Abstract

Traditional laparoscopic optical systems consisting of about 30 lenses have low optical magnification. To magnify tissue during surgical operations, one must change from one laparoscope to another or use a magnifying adapter between the laparoscope and the sensor. Our work focuses on how to change the sag of a liquid lens while zooming from 1 × zoom, to 2 × , and 4 × in an optical design for a laparoscope. The design includes several lenses and two liquid lenses with variable focal lengths. A pair of laparoscopes for 3-D stereoscopy is placed within a tube 11 mm in diameter. The predicted depth resolution of tissue is 0.5 mm without interpolation at 4 × zoom.

© 2013 OSA

1. Introduction

Traditional laparoscopes used in minimally invasive surgery consist of many lenses and have limited visual properties, such as a fixed field of view, low magnification of 1 × –1.5 × , and high F-number at high zoom. High-definition (HD) image quality and 3-D imaging have recently become necessary in laparoscopes. A conventional surgical laparoscope consisting of more than 30 lenses is 30–40 cm long and 5–11 mm in diameter. The magnification is limited in optical systems using a zoom adaptor between the lens and the sensor. A zoom of 4 × was reported in a laparoscope using liquid lenses, called bio-inspired fluidic lenses [1]. In this paper, a laparoscope offering high zoom and 3-D stereoscopy by using a fluidic lens is proposed. The aim of this work is to determine how to change the sag of liquid lenses from 1 × zoom to 2 × and 4 × with no moving parts. It has been shown experimentally that stereoscopes, which provide 3-D vision, improve the precision and speed of endoscopic surgery [2, 3]. The transverse resolution depends mostly on the size of the lens, wavelength of the light, and CCD [4]. The depth of resolution in stereoscopy, δz (also referred to as the axial resolution) is expressed as follows [5]:

δz=Z2δP1Bf
where Z is the distance from the tissue at the point of interest in object space to the CMOS sensor, δP1 is the minimum detectable disparity in the image sensor plane (resolution in the xy plane), P1 = P(L) - P(R), B is the camera lens separation, and f is the focal length of the camera lenses. According to Eq. (1), the depth of resolution of 3-D stereoscope will be small at long focal lengths. The depth of resolution of 3-D stereoscope in zoom 4 × is 4 times smaller than zoom 1 × .

2. Tunable focal length by varying the curvature of a liquid lens for zooming

A simplified conceptual model of the zoom system consists of two tunable liquid lenses which works together to adjust the total zoom as shown Fig. 1. Variable focal length in a lens can be achieved by changing its shape. Both liquid lenses are enclosed in a thin, transparent elastomer membrane. The curvature of the liquid-filled lenses at either end of the membrane is changed under pneumatic control. The effective focal length f of the two variable liquid lenses can be expressed as

1f=(n11)(n21)(1R1(n21)1R2(n11)+(d1n1+d2n2)1R1R2)
where n1 and n2 are the refractive index of liquids 1 and 2, respectively, and d1 and d2 are their lengths; R1 and R2 are the curvatures of lenses 1 and 2, respectively. If we use liquids having n1 = n2, then Eq. (2) can be expressed as follows.

 

Fig. 1 Optical lens configuration using two liquids.

Download Full Size | PPT Slide | PDF

1f=(n11)(1R11R2+(d1+d2)(n11)R1R2n1)

The general lens shape can be expressed by Eq. (4), where c is the vertex curvature of the lens, r is the radius of the lens aperture, k is a conic constant, and A2, A4, etc., are the coefficients of the polynomial.

z(r)=(cr21+(1(1+k)c2r2)0.5)+A2r4+A4r6+Ar88......
In a liquid lens having large sag, the spherical lens profile z(r) is given by Eq. (5), where k = A2 = A4 = … = 0. The radius of curvature of the lens, R1, is related to the lens sag z(b1) and aperture b1 as shown in Eq. (6).
z(r)=(cr21+(1c2r2)0.5)
R1=((b12+z(b1)2)2z(b1))
The effective focal length versus the lens sag z(b1) of lens 1 and the sag z(b2) can be obtained using Eqs. (2) and (6). Figure 2 illustrates how the focal length changes with the lens sag. This fluidic lens design has the advantage of being convertible between a convex and a concave shape.

 

Fig. 2 (a) Effective focal length as a function of changes in the sag of two liquid lenses, (b) ray tracing of liquid lens.

Download Full Size | PPT Slide | PDF

3. Lens design conditions

The effective focal length of a lens system depends on the refractive index and Abbe number of the lenses. The refractive index and Abbe number of liquid lenses can be modified by making a salt solution, as shown in Fig. 3, that can have a refractive index ranging from n = 1.32 to n = 1.46. The refractive index of oil ranges widely from n = 1.3 to n = 2.3. But it is not easy to keep oil from permeating through polydimethylsiloxane (PDMS). It is known that PDMS can block water, which has a surface energy density of 72.8 mJ/m2, and the surface energy of a liquid increases as the salt concentration increases [6]. In this paper, the optical lenses are designed to use a liquid based on deionized water instead of oil. The liquid lens is enclosed by a transparent PDMS membrane (Sylgard 186, Dow Corning). PDMS has several excellent characteristics and is widely used for micro fabrication of various lab-on-a-chip devices because it is inexpensive, biocompatible, self-sealable, and highly elastic; further, it has excellent optical transparency and allows for easy device fabrication [7, 8]. The refractive index and Abbe number of LiCl solution increases 0.002 and 0.1377 times the salt concentration, respectively, as shown in Fig. 3. The design boundary conditions and goals for the 3-D laparoscope are given in Table 1. The maximum lens radius must be less 2.5 mm in order to insert two lens systems.

