Skip to main content
Log in

Flexible ureteroscope capable of acute-angled and balanced omnidirectional bending based on soft and flexible porous tube and crossed control wiring

  • Original Article
  • Published:
Medical & Biological Engineering & Computing Aims and scope Submit manuscript

Abstract

Flexible ureteroscopes (fURSs) have performance limitations in accessing acute-angled calyxes and omnidirectional bending. We propose and develop a fURS based on a soft and flexible porous tube and crossed control wiring to overcome these limitations. The fURS prototype comprises a flexible solid polyamide-12 tube and a stretch-retractable expanded polytetrafluoroethylene distal tube with 40% porosity connected by a unique cylindrical wire-routing hook (CWH). The series tube includes four crossed but not contacting loop-formed control wires to provide balanced omnidirectional bending and optimized distal tube bending performance. Bending performance was assessed compared with a conventional fURS, and feasibility studies were performed using a renal phantom. The prototype achieved a 275° omnidirectional maximum bend angle by combining up-down and right-left directions. The bent shape was more compact than the conventional fURS. Thus, the prototype achieved approximately a 1.6-fold larger maximal active bending angle within the restricted environment and a 5.5-fold larger passive bending angle. The crossed control wiring design reduced CWH offset distance by about 75% compared with conventional straight wire routing. The prototype exhibited considerably improved steering performance, exemplified by its ability to access an acutely angled calyx. Our design could improve treatment outcomes and shorten operation times associated with calyceal stone removal.

Graphical Abstract

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8

Similar content being viewed by others

References

  1. Reddy TG, Assimos GA (2015) Optimizing stone-free rates with ureteroscopy. Rev Urol 17(3):160–164. https://doi.org/10.3909/riu0665

    Article  PubMed  PubMed Central  Google Scholar 

  2. Jessen JP, Honeck P, Knoll T, Wendt-Nordahi G (2014) Flexible ureterorenoscopy for lower pole stones: influence of the collecting system’s anatomy. J Endourol 28(2):146–151. https://doi.org/10.1089/end.2013.0401

    Article  PubMed  Google Scholar 

  3. Somani BK, AI-Qahtani SM, Gil de Medina SD, Traxer O (2013) Outcomes of flexible ureterorenoscopy and laser fragmentation for renal stones: comparison between digital and conventional ureteroscope. Urology 82(5):1017–1019. https://doi.org/10.1016/j.urology.2013.07.017

    Article  PubMed  Google Scholar 

  4. Alenezi H, Denstedt JD (2015) Flexible ureteroscopy: technological advancements, current indications and outcomes in the treatment of urolithiasis. Asian J Urol 2:133–141. https://doi.org/10.1016/j.ajur.2015.06.002

    Article  PubMed  PubMed Central  Google Scholar 

  5. Villarage DA, Parra JDI, Sandoval GP, Soto JC, Cardona DD (2016) Flexible ureteroscopy: state of the art and practical guide of tips and tricks. Urol Colomb 25(3):250–260. https://doi.org/10.1016/j.uroco.2016.08.001

    Article  Google Scholar 

  6. Hosny K, Clark J, Srirangam SJ (2019) Handling and protecting your flexible ureteroscope: how to maximise scope usage. Transl Androl Urol 8(Suppl 4):S426–S435. https://doi.org/10.21037/tau.2019.07.08

  7. Salvado J, Olivares R, Cabello JM, Cabello R, Moreno S, Pfeifer J, Roman C, Velasco A (2018) Retrograde intrarenal surgery using the single-use flexible ureteroscope Scope 3022 (Pusen): evaluation of clinical results. Cent European J Urol 71:202–207. https://doi.org/10.5173/ceju.2018.1653

    Article  PubMed  PubMed Central  Google Scholar 

  8. Michel MS, Knoll T, Ptaschnyk T, Kohrmann KU, Alken P (2002) Flexible ureterorenoscopy for the treatment of lower pole calyx stones: influence of Different Lithotripsy Probes and Stone Extraction Tools on Scope Deflection and Irrigation Flow. Eur Urol 41:312–317

    Article  PubMed  Google Scholar 

  9. Shah K, Monga M, Knudsen B (2015) Prospective randomized trial comparing 2 flexible digital ureteroscopes: ACMI/Olympus Invisio DUR-D and Olympus URF-V. Urology 85(6):1267–1271. https://doi.org/10.1016/j.urology.2014.12.012

    Article  PubMed  Google Scholar 

  10. Leveillee RJ, Kelly EF (2016) Impressive performance: new disposable digital ureteroscope allows for extreme lower pole access and use of 365 μm holmium laser fiber. JE Case Reports 2(1):114–116. https://doi.org/10.1089/cren.2016.0051

    Article  PubMed  PubMed Central  Google Scholar 

  11. Knudsen B, Miyaoka R, Shah K, Holden T, Turk TMT, Pedro RN, Kriedberg C, Hinck B, Ortiz-Alvarado O, Mona M (2010) Durability of the next-generation flexible fiberoptic ureteroscopes: a randomized prospective multi-institutional clinical trial. Urology 75:534–539. https://doi.org/10.1016/j.urology.2009.06.093

