness; in terms of its FTF spectrum, and in terms of its coefficients. In other words, we find the PSA's estimated phase variance, in the spectral space as well as in the PSA's coefficients space.
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Affiliation(s)
- M Servin
- Centro de Investigaciones en Óptica A. C., Loma del bosque 115, Col. Lomas del Campestre, León Guanajuato, 37150, Mexico.
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14
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Abstract
A two-step self-tuning phase-shifting method is presented. The phase-step between the two interferograms is not known when the experiment is performed. Our demodulating method finds, in a robust way, this unknown phase-step. Once the phase-step is estimated we proceed to phase demodulate the interferograms. Moreover our method only requires the fringe patterns to have a constant unknown phase-shift between them. As a consequence, this technique can be used to demodulate open and closed-fringed patterns without phase-sign ambiguity. The method may be regarded as a self-tuning quadrature filter, which determines the phase-shift between the two fringe patterns and finally estimates the demodulated phase map. The proposed technique has been tested with simulated and real interferograms obtaining satisfactory results.
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Affiliation(s)
- J Vargas
- Laboratorio de Instrumentación Espacial, Instituto Nacional de Técnica Aeroespacial, Madrid, Spain.
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15
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Abstract
Recently, pixelated spatial carrier interferograms have been used in optical metrology and are an industry standard nowadays. The main feature of these interferometers is that each pixel over the video camera may be phase-modulated by any (however fixed) desired angle within [0,2pi] radians. The phase at each pixel is shifted without cross-talking from their immediate neighborhoods. This has opened new possibilities for experimental spatial wavefront modulation not dreamed before, because we are no longer constrained to introduce a spatial-carrier using a tilted plane. Any useful mathematical model to phase-modulate the testing wavefront in a pixel-wise basis can be used. However we are nowadays faced with the problem that these pixelated interferograms have not been correctly demodulated to obtain an error-free (exact) wavefront estimation. The purpose of this paper is to offer the general theory that allows one to demodulate, in an exact way, pixelated spatial-carrier interferograms modulated by any thinkable two-dimensional phase carrier.
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Affiliation(s)
- M Servin
- Centro de Investigaciones en Optica A.C., Loma del Bosque 115, 37150 Leon Guanajuato, Mexico.
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16
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Servin M, Estrada JC, Medina O. Fourier transform demodulation of pixelated phase-masked interferograms. Opt Express 2010; 18:16090-16095. [PMID: 20720993 DOI: 10.1364/oe.18.016090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Recently a new type of spatial phase shifting interferometer was proposed that uses a phase-mask over the camera's pixels. This new interferometer allows one to phase modulate each pixel independently by setting the angle of a linear polarizer built in contact over the camera's CCD. In this way neighbor pixels may have any desired (however fixed) phase shift without cross taking. The standard manufacturing of these interferometers uses a 2x2 array with phase-shifts of 0, pi/2, pi, and 3 pi/2 radians. This 2x2 array is tiled all over the video camera's CCD. In this paper we propose a new way to phase demodulate these phase-masked interferograms using the squeezing phase-shifting technique. A notable advantage of this squeezing technique is that it allows one the use of Fourier interferometry wiping out the detuning error that most phase shifting algorithms suffers. Finally we suggest the use of an alternative phase-mask to phase modulate the camera's pixels using a linear spatial carrier along a given axis.
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Affiliation(s)
- M Servin
- Centro de Investigaciones en Optica A. C. Loma del Bosque 115, Col. Lomas del Campestre, 37150 Leon Guanajuato, Mexico.
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17
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Abstract
We have been reporting several new techniques of analysis and synthesis applied to Phase Shifting Interferometry (PSI). These works are based upon the Frequency Transfer Function (FTF) and how this new tool of analysis and synthesis in PSI may be applied to obtain very general results, among them; rotational invariant spectrum; complex PSI algorithms synthesis based on simpler first and second order quadrature filters; more accurate formulae for estimating the detuning error; output-power phase noise estimation. We have made our cases exposing these aspects of PSI separately. Now in the light of a better understanding provided by our past works we present and expand in a more coherent and holistic way the general theory of PSI algorithms. We are also providing herein new material not reported before. These new results are on; a well defined way to combine PSI algorithms and recursive linear PSI algorithms to obtain resonant quadrature filters.
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Affiliation(s)
- M Servin
- Centro de Investigaciones en Optica A C, Loma del Bosque 115, Col. Lomas del Campestre, León Guanajuato, México.
