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Ulrich Haueter

Bio: Ulrich Haueter is an academic researcher from Hoffmann-La Roche. The author has contributed to research in topics: Insulin pump & Piston. The author has an hindex of 12, co-authored 42 publications receiving 1476 citations.

Papers
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Journal ArticleDOI
TL;DR: Adapt nonlinear model predictive control is promising for the control of glucose concentration during fasting conditions in subjects with type 1 diabetes.
Abstract: A nonlinear model predictive controller has been developed to maintain normoglycemia in subjects with type 1 diabetes during fasting conditions such as during overnight fast. The controller employs a compartment model, which represents the glucoregulatory system and includes submodels representing absorption of subcutaneously administered short-acting insulin Lispro and gut absorption. The controller uses Bayesian parameter estimation to determine time-varying model parameters. Moving target trajectory facilitates slow, controlled normalization of elevated glucose levels and faster normalization of low glucose values. The predictive capabilities of the model have been evaluated using data from 15 clinical experiments in subjects with type 1 diabetes. The experiments employed intravenous glucose sampling (every 15 min) and subcutaneous infusion of insulin Lispro by insulin pump (modified also every 15 min). The model gave glucose predictions with a mean square error proportionally related to the prediction horizon with the value of 0.2 mmol L(-1) per 15 min. The assessment of clinical utility of model-based glucose predictions using Clarke error grid analysis gave 95% of values in zone A and the remaining 5% of values in zone B for glucose predictions up to 60 min (n = 1674). In conclusion, adaptive nonlinear model predictive control is promising for the control of glucose concentration during fasting conditions in subjects with type 1 diabetes.

1,164 citations

Journal ArticleDOI
TL;DR: The performance of the viscometric affinity sensor shows the potential of the measuring principle under in vivo conditions, and forearm and abdomen seem to be similarly well suited for the application of subcutaneous sensors.
Abstract: Objective: A viscometric affinity sensor has been developed to measure the interstitial glucose concentration continuously. In a pilot clinical study its performance was assessed under conditions close to everyday life. Additionally, different insertion sites were tested for their suitability to apply subcutaneous glucose sensors. Methods: Twelve subjects, 10 of whom with type 1 diabetes, were examined for 8 h. Sensors were applied subcutaneously at the forearm and the abdomen of each subject. Capillary blood glucose references were obtained from the finger tip every 30 min. Retrospective calibration was carried out individually with Deming regression. Results: After retrospective calibration the 95% limits of agreement in the plot of the differences between sensor signals and references versus their means were ±60 mg/dL. The sensitivity of the sensors remained stable over the entire measuring period, without any significant differences between the sensors at forearm and abdomen. Correcting for the observ...

52 citations

Patent
04 Nov 2010
TL;DR: In this article, a device, kit, and method for transferring a liquid medicament from a supply container to a flexible reservoir container are disclosed, consisting of a compartment unit and an adapter unit.
Abstract: A device, kit, and method for transferring a liquid medicament from a supply container to a flexible reservoir container are disclosed. The device may comprise a compartment unit and an adapter unit. The compartment unit may have a sealingly closable chamber, arranged for housing the flexible reservoir container and for being fluidly connected with a pump mechanism. The adapter unit may have at least one transfer passage for transferring liquid from a supply container connected to the adapter unit to the flexible reservoir container, and a separator arranged in the transfer passage for separating gas bubbles from a liquid streaming through the transfer passage. The separator may be fluidly connected to the chamber.

42 citations

Patent
05 Sep 2002
TL;DR: In this paper, a light emitter which emits light in a wavelength range to which the constituent is sensitive and which is implantable in living tissue, and a light detector which, when the device is in a measuring position, receives the light emitted by the emitter and outputs a signal depending on the amount of light received, from which signal the constituent may be measured.
Abstract: A device for the in-vivo measuring of a constituent of a body fluid, the device including a light emitter which emits light in a wavelength range to which the constituent is sensitive and which is implantable in living tissue, and a light detector which, when the device is in a measuring position, receives the light emitted by the emitter and outputs a signal depending on the amount of light received, from which signal the constituent may be measured, wherein the light detector is situated outside the tissue when the device is in the measuring position.

35 citations

Patent
28 Aug 2003
TL;DR: In this article, the propulsion mechanism permanently acts on the piston with a propulsive force, and a blocking mechanism is provided whereby a piston advance is permanently blocked and, in order to expel the agent, released.
Abstract: The invention relates to a device for the dosed expelling of a liquid agent, especially for an infusion pump, comprising a receptacle (1) for the storing of the liquid agent and a propulsion mechanism for the propelling of a piston (2) toward an outlet of the receptacle in order to expel the agent, characterized in that the propulsion mechanism permanently acts on the piston with a propulsive force, a blocking mechanism (9, 11; 9, 16) being provided whereby a piston advance is permanently blocked and, in order to expel the agent, released; the invention also relates to an infusion pump for the long-term release of an agent, including a device according to one of the previous claims and a control apparatus that repeatedly releases the blocking mechanism in order to expel the agent.

34 citations


Cited by
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Patent
26 Jan 2006
TL;DR: In this paper, the present paper relates to systems and methods for transcutaneous measurement of glucose in a host, and the present invention relates to the system and method for measuring an analyte in the host.
Abstract: The present invention relates generally to systems and methods for measuring an analyte in a host. More particularly, the present invention relates to systems and methods for transcutaneous measurement of glucose in a host.

