Design and evaluation of a new bioelectrical impedance sensor for micro-surgery: application to retinal vein cannulation

  • Laurent SchoevaerdtsEmail author
  • Laure Esteveny
  • Andy Gijbels
  • Jonas Smits
  • Dominiek Reynaerts
  • Emmanuel Vander Poorten
Original Article



Nowadays, millions of people suffer from retinal vein occlusion, a blind-making eye disease. No curative treatment currently exists for this vascular disorder. However, a promising treatment consists in injecting a thrombolytic drug directly inside the affected retinal vessel. Successfully puncturing miniature vessels with diameters between 50 and 400 \(\upmu \hbox {m}\) remains a real challenge, amongst others due to human hand tremor, poor visualisation and depth perception. As a consequence, there is a significant risk of double-puncturing the targeted vessel. Sub-surfacic injection of thrombolytic agent could potentially lead to severe retinal damage.


A new bio-impedance sensor has been developed to visually display the instant of vessel puncture. The physical working principle of the sensor has been analysed, and a representative electrical model has been derived. Based on this model, the main design parameters were derived to maximise the sensor sensitivity. A detailed characterisation and experimental validation of this concept were conducted.


Stable, repeatable and robust impedance measurements were obtained. In an experimental campaign, 35 puncture attempts on ex vivo pig eyes vessels were conducted. A confusion matrix shows a detection accuracy of 80% if there is a puncture, a double puncture or no puncture. The 20% of inaccuracy most probably comes from the limitations of the employed eye model and the experimental conditions.


The developed bio-impedance sensor has shown great promise to help in avoiding double punctures when cannulating retinal veins. Compared to other puncture detection methods, the proposed sensor is simple and therefore potentially more affordable. Future research will include validation in an in vivo situation involving vitreoretinal surgeons.


Vitreoretinal surgery Sensorised instruments Bio-impedance sensor Robot-assisted surgery 



This study was funded by a C3-fund (3E160419) from KU Leuven.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

Ethical approval

This article does not contain any studies with human participants or living animals performed by any of the authors. All applicable national and/or institutional guidelines for the care and use of ex vivo animal material were followed.

Informed consent

This article does not contain patient data.