 

Fig. 3 (a) Refractive index vs. salt concentration; (b) Abbe number vs. salt concentration.

Download Full Size | PPT Slide | PDF

Tables Icon

Table 1. Design conditions and goals for optical lens

4. Lens design results

The optical lens module consists of six glass lenses, one polymer lens, one iris with diffraction optical element (DOE), and two liquid lenses. The lens module was designed in Code V using a two-mega pixel CMOS sensor having a pixel size of 1.75 μm. Figure 4(a) shows the zoom lens configuration, and Fig. 4(b) shows the structure of iris. Figure 4(c) illustrates how to change the lens curvature for different focal lengths. It was designed using the CODE V software from the Optical Solutions Group at Synopsys. In Fig. 4(a), a liquid iris is adapted because it can be made thin and in pairs. The blocking fluid of the iris is moved by the electrowetting force [9] and can absorb visible light using black ink [10]. Figure 5 illustrates how the two sags of the lens module vary with the focal length. The relation between the effective focal length and the sag of the second lens can be expressed as y = −0.0937 Sag + 0.7357, but the relationship between the focal length and the sag of the first liquid lens is expressed by a curve marked with diamonds, as shown in Fig. 5. Figure 6 shows that the image resolution is changed by iris aperture due to zoom ratio. The F-number can be fixed by control the iris aperture. There is 4 mm gap from the stop to next lens. We designed the F-number 4.9–6.4 by using the slim liquid iris, 2 mm thickness like Fig. 4(b).

 

Fig. 4 (a) Schematic of lens module; (b) structure of IRIS; (c) Ray tracing and liquid lens shape at wide angle, middle angle, and tele angle.

Download Full Size | PPT Slide | PDF

 

Fig. 5 Change in lens sag vs. focal length.

Download Full Size | PPT Slide | PDF

 

Fig. 6 The image resolution by the IRIS aperture diameter.

Download Full Size | PPT Slide | PDF

To reduce the chromatic aberration of the optical module, a DOE lens is applied to the iris cover surface using PDMS. The DOE is described in Code V by a continuous profile. The profile can be a function of x and y, φ(x, y), or rotationally symmetric, φ(r). The form of the phase profile is determined by the command HCT (Polynomial Grating Type). In a rotationally symmetric model, φ(r) is described by Eq. (7), where C1 = −0.000183, and C2 = −0.000445. The height and focal length of the DOE can be calculated by Eqs. (8) and (9), respectively, where λ0 is the design wavelength of light; n1(λ0) and n2(λ0) are the refractive index of the DOE lens and the surrounding refractive material, respectively. Figure 7 shows the phase function of the DOE. The number of DOE rings obtained using Eqs. (7) and (8) is 2.

 

Fig. 7 Phase profile of DOE.

Download Full Size | PPT Slide | PDF

φ(r)=2πλon=110Cnr2n
height=λon2(λo)n1(λo)=0.572μm1.49231=1.17μm
f=0.5Qudratic_Phase_Coefficient=0.5C1=2735.6

5. Lens design characterizations

The modulation transfer function (MTF) is an important parameter for evaluating the optical performance. Figures 8(a)8(f) illustrate the MTF value and the optical distortion is shown in Fig. 9 in wide-angle, medium-angle, and tele-angle mode. The optical performances are summarized in Table 2. Figure 10 is the result of 2D image simulation using USAF 1951 chart by CODE V utility.

 

Fig. 8 Design result; MTF (a),(b) Wide angle mode 1 × , (left 0–0.5F, right 0.6F–1.0F). (c),(d) Middle angle zoom 2 × ; (c), (d) Tele angle, zoom 4 ×.

Download Full Size | PPT Slide | PDF

 

Fig. 9 Design result; Optical distortion.

Download Full Size | PPT Slide | PDF

Tables Icon

Table 2. Summary of design result

 

Fig. 10 Image simulation result using USAF1951 chart; (a) zoom 1 × , (b) zoom 2 × ,(c) zoom 4 ×.

