Open Access. Powered by Scholars. Published by Universities.®

Computer Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Computer Sciences

CPS Medical

Articles 1 - 29 of 29

Full-Text Articles in Computer Engineering

Reducing Pulse Oximetry False Alarms Without Missing Life-Threatening Events, Hung Nguyen, Sooyong Jang, Radoslav Ivanov, Christopher P. Bonafide, James Weimer, Insup Lee Sep 2018

Reducing Pulse Oximetry False Alarms Without Missing Life-Threatening Events, Hung Nguyen, Sooyong Jang, Radoslav Ivanov, Christopher P. Bonafide, James Weimer, Insup Lee

Departmental Papers (CIS)

Alarm fatigue has been increasingly recognized as one of the most significant problems in the hospital environment. One of the major causes is the excessive number of false physiologic monitor alarms. An underlying problem is the inefficient traditional threshold alarm system for physiologic parameters such as low blood oxygen saturation (SpO2). In this paper, we propose a robust classification procedure based on the AdaBoost algorithm with reject option that can identify and silence false SpO2 alarms, while ensuring zero misclassified clinically significant alarms. Alarms and vital signs related to SpO2 such as heart rate and pulse rate ...


Openice-Lite: Towards A Connectivity Platform For The Internet Of Medical Things, Radoslav Ivanov, Hung Nguyen, James Weimer, Oleg Sokolsky, Insup Lee May 2018

Openice-Lite: Towards A Connectivity Platform For The Internet Of Medical Things, Radoslav Ivanov, Hung Nguyen, James Weimer, Oleg Sokolsky, Insup Lee

Departmental Papers (CIS)

The Internet of Medical Things (IoMT) is poised to revolutionize medicine. However, medical device communication, coordination, and interoperability present challenges for IoMT applications due to safety, security, and privacy concerns. These challenges can be addressed by developing an open platform for IoMT that can provide guarantees on safety, security and privacy. As a first step, we introduce OpenICE-lite, a middleware for medical device interoperability that also provides security guarantees and allows other IoMT applications to view/analyze the data in real time. We describe two applications that currently utilize OpenICE-lite, namely (i) a critical pulmonary shunt predictor for infants during ...


Context-Aware Detection In Medical Cyber-Physical Systems, Radoslav Ivanov, James Weimer, Insup Lee Apr 2018

Context-Aware Detection In Medical Cyber-Physical Systems, Radoslav Ivanov, James Weimer, Insup Lee

Departmental Papers (CIS)

This paper considers the problem of incorporating context in medical cyber-physical systems (MCPS) applications for the purpose of improving the performance of MCPS detectors. In particular, in many applications additional data could be used to conclude that actual measurements might be noisy or wrong (e.g., machine settings might indicate that the machine is improperly attached to the patient); we call such data context. The first contribution of this work is the formal definition of context, namely additional information whose presence is associated with a change in the measurement model (e.g., higher variance). Given this formulation, we developed the ...


Parameter-Invariant Monitor Design For Cyber Physical Systems, James Weimer, Radoslav Ivanov, Sanjian Chen, Alexander Roederer, Oleg Sokolsky, Insup Lee Jan 2018

Parameter-Invariant Monitor Design For Cyber Physical Systems, James Weimer, Radoslav Ivanov, Sanjian Chen, Alexander Roederer, Oleg Sokolsky, Insup Lee

Departmental Papers (CIS)

The tight interaction between information technology and the physical world inherent in Cyber-Physical Systems (CPS) can challenge traditional approaches for monitoring safety and security. Data collected for robust CPS monitoring is often sparse and may lack rich training data describing critical events/attacks. Moreover, CPS often operate in diverse environments that can have significant inter/intra-system variability. Furthermore, CPS monitors that are not robust to data sparsity and inter/intra-system variability may result in inconsistent performance and may not be trusted for monitoring safety and security. Towards overcoming these challenges, this paper presents recent work on the design of parameter-invariant ...


