Subcutaneous Insulin Infusion Systems Research Articles

Data driven nonparametric identification and model based control of glucose-insulin process in type 1 diabetics

Closed loop control of glucose homeostasis via subcutaneous insulin infusion and continuous glucose monitoring system can give better living to a type 1 diabetic patient. This paper deals with the real time implementation of internal model control (IMC) of subcutaneous insulin infusion. The model based control is applied on the nonparametric model of the patient identified in real time from input–output data. Meal simulation model of the glucose-insulin system of type 1 diabetic patient based on the work of Dalla Man et. al. is considered. This model is constructed in hardware platform that acts as the virtual patient. The data-driven nonparametric model of the virtual patient is identified in real time by computing Volterra kernels. The kernels are solved up to second order using recursive least squares (RLS) algorithm with short memory length of M=2. The validation results of the identified model output and the actual output have shown good fit in both simulation and real time environments. The frequency domain kernels are used in internal model control to generate insulin dosage. The control algorithm is developed in simulation and implemented in real time with hardware in loop on dSPACE platform. The closed loop system yields good meal disturbance rejection, less undershoots, settling time and more profoundly smaller requirement of insulin infusion as compared to the earlier reported data.

The current status of continuous subcutaneous insulin infusion and continuous glucose monitoring systems in the Community of Madrid

Abstract Objective To analyze the available information about continuous subcutaneous insulin infusion (CSII) and continuous glucose monitoring (CGM) systems in the public health care system of the Community of Madrid. Material and methods A survey consisting of 31 items was sent to the 28 endocrinology department of the Madrid public hospitals. Items focused on CSII and CGM and included patients’ registrations, as well as data regarding healthcare, administrative, and logistic aspects. Responses from a total of 20 hospitals where these procedures are used were received from March 2013 to May 2014. Data about pediatric patients were obtained from adult endocrinology departments, except for two hospitals which directly reported the information. Results A total of 1256 CSII pumps were recorded in the Madrid region, of which 1089 were used by adults, and the remaining 167 by pediatric patients. During 2013, 151 new CSII systems were implanted (12% of the total), while 14 pumps were withdrawn. Availability of human resources (medical assistance) and the number of staff practitioners experienced in management of these systems widely varied between hospitals. Eighty-five percent of hospitals used retrospective CGM systems, and 40% routinely placed them before starting an insulin pump. Thirteen hospitals (65%) used long-term, real-time CGM systems in selected cases (a total of 67 patients). Conclusions Use of these technologies in diabetes is unequal between public health care hospitals in Madrid, and is still significantly lower as compared to other countries with similar incomes. However, there appears to be a trend to an increase in their use.

Estado actual de los sistemas de infusión subcutánea continua de insulina y monitorización continua de glucosa en la Comunidad de Madrid

ObjectiveTo analyze the available information about continuous subcutaneous insulin infusion (CSII) and continuous glucose monitoring (CGM) systems in the public health care system of the Community of Madrid. Material and methodsA survey consisting of 31 items was sent to the 28 endocrinology department of the Madrid public hospitals. Items focused on CSII and CGM and included patients’ registrations, as well as data regarding healthcare, administrative, and logistic aspects. Responses from a total of 20 hospitals where these procedures are used were received from March 2013 to May 2014. Data about pediatric patients were obtained from adult endocrinology departments, except for two hospitals which directly reported the information. ResultsA total of 1256 CSII pumps were recorded in the Madrid region, of which 1089 were used by adults, and the remaining 167 by pediatric patients. During 2013, 151 new CSII systems were implanted (12% of the total), while 14 pumps were withdrawn. Availability of human resources (medical assistance) and the number of staff practitioners experienced in management of these systems widely varied between hospitals. Eighty-five percent of hospitals used retrospective CGM systems, and 40% routinely placed them before starting an insulin pump. Thirteen hospitals (65%) used long-term, real-time CGM systems in selected cases (a total of 67 patients). ConclusionsUse of these technologies in diabetes is unequal between public health care hospitals in Madrid, and is still significantly lower as compared to other countries with similar incomes. However, there appears to be a trend to an increase in their use.

