A Synthesis Method for Automatic Handling of Inter-patient Variability in Closed-loop Anesthesia

This paper presents a convex-optimization-based technique to obtain parameters for a PID feedback controller, used to control the infusion rate of the anesthetic drug propofol. The controller design is based on a set of identified patient models, relating propofol infusion to an EEG-based conciousness index. The main contribution lies in the method automatically taking inter-patient variability into account, i.e., it guarantees robustness (sensitivity peak) and performance (disturbance rejection) over a set of patient models, without the need for manual intervention. The method is demonstrated using a clinically relevant design example. A controller designed using the proposed method is currently scheduled for clinical evaluation

Quantification of the variability in response to propofol administration in children

Closed-loop control of anesthesia is expected to decrease drug dosage and wake up time while increasing patient safety and decreasing the work load of the anesthesiologist. The potential of closed-loop control in anesthesia has been demon- strated in several clinical studies. One of the challenges in the development of a closed-loop system that can be widely accepted by clinicians and regulatory authorities is the effect of inter- patient variability in drug sensitivity. This system uncertainty may lead to unacceptable performance, or even instability of the closed-loop system for some individuals. The development of reliable models of the effect of anesthetic drugs and charac- terization of the uncertainty is therefore an important step in the development of a closed-loop system. Model identification from clinical data is challenging due to limited excitation and the lack of validation data. In this paper, approximate models are therefore validated for controller design by evaluating the predictive accuracy of the closed-loop behavior. A set of 47 validated models that describe the inter-patient variability in the response to propofol in children is presented. This model set can be used for robust linear controller design provided that the experimental conditions are similar to the conditions during data collection

Impact and feasibility of a tailor-made patient communication quality improvement programme for hospital-based physiotherapists:a mixed-methods study

Background In tailoring a quality improvement programme for hospital-based physiotherapy, the original use of video recordings was replaced by using the tracer methodology. Objective To examine the impact of a tailor-made quality improvement programme addressing patient communication on the professional development of hospital-based physiotherapists, and to evaluate barriers and facilitators as determinants of feasibility of the programme. Methods A mixed-methods study was conducted. Participants were clustered in groups per hospital and linked with an equally sized group in a nearby hospital. Within the groups, fixed couples carried out a 2-hour tracer by directly observing each other's daily work routine. This procedure was repeated 6 months later. Data from feedback forms were analysed quantitatively, and a thematic analysis of transcripts from group interviews was conducted. Results Fifty hospital-based physiotherapists from 16 hospitals participated. They rated the impact of the programme on professional development, on a scale from 1 (much improvement needed) to 5 (no improvement needed), as 3.99 (SD 0.64) after the first tracer and 4.32 (SD 0.63) 6 months later; a mean improvement of 0.33 (95% CI 0.16 to 0.50). Participants scored, on a scale ranging from 1 to 5 on barriers and facilitators (feasibility), a mean of 3.45 (SD 0.95) on determinants of innovation, 3.47 (SD 0.86) on probability to use and 2.63 (SD 1.07) on the user feedback list. All participants emphasised the added value of the tracer methodology and mentioned effects on self-reflection and awareness most. Conclusions The tailor-made quality improvement programme, based on principles of the tracer methodology, was associated with a significant impact on professional development. Barriers and facilitators as determinants of feasibility of the programme showed the programme being feasible

Omgaan met digitale nationale beleidskaarten

In dit werkdocument worden de resultaten besproken van een casestudy die onderdeel is van het project GeO3 - Omgaan met onzekerheid binnen Ruimtelijke Ordening. De directie Platteland van het ministerie van LNV heeft bij het publiceren van het meerjarenprogramma van Agenda Vitaal Platteland geen digitale viewer gepubliceerd omdat men bang was voor verkeerde interpretatie van de digitale kaarten. In dit project is gekeken naar methoden en cartografische oplossingen om voortaan zonder angst voor misinterpretaties digitale nationale beleidskaarten te kunnen verspreiden. De oplossing is gezocht in het opstellen van een handreiking, zodat kaarten ook daadwerkelijk weergeven wat er bedoeld is door de maker

Quality aspects of hospital-based physiotherapy from the perspective of key stakeholders:a qualitative study

Background For the design of a robust quality system for hospital-based physiotherapy, it is important to know what key stakeholders consider quality to be. Objective To explore key stakeholders' views on quality of hospital-based physiotherapy. Methods We conducted 53 semi-structured interviews with 62 representatives of five key stakeholder groups of hospital-based physiotherapy: medical specialists, hospital managers, boards of directors, multidisciplinary colleagues and patients. Audio recordings of these interviews were transcribed verbatim and analysed with thematic analysis. Results According to the interviewees, quality of hospital-based physiotherapy is characterised by: (1) a human approach, (2) context-specific and up-to-date applicable knowledge and expertise, (3) providing the right care in the right place at the right time, (4) a proactive departmental policy in which added value for the hospital is transparent, (5) professional development and innovation based on a vision on science and developments in healthcare, (6) easy access and awareness of one's own and others' position within the interdisciplinary cooperation and (7) ensuring a continuum of care with the inclusion of preclinical and postclinical care of patients. Conclusions Important quality aspects in the perspective of all stakeholders were an expertise that matches the specific pathology of the patient, the hospital-based physiotherapist being a part of the care team, and the support and supervision of all patients concerning physical functioning during the hospitalisation period. Whereas patients mainly mentioned the personal qualities of the physiotherapist, the other stakeholders mainly focused on professional and organisational factors. The results of this study offer opportunities for hospital-based physiotherapy to improve the quality of provided care seen from the perspective of key stakeholders

Optimizing robust PID control of propofol anesthesia for children; design and clinical evaluation

Objective: The goal of this study was to optimize robust PID control for propofol anesthesia in children aged 5-10 years to improve performance, particularly to decrease the time of induction of anesthesia while maintaining robustness.Methods: We analyzed results of a previous study conducted by our group to identify opportunities for system improvement. Allometric scaling was introduced to reduce the interpatient variability and a new robust PID controller was designed using an optimization based method. We evaluated this optimized design in a clinical study involving 16 new cases.Results: The optimized controller design achieved the performance predicted in simulation studies in the design stage. Time of induction of anesthesia was median [Q1, Q3] 3.7 [2.3, 4.1] minutes and the achieved global score was 13.4 [9.9, 16.8]. Conclusion: Allometric scaling reduces the interpatient variability in this age group, and allows for improved closed-loop performance. The uncertainty described by the model set, the predicted closedloop responses and the predicted robustness margins are realistic. The system meets the design objectives of improved speed of induction of anesthesia while maintaining robustness, improving clinically relevant system behavior.Significance: Control system optimization and ongoing system improvement are essential to the development of a clinically relevant commercial device. This paper demonstrates the validity of our approach, including system modeling, controller optimization and pre-clinical testing in simulation