Symptoms assessment and decision to treat patients with advanced Parkinson's disease based on wearables data.

Body-worn sensors (BWS) could provide valuable information in the management of Parkinson's disease and support therapeutic decisions based on objective monitoring. To study this pivotal step and better understand how relevant information is extracted from BWS results and translated into treatment adaptation, eight neurologists examined eight virtual cases composed of basic patient profiles and their BWS monitoring results. Sixty-four interpretations of monitoring results and the subsequent therapeutic decisions were collected. Relationship between interrater agreements in the BWS reading and the severity of symptoms were analyzed via correlation studies. Logistic regression was used to identify associations between the BWS parameters and suggested treatment modifications. Interrater agreements were high and significantly associated with the BWS scores. Summarized BWS scores reflecting bradykinesia, dyskinesia, and tremor predicted the direction of treatment modifications. Our results suggest that monitoring information is robustly linked to treatment adaptation and pave the way to loop systems able to automatically propose treatment modifications from BWS recordings information.

All Insulin Pumps Are Not Equivalent: A Bench Test Assessment for Several Basal Rates.

Background and Aims: Continuous subcutaneous insulin infusion (CSII) is a widely adopted treatment for type 1 diabetes and is a component of an artificial pancreas. CSII accuracy is essential for glycemic control, however, this metric has not been given sufficient study, especially at the range of the lowest basal rates (BRs), which are commonly used in a pediatric population and in closed-loop systems (CLSs). Our study presents accuracy results of four off-the-shelf CSII systems using a new accurate method for CSII system evaluation. Materials and Methods: The accuracy of four off-the-shelf CSII systems was assessed: Medtronic MiniMed 640G®, Ypsomed YpsoPump®, Insulet Omnipod®, and Tandem t:slim X2®. The assessment was performed using a double-measurement approach through a direct mass flow meter and a time-stamped microgravimetric test bench combined with a Kalman mathematical filter. CSII accuracy was evaluated using mean of dose error. Mean absolute relative difference (MARD) of error was calculated at different observation windows over the whole series of tests. Peakwise insulin deliverance was assessed regarding stroke regularity in terms of frequency and volume. Results: Mean error values indicate a general tendency to underdeliver with up to -16%. MARD of error shows very wide results for each pump and each BR from 7.4% (2 UI/h) to 61.3% (0.1 UI/h). Peakwise analysis shows several choices for BR adaptation (frequency for Omnipod, volume for Tandem, both for YpsoPump and MiniMed 640G). Precision in interstroke time appears to be better (standard deviation [SD] at 0.1 UI/h: 4.6%-12.9%) than stroke volume precision (SD at 0.1 UI/h 38.3%-46.4%). Conclusions: The accuracy of four off-the-shelf CSII systems is model and BR dependent. CSII imprecision could be due to a variability in volume and/or frequency of strokes for every pump. Some models appear better adapted for the smallest insulin needs, or for inclusion in a CLS. The clinical implications of these delivery errors on glucose instability must be evaluated.

Kalman Filter-Based Novel Methodology to Assess Insulin Pump Accuracy.

Background: Insulin pump or continuous subcutaneous insulin infusion (CSII) system is a widely adopted contemporary treatment for type 1 diabetes and is a major component of an artificial pancreas (AP). CSII accuracy is essential for glycemic control and to-date such metric has not been given sufficient study, especially at the range of the lowest basal rate. The gold-standard assessment method IEC (International Electrotechnical Commission) 60601-2-24 has some limitations. Our study presents a new accurate and reactive method for CSII system evaluation based on direct flow measurement. Materials and Methods: A leading-edge assessment method based on a double measurement approach utilizing a direct mass flow meter and a time-stamped microgravimetric bench test was combined with a Bayesian-based mathematical filter (Kalman). The performance of this new method was evaluated while assessing the delivery precision of an off-the-shelf insulin pump at several basal rates. The proposed methodology offers a double reading-volume and flow rate-which provides direct instantaneous flow rate. CSII dose errors were evaluated using mean absolute relative dispersion (MARD) at different time intervals windows over the whole test. Results: The metrological aspect of the measurements and filtering performance were consistent. CSII precision is shown to be different in terms of the flow rate value: MARD15min (2 UI/h) = 12.7%, MARD15min (0.5 UI/h) = 20.4%, and MARD15min (0.1 UI/h) = 65.0%. MARD240min (2 UI/h) = 8.1%, (0.5 UI/h), MARD240min (0.5 UI/h) = 18.8%, and MARD240min (0.1 UI/h) = 18.4%. Instantaneous flow rate results highlight an irregular stroke-based delivery. Conclusion: This new method to assess insulin pump administration has been validated and highlights the current imprecision in insulin delivery, especially for the lowest basal rate, which is mainly used in pediatric cases and AP system delivery. This leading-edge method should be used to precisely compare several CSII performances in those contexts.