Objective: Grasping force control is crucial for safe laparoscopic surgery. However, force feedback is limited as haptic information on grasping strength and tissue stiffness is mostly lost due to internal instrument backlash and friction. This increases tissue trauma risk as excessive grasping forces can lead to (postoperative) complications. This study aims to develop a grasping force feedback providing add-on for a laparoscopic grasper and to validate its impact on skills acquisition in basic laparoscopic skills training. Method: The ShaftFlex, a shaft-based grasping force measurement system providing feedback was designed as an add-on for standard reusable instruments. It consists of a compliant element deflecting proportionally to the applied grasping force, and a Hall sensor measuring that deflection. Influence on skills acquisition was evaluated in a comparative study where novices were divided into a Feedback and No feedback group, performing five training trials of a silicon torus transfer boxtrainer task. Afterwards, both groups performed a post-training task without feedback. Grasping force, time to completion and number of errors were measured. Results: There was a significant difference in mean grasping force between groups for all training trials and the post-training trial. In the Feedback group, there was no significant increase in grasping force when feedback was removed. Conclusions: The ShaftFlex working principle provided a feasible, sustainable method to measure grasping forces exerted by a laparoscopic grasper, enabling immediate haptic feedback. It potentially enhances objective skill assessment, providing feedback on training performance. In a clinical context, the ShaftFlex might be useful in surgery where delicate tissue is grasped.

Objective This study aimed to explore the fetal heart rate trend in the week before birth, the transition from fetal to neonatal heart rate, and the neonatal heart rate trend in the week after birth in preterm neonates admitted to a tertiary care hospital, considering maternal and neonatal factors. Study Design A retrospective cohort study was conducted, including neonates born between 24 and 34 weeks of gestation. Baseline heart rate, average deceleration capacity, standard deviation, skewness, and sample entropy were assessed using interrupted time series and difference-in-differences analyses. Subgroup analyses were performed according to gestational age at birth, sex, birth weight, mode of delivery, Apgar score at 5minutes, umbilical cord pH, and neonatal medication. Results The fetal and neonatal heart rate of 123 patients was analyzed. After birth, step change of baseline (2.23bpm,p<0.05), average deceleration capacity (0.43bpm,p<0.001), and skewness (0.47 nu,p<0.001) increased, while sample entropy (−0.68 bits,p<0.001) and standard deviation (−1.15bpm,p<0.001) decreased. Postnatally, baseline increased in linear slope and decreased in quadratic slope (bothp<0.001). Average deceleration capacity decreased in linear slope (p<0.001). Sample entropy and standard deviation increased in linear slopes (bothp<0.001). Skewness increased in quadratic slope (p<0.05). Subgroup analyses revealed that delivery mode, medication, and birth weight modulated these trends. Conclusion This study provides unique insights into heart rate frequency and variability trends during the period around preterm birth. It highlights the dynamic physiological adaptation that occurs during the transition from intrauterine to extrauterine life in preterm infants and may help inform future research on fetal and neonatal monitoring and clinical management. Key Points Heart rate frequency and variability dynamics were assessed around preterm birth in a NICU cohort. After birth, heart rate frequency increased while variability measures decreased. Heart rate frequency and variability differed by gestational age, birth weight, medication, and delivery mode.

This study aimed to establish reference values for heart rate frequency and variability indices in preterm neonates admitted to a neonatal intensive care unit of a tertiary care hospital during their first week of life. In this retrospective cohort study, the Generalized Additive Models for Location Scale and Shape framework was employed to establish reference values for heart rate indices across time-domain, frequency-domain and nonlinear-domain in neonates considering gestational age, postnatal age, sex and birth weight. Heart rate tracings of 594 neonates (45% female; median gestational age at birth 29⁰ (IQR 26⁶-30⁵); 38% birth weight <p10, 6% birth weight >p90) were analyzed. Reference values were established for 25 heart rate indices. Nearly all heart rate indices were significantly influenced by gestational age, postnatal age and sex. Baseline heart rate decreased with gestational age, increased with postnatal age and was higher in females. Heart rate standard deviation increased with gestational age and postnatal age and was lower in female. Inclusion of birth weight significantly improved model fit for all HRV indices. This study highlights the importance of considering gestational and postnatal age, sex and birth weight when interpreting neonatal heart rate frequency and variability in preterm neonates. These findings support the need for personalized approaches for neonatal monitoring and interpretation. Future research should validate these values in larger, more diverse populations, including additional clinical factors such as neonatal complications and medication administration, to determine their clinical relevance.