Download Full Size | PPT Slide | PDF

Tables Icon

Table 3. Optical lens parameters

Tables Icon

Table 4. Lens parameters of liquid lens and iris

Tables Icon

Table 5. Lens parameters of aspheric polymer lens

6. Conclusion

Using two tunable liquid lenses, several lenses, a DOE, and one iris, we designed a variable zoom system that can achieve 1 × , 2 × , and 4 × zoom for a laparoscope with no moving parts. The trace of the sag of the liquid lens from 1 × zoom to 4 × zoom was optimized in the liquid lens module. The total length of the module is 23.26 mm. Its diameter is less than 4.1 mm, so two modules can be placed in a laparoscope 11 mm in diameter. The effective focal lengths of the wide-angle zoom, medium-angle zoom, and zoom-in modes are 3.24 mm, 6.4 mm, and 12.94 mm, respectively. The MTFs in the zoom-out and zoom-in modes are 35% and 30% at a frequency of 140 lp/mm. The fluidic zoom at lower F-number (4.9–6.04) is brighter than that of a conventional solid laparoscope. The optical distortions in the zoom-out and zoom-in modes are 16% and 3%, respectively The z-direction depth resolutions of this 3-D laparoscope are expected to be <0.5 mm and <2 mm in zoom-in and zoom-out modes, respectively, without interpolation.

References and links

1. F. S. Tsai, D. Johnson, C. S. Francis, S. H. Cho, W. Qiao, A. Arianpour, Y. Mintz, S. Horgan, M. Talamini, and Y.-H. Lo, “Fluidic lens laparoscopic zoom camera for minimally invasive surgery,” J. Biomed. Opt. 15(3), 030504 (2010). [CrossRef]   [PubMed]  

2. N. Taffinder, S. G. T. Smith, J. Huber, R. C. G. Russell, and A. Darzi, “The effect of a second-generation 3D endoscope on the laparoscopic precision of novices and experienced surgeons,” Surg. Endosc. 13(11), 1087–1092 (1999). [CrossRef]   [PubMed]  

3. W. B. Verwey, S. Stroomer, R. Lammens, S. N. Schulz, and W. H. Ehrenstein, “Comparing endoscopic systems on two simulated tasks,” Ergonomics 48(3), 270–287 (2005). [CrossRef]   [PubMed]  

4. C. Pitris, M. E. Brezinski, B. E. Bouma, G. J. Tearney, J. F. Southern, and J. G. Fujimoto, “High resolution imaging of the upper respiratory tract with optical coherence tomography: a feasibility study,” Am. J. Respir. Crit. Care Med. 157(5 Pt 1), 1640–1644 (1998). [PubMed]  

5. J. P. O. Evens, M. Robinson, S. X. Godber, and R. S. Petty, “The development of 3-D (stereoscopic) imaging systems for security applications,” in International Carnahan Conference on Security Technology (Sanderstead, England, 1995), 505–511.

6. W. Yao, H. Bjurstroem, and F. Setterwall, “Surface tension of lithium bromide solutions with heat-transfer additives,” J. Chem. Eng. Data 36(1), 96–98 (1991). [CrossRef]  

7. J. C. McDonald, D. C. Duffy, J. R. Anderson, D. T. Chiu, H. Wu, O. J. A. Schueller, and G. M. Whitesides, “Fabrication of microfluidic systems in poly(dimethylsiloxane),” Electrophoresis 21(1), 27–40 (2000). [CrossRef]   [PubMed]  

8. J. M. K. Ng, I. Gitlin, A. D. Stroock, and G. M. Whitesides, “Components for integrated poly(dimethylsiloxane) microfluidic systems,” Electrophoresis 23(20), 3461–3473 (2002). [CrossRef]   [PubMed]  

9. J.-H. Chang, K.-D. Jung, E. Lee, M. Choi, and S. Lee, “Microelectrofluidic iris for variable aperture,” Proc. SPIE 8252, 82520O, 82520O-6 (2012). [CrossRef]  

10. P. Muller, N. Spengler, H. Zappe, and W. Monch, “An optofluidic concept for a tunable micro-iris,” J. Microelectromech. Syst. 19(6), 1477–1484 (2010). [CrossRef]  

References

  • View by:
  • |
  • |
  • |

  1. F. S. Tsai, D. Johnson, C. S. Francis, S. H. Cho, W. Qiao, A. Arianpour, Y. Mintz, S. Horgan, M. Talamini, and Y.-H. Lo, “Fluidic lens laparoscopic zoom camera for minimally invasive surgery,” J. Biomed. Opt.15(3), 030504 (2010).
    [CrossRef] [PubMed]
  2. N. Taffinder, S. G. T. Smith, J. Huber, R. C. G. Russell, and A. Darzi, “The effect of a second-generation 3D endoscope on the laparoscopic precision of novices and experienced surgeons,” Surg. Endosc.13(11), 1087–1092 (1999).
    [CrossRef] [PubMed]
  3. W. B. Verwey, S. Stroomer, R. Lammens, S. N. Schulz, and W. H. Ehrenstein, “Comparing endoscopic systems on two simulated tasks,” Ergonomics48(3), 270–287 (2005).
    [CrossRef] [PubMed]
  4. C. Pitris, M. E. Brezinski, B. E. Bouma, G. J. Tearney, J. F. Southern, and J. G. Fujimoto, “High resolution imaging of the upper respiratory tract with optical coherence tomography: a feasibility study,” Am. J. Respir. Crit. Care Med.157(5 Pt 1), 1640–1644 (1998).
    [PubMed]
  5. J. P. O. Evens, M. Robinson, S. X. Godber, and R. S. Petty, “The development of 3-D (stereoscopic) imaging systems for security applications,” in International Carnahan Conference on Security Technology (Sanderstead, England, 1995), 505–511.
  6. W. Yao, H. Bjurstroem, and F. Setterwall, “Surface tension of lithium bromide solutions with heat-transfer additives,” J. Chem. Eng. Data36(1), 96–98 (1991).
    [CrossRef]
  7. J. C. McDonald, D. C. Duffy, J. R. Anderson, D. T. Chiu, H. Wu, O. J. A. Schueller, and G. M. Whitesides, “Fabrication of microfluidic systems in poly(dimethylsiloxane),” Electrophoresis21(1), 27–40 (2000).
    [CrossRef] [PubMed]
  8. J. M. K. Ng, I. Gitlin, A. D. Stroock, and G. M. Whitesides, “Components for integrated poly(dimethylsiloxane) microfluidic systems,” Electrophoresis23(20), 3461–3473 (2002).
    [CrossRef] [PubMed]
  9. J.-H. Chang, K.-D. Jung, E. Lee, M. Choi, and S. Lee, “Microelectrofluidic iris for variable aperture,” Proc. SPIE8252, 82520O, 82520O-6 (2012).
    [CrossRef]
  10. P. Muller, N. Spengler, H. Zappe, and W. Monch, “An optofluidic concept for a tunable micro-iris,” J. Microelectromech. Syst.19(6), 1477–1484 (2010).
    [CrossRef]