Data-Driven Adaptive Safety Monitoring Using Virtual Subjects In Medical Cyber-Physical Systems: A Glucose Control Case Study, Sanjian Chen, Oleg Sokolsky, James Weimer, Insup Lee Sep 2016

Data-Driven Adaptive Safety Monitoring Using Virtual Subjects In Medical Cyber-Physical Systems: A Glucose Control Case Study, Sanjian Chen, Oleg Sokolsky, James Weimer, Insup Lee

Departmental Papers (CIS)

Medical cyber-physical systems (MCPS) integrate sensors, actuators, and software to improve patient safety and quality of healthcare. These systems introduce major challenges to safety analysis because the patient’s physiology is complex, nonlinear, unobservable, and uncertain. To cope with the challenge that unidentified physiological parameters may exhibit short-term variances in certain clinical scenarios, we propose a novel run-time predictive safety monitoring technique that leverages a maximal model coupled with online training of a computational virtual subject (CVS) set. The proposed monitor predicts safety-critical events at run-time using only clinically available measurements. We apply the technique to a surgical glucose control ...


Clinician-In-The-Loop Annotation Of Icu Bedside Alarm Data, Alexander Roederer, Joseph Dimartino, Jacob Gutsche, Margaret Mullen-Fortino, Sachin Shah, C. William Hanson Iii, Insup Lee Jun 2016

Clinician-In-The-Loop Annotation Of Icu Bedside Alarm Data, Alexander Roederer, Joseph Dimartino, Jacob Gutsche, Margaret Mullen-Fortino, Sachin Shah, C. William Hanson Iii, Insup Lee

Departmental Papers (CIS)

In this work, we describe the state of clinical monitoring in the intensive care unit and operating room, where patients are at their most fragile and thus monitoring is most heightened. We describe how large amounts of data generated by monitoring patients’ physiologic signals, along with the ubiquitous aspecific threshold alarms in use today, cause dangerous alarm fatigue for medical caregivers. In order to build more specific, more useful alarms, we gathered a novel data set that would allow us to assess the number, types, and utility of alarms currently in use in the intensive care unit. To do this ...


Estimation Of Blood Oxygen Content Using Context-Aware Filtering, Radoslav Ivanov, Nikolay Atanasov, James Weimer, Miroslav Pajic, Allan F. Simpao, Mohamed A. Rehman, George Pappas, Insup Lee Apr 2016

Estimation Of Blood Oxygen Content Using Context-Aware Filtering, Radoslav Ivanov, Nikolay Atanasov, James Weimer, Miroslav Pajic, Allan F. Simpao, Mohamed A. Rehman, George Pappas, Insup Lee

Departmental Papers (CIS)

In this paper we address the problem of estimating the blood oxygen concentration in children during surgery.Currently, the oxygen content can only be measured through invasive means such as drawing blood from the patient. In this work, we attempt to perform estimation by only using other non-invasive measurements (e.g., fraction of oxygen in inspired air, volume of inspired air) collected during surgery. Although models mapping these measurements to blood oxygen content contain multiple parameters that vary widely across patients, the non-invasive measurements can be used to provide binary information about whether the oxygen concentration is rising or dropping ...


Protecting Interoperable Clinical Environment With Authentication, Liang Cheng, Zhangtan Li, Yi Zhang, Yang Zhang, Insup Lee Apr 2016

Protecting Interoperable Clinical Environment With Authentication, Liang Cheng, Zhangtan Li, Yi Zhang, Yang Zhang, Insup Lee

Departmental Papers (CIS)

The Integrated Clinical Environment (ICE) is a standard dedicated to promote open coordination of heterogeneous medical devices in a plug-and-play manner. This carries the potential to radically improve medical care through coordinating, cooperating devices, but also to undermine the patient safety by giving rise to security vulnerabilities in the cyber world. In this paper, we propose an authentication framework as the first step to build an ICE security architecture. This framework is designed in a three-layered structure, allowing it to fit in the variety of authentication requirements from different ICE entities and of networking middleware from ICE instantiations. We implement ...