Objective: To establish reference values for fetal heart rate (FHR) indices across time, frequency and nonlinear domains throughout pregnancy in a tertiary hospital population, considering sex. The influence of the number of fetuses, birth weight,and time to delivery on FHR was evaluated. Methods: This retrospective cohort study analyzed the initial FHR tracing upon hospital admission between 24° and 41° weeks of gestation, excluding cases in labor, with medication use, or a confirmed medical indication. Reference values were established using the Generalized Additive Models for Location Scale and Shape framework. Likelihood ratio test assessed whether including clinical variables significantly improved model fit. Results: The cohort included 3219 fetuses, of which 48% were female and 91% singleton pregnancies. Median gestational age was 32⁺⁶. Birth weight was below p10 in 22% and above p90 in 9%. Median tracing duration was 42.5 min and median signal loss was 1.95%. Most indices were significantly associated with gestational age and several showed significant sex differences. Model fit significantly improved for multiple indices when including number of fetuses, birth weight, or time to delivery. Conclusions: This article presents gestational age- and sex-specific reference values for FHR in a large tertiary hospital population. The influence of gestational age was reaffirmed and significant differences related to sex, number of fetuses, birth weight, and time to delivery were identified. This enhances understanding of fetal autonomic regulation and supports a more individualized approach to predictive fetal monitoring. Further research is needed to determine the clinical utility of these reference values in practical monitoring and risk assessment.

BACKGROUND AND PURPOSE: Although dose planning aims in cervical cancer brachytherapy are well-defined, variability in clinical practices makes it difficult to draw generalizable conclusions on achievable dosimetry. This review and meta-regression aim to assess clinical practices in terms of their therapeutic dose window, that is, the balance between target and organs-at-risk (OAR) doses. MATERIALS AND METHODS: A search of the literature was performed in Scopus, PubMed, and Web of Science databases. Peer-reviewed articles were included that described planning constraints and reported high-risk clinical target volume (CTV_HR) D_90% and OAR D_2cm³ for intracavitary (IC) tandem and ring (T&R) / tandem and ovoid (T&O) / mold (M) applicators, possibly supplemented with interstitial (IS) needles (+N). To determine factors associated with target volume coverage (D_90%) and OAR sparing (D_2cm³), multivariate meta-regressions were performed. RESULTS: Out of 1590 articles, 34 met the full inclusion criteria. In most studies, the CTV_HR D_90% aimed at ≥84–86 Gy EQD2_{α/β = 10Gy}, and constraints for the OARs were 80–90 Gy, 65–75 Gy and 70–75 Gy EQD2_{α/β = 3Gy} for the bladder, rectum and sigmoid D_2cm³, respectively. Studies using IC/IS applicators were associated with a ∼4 Gy increase in CTV_HR D_90% compared to IC only, with no effect on OAR dose. T&R studies achieved improvements of 3.2 Gy and 2.8–3.4 Gy at typical planning aims in comparison with T&O applicators in target and OAR doses. In 100% (15/15) of patient groups treated with T&R + N both CTV_HR and OAR objectives were met for the population average. For T&R, T&O, and T&O + N groups, this was the case in 89% (8/9), 43% (6/14), and 50% (4/8), respectively. CONCLUSION: Studies using interstitial needles with T&R applicators in MR-guided brachytherapy for cervical cancer seem to be associated with a favorable therapeutic target dose/OAR sparing ratio.

Background and purpose Clinical introduction of in-house developed medical devices in Europe requires conformity to the Medical Device Regulation (MDR) 2017/745 Article 5(5). Published experience on regulatory aspects of these devices is limited. This work describes our in-house development and verifications of the 3D printed patient-tailored ARCHITECT brachytherapy applicator and accompanying software, prepared to support clinical investigation and in-house use. Materials and methods Article 5(5) mandates an ‘appropriate’ quality management system (QMS) and exempts in-house medical devices from all MDR requirements except general safety and performance requirements (GSPRs). An institutional QMS was available, comprising documented procedures and fill-in templates for all project phases to compile technical documentation. In the first phase, the QMS requires a market analysis to justify the in-house exemption. In the design phase a prototype is developed, to be iteratively improved during manufacturing and verification phases, based on risk evaluations, verification tests, and processing constraints. Documentation is lastly compiled to support clinical investigations and routine use of the device. Results After confirming that no suitable marketed device was available, risk-based design and manufacturing approaches were used to safeguard in-house development. Verifications of material, manufacturing, mechanical safety, cleaning and sterilisation, use and workflow, and compatibility with procedures showed compliance with GSPRs. Simulated dosimetric benefits were observed compared to marketed devices. Conclusion The ARCHITECT applicator was developed in a systematic process, resulting in documented workflows and verification steps. Our approach provides a practical framework for MDR-compliant introduction of in-house equipment and can inform future best practice guidelines.

