Karl Øyri

Wireless continuous arterial blood pressure monitoring during surgery: a pilot study.

Patient monitoring devices supporting wireless transmission can facilitate transport and ambulation of patients in hospitals. To replace wired sensors with wireless sensors, the accuracy and resistance to interference of the wireless sensors have to be documented. We compared the performance of a wireless arterial blood pressure biomedical sensor prototype with standard wired sensors in a clinical setting. Four patients undergoing laparoscopic abdominal surgery were recruited for testing of the device. Lines to a wireless arterial blood pressure sensor and standard wired sensor were connected to the same arterial cannula inserted in the right radial artery. Data from both systems were logged for postprocedure statistical comparison. During the procedure, 13 other electric devices were used, either continuously or intermittently. A sample-by-sample comparison was performed for both wired and wireless data. Statistical tests showed mean difference of 0.71, standard deviation of 0.14, and confidence interval of –1.28 to 1.56), indicating no significant electromagnetic interference on invasive arterial blood pressure monitoring caused by biomedical devices used during surgery. The wireless pressure biomedical sensor with Bluetooth wireless transmission of signals did not interfere with biomedical devices used in the operating room or vice versa.

osni.info—Using free/libre/open source software to build a virtual international community for open source nursing informatics

Many health informatics organizations seem to be slow to take up the advantages of dynamic, web-based technologies for providing services to, and interaction with, their members; these are often the very technologies they promote for use within healthcare environments. This paper aims to introduce some of the many free/libre/open source (FLOSS) applications that are now available to develop interactive websites and dynamic online communities as part of the structure of health informatics organizations, and to show how the Open Source Nursing Informatics Working Group (OSNI) of the special interest group in nursing informatics of the International Medical Informatics Association (IMIA-NI) is using some of these tools to develop an online community of nurse informaticians through their website, at . Some background introduction to FLOSS applications is used for the benefit of those less familiar with such tools, and examples of some of the FLOSS content management systems (CMS) being used by OSNI are described. The experiences of the OSNI will facilitate a knowledgeable nursing contribution to the wider discussions on the applications of FLOSS within health and healthcare, and provides a model that many other groups could adopt.

Short-range wireless sensor network for critical care monitoring

A Scandinavian research consortium collaborated to develop a wireless clinical monitoring platform. A collection of experimental wireless sensor prototypes were implemented in complex, process-control software modified for the project. The objective was to facilitate real-time and historical point-of-care sensor data for clinical decision support in critical care. The short-range wireless radio frequency platform used in the project was the IEEE 802.15.4 wireless personal area network standard. Invasive sensors included an arterial blood pressure sensor, an epicardial three-axis accelerometer and a digital pulmonary air leakage system. Non-invasive sensor signals came from an electrocardiogram sensor, a pulse oximeter, a medical radar prototype and a temperature sensor. Radio frequency signals from sensors to base stations and onwards in the wireless sensor network architecture were scrutinised during experimental surgery. Qualitative assessment of the sensor data presentation was made. Shadowing effects influencing the radio frequency channel performance was quantified. The shadowing effects were caused by the dynamic work pattern of the clinical team in combination with stationary equipment in the operating room during surgery. Shadowing effects did not compromise the quality of wireless sensor data severely. An evaluation of the communication links between individual sensors and two separate base stations are provided in this paper.