    Article  PubMed  Google Scholar 

  12. Dragos LB, Somani BK, Sener ET, Proietti S, Ploumidis A, Iacoboaie C, Doizi S, Traxer O (2017) Which flexible ureteroscopes (digital vs. fiber-optic) can easily reach the difficult lower pole calices and have better end-tip deflection: in vitro study on K-box. A PETRA evaluation. J Endourol 31(7):630–637

    Article  PubMed  Google Scholar 

  13. Kam J, Yuminaga Y, Beattie K, Ling KY, Arianayagam M, Canagasingham B, Ferguson R, Varol C, Khadra M, Winter M, Ko R (2019) Single use versus reusable digital flexible ureteroscopes: a prospective comparative study. Int J Urol 26:999–1005. https://doi.org/10.1111/iju.14094

    Article  PubMed  Google Scholar 

  14. Gridley CM, Knudsen BE (2017) Digital ureteroscopes: technology update. Res Rep Urol 9:19–25

    PubMed  PubMed Central  Google Scholar 

  15. Multescu R, Geavlete B, Georgescu D, Geavlete P (2010) Conventional fiberoptic flexible ureteroscope versus fourth generation digital flexible ureteroscope: a critical comparison. J Endourol 24(1):17–21. https://doi.org/10.1089/end.2009.0390

    Article  PubMed  Google Scholar 

  16. Lei MC, Du R (2010) A study on the bending mechanism of the flexible ureteroscope. In Proc Control Autom Syst (ICCAS) 2010 Int Conf on 2019–2023. https://doi.org/10.13140/2.1.4511.0727

  17. Buscarini M, Conlin M (2008) Update on flexible ureteroscopy. Urol Int 80:1–7. https://doi.org/10.1159/000111721

    Article  PubMed  Google Scholar 

  18. Tambo M, Inoue T, Miura H, Matsuzaki J, Nutahara K, Hamamoto S, Okada S, Fukuhara H, Fujisawa M, Matsuda T (2020) A novel flexible ureteroscope with omnidirectional bending tip using joystick-type control unit (URF-Y0016): initial validation study in bench models. J Endourol 34(6):676–681

    Article  PubMed  Google Scholar 

  19. Alnadhari I, Ali O, Abdeljaleel O, PaiSampige VR, Shamsodini A, Salah M (2021) Ergonomics and surgeon comfort during flexible ureteroscopy. Res Rep Urol 13:415–424

    PubMed  PubMed Central  Google Scholar 

  20. Keller EX, De Coninck V, Traxer O (2019) Next-generation fiberoptic and digital ureteroscopes. Urol Clin North Am 46(2):147–163. https://doi.org/10.1016/j.ucl.2018.12.001

    Article  PubMed  Google Scholar 

  21. Zhao J, Li J, Cui L, Shi C, Wei G (2021) Design and performance investigation of a robot-assisted flexible ureteroscopy system. Hindawi Appl Bionics Biomech 2021:6911202. https://doi.org/10.1155/2021/6911202

    Article  Google Scholar 

  22. Legrand J, Java A, Our M, Winemakers D, Vercauteren T, Deprest J, Ourselin S, Denis K, Vander Poorten E (2019) Handheld active add-on control unit for a cable-driven flexible endoscope. Front Robot AI 6:87. https://doi.org/10.3389/frobt.2019.00087

    Article  PubMed  PubMed Central  Google Scholar 

  23. Inoue T, Okada S, Hamamoto S, Miura H, Matsuzaki J, Tambo M, Fukuhara H, Fujisawa M, Matsuda T, Nutahara K (2021) Evaluation of flexible ureteroscope with an omni-directional bending tip, using a JOYSTICK unit (URF-Y0016): an ex-vivo study. World J Urol 39:209–215. https://doi.org/10.1007/s00345-020-03151-w

    Article  CAS  PubMed  Google Scholar 

  24. Radzali NAM, Hidzir NM, Rahman IA, Mokhtar AK (2021) Mechanical properties of polymeric biomaterials: modified ePTFE using gamma irradiation. Open Chem 19:1207–1215. https://doi.org/10.1515/chem-2021-0112

    Article  CAS  Google Scholar 

  25. Zhu G, Yuan Q, Hock Yeo J, Nakao M (2015) Thermal treatment of expanded polytetrafluoroethylene (ePTFE) membranes for reconstruction of a valved conduit. Biomed Mater Eng 26(1):S55-62. https://doi.org/10.3233/BME-151289

    Article  CAS  PubMed  Google Scholar 

  26. Mun CH, Jung Y, Kim SH, Lee SH, Kim HC, Kwon IK, Kim SH (2012) Three-dimensional electrospun poly(lactide-co-ε-caprolactone) for small-diameter vascular grafts. Tissue Eng Part A 18(15–16):1608–1616. https://doi.org/10.1089/ten.tea.2011.0695