A novel tool to predict youth who will show recommended usage of diabetes technologies.

Controversy exists regarding which individuals will benefit most from commencement of diabetes technologies such as continuous subcutaneous insulin infusion (CSII) or continuous glucose monitoring systems (CGMS), such as 'real-time' sensor-augmented pumping (SAP). Because higher usage correlates with haemoglobin A1c (HbA1c) achieved, we aimed to predict future usage of technologies using a questionnaire-based tool. The tool was distributed to two groups of youth with type 1 diabetes; group A (n = 50; mean age 12 ± 2.5 yr) which subsequently commenced 'real-time' CGMS and group B (n = 47; mean age 13 ± 3 yr) which commenced CSII utilisation. For the CGMS group, recommended usage was ≥5 days (70%) per week [≥70% = high usage (HU); <70% = low usage (LU)], assessed at 3 months. In the CSII group, HU was quantified as entering ≥5 blood sugars per day to the pump and LU as <5 blood sugars per day, at 6 months from initiation. Binary logistic regression with forward stepwise conditional was used to utilise tool scales and calculate an applied formula. Of the CGMS group, using gender, baseline HbA1c, and two subscales of the tool generated a formula which predicted both high and low usage with 92% accuracy. Twelve (24%) showed HU vs. 38 who exhibited LU at 3 months. Of the CSII group, 32 (68%) exhibited HU vs. 15 who exhibited LU at 6 months. Four tool items plus gender predicted HU/LU with 95% accuracy. This pilot study resulted in successful prediction of individuals who will and those who will not go on to show recommended usage of CSII and CGMS.

Impact of new technologies on diabetes care.

Technologies for diabetes management, such as continuous subcutaneous insulin infusion (CSII) and continuous glucose monitoring (CGM) systems, have improved remarkably over the last decades. These developments are impacting the capacity to achieve recommended hemoglobin A1c levels and assisting in preventing the development and progression of micro- and macro vascular complications. While improvements in metabolic control and decreases in risk of severe and moderate hypoglycemia have been described with use of these technologies, large epidemiological international studies show that many patients are still unable to meet their glycemic goals, even when these technologies are used. This editorial will review the impact of technology on glycemic control, hypoglycemia and quality of life in children and youth with type 1 diabetes. Technologies reviewed include CSII, CGM systems and sensor-augmented insulin pumps. In addition, the usefulness of advanced functions such as bolus profiles, bolus calculators and threshold-suspend features will be also discussed. Moreover, the current editorial will explore the challenges of using these technologies. Indeed, despite the evidence currently available of the potential benefits of using advanced technologies in diabetes management, many patients still report barriers to using them. Finally this article will highlight the importance of future studies tailored toward overcome these barriers to optimizing glycemic control and avoiding severe hypoglycemia.

Transition of continuous subcutaneous insulin infusion systems in a very short time frame as a consequence of a public tender process

AimThe procurement of pumps/supplies through a tender process is common practice among public services. A report is presented on the feasibility and safety of the transition from one continuous subcutaneous insulin infusion (CSII) system to another within a very short time frame (4-weeks) as the consequence of a public tender. MethodsThe program consisted of: Session-1 was a system start-up training session. Patient satisfaction was evaluated. Session-2 consisted of a call from technical staff 72h after Session-1 to provide support regarding the programming or the change of infusion set. Session-3 was a training session regarding the use of therapy management software. During and 2 months after Session-2, clinical events, technical issues, and training reinforcement incidents were registered. HbA1c data were collected retrospectively. ResultsA total of 219 patients were enrolled. During the second week, 81% of patients were transferred to the new system. Patient overall satisfaction scored 9.4/10 (none <7). There were 30 training reinforcement events and 7 technical issues, with all 37 of them being were sorted out over the telephone. There were 31 additional clinical events (infusion set issues). Twenty-four were considered mild, and were solved by phone technical support. Medical assistance was needed in six (five unexpected hyperglycemia, one ketosis). There was only one severe event (ketoacidosis requiring hospitalization). HbA1c did not deteriorate during the transition process. One hundred twenty-eight patients attended the therapy management software training. ConclusionsWith the assistance of a specific program, a complete switch to a new insulin pump in a large population of patients with T1D in the context of a public tender in a very short time was carried out safely and without deterioration of metabolic control.

