Do-It-Yourself (DIY) Artificial Pancreas Systems for Type 1 Diabetes: Perspectives of Two Adult Users, Parent of a User and Healthcare Professionals.

The artificial pancreas system or an automated insulin dosing system has been the 'holy grail' for patients with type 1 diabetes and their caregivers who have over the years wanted to 'close the loop' between monitoring of glucose and delivery of insulin. The launch of the Medtronic MiniMed 670G system in 2017 and the subsequent release of the Tandem t:slim with Control-IQ system, the DANA RS pump compatible-CamAPS FX app and the more recent announcement of the Medtronic MiniMed 780G system have come as answers to their prayers. However, in the time taken to develop and launch these commercial systems, creative and ebullient parents of young patients with type 1 diabetes, along with other patients, technologists and healthcare professionals have developed mathematical models as software solutions to determine insulin delivery that in conjunction with compatible hardware have helped 'close the loop'. Under an umbrella movement #WeAreNotWaiting, they have, as a community, refined and disseminated technologies that are open source and ubiquitously available as do-it-yourself (DIY) closed-loop systems or DIY artificial pancreas systems (APS). There are presently three systems-OpenAPS, AndroidAPS and Loop. We present perspectives of two patients, parent of a patient, and their healthcare providers; the users spanning an age spectrum most likely to use this technology-a child, an adolescent in transitional care and a 31-yr old adult patient, highlighting how looping has helped them self-manage diabetes within the routine of their lives and the challenges they faced.

Minimum toe clearance and tripping probability in people with unilateral transtibial amputation walking on ramps with different prosthetic designs.

BACKGROUND: Minimum Toe Clearance (MTC) is defined as the minimum vertical distance between the lowest point under the front part of the foot and the ground, during mid-swing. Low values of MTC and walking on inclines are both related to higher probability of tripping and falling in lower limb amputees. New prosthetic designs aim at improving MTC, especially on ramps, however the real effect on MTC still needs investigation. The objective of this study was then to evaluate the effect of different prosthetic designs on MTC in inclined walking. METHODS: Thirteen transtibial amputees walked on a ramp using three different prostheses: non articulating ankle (NAA), articulating hydraulic ankle (AHA), and articulating hydraulic ankle with microprocessor (AHA-MP). Median MTC, coefficient of variation (CV), and tripping probability (TP) for obstacles of 10 and 15 mm were compared across ankle type in ascent and descent. FINDINGS: When using AHA-MP, larger MTC median values for ascending (P ≤ 0.001, W = 0.58) and descending the ramp (P = 0.003, W = 0.47) were found in the prosthetic limb. Also significantly lower CV was found on the prosthetic limb for both types of AHA feet when compared to NAA for descending the ramp (P = 0.014, W = 0.45). AHA-MP showed the lowest TP for the prosthetic leg in three conditions evaluated. On the sound limb results showed the median MTC was significantly larger (P = 0.009, W = 0.43) and CV significantly lower (P = 0.005, W = 0.41) when using an AHA in ascent. INTERPRETATION: Both AHA prosthetic designs help reduce the risk of tripping of the prosthetic limb by increasing the median MTC, lowering its variability and reducing TP for both legs when ascending and descending the ramp. For most of the conditions, AHA-MP showed the lowest TP values. Findings suggest that AHA prostheses, especially AHA-MP could reduce the risk of tripping on ramps in amputees.

A biomechanical assessment of hydraulic ankle-foot devices with and without micro-processor control during slope ambulation in trans-femoral amputees.