  1. 1.
    Klein R, Moss SE, Meuer SM, Klein BE (2008) The 15-year cumulative incidence of retinal vein occlusion: the beaver dam eye study. Arch Ophthalmol 126(4):513–518CrossRefGoogle Scholar
  2. 2.
    Rogers S, McIntosh R, Cheung N, Lim L, Wang J, Mitchell P, Kowalski J, Nguyen H, Wong T, International Eye Disease Consortium (2010) The prevalence of retinal vein occlusion: pooled data from population studies from the united states, europe, asia, and australia. Ophthalmology 140(2):313–319CrossRefGoogle Scholar
  3. 3.
    Rehak J, Rehak M (2008) Branch retinal vein occlusion: pathogenesis, visual prognosis, and treatment modalities. Curr Eye Res 33(2):111–131CrossRefGoogle Scholar
  4. 4.
    Weiss J (2000) Retinal surgery for treatment of central retinal vein occlusion. Ophthalmic Surg Lasers Imaging Retina 31(2):162Google Scholar
  5. 5.
    Skovborg F, Nielsen A, Lauritzen E, Hartkopp O (1969) Diameters of the retinal vessels in diabetic and normal subjects. Diabetes 18(5):292–298CrossRefGoogle Scholar
  6. 6.
    Riviere C, Jensen P (2000) A study of instrument motion in vitreoretinal microsurgery. In: Proceedings of the 22nd international conference of the IEEE engineering in medicine and biology societyGoogle Scholar
  7. 7.
    Weiss J, Bynoe L (2001) Injection of tissue plasminogen activator into a branch retinal vein in eyes with central retinal vein occlusion. Ophthalmology 108(12):2249–2257CrossRefGoogle Scholar
  8. 8.
    van Overdam K, Missotten T, Spielberg L (2015) Updated cannulation technique for tissue plasminogen activator injection into peripapillary retinal vein for central retinal vein occlusion. Acta Ophthalmol 93:739–744CrossRefGoogle Scholar
  9. 9.
    Feltgen N, Junker B, Agostini H, Hansen LL (2007) Retinal endovascular lysis in ischemic central retinal vein occlusion: one-year results of a pilot study. Ophthalmology 114(4):716–723CrossRefGoogle Scholar
  10. 10.
    KU Leuven (2017) Surgical eye robot performs precision injection in patient with retinal vein occlusion. MedicalXpress. Accessed 9 Mar 2018
  11. 11.
    Gonenc B, Taylor RH, Iordachita I, Gehlbach P, Handa J (2014) Force-sensing microneedle for assisted retinal vein cannulation. In: IEEE sensors, pp 698–701Google Scholar
  12. 12.
    Gijbels A, Vander Poorten EB, Stalmans P, Reynaerts D (2015) Development and experimental validation of a force sensing needle for robotically assisted retinal vein cannulations. In: IEEE international conference on robotics and automation, pp 2270–2276Google Scholar
  13. 13.
    Smits J, Ourak M, Gijbels A, Esteveny L, Borghesan G, Schoevaerdts L, Willekens L, Stalmans P, Lankenau P, Schulz-Hildebrandt P, Huttmann P, Reynaerts D, Vander Poorten E (2018) Development and experimental validation of a combined FBG force and OCT distance sensing needle for robot-assisted retinal vein cannulation. In: 2018 IEEE international conference on robotics and automation (ICRA)Google Scholar
  14. 14.
    Lee B, Roberts W, Smith D, Ko H, Epstein J, Lecksell K, Partin A, Walsh P (1999) Bioimpedance: novel use of a minimally invasive technique for cancer localization in the intact prostate. The Prostate 162:1546–1547Google Scholar
  15. 15.
    Ko HW, Smith DG (2003) Apparatus for sensing human prostate tumor. Johns Hopkins University, US patent US7283868B2Google Scholar
  16. 16.
    Hernandez D, Sinkov V, Roberts W, Allaf M, Patriciu A, Jarrett T, Kavoussi L, Stoianovici D (2001) Measurement of bio-impedance with a smart needle to confirm percutaneous kidney access. J Urol 166:1520–1523CrossRefGoogle Scholar
  17. 17.
    Lum P, Melton H, Simons T, Greenstein M (2002) Apparatus and method for penetration with shaft having a sensor for sensing penetration depth. Sanofi-Aventis Deutschland GmbH, US patent US6391005B1Google Scholar
  18. 18.
    Saito H, Mitsubayashi K, Togawa T (2006) Detection of needle puncture to blood vessel by using electric conductivity of blood for automatic blood sampling. Sens Actuators A Phys 125(2):446–450CrossRefGoogle Scholar
  19. 19.
    Cheng Z, Davies BL, Caldwell D, Mattos L (2018) A new venous entry detection method based on electrical bio-impedance sensing. In: Annals of biomedical engineering pp 1–10. Accessed 21 Aug 2018
  20. 20.
    Injeq (2017) Because every procedure matters. INJEQ. Accessed 9 Mar 2018
  21. 21.
    Halonen S, Annala K, Kari J, Jokinen S, Lumme A, Kronström K, Yli-Hankala A (2016) Detection of spine structures with bioimpedance probe (bip) needle in clinical lumbar punctures. J Clin Monit Comput 31(5):1065–1072CrossRefGoogle Scholar
  22. 22.
    Gijbels A, Vander Poorten E, Gorissen B, Devreker A, Stalmans P, Reynaerts D (2014) Experimental validation of a robotic comanipulation and telemanipulation system for retinal surgery. In: IEEE international conference on biomedical robotics and biomechatronicsGoogle Scholar

Copyright information

© CARS 2018

Authors and Affiliations

  1. 1.Department of Mechanical EngineeringKU Leuven - University of LeuvenLouvainBelgium

Personalised recommendations