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T.A. Lenssen

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6 records found

Journal article (2025) - Tomas Lenssen, R. Postema Roelf, Christian Camenzuli, Jean Calleja-Agius, Jenny Dankelman, Tim Horeman-Franse
Background: To validate whether the SATA-LRS, a novel reusable articulating laparoscopic instrument, fits surgical practice, a pre-clinical study was performed. Methods: Thirteen medical doctors used the instrument in a laparoscopic endoscopic inguinal hernia repair (TEP)-like task inside a cadaver. A set of sensors on the instrument handle detected motion and articulation of the instrument tip. Data from the sensors and video recordings were used to assess the amount and type of movement of the instrument and the time spent on tasks. questionnaire was used to gain insight into the participants’ perception of the contextual factors. Results: There was no difference between task time and instrument tip velocities when using articulation (or not) and all participants used articulation at least half of the task time. Instrument-handle movement, indicating the user’s hand and arm movement, was significantly reduced when using articulation. The questionnaire indicated strong acceptance of the instrument and the experimental setup, and a desire to use the instrument in surgery by most participants. Conclusions: The added articulation feature of the SATA-LRS instrument was deemed beneficial by the participants, showed no increased handling complexity or time spent on the task and was used frequently when enabled, indicating intuitiveness. ...

A Modular Robotic Drive for Reusable Steerable Laparoscopic Instruments

Journal article (2024) - Tomas Lenssen, Jenny Dankelman, Tim Horeman
Introduction: Most robotic instruments and their drives still risk residual contamination due to cleaning complexities, rendering them limited reusable, and tend to have larger instruments than the 5mm laparoscopic standard. The novel steerable laparoscopic SATA-LRS uses modularity for cleanability and exchangeability. The SATA-Drive: a robotic driver designed for the actuation of a 3mm scaled version of the SATA-LRS is presented. Methods: A modular, expandable gear mechanism was designed to efficiently rotate and translate the instrument shafts. The 3mm SATA-LRS is controlled as proof. An user-experiment is conducted to test the (de)coupling of the instrument to and from the drive. Results: A video shows the SATA-Driver successfully articulating, rotating and grasping the end-effector. End-effector dis- and reassembly is possible in 36 (13 SD) seconds, while complete instrument coupling requires 28(8 SD) seconds and de-coupling requires 16 (7 SD) seconds. Discussion: A non-surgical robot arm, mounted with the SATA-drive has effectively been transformed into a system similar to robot assisted laparoscopy. The modularity of the drive's segmented build can easily be adapted and could benefit the adoption of future instruments. The SATA-LRS's cleanability features and its end-effector changes without disassembly are expected to benefit medical robotics. The 3mm SATA-LRS shows the instrument's potential for mini-laparoscopy. ...
Journal article (2023) - T.A. Lenssen, R. Bîrjac, J. Dankelman, T. Horeman
Introduction: Based on the success of the former “Shaft-Actuated, Tip-Articulated” SATA-Drive, a prototype robotic instrument driver for modular, steerable, laparoscopic instruments, a new driver is designed and tested to improve previously lacking features concerning cleanability, instrument adaptation, practical application and control. The design of the driver engages these issues with a modular design aimed at re-use of both the instrument and the driver, for which a set of design requirements are established.

Methods: A new modular design has been developed to improve cleanability through separation of the electro-motors and the instrument mechanism which clutches the instrument. Contamination of the driver’s robotic side is prevented though a combination of a drape and a Sterile barrier interface, while the instrument side is made sterilizable. A novel instrument clutching mechanism enables quick-release features, while a motor-axis latching mechanism enables plug-and-play assembly. Embedded sensors allow precise and fast control. A user-experiment was conducted on instrument exchange and assembly time, while mechanical and electrical tests were conducted on the driver’s responsiveness.