Slope ambulation is a challenge for trans-femoral amputees due to a relative lack of knee function. The assessment of prosthetic ankles on slopes is required for supporting the design, optimisation, and selection of prostheses. This study assessed two hydraulic ankle-foot devices (one of the hydraulic ankles is controlled by a micro-processor that allows real-time adjustment in ankle resistance and range of motion) used by trans-femoral amputees in ascending and descending a 5-degree slope walking, against a rigid ankle-foot device. Five experienced and active unilateral trans-femoral amputees performed ascending and descending slope tests with their usual prosthetic knee and socket fitted with a rigid ankle-foot, a hydraulic ankle-foot without a micro-processor, and a hydraulic ankle-foot with a micro-processor optimised for ascending and descending slopes. Peak values in hip, knee and ankle joint angles and moments were collected and the normalcy Trend Symmetry Index of the prosthetic ankle moments (as an indication of bio-mimicry) were calculated and assessment. Particular benefits of the hydraulic ankle-foot devices were better bio-mimicry of ankle resistance moment, greater range of motion, and improved passive prosthetic knee stability according to the greater mid-stance external knee extensor moment (especially in descending slope) compared to the rigid design. The micro-processor controlled device demonstrated optimised ankle angle and moment patterns for ascending and descending slope respectively, and was found to potentially further improve the ankle moment bio-minicry and prosthetic knee stability compared to the hydraulic device without a micro-processor. However the difference between the micro-processor controlled device and the one without a micro-processor does not reach a statistically significant level.

Reactive hypoglycaemia: a rarely considered 'stroke mimic' in non-diabetic individuals.

Hypoglycaemia is a well-documented 'stroke mimic'. The literature documents numerous case reports of patients presenting with focal neurological deficits subsequently attributed to hypoglycaemia. The significant majority of these cases are found in patients with pre-existing diabetes. We present case histories of two patients with no history of diabetes presenting to secondary care with reactive hypoglycaemia causing transient symptoms that were responsible for referral as a possible transient ischaemic attack. Although uncommon, metabolic disturbances such as hypoglycaemia should be considered in all patients presenting as a suspected stroke, even if they are not known to have diabetes.

The impact a surgeon has on primary amputee prosthetic rehabilitation: A survey of residual lower limb quality.

BACKGROUND: Substantial improvements have been perceived in surgical results following major lower limb amputation, but there remains observed variation in amputation quality for patients referred for prosthetic rehabilitation from different hospitals. OBJECTIVES: To assess various elements that influence residual limb quality and evaluate their impact on progress through initial prosthetic rehabilitation and mobility outcome after rehabilitation. STUDY DESIGN: Clinical survey. METHODS: A revised 10-item residual limb scoring system was used to survey a succession of 95 primary amputees with transtibial and transfemoral amputations (100 residual limbs) presenting for rehabilitation. RESULTS: The majority of residual limbs scored highly, supporting the perception of generally good amputation quality. There were significant differences in average residual limb scores between some hospitals. The overall scores showed weak or minimal correlation to progress through rehabilitation and mobility outcome but residual limbs scoring higher in seven of the items of the score showed significant advantages in key aspects of progress or mobility at discharge. CONCLUSION: There is need for continued collaboration between surgeons and rehabilitation centres to ensure consistent high standards. The revised residual limb score used in this survey needs further refinement for future use. Clinical relevance Residual limb quality is an important component influencing prosthetic rehabilitation. This survey of residual limbs at one Rehabilitation Centre suggests encouragingly good surgical results but highlights differences between hospitals. A particular issue is the need for effective collaboration between surgeons and prosthetic rehabilitation professionals to optimise residual limb preparation.

Ectopic Cushing's syndrome secondary to olfactory neuroblastoma.

We present the case of a patient with Cushing's syndrome secondary to ectopic ACTH secretion. A MR of the head showed a left-sided nasal mass extending down from the cribriform plate. The patient underwent endoscopic resection with nearly complete removal of the mass. Histological examination showed an ACTH-secreting olfactory neuroblastoma (ONB). The patient's cortisol levels returned to normal range after surgery and have remained normal for over a year. ONB is a rare cause for ectopic ACTH secretion. This case highlights the diagnostic and management difficulties in patients with ectopic ACTH secretion, and provides a brief review of ONB.

Effects of lighting illuminance levels on stair negotiation performance in individuals with visual impairment.