Platform-Specific Code Generation From Platform-Independent Timed Models, Baekgyu Kim, Lu Feng, Oleg Sokolsky, Insup Lee Dec 2015

Platform-Specific Code Generation From Platform-Independent Timed Models, Baekgyu Kim, Lu Feng, Oleg Sokolsky, Insup Lee

Departmental Papers (CIS)

Many safety-critical real-time embedded systems need to meet stringent timing constraints such as preserving delay bounds between input and output events. In model-based development, a system is often implemented by using a code generator to automatically generate source code from system models, and integrating the generated source code with a platform. It is challenging to guarantee that the implemented systems preserve required timing constraints, because the timed behavior of the source code and the platform is closely intertwined. In this paper, we address this challenge by proposing a model transformation approach for the code generation. Our approach compensates the platform-processing ...


Executing Model-Based Tests On Platform-Specific Implementations, Dongjiang You, Sanjai Rayadurgam, Mats Heimdahl, John Komp, Baekgyu Kim, Oleg Sokolsky Nov 2015

Executing Model-Based Tests On Platform-Specific Implementations, Dongjiang You, Sanjai Rayadurgam, Mats Heimdahl, John Komp, Baekgyu Kim, Oleg Sokolsky

Departmental Papers (CIS)

Model-based testing of embedded real-time systems is challenging because platform-specific details are often abstracted away to make the models amenable to various analyses. Testing an implementation to expose non-conformance to such a model requires reconciling differences arising from these abstractions. Due to stateful behavior, naive comparisons of model and system behaviors often fail causing numerous false positives. Previously proposed approaches address this by being reactively permissive: passing criteria are relaxed to reduce false positives, but may increase false negatives, which is particularly bothersome for safety-critical systems. To address this concern, we propose an automated approach that is proactively adaptive: test ...


An Intraoperative Glucose Control Benchmark For Formal Verification, Sanjian Chen, Matthew O'Kelly, James Weimer, Oleg Sokolsky, Insup Lee Oct 2015

An Intraoperative Glucose Control Benchmark For Formal Verification, Sanjian Chen, Matthew O'Kelly, James Weimer, Oleg Sokolsky, Insup Lee

Departmental Papers (CIS)

Diabetes associated complications are affecting an increasingly large population of hospitalized patients. Since glucose physiology is significantly impacted by patient-specific parameters, it is critical to verify that a clinical glucose control protocol is safe across a wide patient population. A safe protocol should not drive the glucose level into dangerous low (hypoglycemia) or high (hyperglycemia) ranges. Verification of glucose controllers is challenging due to the high-dimensional, non-linear glucose physiological models which contain both unobservable states and unmeasurable patient-specific parameters. This paper presents a hybrid system model of a closed-loop physiological system that includes an existing FDA-accepted high-fidelity physiological model tailored ...


A Data-Driven Behavior Modeling And Analysis Framework For Diabetic Patients On Insulin Pumps, Sanjian Chen, Lu Feng, Michael R. Rickels, Amy Peleckis, Oleg Sokolsky, Insup Lee Oct 2015

A Data-Driven Behavior Modeling And Analysis Framework For Diabetic Patients On Insulin Pumps, Sanjian Chen, Lu Feng, Michael R. Rickels, Amy Peleckis, Oleg Sokolsky, Insup Lee

Departmental Papers (CIS)

About 30%-40% of Type 1 Diabetes (T1D) patients in the United States use insulin pumps. Current insulin infusion systems require users to manually input meal carb count and approve or modify the system-suggested meal insulin dose. Users can give correction insulin boluses at any time. Since meal carbohydrates and insulin are the two main driving forces of the glucose physiology, the user-specific eating and pump-using behavior has a great impact on the quality of glycemic control.