2012 (1)

J.-H. Chang, K.-D. Jung, E. Lee, M. Choi, and S. Lee, “Microelectrofluidic iris for variable aperture,” Proc. SPIE8252, 82520O, 82520O-6 (2012).
[CrossRef]

2010 (2)

P. Muller, N. Spengler, H. Zappe, and W. Monch, “An optofluidic concept for a tunable micro-iris,” J. Microelectromech. Syst.19(6), 1477–1484 (2010).
[CrossRef]

F. S. Tsai, D. Johnson, C. S. Francis, S. H. Cho, W. Qiao, A. Arianpour, Y. Mintz, S. Horgan, M. Talamini, and Y.-H. Lo, “Fluidic lens laparoscopic zoom camera for minimally invasive surgery,” J. Biomed. Opt.15(3), 030504 (2010).
[CrossRef] [PubMed]

2005 (1)

W. B. Verwey, S. Stroomer, R. Lammens, S. N. Schulz, and W. H. Ehrenstein, “Comparing endoscopic systems on two simulated tasks,” Ergonomics48(3), 270–287 (2005).
[CrossRef] [PubMed]

2002 (1)

J. M. K. Ng, I. Gitlin, A. D. Stroock, and G. M. Whitesides, “Components for integrated poly(dimethylsiloxane) microfluidic systems,” Electrophoresis23(20), 3461–3473 (2002).
[CrossRef] [PubMed]

2000 (1)

J. C. McDonald, D. C. Duffy, J. R. Anderson, D. T. Chiu, H. Wu, O. J. A. Schueller, and G. M. Whitesides, “Fabrication of microfluidic systems in poly(dimethylsiloxane),” Electrophoresis21(1), 27–40 (2000).
[CrossRef] [PubMed]

1999 (1)

N. Taffinder, S. G. T. Smith, J. Huber, R. C. G. Russell, and A. Darzi, “The effect of a second-generation 3D endoscope on the laparoscopic precision of novices and experienced surgeons,” Surg. Endosc.13(11), 1087–1092 (1999).
[CrossRef] [PubMed]

1998 (1)

C. Pitris, M. E. Brezinski, B. E. Bouma, G. J. Tearney, J. F. Southern, and J. G. Fujimoto, “High resolution imaging of the upper respiratory tract with optical coherence tomography: a feasibility study,” Am. J. Respir. Crit. Care Med.157(5 Pt 1), 1640–1644 (1998).
[PubMed]

1991 (1)

W. Yao, H. Bjurstroem, and F. Setterwall, “Surface tension of lithium bromide solutions with heat-transfer additives,” J. Chem. Eng. Data36(1), 96–98 (1991).
[CrossRef]

Anderson, J. R.

J. C. McDonald, D. C. Duffy, J. R. Anderson, D. T. Chiu, H. Wu, O. J. A. Schueller, and G. M. Whitesides, “Fabrication of microfluidic systems in poly(dimethylsiloxane),” Electrophoresis21(1), 27–40 (2000).
[CrossRef] [PubMed]

Arianpour, A.

F. S. Tsai, D. Johnson, C. S. Francis, S. H. Cho, W. Qiao, A. Arianpour, Y. Mintz, S. Horgan, M. Talamini, and Y.-H. Lo, “Fluidic lens laparoscopic zoom camera for minimally invasive surgery,” J. Biomed. Opt.15(3), 030504 (2010).
[CrossRef] [PubMed]

Bjurstroem, H.

W. Yao, H. Bjurstroem, and F. Setterwall, “Surface tension of lithium bromide solutions with heat-transfer additives,” J. Chem. Eng. Data36(1), 96–98 (1991).
[CrossRef]

Bouma, B. E.