Shock is a life-threatening condition marked by inadequate tissue perfusion and oxygen supply, leading to organ failure if not rapidly addressed. Clinical management of shock involves detecting and correcting altered macro hemodynamic parameters. However, these parameters may not accurately reflect microcirculatory alterations or abnormalities in oxygenation. A resuscitation strategy focused on peripheral perfusion, which can be non-invasively monitored, may allow for earlier shock detection and treatment, potentially reducing mortality. This literature review aims to study the available technologies found in literature and in patents to non-invasively monitor peripheral perfusion. PRISMA method was employed to systematically select or exclude articles and patents, resulting in 44 studies and 21 patents included in the review. The found technologies were classified based on the sensing principle in light (reflected, transmitted, or scattered), Doppler effect, temperature, and skin mottling. Combining the monitorization of microcirculatory with macrocirculatory parameters has the potential to have an accurate prognosis value for shock and other diseases. However, the various technologies that have been developed to monitor peripheral perfusion require further research and testing in diverse conditions.

Laparoscopic surgery offers significant benefits to patients in low-resource settings compared to open surgery such as faster recovery, less pain, and lower infection rate. However, there exist significant barriers to the safe introduction of laparoscopy such as high costs and limited availability of trained staff. Low- and middle-income country (LMIC) hospitals suffer from higher post-surgical infection which might be due to the limited facilities for the sterile reprocessing of laparoscopic instruments. To design a solution to this issue, a detailed understanding of local settings was needed. Therefore, this research applied a context-driven design approach, based on the Roadmap for Design of Surgical Equipment for Safe Surgery Worldwide. Over several design phases, the need for a reprocessing device was established. An analysis of the sterile reprocessing of laparoscopic instruments led to a list of context-specific design requirements. These were translated to a final conceptual design of a laparoscopic instrument cleaner using a waterfall design method. Finally, a usability study of the loading system of the device was conducted with nurses in four Indian hospitals. A root-cause analysis of the usability study showed that the device was not intuitive enough to use for Indian nurses. A redesign of the loading system was made to improve its ease of use. The design process used in this study can be used as an example for designers wanting to address the critical issue of context-specific medical devices worldwide, or more specifically, the sterile supply of surgical instruments in resource-constrained environments.

This systematic review explores machine learning (ML) applications in surgical motion analysis using non-optical motion tracking systems (NOMTS), alone or with optical methods. It investigates objectives, experimental designs, model effectiveness, and future research directions. From 3632 records, 84 studies were included, with Artificial Neural Networks (38%) and Support Vector Machines (11%) being the most common ML models. Skill assessment was the primary objective (38%). NOMTS used included internal device kinematics (56%), electromagnetic (17%), inertial (15%), mechanical (11%), and electromyography (1%) sensors. Surgical settings were robotic (60%), laparoscopic (18%), open (16%), and others (6%). Procedures focused on bench-top tasks (67%), clinical models (17%), clinical simulations (9%), and non-clinical simulations (7%). Over 90% accuracy was achieved in 36% of studies. Literature shows NOMTS and ML can enhance surgical precision, assessment, and training. Future research should advance ML in surgical environments, ensure model interpretability and reproducibility, and use larger datasets for accurate evaluation.

Negative Pressure Wound Therapy (NPWT) is a treatment that promotes healing of chronic wounds. Despite high prevalence of chronic wounds in Low- and Middle-Income Countries (LMICs), NPWT devices are not available nor affordable. This study aims to improve chronic wound care in LMICs by presenting the Wound Care (WOCA) system, designed for building, testing and use in LMICs. Design requirements were formulated using input from literature, ISO standards, and wound care experts. The WOCA design was developed to provide safe, portable, user-friendly and affordable NPWT to patients in LMICs. The design features an adjustable operating pressure ranging from −75 to −125 mmHg, a battery for portability, a 300 ml canister, overflow protection, and system state alarms. An Arduino controls the pressure and monitors the system state. Three prototypes were developed and built in Nepal, and their performance was evaluated. Pressure control was 125 ± 10 % mmHg, internal leakage was 7.5 ± 4.3 mmHg/min, reserve capacity was 189 ± 16.9 ml/min, and overflow protection and alarm systems were effectively working. Prototype cost was approximately 280 USD. The WOCA demonstrates to be a locally producible NPWT device that can safely generate a stable vacuum. Future research will include clinical trials situated in LMICs.