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18
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Abstract
Systematic spectral analysis of Phase Shifting Interferometry (PSI) algorithms was first proposed in 1990 by Freischlad and Koliopoulos (F&K). This analysis was proposed with the intention that "in a glance" the main properties of the PSI algorithms would be highlighted. However a major drawback of the F&K spectral analysis is that it changes when the PSI algorithm is rotated or its reference signal is time-shifted. In other words, the F&K spectral plot is different when the PSI algorithm is rotated or its reference is time-shifted. However, it is well known that these simple operations do not alter the basic phase demodulation properties of PSI algorithms, except for an unimportant piston. Here we propose a new way to analyze the spectra of PSI algorithms which is invariant to rotation and/or reference time-shift among other advantages over the nowadays standard PSI spectral analysis by F&K.
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Affiliation(s)
- M Servin
- Centro de Investigaciones en Optica A. C., Loma del Bosque 115, Col. Lomas del Campestre, 37150, León Guanajuato, México.
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19
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Abstract
We present a theoretical analysis to estimate the amount of phase noise due to noisy interferograms in Phase Shifting Interferometry (PSI). We also analyze the fact that linear filtering transforms corrupting multiplicative noise in Electronic Speckle Pattern Interferometry (ESPI) into fringes corrupted by additive gaussian noise. This fact allow us to obtain a formula to estimate the standard deviation of the noisy demodulated phase as a function of the spectral response of the preprocessing spatial filtering combined with the PSI algorithm used. This phase noise power formula is the main result of this contribution.
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Affiliation(s)
- M Servin
- Centro de Investigaciones en Optica A. C., Loma del Bosque 115, 37150 Leon Guanajuato, Mexico.
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20
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Abstract
Phase error analysis in Temporal Phase Shifting (TPS) algorithms due to frequency detuning has been to date only performed numerically. In this paper, we show an exact analytical expression to obtain this phase error due to detuning using the spectral TPS response. The new proposed method is based on the phasorial representation of the output of the TPS quadrature filter. Doing this, the detuning problem is reduced to a ratio of two symmetrical spectral responses of the quadrature filter at the detuned frequency. Finally, some popular cases of TPS algorithms are analyzed to show the usefulness of the proposed method.
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Affiliation(s)
- J F Mosiño
- Centro de Investigaciones en Optica, Loma del Bosque 115, León, México.
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Estrada JC, Servin M, Quiroga JA. Easy and straightforward construction of wideband phase-shifting algorithms for interferometry. Opt Lett 2009; 34:413-415. [PMID: 19373325 DOI: 10.1364/ol.34.000413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We show a practical way for building wideband phase-shifting algorithms for interferometry. The idea presented combines first- and second-order quadrature filters to obtain wideband phase-shifting algorithms. These first- and second-order quadrature filters are analogous to the first- and second-order filters commonly used in communications engineering, named building blocks. We present a systematic way to develop phase-shifting algorithms with large detuning robustness or large bandwidth. In general, the approach presented here gives a powerful frequency analysis and design tool for phase-shifting algorithms robust to detuning for interferometry.
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Affiliation(s)
- J C Estrada
- Centro de Investigaciones en Optica Asociacion Civil, León Guanajuato 20036, México.
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22
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Servin M, Cywiak M, Malacara-Hernandez D, Estrada JC, Quiroga JA. Spatial carrier interferometry from M temporal phase shifted interferograms: Squeezing Interferometry. Opt Express 2008; 16:9276-9283. [PMID: 18575491 DOI: 10.1364/oe.16.009276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
It is well known that having 3 temporal phase shifting (PS) interferograms we do not have many possibilities of using an algorithm with a desired frequency spectrum, detuning, and harmonic robustness. This imposes severe restrictions on the possibilities to demodulate such set of temporal interferograms. It would be nice to apply for example a 7 step PS algorithm to these 3 images in order to have more possibilities to phase demodulate them; even further, it would be even better to apply a quadrature filter having a spatial spread given by a real number to these 3 interferograms. In this paper we propose to do just that; namely we show how to demodulate a set of M-steps phase shifting images with a quadrature filter having a real-number as spatial spread. The interesting thing in this paper is to use a higher than M spread quadrature filter to demodulate our interferograms; in traditional PS interferometry one is stuck to the use of M step phase shifting formula to obtain the searched phase. Using a less than M PS formula is not interesting at all given that we would not use all the available information. The main idea behind the "squeezing" phase shifting method is to re-arrange the information of the M phase shifted fringe patterns in such a way to obtain a single carrier frequency interferogram (a spatio-temporal fringe image) and use any two dimensional quadrature filter to demodulate it. In particular we propose the use of Gabor quadrature filters with a spread given by real-numbers along the spatial coordinates. The Gabor filter may be designed in such way that we may squeeze the frequency response of the filter along any desired spatio-temporal dimension, and obtain better signal to noise demodulation ratio, and better harmonic rejection on the estimated phase.