C. Pitris, M. E. Brezinski, B. E. Bouma, G. J. Tearney, J. F. Southern, and J. G. Fujimoto, “High resolution imaging of the upper respiratory tract with optical coherence tomography: a feasibility study,” Am. J. Respir. Crit. Care Med.157(5 Pt 1), 1640–1644 (1998).
[PubMed]

Brezinski, M. E.

C. Pitris, M. E. Brezinski, B. E. Bouma, G. J. Tearney, J. F. Southern, and J. G. Fujimoto, “High resolution imaging of the upper respiratory tract with optical coherence tomography: a feasibility study,” Am. J. Respir. Crit. Care Med.157(5 Pt 1), 1640–1644 (1998).
[PubMed]

Chang, J.-H.

J.-H. Chang, K.-D. Jung, E. Lee, M. Choi, and S. Lee, “Microelectrofluidic iris for variable aperture,” Proc. SPIE8252, 82520O, 82520O-6 (2012).
[CrossRef]

Chiu, D. T.

J. C. McDonald, D. C. Duffy, J. R. Anderson, D. T. Chiu, H. Wu, O. J. A. Schueller, and G. M. Whitesides, “Fabrication of microfluidic systems in poly(dimethylsiloxane),” Electrophoresis21(1), 27–40 (2000).
[CrossRef] [PubMed]

Cho, S. H.

F. S. Tsai, D. Johnson, C. S. Francis, S. H. Cho, W. Qiao, A. Arianpour, Y. Mintz, S. Horgan, M. Talamini, and Y.-H. Lo, “Fluidic lens laparoscopic zoom camera for minimally invasive surgery,” J. Biomed. Opt.15(3), 030504 (2010).
[CrossRef] [PubMed]

Choi, M.

J.-H. Chang, K.-D. Jung, E. Lee, M. Choi, and S. Lee, “Microelectrofluidic iris for variable aperture,” Proc. SPIE8252, 82520O, 82520O-6 (2012).
[CrossRef]

Darzi, A.

N. Taffinder, S. G. T. Smith, J. Huber, R. C. G. Russell, and A. Darzi, “The effect of a second-generation 3D endoscope on the laparoscopic precision of novices and experienced surgeons,” Surg. Endosc.13(11), 1087–1092 (1999).
[CrossRef] [PubMed]

Duffy, D. C.

J. C. McDonald, D. C. Duffy, J. R. Anderson, D. T. Chiu, H. Wu, O. J. A. Schueller, and G. M. Whitesides, “Fabrication of microfluidic systems in poly(dimethylsiloxane),” Electrophoresis21(1), 27–40 (2000).
[CrossRef] [PubMed]

Ehrenstein, W. H.

W. B. Verwey, S. Stroomer, R. Lammens, S. N. Schulz, and W. H. Ehrenstein, “Comparing endoscopic systems on two simulated tasks,” Ergonomics48(3), 270–287 (2005).
[CrossRef] [PubMed]

Francis, C. S.

F. S. Tsai, D. Johnson, C. S. Francis, S. H. Cho, W. Qiao, A. Arianpour, Y. Mintz, S. Horgan, M. Talamini, and Y.-H. Lo, “Fluidic lens laparoscopic zoom camera for minimally invasive surgery,” J. Biomed. Opt.15(3), 030504 (2010).
[CrossRef] [PubMed]

Fujimoto, J. G.

C. Pitris, M. E. Brezinski, B. E. Bouma, G. J. Tearney, J. F. Southern, and J. G. Fujimoto, “High resolution imaging of the upper respiratory tract with optical coherence tomography: a feasibility study,” Am. J. Respir. Crit. Care Med.157(5 Pt 1), 1640–1644 (1998).
[PubMed]

Gitlin, I.

J. M. K. Ng, I. Gitlin, A. D. Stroock, and G. M. Whitesides, “Components for integrated poly(dimethylsiloxane) microfluidic systems,” Electrophoresis23(20), 3461–3473 (2002).
[CrossRef] [PubMed]

Horgan, S.

F. S. Tsai, D. Johnson, C. S. Francis, S. H. Cho, W. Qiao, A. Arianpour, Y. Mintz, S. Horgan, M. Talamini, and Y.-H. Lo, “Fluidic lens laparoscopic zoom camera for minimally invasive surgery,” J. Biomed. Opt.15(3), 030504 (2010).
[CrossRef] [PubMed]

Huber, J.

N. Taffinder, S. G. T. Smith, J. Huber, R. C. G. Russell, and A. Darzi, “The effect of a second-generation 3D endoscope on the laparoscopic precision of novices and experienced surgeons,” Surg. Endosc.13(11), 1087–1092 (1999).
[CrossRef] [PubMed]

Johnson, D.

F. S. Tsai, D. Johnson, C. S. Francis, S. H. Cho, W. Qiao, A. Arianpour, Y. Mintz, S. Horgan, M. Talamini, and Y.-H. Lo, “Fluidic lens laparoscopic zoom camera for minimally invasive surgery,” J. Biomed. Opt.15(3), 030504 (2010).
[CrossRef] [PubMed]

Jung, K.-D.