In this paper, we propose an “Eat, Trust, and Correct” (ETC) framework to model the T1D insulin pump users’ behavior. We use machine ...


Towards Assurance For Plug & Play Medical Systems, Andrew L. King, Lu Feng, Sam Procter, Sanjian Chen, Oleg Sokolsky, John Hatcliff, Insup Lee Sep 2015

Towards Assurance For Plug & Play Medical Systems, Andrew L. King, Lu Feng, Sam Procter, Sanjian Chen, Oleg Sokolsky, John Hatcliff, Insup Lee

Departmental Papers (CIS)

Traditional safety-critical systems are designed and integrated by a systems integrator. The system integrator can asses the safety of the completed system before it is deployed. In medicine, there is a desire to transition from the traditional approach to a new model wherein a user can combine various devices post-hoc to create a new composite system that addresses a specific clinical scenario. Ensuring the safety of these systems is challenging: Safety is a property of systems that arises from the interaction of system components and it’s not possible to asses overall system safety by assessing a single component in ...


Requirement Engineering For Functional Alarm System For Interoperable Medical Devices, Krishna Venkatasubramanian, Eugene Vasserman, Vasiliki Sfyrla, Oleg Sokolsky, Insup Lee Sep 2015

Requirement Engineering For Functional Alarm System For Interoperable Medical Devices, Krishna Venkatasubramanian, Eugene Vasserman, Vasiliki Sfyrla, Oleg Sokolsky, Insup Lee

Departmental Papers (CIS)

This paper addresses the problem of high-assurance operation for medical cyber-physical systems built from interoperable medical devices. Such systems are diferent from most cyber-physical systems due to their "plug-and-play" nature: they are assembled as needed at a patient's bedside according to a specification that captures the clinical scenario and required device types. We need to ensure that such a system is assembled correctly and operates according to its specification. In this regard, we aim to develop an alarm system that would signal interoperability failures. We study how plug-and-play interoperable medical devices and systems can fail by means of hazard ...


A Hybrid Approach To Causality Analysis, Shaohui Wang, Yoann Geoffroy, Gregor Gössler, Oleg Sokolsky, Insup Lee Sep 2015

A Hybrid Approach To Causality Analysis, Shaohui Wang, Yoann Geoffroy, Gregor Gössler, Oleg Sokolsky, Insup Lee

Departmental Papers (CIS)

In component-based safety-critical systems, when a system safety property is violated, it is necessary to analyze which components are the cause. Given a system execution trace that exhibits component faults leading to a property violation, our causality analysis formalizes a notion of counterfactual reasoning (\what would the system behavior be if a component had been correct?") and algorithmically derives such alternative system behaviors, without re-executing the system itself. In this paper, we show that we can improve precision of the analysis if 1) we can emulate execution of components instead of relying on their contracts, and 2) take into consideration ...


Robust Monitoring Of Hypovolemia In Intensive Care Patients Using Photoplethysmogram Signals, Alexander Roederer, James Weimer, Joseph Dimartino, Jacob Gutsche, Insup Lee Aug 2015

Robust Monitoring Of Hypovolemia In Intensive Care Patients Using Photoplethysmogram Signals, Alexander Roederer, James Weimer, Joseph Dimartino, Jacob Gutsche, Insup Lee

Departmental Papers (CIS)

The paper presents a fingertip photoplethysmography based technique to assess patient fluid status that is robust to waveform artifacts and health variability in the underlying patient population. The technique is intended for use in intensive care units, where patients are at risk for hypovolemia, and signal artifacts and inter-patient variations in health are common. Input signals are preprocessed to remove artifact, then a parameter-invariant statistic is calculated to remove effects of patient-specific physiology. Patient data from the Physionet MIMICII database was used to evaluate the performance of this technique. The proposed method was able to detect hypovolemia within 24 hours ...