BACKGROUND: Stair-related falls of older people cause a substantial financial and social burden. Deterioration of the visual system amongst other factors put older people at a high risk of falling. Improved lighting is often recommended. The aim of this study was to investigate the effect of lighting illuminance on stair negotiation performance in older individuals with visual impairment. METHODS: Eleven participants aged 60 or over with a vision of 6/18 or worse ascended and descended a staircase under: 50 lx, 100 lx, 200 lx, 300 lx and distributed 200 lx lighting. A motion capture system was used to measure movements of the lower limb. Clearance, clearance variability, temporal and spatial parameters and joint/segment kinematics were computed. FINDINGS: There was no effect on clearance or clearance variability. Participants had lower speed, cadence, increased cycle time and stance time in the 50 lx compared to 300 lx and distributed 200 lx lighting in descent. The minimum hip angle in ascent was increased in the 200 lx lighting. Clearance was found to be moderately correlated with balance scores. INTERPRETATION: Individuals with visual impairment adopt precautionary gait in dim lighting conditions. This does not always result in improvements in the parameters associated with risk of falling (e.g. clearance).

Kinematic and biomimetic assessment of a hydraulic ankle/foot in level ground and camber walking.

Improved walking comfort has been linked with better bio-mimicking of the prosthetic ankle. This study investigated if a hydraulic ankle/foot can provide enough motion in both the sagittal and frontal planes during level and camber walking and if the hydraulic ankle/foot better mimics the biological ankle moment pattern compared with a fixed ankle/foot device. Five active male unilateral trans-femoral amputees performed level ground walking at normal and fast speeds and 2.5° camber walking in both directions using their own prostheses fitted with an "Echelon" hydraulic ankle/foot and an "Esprit" fixed ankle/foot. Ankle angles and the Trend Symmetry Index of the ankle moments were compared between prostheses and walking conditions. Significant differences between prostheses were found in the stance plantarflexion and dorsiflexion peaks with a greater range of motion being reached with the Echelon foot. The Echelon foot also showed significantly improved bio-mimicry of the ankle resistance moment in all walking conditions, either compared with the intact side of the same subject or with the "normal" mean curve from non-amputees. During camber walking, both types of ankle/foot devices showed similar changes in the frontal plane ankle angles. Results from a questionnaire showed the subjects were more satisfied with Echelon foot.

System accuracy evaluation of the GlucoRx nexus voice TD-4280 blood glucose monitoring system.

Use of blood glucose (BG) meters in the self-monitoring of blood glucose (SMBG) significantly lowers the risk of diabetic complications. With several BG meters now commercially available, the International Organization for Standardization (ISO) ensures that each BG meter conforms to a set degree of accuracy. Although adherence to ISO guidelines is a prerequisite for commercialization in Europe, several BG meters claim to meet the ISO guidelines yet fail to do so on internal validation. We conducted a study to determine whether the accuracy of the GlucoRx Nexus TD-4280 meter, utilized by our department for its cost-effectiveness, complied with ISO guidelines. 105 patients requiring laboratory blood glucose analysis were randomly selected and reference measurements were determined by the UniCel DxC 800 clinical system. Overall the BG meter failed to adhere to the ≥95% accuracy criterion required by both the 15197:2003 (overall accuracy 92.4%) and 15197:2013 protocol (overall accuracy 86.7%). Inaccurate meters have an inherent risk of over- and/or underestimating the true BG concentration, thereby risking patients to incorrect therapeutic interventions. Our study demonstrates the importance of internally validating the accuracy of BG meters to ensure that its accuracy is accepted by standardized guidelines.

Gait event detection during stair walking using a rate gyroscope.