J.-H. Chang, K.-D. Jung, E. Lee, M. Choi, and S. Lee, “Microelectrofluidic iris for variable aperture,” Proc. SPIE8252, 82520O, 82520O-6 (2012).
[CrossRef]

Lammens, R.

W. B. Verwey, S. Stroomer, R. Lammens, S. N. Schulz, and W. H. Ehrenstein, “Comparing endoscopic systems on two simulated tasks,” Ergonomics48(3), 270–287 (2005).
[CrossRef] [PubMed]

Lee, E.

J.-H. Chang, K.-D. Jung, E. Lee, M. Choi, and S. Lee, “Microelectrofluidic iris for variable aperture,” Proc. SPIE8252, 82520O, 82520O-6 (2012).
[CrossRef]

Lee, S.

J.-H. Chang, K.-D. Jung, E. Lee, M. Choi, and S. Lee, “Microelectrofluidic iris for variable aperture,” Proc. SPIE8252, 82520O, 82520O-6 (2012).
[CrossRef]

Lo, Y.-H.

F. S. Tsai, D. Johnson, C. S. Francis, S. H. Cho, W. Qiao, A. Arianpour, Y. Mintz, S. Horgan, M. Talamini, and Y.-H. Lo, “Fluidic lens laparoscopic zoom camera for minimally invasive surgery,” J. Biomed. Opt.15(3), 030504 (2010).
[CrossRef] [PubMed]

McDonald, J. C.

J. C. McDonald, D. C. Duffy, J. R. Anderson, D. T. Chiu, H. Wu, O. J. A. Schueller, and G. M. Whitesides, “Fabrication of microfluidic systems in poly(dimethylsiloxane),” Electrophoresis21(1), 27–40 (2000).
[CrossRef] [PubMed]

Mintz, Y.

F. S. Tsai, D. Johnson, C. S. Francis, S. H. Cho, W. Qiao, A. Arianpour, Y. Mintz, S. Horgan, M. Talamini, and Y.-H. Lo, “Fluidic lens laparoscopic zoom camera for minimally invasive surgery,” J. Biomed. Opt.15(3), 030504 (2010).
[CrossRef] [PubMed]

Monch, W.

P. Muller, N. Spengler, H. Zappe, and W. Monch, “An optofluidic concept for a tunable micro-iris,” J. Microelectromech. Syst.19(6), 1477–1484 (2010).
[CrossRef]

Muller, P.

P. Muller, N. Spengler, H. Zappe, and W. Monch, “An optofluidic concept for a tunable micro-iris,” J. Microelectromech. Syst.19(6), 1477–1484 (2010).
[CrossRef]

Ng, J. M. K.

J. M. K. Ng, I. Gitlin, A. D. Stroock, and G. M. Whitesides, “Components for integrated poly(dimethylsiloxane) microfluidic systems,” Electrophoresis23(20), 3461–3473 (2002).
[CrossRef] [PubMed]

Pitris, C.

C. Pitris, M. E. Brezinski, B. E. Bouma, G. J. Tearney, J. F. Southern, and J. G. Fujimoto, “High resolution imaging of the upper respiratory tract with optical coherence tomography: a feasibility study,” Am. J. Respir. Crit. Care Med.157(5 Pt 1), 1640–1644 (1998).
[PubMed]

Qiao, W.

F. S. Tsai, D. Johnson, C. S. Francis, S. H. Cho, W. Qiao, A. Arianpour, Y. Mintz, S. Horgan, M. Talamini, and Y.-H. Lo, “Fluidic lens laparoscopic zoom camera for minimally invasive surgery,” J. Biomed. Opt.15(3), 030504 (2010).
[CrossRef] [PubMed]

Russell, R. C. G.

N. Taffinder, S. G. T. Smith, J. Huber, R. C. G. Russell, and A. Darzi, “The effect of a second-generation 3D endoscope on the laparoscopic precision of novices and experienced surgeons,” Surg. Endosc.13(11), 1087–1092 (1999).
[CrossRef] [PubMed]

Schueller, O. J. A.

J. C. McDonald, D. C. Duffy, J. R. Anderson, D. T. Chiu, H. Wu, O. J. A. Schueller, and G. M. Whitesides, “Fabrication of microfluidic systems in poly(dimethylsiloxane),” Electrophoresis21(1), 27–40 (2000).
[CrossRef] [PubMed]

Schulz, S. N.

W. B. Verwey, S. Stroomer, R. Lammens, S. N. Schulz, and W. H. Ehrenstein, “Comparing endoscopic systems on two simulated tasks,” Ergonomics48(3), 270–287 (2005).
[CrossRef] [PubMed]

Setterwall, F.

W. Yao, H. Bjurstroem, and F. Setterwall, “Surface tension of lithium bromide solutions with heat-transfer additives,” J. Chem. Eng. Data36(1), 96–98 (1991).
[CrossRef]

Smith, S. G. T.

N. Taffinder, S. G. T. Smith, J. Huber, R. C. G. Russell, and A. Darzi, “The effect of a second-generation 3D endoscope on the laparoscopic precision of novices and experienced surgeons,” Surg. Endosc.13(11), 1087–1092 (1999).
[CrossRef] [PubMed]

Southern, J. F.

