Baseline Study of Ultra-Clean Air Change Rate, Number, and Type of Microorganisms and Level of Particles During Trauma Surgery.

The objective of an operating room (OR) ultra-clean ventilation system is to eliminate or reduce the quantity of dust particles and colony-forming units per cubic meter of air (CFU/m). To achieve this, ultra-clean goal high air change rates per hour are required to reduce the particle load and number of CFU/m. To determine the air quality in an ultra-clean OR during surgery, in terms of the number and type of microorganism and quantity of dust particles in order to establish a benchmark.

Dosimetric benefits and preclinical performance of steerable needles in HDR prostate brachytherapy.

Prostate cancer patients with an enlarged prostate and/or excessive pubic arch interference (PAI) are generally considered non-eligible for high-dose-rate (HDR) brachytherapy (BT). Steerable needles have been developed to make these patients eligible again. This study aims to validate the dosimetric impact and performance of steerable needles within the conventional clinical setting.

What is the effect of reducing the air change rate on the ventilation effectiveness in ultra-clean operating rooms?

Background: The operating room (OR) department is one of the most energy-intensive departments of a hospital. The majority of ORs in the Netherlands have an air-handling installation with an ultra-clean ventilation system. However, not all surgeries require an ultra-clean OR.

Changes in needle maneuver space and optimal insertion site for midline neuraxial puncture with progressive age: an analysis in computed tomography scans.

Introduction: We systematically describe the morphology and accessibility of interspinous spaces across age groups of patients. Our primary goal was to objectively estimate if the maneuver space for a virtual spinal needle changes with age. Our secondary goal was to estimate if the optimal site and angle for midline neuraxial puncture change with age.

MR-guided HDR prostate brachytherapy with teleoperated steerable needles.

Conformity of tumour volumes and dose plans in prostate brachytherapy (BT) can be constrained by unwanted needle deflections, needle access restrictions and visualisation limitations. This work validates the feasibility of teleoperated robotic control of an active steerable needle using magnetic resonance (MR) for guidance. With this system, perturbations can be counteracted and critical structures can be circumvented to access currently inaccessible areas.

Operating Room Performance Optimization Metrics: a Systematic Review.

Literature proposes numerous initiatives for optimization of the Operating Room (OR). Despite multiple suggested strategies for the optimization of workflow on the OR, its patients and (medical) staff, no uniform description of 'optimization' has been adopted. This makes it difficult to evaluate the proposed optimization strategies.

Overcoming pubic arch interference in prostate brachytherapy using steerable needles.

Purpose: A proportion of patients are not directly eligible for prostate brachytherapy (BT) due to pubic arch interference (PAI). Constraints in positioning sources behind the pubic arch due to linear, horizontal needle paths, may hamper effective irradiation of the target volume. This work evaluated the effect of prostate volume (V) and patient posture change on the amount of PAI, and demonstrated that steerable needles may broaden the inclusion criteria for patients with enlarged prostates and observed PAI.

Minimally Invasive Tensiometry: A New Modality for Per-Operative Measurement of Medialization and Tension During Laparoscopic Hernia Surgery.

Newly developed techniques for minimally invasive abdominal wall reconstruction (AWR) for complex ventral hernia are continuously evolving. In order to achieve hernia defect closure, the aponeurotic edges of the hernia defect need to be approximated. Currently, surgeons have no way to objectively measure and quantify the traction required to approximate these edges.

Operating room ventilation systems: recovery degree, cleanliness recovery rate and air change effectiveness in an ultra-clean area.

Background: Entrainment test methods are described in most European standards and guidelines to determine the protected area for ultra-clean ventilation (UCV) systems. New UCV systems, such as temperature-controlled airflow (TcAF) and controlled dilution ventilation (cDV) systems, claim the whole operating room (OR) to be ultra-clean. However, current test standards were not developed to assess ventilation effectiveness outside the standard protected area.

Axially rigid steerable needle with compliant active tip control.

Steerable instruments allow for precise access to deeply-seated targets while sparing sensitive tissues and avoiding anatomical structures. In this study we present a novel omnidirectional steerable instrument for prostate high-dose-rate (HDR) brachytherapy (BT). The instrument utilizes a needle with internal compliant mechanism, which enables distal tip steering through proximal instrument bending while retaining high axial and flexural rigidity.