Early Detection Of Critical Pulmonary Shunts In Infants, Radoslav Ivanov, James Weimer, Allan F. Simpao, Mohamed A. Rehman, Insup Lee Apr 2015

Early Detection Of Critical Pulmonary Shunts In Infants, Radoslav Ivanov, James Weimer, Allan F. Simpao, Mohamed A. Rehman, Insup Lee

Departmental Papers (CIS)

This paper aims to improve the design of modern Medical Cyber Physical Systems through the addition of supplemental noninvasive monitors. Specifically, we focus on monitoring the arterial blood oxygen content (CaO2), one of the most closely observed vital signs in operating rooms, currently measured by a proxy - peripheral hemoglobin oxygen saturation (SpO2). While SpO2 is a good estimate of O2 content in the finger where it is measured, it is a delayed measure of its content in the arteries. In addition, it does not incorporate system dynamics and is a ...


Towards Non-Invasive Monitoring Of Hypovolemia In Intensive Care Patients, Alexander Roederer, James Weimer, Joseph Dimartino, Jacob Gutsche, Insup Lee Apr 2015

Towards Non-Invasive Monitoring Of Hypovolemia In Intensive Care Patients, Alexander Roederer, James Weimer, Joseph Dimartino, Jacob Gutsche, Insup Lee

Departmental Papers (CIS)

Hypovolemia caused by internal hemorrhage is a major cause of death in critical care patients. However, hypovolemia is difficult to diagnose in a timely fashion, as obvious symptoms do not manifest until patients are already nearing a critical state of shock. Novel non-invasive methods for detecting hypovolemia in the literature utilize the photoplethysmogram (PPG) waveform generated by the pulse-oximeter attached to a finger or ear. Until now, PPG-based alarms have been evaluated only on healthy patients under ideal testing scenarios (e.g., motionless patients); however, the PPG is sensitive to patient health and significant artifacts manifest when patients move. Since ...


Towards A Model-Based Meal Detector For Type I Diabetics, Sanjian Chen, James Weimer, Michael R. Rickels, Amy Peleckis, Insup Lee Apr 2015

Towards A Model-Based Meal Detector For Type I Diabetics, Sanjian Chen, James Weimer, Michael R. Rickels, Amy Peleckis, Insup Lee

Departmental Papers (CIS)

Blood glucose management systems are an important class of Medical Cyber-Physical Systems that provide vital everyday decision support service to diabetics. An artificial pancreas, which integrates a continuous glucose monitor, a wearable insulin pump, and control algorithms running on embedded computing devices, can significantly improve the quality of life for millions of Type 1 diabetics. A primary problem in the development of an artificial pancreas is the accurate detection and estimation of meal carbohydrates, which cause significant glucose system disturbances. Meal carbohydrate detection is challenging since post-meal glucose responses greatly depend on patient-specific physiology and meal composition.

In this paper ...


From Requirements To Code: Model Based Development Of A Medical Cyber Physical System, Anitha Murugesan, Mats Heimdahl, Michael Whalen, Sanjai Rayadurgam, John Komp, Lian Duan, Baekgyu Kim, Oleg Sokolsky, Insup Lee Jul 2014

From Requirements To Code: Model Based Development Of A Medical Cyber Physical System, Anitha Murugesan, Mats Heimdahl, Michael Whalen, Sanjai Rayadurgam, John Komp, Lian Duan, Baekgyu Kim, Oleg Sokolsky, Insup Lee

Departmental Papers (CIS)

The advanced use of technology in medical devices has improved the way health care is delivered to patients. Unfortunately, the increased complexity of modern medical devices poses challenges for development, assurance, and regulatory approval. In an e ort to improve the safety of advanced medical devices, organizations such as FDA have supported exploration of techniques to aid in the development and regulatory approval of such systems. In an ongoing research project, our aim is to provide effective development techniques and exemplars of system development artifacts that demonstrate state of the art development techniques.

In this paper we present an end-to-end ...