Assessment of use of specific features of subcutaneous insulin infusion systems and their relationship to metabolic control in patients with type 1 diabetes

Abstract Background and objective Patients with type 1 diabetes (T1DM) treated with continuous subcutaneous insulin infusion (CSII) have the availability of several specific features of these devices. The aim of this study was to evaluate the relationship between real use of them and the degree of glycemic control in patients using this therapy. Patients and methods Forty-four T1DM patients on CSII therapy with or without real-time continuous glucose monitoring (CGM) were included. Data from 14 consecutive days were retrospectively collected using the therapy management software CareLink Personal/Pro ® and HbA1c measurement performed at that period. The relationship between the frequency of use of specific features of insulin pumps (non-sensor augmented or sensor-augmented) and glycemic control was analyzed. Results Mean HbA1c in the group was 7.5 ± .8%. Mean daily number of boluses administered was 5.1 ± 1.8, with 75.4% of them being bolus wizards (BW). Daily number of boluses was significantly greater in patients with HbA1c 7.5% (5.3 ± 1.6 vs 4.3 ± 1.6, P = .056). There was a trend to greater use of BW in patients with better control (82.8 ± 21.4% vs 69.9 ± 29.1%, P = .106). HbA1c was lower in patients using CGM (n = 8) as compared to those not using sensor-augmented pumps (7.6 ± .8 vs 7.1 ± .7, P = .067), but the difference was not statistically significant. Conclusions More frequent use of BW appears to be associated to better metabolic control in patients with T1DM using pump therapy. In standard clinical practice, augmentation of insulin pump with CGM may be associated to improved glycemic control.

Description and Preliminary Evaluation of a Diabetes Technology Simulation Course

We aim to provide data on a diabetes technology simulation course (DTSC) that instructs internal medicine residents in the use of continuous subcutaneous insulin infusion (CSII) and continuous glucose monitoring system (CGMS) devices. The DTSC was implemented during calendar year 2012 and conducted in the institution's simulation center. It consisted of a set of prerequisites, a practicum, and completion of a web-based inpatient CSII-ordering simulation. DTSC participants included only those residents in the outpatient endocrinology rotation. Questionnaires were used to determine whether course objectives were met and to assess the satisfaction of residents with the course. Questionnaires were also administered before and after the endocrine rotation to gauge improvement in familiarity with CSII and CGMS technologies. During the first year, 12 of 12 residents in the outpatient endocrinology rotation completed the DTSC. Residents reported that the course objectives were fully met. The mean satisfaction score with the course ranged from 4.0 to 4.9 (maximum, 5), with most variables rated above 4.5. Self-reported familiarity with the operation of CSII and CGMS devices increased significantly in the postrotation survey compared with that on the prerotation survey (both p < .01). In this pilot program, simulation-based education increased the perceived familiarity of residents with CSII and CGMS technologies. In light of these preliminary findings, the course will continue to be offered, with further data accrual. Future work will involve piloting the DTSC approach among other types of providers, such as residents in other specialties or inpatient nursing staff.

ProAct Study: New Features of Insulin Pumps Improve Diabetes Management and Glycemic Control in Patients after Transition of Continuous Subcutaneous Insulin Infusion Systems