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.

Background: Preoperative planning of patients diagnosed with pancreatic head cancer is difficult and requires specific expertise. This pilot study assesses the added value of three-dimensional (3D) patient models and computer-aided detection (CAD) algorithms in determining the resectability of pancreatic head tumors. Methods: This study included 14 hepatopancreatobiliary experts from eight hospitals. The participants assessed three radiologically resectable and three radiologically borderline resectable cases in a simulated setting via crossover design. Groups were divided in controls (using a CT scan), a 3D group (using a CT scan and 3D models), and a CAD group (using a CT scan, 3D and CAD). For the perceived fulfillment of preoperative needs, the quality and confidence of clinical decision-making were evaluated. Results: A higher perceived ability to determine degrees and the length of tumor–vessel contact was reported in the CAD group compared to controls (p = 0.022 and p = 0.003, respectively). Lower degrees of tumor–vessel contact were predicted for radiologically borderline resectable tumors in the CAD group compared to controls (p = 0.037). Higher confidence levels were observed in predicting the need for vascular resection in the 3D group compared to controls (p = 0.033) for all cases combined. Conclusions: “CAD (including 3D) improved experts’ perceived ability to accurately assess vessel involvement and supports the development of evolving techniques that may enhance the diagnosis and treatment of pancreatic cancer”.

Endovascular intervention is a minimally invasive method for treating cardiovascular diseases. Although fluoroscopy, known for real-time catheter visualization, is commonly used, it exposes patients and physicians to ionizing radiation and lacks depth perception due to its 2D nature. To address these limitations, a study was conducted using teleoperation and 3D visualization techniques. This in-vitro study involved the use of a robotic catheter system and aimed to evaluate user performance through both subjective and objective measures. The focus was on determining the most effective modes of interaction. Three interactive modes for guiding robotic catheters were compared in the study: 1) Mode GM, using a gamepad for control and a standard 2D monitor for visual feedback; 2) Mode GH, with a gamepad for control and HoloLens providing 3D visualization; and 3) Mode HH, where HoloLens serves as both control input and visualization device. Mode GH outperformed other modalities in subjective metrics, except for mental demand. It exhibited a median tracking error of 4.72 mm, a median targeting error of 1.01 mm, a median duration of 82.34 s, and a median natural logarithm of dimensionless squared jerk of 40.38 in the in-vitro study. Mode GH showed 8.5%, 4.7%, 6.5%, and 3.9% improvements over Mode GM and 1.5%, 33.6%, 34.9%, and 8.1% over Mode HH for tracking error, targeting error, duration, and dimensionless squared jerk, respectively. To sum up, the user study emphasizes the potential benefits of employing HoloLens for enhanced 3D visualization in catheterization. The user study also illustrates the advantages of using a gamepad for catheter teleoperation, including user-friendliness and passive haptic feedback, compared to HoloLens. To further gauge the potential of using a more traditional joystick as a control input device, an additional study utilizing the Haption Virtuose robot was conducted. It reveals the potential for achieving smoother trajectories, with a 38.9% reduction in total path length compared to a gamepad, potentially due to its larger range of motion and single-handed control.

Background: The Veress Needle (VN) is commonly used in establishing pneumoperitoneum in laparoscopic surgery. However, severe vascular and/or visceral complications can occur due to overshoot at the insertion of the VN in the abdominal cavity. In order to investigate whether the new VeressPLUS needle (VN+) could improve safety, the learning curve of this needle was compared to that of a conventional VN, under standardized conditions. Methods: In total, 26 residents and med students, without prior Veress needle experience, were recruited and randomly assigned to VN or the VN+ group. A learning curve plateau phase recognition model was developed and used to determine the learning curve of the participants who used either the VN or the VN+ needle on two Thiel-embalmed human cadavers. Insertion of the needles was done in a systematic way in the upper abdomen and insertion depth was measured under direct laparoscopic vision. At the end of the learning curve, the number of participants that reached a safe insertion depth between 5 and 15 mm was compared. Results: On average, it took the VN group 8 trials to reach and establish the plateau phase of the learning curve. The VN+ group showed no learning curve at all. At the 8th trial, a significant difference (p < 0.002) in average insertion depth was found in favor of the VN+ (mean: 5.4 mm SD 1.4) compared to the VN (mean: 12.7 mm SD 6). In the VN group and VN+ group, 46% versus 8% exceeded the safe insertion depth of 10 mm at the end of the learning curve. Conclusion: This study indicates that for novices, there is no learning curve for the VN+, when compared to VN. Moreover, in all cases, the insertion depths were significantly reduced (with more than 50%) while using the VN+ when compared to the VN.