C. Pitris, M. E. Brezinski, B. E. Bouma, G. J. Tearney, J. F. Southern, and J. G. Fujimoto, “High resolution imaging of the upper respiratory tract with optical coherence tomography: a feasibility study,” Am. J. Respir. Crit. Care Med.157(5 Pt 1), 1640–1644 (1998).
[PubMed]

Spengler, N.

P. Muller, N. Spengler, H. Zappe, and W. Monch, “An optofluidic concept for a tunable micro-iris,” J. Microelectromech. Syst.19(6), 1477–1484 (2010).
[CrossRef]

Stroock, A. D.

J. M. K. Ng, I. Gitlin, A. D. Stroock, and G. M. Whitesides, “Components for integrated poly(dimethylsiloxane) microfluidic systems,” Electrophoresis23(20), 3461–3473 (2002).
[CrossRef] [PubMed]

Stroomer, S.

W. B. Verwey, S. Stroomer, R. Lammens, S. N. Schulz, and W. H. Ehrenstein, “Comparing endoscopic systems on two simulated tasks,” Ergonomics48(3), 270–287 (2005).
[CrossRef] [PubMed]

Taffinder, N.

N. Taffinder, S. G. T. Smith, J. Huber, R. C. G. Russell, and A. Darzi, “The effect of a second-generation 3D endoscope on the laparoscopic precision of novices and experienced surgeons,” Surg. Endosc.13(11), 1087–1092 (1999).
[CrossRef] [PubMed]

Talamini, M.

F. S. Tsai, D. Johnson, C. S. Francis, S. H. Cho, W. Qiao, A. Arianpour, Y. Mintz, S. Horgan, M. Talamini, and Y.-H. Lo, “Fluidic lens laparoscopic zoom camera for minimally invasive surgery,” J. Biomed. Opt.15(3), 030504 (2010).
[CrossRef] [PubMed]

Tearney, G. J.

C. Pitris, M. E. Brezinski, B. E. Bouma, G. J. Tearney, J. F. Southern, and J. G. Fujimoto, “High resolution imaging of the upper respiratory tract with optical coherence tomography: a feasibility study,” Am. J. Respir. Crit. Care Med.157(5 Pt 1), 1640–1644 (1998).
[PubMed]

Tsai, F. S.

F. S. Tsai, D. Johnson, C. S. Francis, S. H. Cho, W. Qiao, A. Arianpour, Y. Mintz, S. Horgan, M. Talamini, and Y.-H. Lo, “Fluidic lens laparoscopic zoom camera for minimally invasive surgery,” J. Biomed. Opt.15(3), 030504 (2010).
[CrossRef] [PubMed]

Verwey, W. B.

W. B. Verwey, S. Stroomer, R. Lammens, S. N. Schulz, and W. H. Ehrenstein, “Comparing endoscopic systems on two simulated tasks,” Ergonomics48(3), 270–287 (2005).
[CrossRef] [PubMed]

Whitesides, G. M.

J. M. K. Ng, I. Gitlin, A. D. Stroock, and G. M. Whitesides, “Components for integrated poly(dimethylsiloxane) microfluidic systems,” Electrophoresis23(20), 3461–3473 (2002).
[CrossRef] [PubMed]

J. C. McDonald, D. C. Duffy, J. R. Anderson, D. T. Chiu, H. Wu, O. J. A. Schueller, and G. M. Whitesides, “Fabrication of microfluidic systems in poly(dimethylsiloxane),” Electrophoresis21(1), 27–40 (2000).
[CrossRef] [PubMed]

Wu, H.

J. C. McDonald, D. C. Duffy, J. R. Anderson, D. T. Chiu, H. Wu, O. J. A. Schueller, and G. M. Whitesides, “Fabrication of microfluidic systems in poly(dimethylsiloxane),” Electrophoresis21(1), 27–40 (2000).
[CrossRef] [PubMed]

Yao, W.

W. Yao, H. Bjurstroem, and F. Setterwall, “Surface tension of lithium bromide solutions with heat-transfer additives,” J. Chem. Eng. Data36(1), 96–98 (1991).
[CrossRef]

Zappe, H.

P. Muller, N. Spengler, H. Zappe, and W. Monch, “An optofluidic concept for a tunable micro-iris,” J. Microelectromech. Syst.19(6), 1477–1484 (2010).
[CrossRef]

Am. J. Respir. Crit. Care Med. (1)

C. Pitris, M. E. Brezinski, B. E. Bouma, G. J. Tearney, J. F. Southern, and J. G. Fujimoto, “High resolution imaging of the upper respiratory tract with optical coherence tomography: a feasibility study,” Am. J. Respir. Crit. Care Med.157(5 Pt 1), 1640–1644 (1998).
[PubMed]

Electrophoresis (2)

J. C. McDonald, D. C. Duffy, J. R. Anderson, D. T. Chiu, H. Wu, O. J. A. Schueller, and G. M. Whitesides, “Fabrication of microfluidic systems in poly(dimethylsiloxane),” Electrophoresis21(1), 27–40 (2000).
[CrossRef] [PubMed]