The Middleware Assurance Substrate: Enabling Strong Real-Time Guarantees In Open Systems With Openflow, Andrew L. King, Sanjian Chen, Insup Lee Jun 2014

The Middleware Assurance Substrate: Enabling Strong Real-Time Guarantees In Open Systems With Openflow, Andrew L. King, Sanjian Chen, Insup Lee

Departmental Papers (CIS)

Middleware designed for use in Distributed Real-Time and Embedded (DRE) systems enable cost and development time reductions by providing simple communications abstractions and hiding operating system-level networking API details from developers. While current middleware technologies can hide many low-level details, designers must provide a static configuration for the system’s underlying network in order to achieve required performance characteristics. This has not been a problem for many types of DRE systems where the configuration of the system is relatively fixed from the factory (e.g., aircraft or naval vessels). However for truly open systems (i.e., systems where end users ...


A Safety Argument Strategy For Pca Closed-Loop Systems: A Preliminary Proposal, Lu Feng, Andrew L. King, Sanjian Chen, Anaheed Ayoub, Junkil Park, Nicola Bezzo, Oleg Sokolsky, Insup Lee Apr 2014

A Safety Argument Strategy For Pca Closed-Loop Systems: A Preliminary Proposal, Lu Feng, Andrew L. King, Sanjian Chen, Anaheed Ayoub, Junkil Park, Nicola Bezzo, Oleg Sokolsky, Insup Lee

Departmental Papers (CIS)

The emerging network-enabled medical devices impose new challenges for the safety assurance of medical cyber-physical systems (MCPS). In this paper, we present a case study of building a high-level safety argument for a patient-controlled analgesia (PCA) closed-loop system, with the purpose of exploring potential methodologies for assuring the safety of MCPS.


Functional Alarms For Systems Of Interoperable Medical Devices, Krishna Venkatasubramanian, Eugene Vasserman, Oleg Sokolsky, Insup Lee Jan 2014

Functional Alarms For Systems Of Interoperable Medical Devices, Krishna Venkatasubramanian, Eugene Vasserman, Oleg Sokolsky, Insup Lee

Departmental Papers (CIS)

Alarms are essential for medical systems in order to ensure patient safety during deteriorating clinical situations and inevitable device malfunction. As medical devices are connected together to become interoperable, alarms become crucial part in making them high-assurance, in nature. Traditional alarm systems for interoperable medical devices have been patient-centric. In this paper, we introduce the need for an alarm system that focuses on the correct functionality of the interoperability architecture itself, along with several considerations and design challenges in enabling them.


Safety-Critical Medical Device Development Using The Upp2sf Model, Miroslav Pajic, Zhihao Jiang, Insup Lee, Oleg Sokolsky, Rahul Mangharam Jan 2014

Safety-Critical Medical Device Development Using The Upp2sf Model, Miroslav Pajic, Zhihao Jiang, Insup Lee, Oleg Sokolsky, Rahul Mangharam

Departmental Papers (CIS)

Software-based control of life-critical embedded systems has become increasingly complex, and to a large extent has come to determine the safety of the human being. For example, implantable cardiac pacemakers have over 80,000 lines of code which are responsible for maintaining the heart within safe operating limits. As firmware-related recalls accounted for over 41% of the 600,000 devices recalled in the last decade, there is a need for rigorous model-driven design tools to generate verified code from verified software models. To this effect we have developed the UPP2SF model-translation tool, which facilitates automatic conversion of verified models (in ...


Evaluation And Enhancement Of An Intraoperative Insulin Infusion Protocol Via In-Silico Simulation, Benjamin A. Kohl, Sanjian Chen, Margaret Mullen-Fortino, Insup Lee Sep 2013

Evaluation And Enhancement Of An Intraoperative Insulin Infusion Protocol Via In-Silico Simulation, Benjamin A. Kohl, Sanjian Chen, Margaret Mullen-Fortino, Insup Lee

Departmental Papers (CIS)

Intraoperative glycemic control, particularly in cardiac surgical patients, remains challenging. Patients with impaired insulin sensitivity and/or secretion (i.e., type 1 diabetes mellitus) often manifest extremely labile blood glucose measurements during periods of stress and inflammation. Most current insulin infusion protocols are developed based on clinical experiences and consensus among a local group of physicians. Recent advances in human glucose metabolism modeling have established a computer model that invokes algorithms representing many of the pathways involved in glucose dysregulation for patients with diabetes. In this study, we used an FDA approved glucose metabolism model to evaluate an existing institutional ...