Continuous subcutaneous insulin infusion (CSII) patients experience switches of pump systems on a regular basis. We investigated the impact of transition from older pumps to the Accu-Chek(®) Combo system (Roche Diagnostics Deutschland GmbH, Mannheim, Germany) on a patient's glycemic control and diabetes management. In total, 299 patients (172 female, 127 male; mean±SD age, 39.4±15.2 years; CSII duration, 7.0±5.2 years) were enrolled by 61 European sites into this uncontrolled prospective trial. Glycemic control, safety, and diabetes management parameters were measured at baseline and after 3 and 6 months. Changes from baseline were analyzed. After transition to the new insulin pump, mean±SD hemoglobin A1c (HbA1c) values decreased from 7.8±1.1% (baseline) to 7.7±1.1% (end point). The proportion of patients with HbA1c <7.0% was slightly higher at the end of the study (29.6%) than at baseline (25.2%), whereas the proportion of patients with HbA1c >8.0% decreased (baseline, 36.2%; end point, 32.7%; P<0.05). The number of hypoglycemic episodes (blood glucose<70 mg/dL) improved slightly during the study (baseline, 40.4±34.0 events/quarter; end point, 39.2±33.9 events/quarter). Glycemic control improved significantly in the group with an initial HbA1c >8.0% (-0.46%; P<0.001) and remained solidly stable in the group with an initial HbA1c <7% (+0.04%; not significant). Short-term (<3 years) pump users (n=48) had a larger HbA1c decrease (-0.40%) than long-term (≥3 years) users (n=251) (-0.07%; P<0.05). The number of blood glucose measurements increased (3.7±1.9/day vs. 4.4±1.8/day; P<0.05), whereas the number of insulin boluses decreased (5.1±1.9/day vs. 4.6±1.5/day; P<0.05) during the study. Transition from older pump systems to the Accu-Chek Combo system in a large patient population resulted in stable glycemic control with significant improvements in HbA1c in patients with unsatisfactory baseline HbA1c and shorter pump use. Increased frequency of self-monitoring of blood glucose and decrease of bolus frequency could suggest a more confident diabetes management and a reduced need for correction boluses.

Continuous glucose monitoring and insulin pump therapy for diabetes in pregnancy

Continuous glucose monitoring (CGM) systems and continuous subcutaneous insulin infusion (CSII) systems, or insulin pumps, offer great promise for improved glycemic control during pregnancy. Combined, these two devices could potentially constitute an artificial pancreas, where real-time blood glucose readings are relayed to an insulin pump that uses a personalized algorithm to decide how much insulin is needed by the patient’s body. However, the promise of these two systems have not yet been proven individually or in combination in controlled clinical trials to improve pregnancy outcomes. Such trials are urgently needed before the widespread use of these devices in pregnancy can be justified.

Insulin pump therapy in type 1 diabetes mellitus: education effectiveness and quality of life

Aim. To compare efficacy of special structured program for type 1 diabetes mellitus (DM) group education between users of an integratedreal-time (RT) continuous glucose monitoring (CGM)/continuous subcutaneous insulin infusion (CSII) systems and patientson CSII and self-monitoring of blood glucose (SMBG).Methods. This 4 months trial included 39 adults (18 male, age 27 [24,0;35,0] years) with type 1 DM (duration of diabetes 12[8,0;18,0] years). All subjects were randomized to study groups: 20 in the CSII/SMBG arm and 19 in the RT-CGM/CSII arm. Allparticipants were provided with special structured program for group education of diabetes patients on insulin pump therapy. Qualityof life (QoL) was assessed with questionnaire SF-36. Results. Both groups were not significantly different in HbA1c, BMI and QoL at baseline. After 4 months HbA1c was significantly lowerin both study groups without increase in rate of hypoglycemia. Improvements in QoL were observed in psychic health score in the CSII/SMBG arm and in physical health and psychic health scores in the RT-CGM/CSII arm. There was no significant difference in HbA1c,BMI and QoL between groups. Conclusion. Transfer to CSII during group training under special structured program for patients with type 1 DM significantly improvesglycemic control regardless of glucose monitoring method. Both RT-CGM+CSII and SMBG+CSII amend several aspects of QoL.Finally, transfer to CSII during group training considerably reduces total consumption of trainers time without loss of training quality.

Insulin therapy in children and adolescents with diabetes

Diabetes type 1 constitutes a growing problem for many children and adolescents worldwide. Diabetic children and adolescents are dependent on insulin for survival. Today, insulin treatment, either in the classic insulin forms or in the form of insulin analogs, is widely used in the pediatrie diabetic population. New methods of insulin administration like the continuous subcutaneous insulin infusion systems (pumps) have been developed to ameliorate metabolic control and reduce diabetic complications.