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Affiliation(s)
- M Servin
- Centro de Investigaciones en Optica A.C., Loma del Bosque 115, C.P. 37000, León, Guanajuato, México.
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Estrada JC, Servin M, Marroquín JL. Local adaptable quadrature filters to demodulate single fringe patterns with closed fringes. Opt Express 2007; 15:2288-2298. [PMID: 19532463 DOI: 10.1364/oe.15.002288] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We propose a new approach to demodulate a single fringe pattern with closed fringes by using Local Adaptable Quadrature Filters (LAQF). Quadrature filters have been widely used to demodulate complete image interferograms with carrier frequency. However, in this paper, we propose the use of quadrature filters locally, assuming that the phase is locally quasimonochromatic, since quadrature filters are not capable to demodulate image interferograms with closed fringes. The idea, in this paper, is to demodulate the fringe pattern with closed fringes sequentially, using a fringe following scanning strategy. In particular we use linear robust quadrature filters to obtain a fast and robust demodulation method for single fringe pattern images with closed fringes. The proposed LAQF method does not require a previous fringe pattern normalization. Some tests with experimental interferograms are shown to see the performance of the method along with comparisons to its closest competitor, which is the Regularized Phase Tracker (RPT), and we will see that this method is tolerant to higher levels of noise.
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Abstract
Existing reports evaluate the management of infected pancreatic necrosis. Most of the authors choose between percutaneous and retroperitoneoscopic drainage. The high morbidity and mortality of this pathology distorts the objective evaluation of the treatment employed. With present a case of infected pancreatic collection favorably resolved with retroperitoneoscopic drainage evidencing the low morbidity of this technique.
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Affiliation(s)
- O Castillo
- Unidad de Laparoscopia Urológica, Clinica Santa Maria, Santiago de Chile.
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Estrada JC, Servín M, Quiroga JA, Marroquín JL. Path independent demodulation method for single image interferograms with closed fringes within the function space C(2). Opt Express 2006; 14:9687-9698. [PMID: 19529359 DOI: 10.1364/oe.14.009687] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
In the last few years, works have been published about demodulating Single Fringe Pattern Images (SFPI) with closed fringes. The two best known methods are the regularized phase tracker (RPT), and the two-dimensional Hilbert Transform method (2D-HT). In both cases, the demodulation success depends strongly on the path followed to obtain the expected estimation. Therefore, both RPT and 2D-HT are path dependent methods. In this paper, we show a novel method to demodulate SFPI with closed fringes which follow arbitrary sequential paths. Through the work presented here, we introduce a new technique to demodulate SFPI with estimations within the function space C(2); in other words, estimations where the phase curvature is continuous. The technique developed here, uses a frequency estimator which searches into a frequency discrete set. It uses a second order potential regularizer to force the demodulation system to look into the function space C(2). The obtained estimator is a fast demodulator system for normalized SFPI with closed fringes. Some tests to demodulate SFPI with closed fringes using this technique following arbitrary paths are presented. The results are compared to those from RPT technique. Finally, an experimental normalized interferogram is demodulated with the herein suggested technique.
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Cott RA, Estrada JC, Lowenthal DT. An uncommon cause of unsteady gait in an elderly gentleman. Int Urol Nephrol 2002; 33:687-9. [PMID: 12452629 DOI: 10.1023/a:1020539906042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- R A Cott
- Geriatric Research, Education and Clinical Center, Veterans Affairs Medical Center, University of Florida, Gainesville, USA
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Estrada JC, Brinn NT, Bossen EH. A rapid method of staining ultrathin sections for surgical pathology TEM with the use of the microwave oven. Am J Clin Pathol 1985; 83:639-41. [PMID: 2581442 DOI: 10.1093/ajcp/83.5.639] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
A rapid microwave method is described for staining ultrathin sections for surgical pathology transmission electron microscopy (TEM). Three sets of Epon sections of human heart biopsy were mounted on unsupported 200-mesh Rhodium-coated copper grids and were stained with uranyl acetate (UA) and lead citrate. The first set of grids was stained for 15 seconds in each solution with the aid of a microwave oven, and the second set was stained routinely for 30 minutes in UA and 10 minutes in lead citrate at room temperature. The third control set was stained for 15 seconds in each solution without microwave bombardment. The overall image quality of the TEM micrographs generated by the "quick-stained" microwave enhanced sections was better than routine stained and control sections. The microwave-treated sections have more contrast, less artifacts in the form of precipitate, and a more uniform overall staining.
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