Introduction: Preterm infants’ growth is typically monitored through weight, body length (BL) and head circumference (HC). However, 3D cranial volume (CrV) is considered a more accurate indicator of brain growth than 2D HC. The PreemieScanner is a novel 3D measuring device that simultaneously measures BL, HC and CrV. Its clinical usability was tested in a simulated NICU setting. Materials and methods: Three extremely low birth weight (ELBW; BW < 1,000 gram) dolls with Optiflow breathing systems, (tubes positioned either at the front or back of the head) were used. Nurses conducted scan sessions and marked anatomical landmarks on 3D PreemieScanner images. As control, nurses measured HC manually with a standard measuring tape. Key outcomes were: (1) Measurement success rate, (2) Precision—percentage within clinically allowed limits, ±0.4 cm for BL, ±0.3 cm for HC, ±12 ml for CrV, and 3) accuracy—mean or median measurement error (MME) relative to the ground truth. Results: Thirty-five scan sessions resulted in 100% successful measurements for BL and HC; 80% for CrV. BL MME −3.3% (p < 0.001); 40% (42/105) within precision limits. HC MME (Optiflow-front) 0.0% (p = 0.63); 89% (51/57) within limits. HC MME (Optiflow-back) −0.4% (p = 0.91). 93% (43/46) within limits. MME HC measuring tape, (Optiflow-front) −0.8% (p < 0.001), 88% (50/57) within limits, and MME (Optiflow-back) −1.1% (p < 0.001), 83% (40/48) within limits. MME CrV (Optiflow-front) −1.8% (p = 0.01), 86% (31/36) within limits, MME CrV (Optiflow-back) −1.3% (p < 0.001), 98% (45/46) within limits. Conclusions: The PreemieScanner is a reliable, comprehensive device for measuring BL, HC and CrV in ELBW infants. It integrates smoothly into routine care with minimal disturbance. HC measurements demonstrated higher accuracy and precision than traditional tape method. CrV measurements, with 93% within precision limits, can be regarded as acceptable, enabling development of CrV growth reference charts, enhancing clinical growth monitoring.

Annually, 14-41 per 100 000 infants get mildly to lethally injured or severely disabled through violent shaking. The incidence and mortality of inflicted head injury by shaking trauma (IHI-ST) are highest in the early months and decrease with age. This may partly be due to the age-related physical characteristics of infants. Younger, smaller infants are more vulnerable owing to their size and material properties. In addition, from basic biomechanics, it is expected that larger or heavier infants may be more difficult to fiercely shake and will exhibit different motion patterns when being shaken violently. Therefore, the aim of this study was to compare the kinematics of shaking a smaller versus a larger infant dummy. We recorded the kinematics of two dummies, representing a 6-week-old and a 1-year-old, while they were violently shaken by volunteers. We found that participants induced higher head and torso accelerations when shaking the 6-week-old, than with the 1-year-old dummy. Moreover, higher peak sagittal angular accelerations coincide with smaller radii of rotation in the 6-week-old than in the 1-year-old. Because it has been suggested in the literature that sagittal angular acceleration of the head is an important mechanism in inducing the injuries associated with IHI-ST; the results of this study show that shaking a smaller/younger infant is more likely to cause the kinematics possibly responsible for IHI-ST.

Background: Laparoscopic surgery requires a complex set of motor skills. Currently, basic laparoscopic skills training is performed in a static environment, while intraoperatively, abdominal tissue is often moving. The aim of this study was to develop a dynamic training platform and evaluate its impact on laparoscopic skills acquisition in a box trainer. Methods: The Dynamic Laparoscopic Platform (DyLaP) includes a moving base which has been intergrated with the Lapron box trainer and the ForceSense objective measurement system. Dynamic training was evaluated in a comparative study where novices were divided into a static and dynamic training group, performing six training trials of a peg transfer task with the DyLaP. Afterwards, both groups performed a dynamic exam task. Task manipulation (force) and instrument efficiency (path length and time) were measured. Results: Participants (n = 12) exhibited a significant difference (p < 0.05) in time, path length, and maximum force between the static and dynamic groups in the first trial. Learning curves were most prevalent in the dynamic group. Conclusions: The DyLaP can be used to provide a challenging and realistic training environment. From the comparative peg transfer study, it can be concluded that dynamic training significantly affects laparoscopic skill acquisition. More research is needed to evaluate dynamic training effects in force-based training tasks.