New-generation diabetes management: glucose sensor-augmented insulin pump therapy

Diabetes is one of the most common chronic disorders with an increasing incidence worldwide. Technologic advances in the field of diabetes have provided new tools for clinicians to manage this challenging disease. For example, the development of continuous subcutaneous insulin infusion systems have allowed for refinement in the delivery of insulin, while continuous glucose monitors provide patients and clinicians with a better understanding of the minute to minute glucose variability, leading to the titration of insulin delivery based on this variability when applicable. Merging of these devices has resulted in sensor-augmented insulin pump therapy, which became a major building block upon which the artificial pancreas (closed-loop systems) can be developed. This article summarizes the evolution of sensor-augmented insulin pump therapy until present day and its future applications in new-generation diabetes management.

Crossing the Technology Divide

To describe the benefits of continuous glucose monitoring (CGM) and continuous subcutaneous insulin infusion (CSII) systems compared with self-monitoring of blood glucose (SMBG) and multiple daily injection (MDI) therapy; to assess the benefits of sensor-augmented pump therapy (SAPT) in patients with type 1 diabetes; and to present an evidence-based practical protocol for introducing SAPT in patients with no prior pump or CGM experience. Continuous glucose monitoring and CSII have advantages over SMBG and MDI, respectively, in terms of A1C and hypoglycemia reduction. The Sensor-Augmented Pump Therapy for A1C Reduction (STAR) 3 trial demonstrated that initiating both CGM and CSII in selected adult and pediatric patients with type 1 diabetes unable to meet glycemic goals with intensive insulin injection therapy significantly improved glucose control. In all subjects using SAPT, A1C levels fell rapidly from baseline to 3 months and remained significantly lower than among subjects in the SMBG+MDI group for 1 year. A distinguishing feature of the STAR 3 study was its stepwise protocol for systematizing education and self-management support using Web-based training modules and therapy management software. The demonstrated strengths of this education protocol recommend it as a model for implementing SAPT in the broader population of patients with type 1 diabetes who have not achieved their glycemic goals with optimized MDI therapy.

The effect of stage - based nursing intervention on the application of double C treatment of the newly diagnosed patients with type 2 diabetes mellitus

Objective To explore the effect of stage - based and individualized nursing intervention on the newly diagnosed type 2 diabetes mellitus (T2DM) patients with the combined treatment of continuous subcutaneous insulin infusion (CSⅡ) and continuous glucose monitoring system (CGMS) . Methods 60 newly diagnosed patients with T2DM were given combined therapy of CSⅡ and CGMS, meanwhile they were given stage - based and individualized nursing intervention. The clinical data of all patients were collected before and after intervention, including general indexes, blood glucose, the score of diabetic knowledge, and the clinical compliance, etc. Results The blood glucose levels of all patients were significantly improved after intervention. Furthermore, the levels of blood pressure were obviously decreased. The pass ratio of test on diabetic knowledge was obviously increased. The clinical compliances of these patients were apparently increased. Conclusions Stage - based and individualized nursing intervention is the important measure to strengthen the clinical compliances of the newly diagnosed patients with T2DM. It ensures the smooth implementation of double C treatmentcan. Furthermore, it may decrease glucotoxicity, increase self - management ability and improve lfie quality of these patients. Key words: Stage-based nursing; Continuous subcutaneous insulin infusion (CSII); Continuous subcutaneous insulin infusion; Newly diagnosed type 2 diabetic mellitus

Treatment Satisfaction and Quality of Life for an Integrated Continuous Glucose Monitoring/Insulin Pump System Compared to Self-Monitoring plus an Insulin Pump