Results: The driver has proven its ability to control the instrument, after which it can be disassembled for cleaning and inspection. The driver is designed for re-use through disassembled sterilization where all possibly contaminated surfaces are exposable for cleaning and inspection. The new standardized instrument clutches allow easy instrument (dis-)assembly. Instrument exchange is possible in two methods, the fastest of which is a median of 11 (6.3–14.6) seconds. The driver’s instrument mechanism is separated in a median of 3.7 (1.8–8.1) seconds. After assembly, the driver is operational in less than 2 s.

Discussion: Instrument exchange times are similar to the semi-reusable Da Vinci systems, yet the MISLI-Drive is designed for sterilization, inspection and continual re-use. The modular build of the driver also allows easier parts replacement during maintenance, and requires minimal adaptation to different future scenarios, which is expected to reduce the overall cost of use. ...
Web publication (2022) - T. Horeman, T.A. Lenssen
Chirurgische robotsystemen winnen aanzienlijk aan populariteit in de medische wereld vanwege hun voordelen op het gebied van precisie, comfort en behendigheid voor de chirurg, wat resulteert in een verbeterd chirurgisch resultaat. Deze voordelen gelden voor ziekenhuizen over de hele wereld, maar zijn niet overal even toegankelijk. Complexe systemen vereisen meer onderhoud, meer training voor gebruik, een aanzienlijke hoeveelheid ruimte, een grote financiële investering en ingewikkelde reinigings- en sterilisatieprocessen. Hierdoor is het integreren van deze robotsystemen toch vaak een uitdaging door de beperkte financiën en infrastructuur in kleinere ziekenhuizen. Dergelijke barricades leiden er vaak toe dat de technologie onbereikbaar wordt in omgevingen die het soms het hardste nodig hebben. De ontwikkeling van goedkope robotsystemen lijkt daarom de sleutel voor minder bedeelde ziekenhuizen om toch toegang te krijgen tot de voordelen die robotchirurgie kent. ...

A modular and novel steerable hand-held laparoscopic instrument platform for low-resource settings

Journal article (2022) - T. Lenssen, J. Dankelman, T. Horeman
Background: Hospitals in low resource settings (LRS) can benefit from modern laparoscopic methodologies. However, cleaning, maintenance and costs requirements play a stronger role while training and technology are less available. Steerable laparoscopic instruments have additional requirements in these settings and need extra identified adaptations in their design. Method: Several modular detachability and tip steerability features were applied to the SATA-LRS instrument platform designed specifically for LRS. Ten subjects participated a dis- and reassembly experiment to validate the modularity, and in a steering experiment using a custom made set-up to validate steering. Results: A new steerable SATA-LRS instrument was developed with the ability to exchange end-effectors through a disassembly of the shafts. Experiments showed an average 34 and 90 s for complete dis- and reassembly, respectively. Participants were able to handle the instrument independently after a single demonstration and 4 rounds of repetitions. Precise tip-target alignment in the box set-up showed a very short learning-curve of 6 repetitions. Conclusion: A novel instrument platform with articulating and rotating end-effector was designed for LRS. Within a minute the SATA-LRS can be disassembled to component level for inspection, cleaning, maintenance and repair, and can be autonomously reassembled by novices after a minimal training. The modular buildup is expected to reduce purchasing and repair costs. The instrument has been shown intuitive by use without extensive training. ...

Towards the design of a synergetic wrist prosthesis

Conference paper (2018) - T. A. Lenssen, L. Cappello, D. H. Plettenburg, C. Cipriani, M. Controzzi
To design an underactuated wrist prosthesis, a preliminary study has been conducted to identify the relationship between the Degrees of Freedom (DoFs) of the wrist during the execution of tasks of daily living. After the identification of the principal orientations of the wrist describing the tasks, polynomial functions were used to define a synergetic relationship between the DoFs. The latter can be implemented in a prosthetic wrist featuring one actuator to obtain motion along three DoFs, with the purpose of reducing compensatory movements. ...