Gyroscopes have been proposed as sensors for ambulatory gait analysis and functional electrical stimulation systems. These applications often require detection of the initial contact (IC) of the foot with the floor and/or final contact or foot off (FO) from the floor during outdoor walking. Previous investigations have reported the use of a single gyroscope placed on the shank for detection of IC and FO on level ground and incline walking. This paper describes the evaluation of a gyroscope placed on the shank for determination of IC and FO in subjects ascending and descending a set of stairs. Performance was compared with a reference pressure measurement system. The absolute mean difference between the gyroscope and the reference was less than 45 ms for IC and better than 135 ms for FO for both activities. Detection success was over 93%. These results provide preliminary evidence supporting the use of a gyroscope for gait event detection when walking up and down stairs.

Muscle activity during stance phase of walking: comparison of males with transfemoral amputation with osseointegrated fixations to nondisabled male volunteers.

A recent development in prosthetics is the osseointegrated fixation (OF), with improvements in comfort, fatigue, hip movement, and ease of prosthetic attachment reported. However, little information is available regarding muscle function. This study reports on selected gait parameters of the residual limb during the stance phase of level overground walking, focusing on muscle activity. Five males with transfemoral amputation (TFA) with OFs were recruited. Ground reaction force (GRF), lower-limb kinematics, and surface electromyography (sEMG) from residual-limb muscles were recorded. sEMG data were also collected from a group of 10 nondisabled male subjects. Interstance variability of gait parameters was assessed by coefficient of multiple correlations. Repeatability of GRF and hip kinematics was high, whereas repeatability of the sEMG was low for four of the five individuals with TFA. Interstance variability of the sEMG for gluteus medius (GMED) was significantly greater in the group with TFA. The main difference in sEMG between the groups was the phase, with GMED and adductor magnus displaying greater differences than their counterparts in the nondisabled group. Results demonstrate that muscles in the residual limb retain aspects of their previous functional pattern.

Neuromuscular electrical stimulation for children with cerebral palsy: a review.

The aim of this review paper is to consider the application of neuromuscular electrical stimulation (NMES) to improve gait or upper limb function in children with cerebral palsy (CP). Although most NMES research has been directed at adults with neurological conditions, there is a growing body of evidence supporting its use in children with CP. In line with a recent meta-analysis, the use of electrical stimulation to minimise impairment and activity limitations during gait is cautiously advocated. A detailed commentary on one of the most common lower limb NMES applications, tibialis anterior stimulation (either with or without gastrocnemius stimulation) is given. Although there is a lack of randomised controlled trials and a predominance of mainly small studies, this review further concludes that the balance of available evidence is in favour of upper limb exercise NMES offering benefits such as increased muscle strength, range of motion and function in children with CP. The use of dynamic splinting with NMES has been shown to be more effective than either treatment on its own in improving function and posture. There is at present little published work to support the application of botulinum toxin type A to temporarily reduce muscle tone as an adjunct intervention to NMES in this population, although the presence of parallel applications to manage similar symptoms in other muscular disorders is noted.

Surface electromyographic activity of five residual limb muscles recorded during isometric contraction in transfemoral amputees with osseointegrated prostheses.

BACKGROUND: Femoral osseointegrated implants represent a new development in amputee rehabilitation, eliminating socket pressure discomfort, improving hip range of movement and facilitating prosthetic limb attachment. A clinical aspect that has not previously been reported on is the function of muscles in the residuum with implications concerning energy expenditure, hip-hiking and viability of the electrogram as a myoprocessor. Typically, amputees fitted with osseointegrated fixation have shorter residuums and weaker attachment of cleaved muscles. Function of muscle can be assessed by surface electromyography through changes in amplitude and median frequency of the signal. METHODS: Five male transfemoral amputees with osseointegrated fixations participated together with a control group comprised of ten adult males. Electrodes recorded surface electromyographic activity of five residual limb muscles or left lower limb muscles of control subjects. Isometric contractions were performed against resistance. The increase in mean rectified amplitude from resting to maximally contracting was calculated and median frequencies estimated. FINDINGS: The amputees were unable to maintain a maximum voluntary contraction of constant amplitude. Amplitude increase was lowest for rectus femoris and adductor magnus. The median frequency of adductor magnus was significantly greater (P=0.02) for the amputees than intact subjects and there was a significant difference (P<0.01) between gluteus maximus and adductor magnus for amputee subjects. INTERPRETATION: High electromyographic amplitude variability suggests that using residuum muscles singly as a myoprocessor might be challenging. Adductor magnus displayed a different sEMG profile compared to intact subjects indicating decreased function and neuromuscular changes. Further work into optimal muscle anchorage is required to ensure maximal mechanical performance.