J. M. K. Ng, I. Gitlin, A. D. Stroock, and G. M. Whitesides, “Components for integrated poly(dimethylsiloxane) microfluidic systems,” Electrophoresis23(20), 3461–3473 (2002).
[CrossRef] [PubMed]

Ergonomics (1)

W. B. Verwey, S. Stroomer, R. Lammens, S. N. Schulz, and W. H. Ehrenstein, “Comparing endoscopic systems on two simulated tasks,” Ergonomics48(3), 270–287 (2005).
[CrossRef] [PubMed]

J. Biomed. Opt. (1)

F. S. Tsai, D. Johnson, C. S. Francis, S. H. Cho, W. Qiao, A. Arianpour, Y. Mintz, S. Horgan, M. Talamini, and Y.-H. Lo, “Fluidic lens laparoscopic zoom camera for minimally invasive surgery,” J. Biomed. Opt.15(3), 030504 (2010).
[CrossRef] [PubMed]

J. Chem. Eng. Data (1)

W. Yao, H. Bjurstroem, and F. Setterwall, “Surface tension of lithium bromide solutions with heat-transfer additives,” J. Chem. Eng. Data36(1), 96–98 (1991).
[CrossRef]

J. Microelectromech. Syst. (1)

P. Muller, N. Spengler, H. Zappe, and W. Monch, “An optofluidic concept for a tunable micro-iris,” J. Microelectromech. Syst.19(6), 1477–1484 (2010).
[CrossRef]

Proc. SPIE (1)

J.-H. Chang, K.-D. Jung, E. Lee, M. Choi, and S. Lee, “Microelectrofluidic iris for variable aperture,” Proc. SPIE8252, 82520O, 82520O-6 (2012).
[CrossRef]

Surg. Endosc. (1)

N. Taffinder, S. G. T. Smith, J. Huber, R. C. G. Russell, and A. Darzi, “The effect of a second-generation 3D endoscope on the laparoscopic precision of novices and experienced surgeons,” Surg. Endosc.13(11), 1087–1092 (1999).
[CrossRef] [PubMed]

Other (1)

J. P. O. Evens, M. Robinson, S. X. Godber, and R. S. Petty, “The development of 3-D (stereoscopic) imaging systems for security applications,” in International Carnahan Conference on Security Technology (Sanderstead, England, 1995), 505–511.

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (10)

Fig. 1
Fig. 1

Optical lens configuration using two liquids.

Fig. 2
Fig. 2

(a) Effective focal length as a function of changes in the sag of two liquid lenses, (b) ray tracing of liquid lens.

Fig. 3
Fig. 3

(a) Refractive index vs. salt concentration; (b) Abbe number vs. salt concentration.

Fig. 4
Fig. 4

(a) Schematic of lens module; (b) structure of IRIS; (c) Ray tracing and liquid lens shape at wide angle, middle angle, and tele angle.

Fig. 5
Fig. 5

Change in lens sag vs. focal length.

Fig. 6
Fig. 6

The image resolution by the IRIS aperture diameter.

Fig. 7
Fig. 7

Phase profile of DOE.

Fig. 8
Fig. 8

Design result; MTF (a),(b) Wide angle mode 1 × , (left 0–0.5F, right 0.6F–1.0F). (c),(d) Middle angle zoom 2 × ; (c), (d) Tele angle, zoom 4 ×.

Fig. 9
Fig. 9

Design result; Optical distortion.

Fig. 10
Fig. 10

Image simulation result using USAF1951 chart; (a) zoom 1 × , (b) zoom 2 × ,(c) zoom 4 ×.

Tables (5)

Tables Icon

Table 1 Design conditions and goals for optical lens

Tables Icon

Table 2 Summary of design result

Tables Icon

Table 3 Optical lens parameters

Tables Icon

Table 4 Lens parameters of liquid lens and iris

Tables Icon

Table 5 Lens parameters of aspheric polymer lens

Equations (9)

Equations on this page are rendered with MathJax. Learn more.

δz= Z 2 δ P 1 Bf
1 f =( n 1 1 )( n 2 1 )( 1 R 1 ( n 2 1) 1 R 2 ( n 1 1) +( d 1 n 1 + d 2 n 2 ) 1 R 1 R 2 )
1 f =( n 1 1 )( 1 R 1 1 R 2 + ( d 1 + d 2 )( n 1 1) R 1 R 2 n 1 )
z(r)=( c r 2 1+ (1(1+k) c 2 r 2 ) 0.5 )+ A 2 r 4 + A 4 r 6 +A r 8 8 ......
z(r)=( c r 2 1+ (1 c 2 r 2 ) 0.5 )
R 1 =( ( b 1 2 +z ( b 1 ) 2 ) 2z( b 1 ) )
φ(r)= 2π λ o n=1 10 C n r 2n
height= λ o n 2 ( λ o ) n 1 ( λ o ) = 0.572μm 1.49231 =1.17μm
f= 0.5 Qudratic_Phase_Coefficient = 0.5 C 1 =2735.6

Metrics