A biomedical wireless sensor network for hemodynamic monitoring

In the Biomedical Wireless Sensor Network (BWSN) project a consortium of Scandinavian research institutions, technology startup companies, sensor producers, software companies and a hospital based clinical test facility collaborated for 36 months. A portfolio of multiple, experimental wireless sensor prototypes were implemented in sophisticated process control software modified for the project. The project objective was to facilitate real time and historical point-of-care sensor data for clinical decision support and monitoring in hemodynamic treatment. The wireless communication platform and results from clinical tests are presented in this paper. The radio frequency platform used in the project was operating in the 2.4 GHz ISM band based on the IEEE 802.15.4 Wireless Personal Area Network standard. Invasive sensors included a non-disposable blood pressure sensor, an epicardial 3- axis accelerometer and a digital pulmonary air leakage system. Non-invasive sensor signals came from an ECG sensor, a pulse oximeter, a medical radar and a temperature sensor. Point-to-point transmission of radio frequency signals from sensors to base stations and onwards in the biomedical wireless sensor network (BWSN) architecture was scrutinized during experimental surgery. A qualitative assessment of the sensor data presentation was made. Occurrence of shadowing effects influencing the radio frequency channel performance was quantified. The shadowing effects were caused by the dynamic work pattern of the clinical team in combination with stationary equipment in the operating room during surgery. The shadowing effects were not found to compromise the quality of the wireless sensor data. Shadowing parameters to reconstruct our measurements and model the communication links between individual sensors and two separate base stations are provided.

Event-Based Methodology for Real-Time Data Analysis in Cyber Physical Systems

Recent developments in wireless sensors enable a broad range of a new generation of applications, e.g., for health monitoring, environmental monitoring, smart cities, etc. However, the complexity of many signals and the need to process sensor data in real-time makes programming such applications a challenging task. This paper motivates the need to step-wise reduce the complexity of sensor data to enable application domain experts to tailor and develop (parts of) applications without having in depth programming skills. To achieve this goal, a methodology for application development with real-time sensor data processing is presented. The methodology is based on the concepts of physical and logical sensors, which can detect atomic and composite events. The combination of using the declarative approach of Complex Event Processing and modularization allows processing most data in the event space instead of signal processing. A use case for a home care application demonstrates the strength of this methodology.

Wireless vital signs from a life-supporting medical device exposed to electromagnetic disturbance

Abstract Objectives: To evaluate the level of agreement of simulated wired and Wi-Fi vital signs output from an intra-aortic balloon pump during exposure to electromagnetic interference from frequency overlapping ZigBee sensors. Material and methods: A series of experiments with interference from single and multiple ZigBee sensors were benchmarked with wired and Wi-Fi output. Tests included single ZigBee sensor adjacent and co-channel interference, and multiple ZigBee interferences towards the Wi-Fi receiver and transmitter. Results: Interference-free differences between wired and wireless aortic blood pressure and electrocardiogram were very small, verified by time domain and Bland – Altman plots. Bland – Altman plots comparing level of agreement in wired and wireless aortic blood pressure and ECG output during interference experiments showed a difference from 0.2 to 0.3 mmHg for blood pressure, and from 0.001 to 0.004 mV for electrocardiogram. Conclusions: Level of agreement in wired and wireless (Wi-Fi) arterial blood pressure and electrocardiogram during single or multiple sensor interference was high. No clinically relevant degradation of Wi-Fi transmission of aortic blood pressure or ECG signals was observed.

Evaluation of the reliability of blood pressure data transmission through an IEEE 802.11 link in the presence of IEEE 802.15.4 interference

Wireless sensors operating in unlicensed frequency bands have been proposed for monitoring physiological signals during surgical procedures in the operating room (OR). The IEEE 802.15.4/ZigBee wireless interface in the 2.4 GHz industrial-scientific-medical (ISM) band has been widely adopted for the implementation of radio transceivers (motes) suitable for medical wireless sensors. However, other medical devices in the OR transmit medical information in the same frequency band through IEEE 802.11/WiFi interfaces. Therefore, the introduction of wireless sensors in current medical practice is conditioned to the assurance of the electromagnetic compatibility (EMC) with the collocated medical devices already operating in the same frequency band. This is especially critical with life-supporting equipment, which cannot be interfered with during medical procedures. This paper presents the evaluation of the reliability of the transmission of blood pressure (BP) data from an intra-aortic balloon pump (IABP) console through an IEEE 802.11/WiFi interface when a collocated IEEE 802.15.4/ZigBee mote is transmitting. The Bland-Altman plotting method was used to assess the effects of cochannel and adjacent-channel interference. The results show that EMC is assured between both systems.