Experimental study on needle insertion force to minimize tissue deformation in tongue tissue.

This study reports on the effects of insertion velocity, needle tip geometry and needle diameter on tissue deformation and maximum insertion force. Moreover, the effect of multiple insertions with the same needle on the maximum insertion force is reported. The tissue deformation and maximum insertion force strongly depend on the insertion velocity and the tip geometry.

Block-matching-based registration to evaluate ultrasound visibility of percutaneous needles in liver-mimicking phantoms.

Purpose: To present a novel methodical approach to compare visibility of percutaneous needles in ultrasound images.

Methods: A motor-driven rotation platform was used to gradually change the needle angle while capturing image data. Data analysis was automated using block-matching-based registration, with a tracking and refinement step.

Dedicated holmium microsphere administration device for MRI-guided interstitial brain microbrachytherapy.

Microbrachytherapy with radioactive holmium-166 (Ho) microspheres (MS) has the potential to be an effective treatment method for brain malignancies. Direct intratumoural delivery of Ho-MS and dose coverage of the whole tumour are crucial requirements. However, currently no dedicated instruments for controlled intratumoural delivery exist.

Performance of the Emprint and Amica Microwave Ablation Systems in ex vivo Porcine Livers: Sphericity and Reproducibility Versus Size.

Purpose: To investigate the performance of two microwave ablation (MWA) systems regarding ablation volume, ablation shape and variability.

Materials And Methods: In this ex vivo study, the Emprint and Amica MWA systems were used to ablate porcine livers at 4 different settings of time and power (3 and 5 minutes at 60 and 80 Watt). In total, 48 ablations were analysed for ablation size and shape using Vitrea Advanced Visualization software after acquisition of a 7T MRI scan.

Steerable needles for radio-frequency ablation in cirrhotic livers.

Accurate needle placement in deep-seated liver tumours can be difficult. In this work, we disclose two new manually controlled steerable needles for 17G radio-frequency ablation probe placement. The needles contain stylets with embedded compliant joints for active tip articulations, and concentric tubes for (curved-path) guidance.

A Rapidly Deployable Test Suite for Respiratory Protective Devices in the COVID-19 Pandemic.

Introduction: The current COVID-19 pandemic has caused large shortages in personal protective equipment, leading to hospitals buying their supplies from alternative suppliers or even reusing single-use items. Equipment from these alternative sources first needs to be tested to ensure that they properly protect the clinicians that depend on them. This work demonstrates a test suite for protective face masks that can be realized rapidly and cost effectively, using mainly off-the-shelf as well as 3D printing components.

Deep learning for surgical phase recognition using endoscopic videos.

Background: Operating room planning is a complex task as pre-operative estimations of procedure duration have a limited accuracy. This is due to large variations in the course of procedures. Therefore, information about the progress of procedures is essential to adapt the daily operating room schedule accordingly.

Reprocessing filtering facepiece respirators in primary care using medical autoclave: prospective, bench-to-bedside, single-centre study.

Objective: There are widespread shortages of personal protective equipment as a result of the COVID-19 pandemic. Reprocessing filtering facepiece particle (FFP)-type respirators may provide an alternative solution in keeping healthcare professionals safe.

Design: Prospective, bench-to-bedside.

Designing and validating a PVA liver phantom with respiratory motion for needle-based interventions.

Purpose: The purpose is to design and validate an anthropomorphic polyvinyl alcohol (PVA) liver phantom with respiratory motion to simulate needle-based interventions. Such a system can, for example, be used as a validation tool for novel needles.

Methods: Image segmentations of CT scans of four patients during inspiration and expiration were used to measure liver and rib displacement.

Face and construct validity of TU-Delft epidural simulator and the value of real-time visualization.

Background And Objectives: Learning epidural anesthesia traditionally involves bedside teaching. Visualization aids or a simulator can help in acquiring motor skills, increasing patient safety and steepening the learning curve. We evaluated the face and construct validity of the TU-Delft Epidural Simulator and the effect of needle visualization.