The effect of neuromuscular electrical stimulation on congenital talipes equinovarus following correction with the Ponseti method: a pilot study.

The Ponseti method for clubfoot treatment offers satisfactory initial correction, but success correlates with abduction brace compliance, which is variable. Electrical stimulation as a dynamic intervention to prevent relapses was investigated. Data were compared to a control group. There was a significant improvement in ankle range of motion only in the study group after short-term intervention, and a trend toward greater increase in calf circumference in this group. Parental perception was positive with no compliance issues. This study suggests stimulation is feasible with potential to increase ankle range of motion and facilitate muscle activity. It could be an important adjunct in preventing relapses, however, further studies with larger groups and longer intervention and follow-up duration are necessary.

Gait event detection on level ground and incline walking using a rate gyroscope.

Gyroscopes have been proposed as sensors for ambulatory gait analysis and functional electrical stimulation systems. Accurate determination of the Initial Contact of the foot with the floor (IC) and the final contact or Foot Off (FO) on different terrains is important. This paper describes the evaluation of a gyroscope placed on the shank for determination of IC and FO in subjects walking outdoors on level ground, and up and down an incline. Performance was compared with a reference pressure measurement system. The mean difference between the gyroscope and the reference was less than -25 ms for IC and less than 75 ms for FO for all terrains. Detection success was over 98%. These results provide preliminary evidence supporting the use of the gyroscope for gait event detection on inclines as well as level walking.

Intraobserver reliability of static measures in the normally developing infant foot and clubfoot.

Static measures data for infants are used in clinical practice and studies without published reliabilities. Intraobserver reliabilities for static measures were assessed in normally developing feet and clubfeet. Coefficient of repeatability was used for reliability. Variability in reliability was found. Ankle dorsiflexion, calf circumference and foot length were considered to be reliable in both groups. Foot width was considered unreliable and reliability for ankle plantarflexion knee flexed or extended does not seem to justify its use clinically. These results suggest that ankle dorsiflexion, calf circumference and foot length are reliable measures in infants and can be used for study conclusions and clinical decisions.

A six degrees-of-freedom marker set for gait analysis: repeatability and comparison with a modified Helen Hayes set.

Kinematic gait analysis is limited by simplified marker sets and related models. The majority of sets in clinical use were developed with low resolution imaging systems so required various assumptions about body behaviour. Further major limitations include soft tissue artefact and ambiguity in landmark identification. An alternative is the use of sets based on six degrees-of-freedom (DOF) principles, primarily using marker clusters for tracking. This study evaluates performance of a 6DOF set, based largely on CAST/ISB recommendations, through comparison with a conventional set and assessment of repeatability. Ten healthy subjects were assessed in treadmill walking, with both sets applied simultaneously on two occasions. Data were analysed using repeatability coefficients, correlation of key features, and comparison of joint angle curves and difference curves with confidence bands. Apart from pelvic tilt all segment and joint angles from both sets showed high within and between session repeatability (CMC>0.80). Hip rotations showed clear differences between the two sets with indications in support of the 6DOF set. Knee coronal angles showed evidence of cross-talk in the conventional set, highlighting difficulties with anatomical identification despite control measures such as a foot alignment template. Knee transverse angles showed inconsistent patterns for both sets. At the ankle the conventional set only allowed true measurement in two planes so with high repeatability the 6DOF set is preferable. The 6DOF set showed comparable performance to the conventional set and overcomes a number of theoretical limitations, however further development is needed prior to clinical implementation.