902 citations

Journal ArticleDOI
TL;DR: A new simulation model in normal humans that describes the physiological events that occur after a meal, by employing the quantitative knowledge that has become available in recent years, is presented.
Abstract: A simulation model of the glucose-insulin system in the postprandial state can be useful in several circumstances, including testing of glucose sensors, insulin infusion algorithms and decision support systems for diabetes. Here, we present a new simulation model in normal humans that describes the physiological events that occur after a meal, by employing the quantitative knowledge that has become available in recent years. Model parameters were set to fit the mean data of a large normal subject database that underwent a triple tracer meal protocol which provided quasi-model-independent estimates of major glucose and insulin fluxes, e.g., meal rate of appearance, endogenous glucose production, utilization of glucose, insulin secretion. By decomposing the system into subsystems, we have developed parametric models of each subsystem by using a forcing function strategy. Model results are shown in describing both a single meal and normal daily life (breakfast, lunch, dinner) in normal. The same strategy is also applied on a smaller database for extending the model to type 2 diabetes.

856 citations

Journal ArticleDOI
TL;DR: A system for in silico testing of control algorithms that has been shown to represent adequate glucose fluctuations in T1DM observed during meal challenges, and has been accepted by the Food and Drug Administration as a substitute to animal trials in the preclinical testing of closed-loop control strategies.
Abstract: Arguably, a minimally invasive system using subcutaneous (s.c.) continuous glucose monitoring (CGM) and s.c. insulin delivery via insulin pump would be a most feasible step to closed-loop control in type 1 diabetes mellitus (T1DM). Consequently, diabetes technology is focusing on developing an artificial pancreas using control algorithms to link CGM with s.c. insulin delivery. The future development of the artificial pancreas will be greatly accelerated by employing mathematical modeling and computer simulation. Realistic computer simulation is capable of providing invaluable information about the safety and the limitations of closed-loop control algorithms, guiding clinical studies, and out-ruling ineffective control scenarios in a cost-effective manner. Thus computer simulation testing of closed-loop control algorithms is regarded as a prerequisite to clinical trials of the artificial pancreas. In this paper, we present a system for in silico testing of control algorithms that has three principal components: (1) a large cohort of n = 300 simulated “subjects” (n = 100 adults, 100 adolescents, and 100 children) based on real individuals’ data and spanning the observed variability of key metabolic parameters in the general population of people with T1DM; (2) a simulator of CGM sensor errors representative of Freestyle Navigator™, Guardian RT, or Dexcom™ STS™, 7-day sensor; and (3) a simulator of discrete s.c. insulin delivery via OmniPod Insulin Management System or Deltec Cozmo ® insulin pump. The system has been shown to represent adequate glucose fluctuations in T1DM observed during meal challenges, and has been accepted by the Food and Drug Administration as a substitute to animal trials in the preclinical testing of closed-loop control strategies.

712 citations

Journal ArticleDOI
TL;DR: This report discusses continuous glucose monitoring in terms of its purposes, technologies, target populations, accuracy, clinical indications, outcomes, and problems.
Abstract: Continuous glucose monitoring provides maximal information about shifting blood glucose levels throughout the day and facilitates the making of optimal treatment decisions for the diabetic patient. This report discusses continuous glucose monitoring in terms of its purposes, technologies, target populations, accuracy, clinical indications, outcomes, and problems. In this context, the medical literature on continuous glucose monitoring available through the end of 2004 is reviewed. Continuous glucose monitoring provides information about the direction, magnitude, duration, frequency, and causes of fluctuations in blood glucose levels. Compared with conventional intensified glucose monitoring, defined as three to four blood glucose measurements per day, continuous monitoring provides much greater insight into glucose levels throughout the day. Continuous glucose readings that supply trend information can help identify and prevent unwanted periods of hypo- and hyperglycemia. The difference between an intermittent and a continuous monitor for monitoring blood glucose is similar to that between a regular camera and a continuous security camera for monitoring an important situation. A regular camera takes discrete, accurate snapshots; its pictures do not predict the future; it produces a small set of pictures that can all be carefully studied; and effort is required to take each picture. A continuous security camera, on the other hand, takes multiple, poorly focused frames; displays a sequential array of frames whose trend predicts the future; produces too much information for each frame to be studied carefully; and operates automatically after it is turned on. The two types of blood glucose monitors differ in much the same way: 1 ) an intermittent blood glucose monitor measures discrete glucose levels extremely accurately, whereas a continuous monitor provides multiple glucose levels of fair accuracy; 2 ) with an intermittent monitor, current blood glucose levels do not predict future glucose levels, but with a continuous monitor, trends in glucose levels do have …

694 citations

Patent
08 May 2008
TL;DR: In this article, a data communication unit to transmit one or more signals related to the monitored analyte level received from the analyte sensor to a remote device is described, including a data communications unit that can be used to collect data from a medical device.
Abstract: Methods and systems for providing data communication in medical systems are disclosed including a data communication unit to transmit one or more signals related to the monitored analyte level received from the analyte sensor to a remote device.

564 citations