A new option in pain prevention with bliss, a therapeutic virtual reality solution in bone marrow biopsy context: Results of a French open-label multicenter randomized phase II/III study (REVEH Trial).

6573 Background: The prevention of care-induced pain is a central concern for all healthcare teams in hematology units. Use of MEOPA (Oxygen + Nitrous Oxide) is today a standard of care for relaxation procedure. Distraction through immersion in virtual reality (VR) has already documented its analgesic effects in several phase II trials but comparison with standard treatments in a large randomized study is needed. Methods: We conducted an open-label multicenter randomized phase III trial (ClinicalTrials.gov identifier: NCT03483194). We assessed the safety and efficacy of a new therapeutic virtual reality solution for pain distraction, Bliss, in prevention of pain and anxiety before performing a bone marrow biopsy. Bliss is a VR software with four imaginary interactive environments in three dimensions with binaural sound (head-mounted display). Efficacy was evaluated by pain intensity with visual analog scale (score from 0 to 10) just after the biopsy and anxiety by 2 questionnaires (fear of pain before the biopsy and revised STAI questionnaire before and after the biopsy). The primary end point was patient-assessed pain intensity after the bone marrow procedure. Results: A total of 126 patients were enrolled with previously untreated malignant hemopathy between September 6, 2018 and May 18, 2020. They were randomly assigned in a 1:1 ratio to receive pain prevention with MEOPA (n=63) or Bliss (n=63) before and during their bone marrow biopsy. All patients received a local anesthesia with lidocaïne before the biopsy. Median age of the study population was 65.5 years old (range 18 to 87) and 54,2% were men. The average pain intensity was 3.5 (standard deviation 2.6) for the MEOPA group and 3.0 (SD 2.4) for the VR group (p=0,26) without any significant difference according to age, gender or hemopathy. Concerning anxiety, 67.5% of patients were afraid before the biopsy and anxiety scores were moderate to very high in 26.3% of patients before the biopsy (STAI questionnaire) and 9.0% after the biopsy for all patients (17.3% of reduction in anxiety for the MEOPA group and 17.2% for the VR group, p=0.83). Immersion in VR was well tolerated in 100% of patients included in the VR group. Physicans were very satisfied by the relaxation procedure in 64.9% of cases (52.5% in the MEOPA group and 77.6% in the VR group, p=0.01) and recommended re-use of the technique in 54.2% in the MEOPA group and 79,1% in the VR group (p=0.02). Conclusion: The intensity of pain did not significantly differ in both arms. Bliss-based relaxation method was well tolerated and the satisfaction of patients and physicians was very high in VR group. This study validates the use of immersion in VR with Bliss as a new digital therapeutics and support the integration of the software in the panel of supportive care. Key words: virtual reality, bone marrow biopsy, pain. Clinical trial information: 03483194.

Numerical simulation of shock wave – dense particles cloud interaction using Godunov solver for Baer–Nunziato equations

Purpose This paper aims to clarify some aspects of the application of the Godunov method for the Baer–Nunziato equations solution on the example of the problem of shock wave – dense particles cloud interaction. Design/methodology/approach The statement of the problem corresponds to the natural experiment. Mathematical model is based on the Baer–Nunziato system of equations with algebraic right-hand side source terms that takes into account the interphase friction force. Two numerical approaches are used: Harten-Lax-van Leer method and Godunov method. Findings For the robust simulation using Godunov method, the application of the pressure relaxation procedure is proposed. The comparative analysis of the simulation results using two methods is carried out. The Godunov method provides significantly smaller numerical diffusion of the solid phase volume fraction in the cloud that leads to the much better agreement of the pressure curves on transducers and the dynamics of the cloud motion with the experimental data. Originality/value Godunov method for the Baer–Nunziato equations is applied for the simulation of the natural experiment on the shock wave particles cloud interaction. Up to now, the examples of the application of the Godunov method for the Baer–Nunziato equations to the investigation of the practical problems have been limited by the works of the authors of the method and the field of detonation in the heterogeneous explosives. For the robust simulations in the presence of interphase boundaries, it is proposed to use the Godunov method together with the pressure relaxation procedure.

A Capacitated Location-Inventory Model with Demand Selection

In this paper, we consider an integrated supply chain network design problem, which incorporates inventory and pricing decisions into the capacitated facility location model. We assume that each warehouse has a capacity limitation that limits the average demand flowing through the warehouse and that the supplier can choose whether to satisfy each potential retailer’s demand. We formulate the problem as a nonlinear integer programming model and solve the model via a Lagrangian relaxation based approach. We develop an efficient algorithm to solve the subproblem that arises from the Lagrangian relaxation procedure. Finally, we conduct extensive computational experiments to test the performance of the algorithms proposed in this paper and provide the managerial insights based on the computational results.

Use an idealized protocol to assess the nesting procedure in regional climate modelling

Newtonian relaxation allowing RCM to follow GCM is a widely used technique for climate downscaling and regional weather forecasting. A thorough assessment on effects of the relaxation procedure in an idealized framework is presented in this paper for both synoptic variability and long-term mean climate. LMDz is a global atmospheric general circulation model that can be configured as a regional model if the outside domain of the focused region is applied with a relaxation. It thus plays the role of both GCM and RCM in this paper. Same physical parameterization and identical dynamical configuration are kept to ensure a rigorous comparison between the two models. The experimental set-up that can be referred to as “Master (GCM) versus Slave (RCM)” considers the GCM as the reference to assess the behavior of RCM. A further simulation with RCM in a higher resolution configuration allows isolating the effect of relaxation procedure from that of mesh refinement. In terms of mean climate in GCM and RCM, there are noticeable differences, not only in the border areas, but also within the domain. In terms of synoptic variability, there is a general spatial resemblance and temporal concomitance between the two models. But there is a dependence on variables, seasons, spatiotemporal scales and spatial mode of atmospheric circulation. Winter/Summer has the most/least resemblance between the RCM and the GCM. A better similarity is noticed when atmospheric circulations manifested on large scales. No-correlation cases can be remarked when the dominant circulation of the region is at a small scale.