Meeting Report: The Fourth Artificial Pancreas Workshop: Testing and Adoption of Current and Emerging Technologies.

On July 6 and 7, 2016 the Fourth Artificial Pancreas Workshop: Testing and Adoption of Current and Emerging Technologies was held on the National Institutes of Health (NIH) Campus at the Lister Hill Auditorium. The meeting was sponsored by a group of governmental organizations and NGOs, listed in Appendix A. This was a very timely meeting as the artificial pancreas appears to be growing from academic studies to commercial projects. The first artificial pancreas may be marketed within 12 months and a few may be approved within 24 months. The NIH, the FDA, the JDRF, Helmsley Trust, Diabetes Technology Society, and other agencies, funders, and organizations have been strongly supportive of advancing artificial pancreas technology and usability, and thus the proceedings from this conference should be of exceptional interest to the diabetes technology community.

Impact of Type 1 Diabetes Technology on Family Members/Significant Others of People With Diabetes.

BACKGROUND: The aim was to explore the impact of diabetes-related technology to ensure that such devices are used in a way that returns maximum benefit from a medical and psychological perspective. METHOD: Spouses and caregivers of people with type 1 diabetes were invited to complete an online questionnaire about their experiences with diabetes technologies used by their family members. Participants were recruited via the Glu online community website. Questions explored impact on daily living, frequency and severity of hypoglycemia, and diabetes-related distress. RESULTS: In all, 100 parents/caregivers and 74 partners participated in this survey. Average (mean) duration of living with a person with type 1 diabetes was 16 years (SD = 13) for partners, with duration of diabetes for children being 4.2 ± 3.2 years. Average duration of current therapy was 8.3 ± 7.3 years for adults and 3.4 ± 2.9 years for children. Of the participants, 86% partners and 82% parents/caregivers reported diabetes technology had made it easier for their family members to achieve blood glucose targets. Compared to partners, parents/caregivers reported more negative emotions (P < .001) and decreased well-being (P < .001) related to their family members type 1 diabetes. Diabetes-related distress was common, as was sleep disturbance associated with device alarms and fear of hypoglycemia. Reduced frequency and severity of hypoglycemia related to device use was reported by approximately half of participants. CONCLUSION: There is little doubt about the medical benefit of diabetes technologies and their uptake is increasing but some downsides were reported. Barriers to uptake of technologies lie beyond the mechanics of diabetes management. Supporting users in using diabetes technology to achieve the best possible glycemic control, in the context of their own life, is crucial. Furthermore, understanding these issues with input from the type 1 diabetes community including family members and caregivers will help innovation and design of new technology.

Prospective assessment of lower-extremity peripheral arterial disease in diabetic patients using a novel automated optical device.

A new optical device based on the photoplethysmograph (PPG) method and an innovative algorithm for the assessment of lower-extremity peripheral arterial disease was investigated prospectively in patients with type II diabetes. This new functional PPG (fPPG) technique uses a cuffless functional test to assess diabetic peripheral arterial disease without operator dependency and the incompressible arteries, issues associated with ankle brachial pressure index (ABPI) measurement. Diabetic patients (n = 24; 47 legs; age, 70 +/- 3 years) were recruited from the vascular clinic, and controls (n = 15; 30 legs; age, 66 +/- 5 years) were recruited from the orthopedic outpatient clinic. All underwent resting ABPI, fPPG, and duplex angiography (DA) as "gold standard." fPPG requires the placement of an optical probe on the toe for acquisition of pulsatile arterial perfusion for a period of 30 seconds with the leg in supine and raised at 45 degrees positions. The data were analyzed, and indices were generated by an automated computer system. In those with diabetes, fPPG correlated significantly with DA (r = -.68, P < .01) and ABPI (r = -.65, P < .01). We also found a significant correlation between ABPI and DA (r = .81, P < .01). The analysis of the receiver operator curve showed that optimum sensitivity and specificity for ABPI and fPPG were 80% and 93% and 83% and 71%, respectively, against DA. This method uses changes in pulsatile arterial blood volume using a simple cuffless functional test. The fPPG investigation period was much shorter (5 minutes) with independence of operator skills, whereas ABPI took longer (10-15 minutes) and required operator experience. Although the fPPG results are promising, further improvement (eg, by incorporation of functional skin color and temperature changes) is required to improve the sensitivity and specificity of the system.

Assessment of lower extremity peripheral arterial disease using a novel automated optical device.

The resting ankle-brachial pressure index (rABPI) is used in the diagnosis of lower extremity peripheral arterial disease (PAD) in symptomatic and asymptomatic patients. This article compares the rABPI with a new optical device based on photoplethysmograph (PPG) technology with new algorithms for the assessment of PAD. Functional PPG (fPPG) is a promising noninvasive automated device using a novel cuffless functional test for assessing mild or significant PAD without the operator dependency issues associated with rABPI. This system utilizes both changes in pulsatile arterial blood volume and skin color redness in lower limbs. All subjects underwent rABPI, fPPG, and duplex angiography (DA). Significant correlation was found between fPPG and DA scores, rABPI and DA, and fPPG and rABPI. In the hands of operators with little experience, fPPG may prove to be superior to rABPI and may be useful as a simple screening tool for early detection of PAD in primary care.

Complex character analysis of heart rate variability following brain asphyxia.

In the present study Renyi entropy and L-Z complexity were used to characterize heart rate variability (HRV) of rats that were suffered from brain asphyxia and ischemia. Two groups of rats were studied: (a) rats (n=5) injected with NAALADase inhibitor, 2-PMPA, which has been proven neuroprotective in asphyxia injury and (b) control subjects (n=5) without medication. Renyi entropy and L-Z complexity of the R-R intervals (RRI) at different experiment stages were investigated in the two groups. The results show that both measures indicate less injury and better recovery in the drug injection group. The dynamic change of 90 min RRI signal after the asphyxia was investigated. The sudden reduction of the two parameters shows their sensitivity to the asphyxia insult.

Poincaré plot analysis for pulse interval extracted from non-contact photoplethysmography.

An analysis of pulse-to-pulse interval (PPI) derived from non-contact photoplethysmography (PPG) is performed using the Poincaré plot technique. Eleven healthy volunteers participated in a protocol utilising both spontaneous and paced breathing methodologies with a customised non-contact PPG system to obtain adequate quality signals for a distance of 80mm between source and detector. An adaptive trough-searching algorithm (ATSA) is developed to extract the PPI which is effective in the presence of artefact during non-contact PPG measurement. A Poincaré plot for each 5 minute period of the protocol shows significant pattern differences between spontaneous and paced breathing measurements. Geometric parameters extracted from the Poincaré plot are shown to be sensitive to breathing interval changes and are a useful indicator for the variation of pulse rate variability measured using non-contact PPG.

Prospective venox feasibility study.

Venox is a propriety Venous Oximetry system, capable of measuring peripheral venous oximetry. In this ongoing study, Venox is being compared against mixed central venous oximetry during human cardiac surgery, with Fibre optic reflectance spectrophotometry being used as the gold standard, placed in the pulmonary artery. A background review of the Pulse oximetry, current venous oximetry techniques and the potential advantage of the VENOX system are discussed. Lessons learnt, Preliminary results, and future plans are included in discussion.