    Article  CAS  PubMed  Google Scholar 

  27. Villa L, Somani BK, Sener TE, Cloutier J, Buttice S, Marson F, Ploumidis A, Proietti S, Trarre O (2016) Comprehensive flexible ureteroscopy (FURS) simulator for training in endourology: the K-box model. Cent European J Urol 69:118–120. https://doi.org/10.5173/ceju.2016.710

    Article  PubMed  PubMed Central  Google Scholar 

  28. Proietti S, Dragos L, Emiliani E, Buttice S, Falso M, Baghdadi M, Villa L, Doizi S, Giusti G, Traxer O (2017) Ureteroscopic skills with and without Roboflex Avicenna in the K-box simulator. Cent European J Urol 70:76–80. https://doi.org/10.5173/ceju.2017/1180

    Article  PubMed  PubMed Central  Google Scholar 

  29. Festas AJ, Ramos A, Davim JP (2020) Medical devices biomaterials – a review. Proc iMechE Part L J Mater: Design Appl 234(1):218–228. https://doi.org/10.1177/1464420719882458

    Article  CAS  Google Scholar 

  30. Hennessey DB, Fojeck GL, Papa NP, Lawrentschuk N, Bolton D (2018) Single-use disposable digital flexible ureteroscopes: an ex vivo assessment and cost analysis. BJU Int 121(3):55–61. https://doi.org/10.1111/bju.14235

    Article  PubMed  Google Scholar 

  31. Yamada A, Yonemichi W, Inatomi O, Andoh A, Tani T (2022) Steerable catheter based on wire-driven seamless artificial blood vessel tube for endoscopic retrograde transpapillary interventions. Int J Comput Assist Radiol Surg. https://doi.org/10.1007/s11548-022-02805-x

  32. Kim Y, Cheng SS, Diakite M, Gullapalli RP, Simard JM, Desai JP (2017) Toward the development of a flexible mesoscale MRI-compatible neurosurgical continuum robot. IEEE Trans Robot 33(6):1386–1397. https://doi.org/10.1109/TRO.2017.2719035

    Article  PubMed  PubMed Central  Google Scholar 

  33. Conrad BL, Jung J, Penning RS, Zinn MR (2013) Interleaved continuum-rigid manipulation: an augmented approach for robotic minimally-invasive flexible catheter-based procedures. IEEE Int Conf Robot Autom 718–724.

  34. Ali A, Plettenburg DH, Breedveld P (2016) Steerable catheters in cardiology: classifying steerability and assessing future challenges. IEEE Trans Biomed Eng 63(4):679–693. https://doi.org/10.1109/TBME.2016.2525785

    Article  PubMed  Google Scholar 

  35. Eisel M, Strittmatter F, Strobl S, Freymuller C, Pongratz T, Stoka R (2020) Comparative investigation of reusable and single-use flexible endoscopes for urological interventions. Sci Rep 10:5701. https://doi.org/10.1038/s41598-020-62657-w

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  36. Marchini GS, Batagello CA, Monga M, Torricelli FCM, Vicentini FC, Danilovic A, Srougi M, Nahas WC, Mazzucchi E (2018) In vitro evaluation of single use digital flexible ureteroscopes: a practical comparison for a patient-centered approach. J Endourol 32(3):184–191. https://doi.org/10.1089/end.2017.0785

    Article  PubMed  Google Scholar 

  37. Geavlete B, Ene C, Iordache V, Geavlete P (2021) Initial experience with the new super thin single-use PUSEN flexible ureteroscope 7.5 fr in renal stones endoscopic treatment. Chirurgia 116(3):354–360. https://doi.org/10.21614/chirurgia.116.3.354

  38. Marchini GS, Torricelli FCM, Monga M, Batagello CA, Vicentini FC, Danilovic A, Srougi M, Nahas WC, Mazzucchi E (2018) Single-use versus reusable flexible ureteroscopes: a comprehensive cost-analysis decision model. Rev Med (Sao Paulo) 97(3):323–333. https://doi.org/10.11606/issn.1679-9836.v97i3p323-333

  39. Agrawal S, Patil A, Sabnis RB, Singh AG, Ganpule AP, Desai MR (2021) Initial experience with slimmest single-use flexible ureteroscope Scope PU3033A (PUSEN) in retrograde infrarenal surgery and its comparison with Scope PU3022a: a single-center prospective study. World J Urol 39(10):3957–3962. https://doi.org/10.1007/s00345-021-03707-4

    Article  PubMed  Google Scholar 

Download references

Funding

This work was partially supported by JSPS KAKENHI, grants 18H01408 and 21K03965.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Atsushi Yamada.

Ethics declarations

Conflict of interest

Atsushi Yamada and Tohru Tani received funding from Nipro Co., Ltd. for this research project.

Additional information

Publisher's note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Yamada, A., Tani, T. Flexible ureteroscope capable of acute-angled and balanced omnidirectional bending based on soft and flexible porous tube and crossed control wiring. Med Biol Eng Comput 61, 799–809 (2023). https://doi.org/10.1007/s11517-022-02762-2

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11517-022-02762-2

Keywords

Navigation