Model-Based Development Of The Generic Pca Infusion Pump User Interface Prototype In Pvs, Paolo Masci, Anaheed Ayoub, Paul Curzon, Insup Lee, Oleg Sokolsky, Harold Thimbleby Sep 2013

Model-Based Development Of The Generic Pca Infusion Pump User Interface Prototype In Pvs, Paolo Masci, Anaheed Ayoub, Paul Curzon, Insup Lee, Oleg Sokolsky, Harold Thimbleby

Departmental Papers (CIS)

A realistic user interface is rigorously developed for the US Food and Drug Administration (FDA) Generic Patient Controlled Analgesia (GPCA) pump prototype. The GPCA pump prototype is intended as a realistic workbench for trialling development methods and techniques for improving the safety of such devices. A model-based approach based on the use of formal methods is illustrated and implemented within the Prototype Verification System (PVS) verification system. The user interface behaviour is formally specified as an executable PVS model. The specification is verified with the PVS theorem prover against relevant safety requirements provided by the FDA for the GPCA pump ...


A Causality Analysis Framework For Component-Based Real-Time Systems, Shaohui Wang, Anaheed Ayoub, Baekgyu Kim, Gregor Gössler, Oleg Sokolsky, Insup Lee Sep 2013

A Causality Analysis Framework For Component-Based Real-Time Systems, Shaohui Wang, Anaheed Ayoub, Baekgyu Kim, Gregor Gössler, Oleg Sokolsky, Insup Lee

Departmental Papers (CIS)

We propose an approach to enhance the fault diagnosis in black-box component-based systems, in which only events on component interfaces are observable, and assume that causal dependencies between component interface events within components are not known. For such systems, we describe a causality analysis framework that helps us establish the causal relationship between component failures and system failures, given an observed system execution trace. The analysis is based on a formalization of counterfactual reasoning, and applicable to real-time systems. We illustrate the analysis with a case study from the medical device domain.


A Modal Specification Approach For On-Demand Medical Systems, Andrew L. King, Lu Feng, Oleg Sokolsky, Insup Lee Aug 2013

A Modal Specification Approach For On-Demand Medical Systems, Andrew L. King, Lu Feng, Oleg Sokolsky, Insup Lee

Departmental Papers (CIS)

The on-demand approach, where systems are assembled from components by lay users, has seen success in the consumer electronics industry. Currently, there is growing demand for on-demand capabilities in medical systems so caregivers can create larger medical systems from smaller medical devices. Unlike consumer electronics, medical systems pose challenges for the on-demand approach due to attributes such as device complexity, device variability and safety requirements. In this paper, we propose a formal specification language for on-demand (medical) systems. Our approach is based on the formalism of Modal I/O Automata, which allows system designers to express complex device requirements and ...


Assuring The Safety Of On-Demand Medical Cyber-Physical Systems, Andrew L. King, Lu Feng, Oleg Sokolsky, Insup Lee Aug 2013

Assuring The Safety Of On-Demand Medical Cyber-Physical Systems, Andrew L. King, Lu Feng, Oleg Sokolsky, Insup Lee

Departmental Papers (CIS)

We present an approach to establish safety of on-demand medical cyber-physical systems which are assembled to treat a patient in a specific clinical scenario. We treat such a system as a virtual medial device (VMD) and propose a model-based framework that includes a modeling language with formal semantics and a medical application platform (MAP) that provides the necessary deployment support for the VMD models.