Little is known about how the most advanced technology affects treatment satisfaction and health-related quality of life (HRQOL) in adults with diabetes. This study was designed to assess treatment satisfaction and HRQOL among users of an integrated real-time (RT) continuous glucose monitoring (CGM)/continuous subcutaneous insulin infusion (CSII) system compared with those using self-monitoring of blood glucose (SMBG) with CSII. Participants were 311 adult respondents to an Internet survey, 162 using RT-CGM/CSII, 149 using SMBG + CSII (median age 43 years; type 1 diabetes 94%; diabetes duration >15 years 61%; median insulin use 15 years). Respondents completed instruments assessing glucose monitoring system and insulin delivery system convenience, interference, burden, glucose control efficacy, cost satisfaction, overall satisfaction, and treatment preference, as well as quality of life (diabetes-related worries, social burden, and psychological well-being). Real-time CGM/CSII users also assessed specific elements of the RT-CGM/CSII system. Group differences were assessed using analysis of covariance controlling for respondent characteristics. The RT-CGM/CSII group gave significantly better ratings than the SMBG + CSII group for their glucose monitoring system's glucose control efficacy, overall satisfaction, desire to switch, and willingness to recommend, and significantly worse ratings for interference with daily activities. The RT-CGM/CSII group gave significantly better ratings than the SMBG + CSII group for their insulin delivery system's convenience and glucose control efficacy, overall satisfaction, desire to switch, and willingness to recommend. Real-time CGM/CSII users gave positive ratings of all system features. Users of the integrated RT-CGM/CSII system reported more benefits of treatment, higher treatment satisfaction and quality of life, and greater preference for this system than SMBG + CSII users.

Malfunction of continuous subcutaneous insulin infusion systems: a one-year prospective study of 127 patients.

Malfunction of portable continuous subcutaneous insulin infusion (CSII) systems may result in either ketoacidosis or serious hypoglycemia. To determine the types and frequencies of infusion system failure and the resulting clinical consequences, we recorded their occurrences in a 1-yr prospective study of 127 patients who were using insulin infusion pumps in a clinical practice setting. Of the 127 patients, 109 (86%) experienced at least one infusion system failure during the study. Most of the infusion system failures (96%) occurred in the syringe, infusion tube and connections, or subcutaneous infusion site. Virtually all malfunctions resulted in interruption of insulin flow, and most were associated with temporary loss of diabetes control. Equipment malfunction was documented in 6 of 7 patients who used insulin pumps and were treated in our hospital for diabetic ketoacidosis during the study. Pump "runaway" was not observed. We conclude that infusion system malfunction resulting in interruption of insulin flow is a common occurrence, is often associated with temporary hyperglycemia, and may account for some of the increased incidence of diabetic ketoacidosis previously described in these patients.

The development of a nonlinear model to describe the blood glucose response for the determination of prandial insulin infusion.

We studied the relationship between the rate of intravenous glucose infusion and the blood glucose concentration at two different physiological levels of hyperinsulinemia in a depancreatized dog. The same degree of changes in the glucose infusion rate generated progressively larger increments in the blood glucose concentration. We then developed a Michaelis-Menten type kinetic model which could appropriately describe this nonlinear relationship of blood glucose response under the condition of hyperinsulinemia. In order to determine the prandial insulin infusion program, we used more simplified equations based on a nonlinear model. The simplified equations were demonstrated to be applicable for estimating the prandial subcutaneous insulin infusion program in the continuous subcutaneous insulin infusion system.

Evaluation of the Bolie model describing blood glucose response for the application to continuous subcutaneous insulin infusion.

In an attempt to develop an appropriate infusion program in a continuous subcutaneous insulin infusion system, a conventional pharmacodynamic model (the Bolie model) for describing the relationship between blood glucose and serum insulin levels was evaluated, using a depancreatized dog preparation. The Bolie model was found useful in estimating the basal insulin infusion rate. However, the model could not predict the serum insulin concentration-time profile required to maintain the postprandial blood glucose levels within a physiological range. It will be necessary to develop a more appropriate model for determining the prandial subcutaneous insulin infusion rates in the continuous subcutaneous insulin infusion system.

Continuous subcutaneous insulin infusion systems. A new approach to management of type I diabetes.

Although continuous subcutaneous insulin infusion (CSII) is not presently the most feasible method of insulin delivery for most type I diabetic patients, unquestionably it is a major therapeutic advance in recent efforts to normalize blood glucose levels in such patients. In selected, highly motivated patients, CSII therapy has been shown to be safe, effective, and physiologically reasonable. Despite the failure of prolonged CSII therapy to reverse established microangiopathic complications in all cases, normoglycemia produced with CSII may reverse early complications and prevent or minimize their development in patients treated by this method from the onset of hyperglycemia. Understanding of the importance of continuous normoglycemia to the psychologic and physical well-being of type I patients should be greatly advanced by the development and use of CSII systems.