Pedestrian Localization with Stride-Wise Error Estimation and Compensation by Fusion of UWB and IMU Data

Indoor positioning enables mobile machines to perform tasks (semi-)automatically, such as following an operator. However, the usefulness and safety of these applications depends on the reliability of the estimated operator localization. Thus, quantifying the accuracy of positioning at runtime is critical for the application in real-world industrial contexts. In this paper, we present a method that produces an estimate of the current positioning error for each user stride. To accomplish this, we construct a virtual stride vector from Ultra-Wideband (UWB) position measurements. The virtual vectors are then compared to stride vectors from a foot-mounted Inertial Measurement Unit (IMU). Using these independent measurements, we estimate the current reliability of the UWB measurements. Positioning errors are mitigated through loosely coupled filtering of both vector types. We evaluate our method in three environments, showing that it improves positioning accuracy, especially in challenging conditions with obstructed line of sight and sparse UWB infrastructure. Additionally, we demonstrate the mitigation of simulated spoofing attacks on UWB positioning. Our findings indicate that positioning quality can be judged at runtime by comparing user strides reconstructed from UWB and IMU measurements. Our method is independent of situation- or environment-specific parameter tuning, and as such represents a promising approach for detecting both known and unknown positioning error states.

IEEE 11073 SDC for Pandemics like COVID-19: Example Implementation of an Isolation Room

Treating patients in an intensive care unit (ICU) isolation room is full of challenges for the caregivers and the patients. While this is known for years, the COVID-19 pandemic has highlighted these challenges as if under a burning glass - intensified by a high number of patients at the same time. The risk of infection for the caregivers is very high inside the isolation room and the time spent for putting on and taking off personal protective equipment (PPE) is enormous. Thus, every treatment that can be performed from the anteroom of the isolation room at the same quality level as if being inside the isolation room is a potential building block for solving the challenges. However, data like vital signs have to be provided to the anteroom, alarms have to be transferred to the right caregiver at the right place, and controlling medical device parameters from the anteroom are prerequisites. The new IEEE 11073 Service-oriented Device Connectivity (SDC) series of standards is a key technology to realize this. Therefore, this paper presents an example implementation of IEEE 11073 SDC-based ICU isolation rooms by means of a demonstrator. Such systems can significantly reduce the amount of time the caregivers have to spend in the isolation room and reduce the number of clothing (PPE) changes while providing care at a level of a non-isolation room. As a midterm goal these are steps for the vision of a “silent/quiet ICU”.

Service-Oriented Medical Device Connectivity: Particular Interoperability Standards for High Frequency Surgical Equipment and External Control Devices

Manufacturer-independent medical device interoperability has been strongly demanded by the clinicians and healthcare delivery organizations (HDOs), however has not been achieved in practice for decades. The ISO/IEEE 11073 Service-oriented Device Connectivity (SDC) family of standards constitutes a paradigm shift. This work supplements SDC with Device Specializations (DevSpecs) or Modular Specifications (ModSpecs): particular interoperability standards for high frequency (HF) surgical equipment and external control devices, such as foot or finger switches. They provide models to describe these devices in a service-oriented medical device system and modes of interaction with other network participants. Additionally, we contribute to the ISO/IEEE 11073-10101 nomenclature standard to provide semantic descriptions of the exchanged information. This is a key enabler for safe and effective medical device interoperability to support the caregivers and improve patient safety as well as clinical outcome.

Enabling artificial intelligence in high acuity medical environments

Acute patient treatment can heavily profit from AI-based assistive and decision support systems, in terms of improved patient outcome as well as increased efficiency. Yet, only very few applications have been reported because of the limited accessibility of device data due to the lack of adoption of open standards, and the complexity of regulatory/approval requirements for AI-based systems. The fragmentation of data, still being stored in isolated silos, results in limited accessibility for AI in healthcare and machine learning is complicated by the loss of semantics in data conversions. We outline a reference model that addresses the requirements of innovative AI-based research systems as well as the clinical reality. The integration of networked medical devices and Clinical Repositories based on open standards, such as IEEE 11073 SDC and HL7 FHIR, will foster novel assistance and decision support. The reference model will make point-of-care device data available for AI-based approaches. Semantic interoperability between Clinical and Research Repositories will allow correlating patient data, device data, and the patient outcome. Thus, complete workflows in high acuity environments can be analysed. Open semantic interoperability will enable the improvement of patient outcome and the increase of efficiency on a large scale and across clinical applications.

OR.NET: a service-oriented architecture for safe and dynamic medical device interoperability

Modern surgical departments are characterized by a high degree of automation supporting complex procedures. It recently became apparent that integrated operating rooms can improve the quality of care, simplify clinical workflows, and mitigate equipment-related incidents and human errors. Particularly using computer assistance based on data from integrated surgical devices is a promising opportunity. However, the lack of manufacturer-independent interoperability often prevents the deployment of collaborative assistive systems. The German flagship project OR.NET has therefore developed, implemented, validated, and standardized concepts for open medical device interoperability. This paper describes the universal OR.NET interoperability concept enabling a safe and dynamic manufacturer-independent interconnection of point-of-care (PoC) medical devices in the operating room and the whole clinic. It is based on a protocol specifically addressing the requirements of device-to-device communication, yet also provides solutions for connecting the clinical information technology (IT) infrastructure. We present the concept of a service-oriented medical device architecture (SOMDA) as well as an introduction to the technical specification implementing the SOMDA paradigm, currently being standardized within the IEEE 11073 service-oriented device connectivity (SDC) series. In addition, the Session concept is introduced as a key enabler for safe device interconnection in highly dynamic ensembles of networked medical devices; and finally, some security aspects of a SOMDA are discussed.

OR.NET RT: how service-oriented medical device architecture meets real-time communication

Today’s landscape of medical devices is dominated by stand-alone systems and proprietary interfaces lacking cross-vendor interoperability. This complicates or even impedes the innovation of novel, intelligent assistance systems relying on the collaboration of medical devices. Emerging approaches use the service-oriented architecture (SOA) paradigm based on Internet protocol (IP) to enable communication between medical devices. While this works well for scenarios with no or only soft timing constraints, the underlying best-effort communication scheme is insufficient for time critical data. Real-time (RT) networks are able to reliably guarantee fixed latency boundaries, for example, by using time division multiple access (TDMA) communication patterns. However, deterministic RT networks come with their own limitations such as tedious, inflexible configuration and a more restricted bandwidth allocation. In this contribution we overcome the drawbacks of both approaches by describing and implementing mechanisms that allow the two networks to interact. We introduce the first implementation of a medical device network that offers hard RT guarantees for control and sensor data and integrates into SOA networks. Based on two application examples we show how the flexibility of SOA networks and the reliability of RT networks can be combined to achieve an open network infrastructure for medical devices in the operating room (OR).

Mechanism for safe remote activation of networked surgical and PoC devices using dynamic assignable controls

The number of devices within an operating room (OR) increases continuously as well as the complexity of the complete system. One key enabler to handle the complexity is an interoperable and vendor independent system of networked medical devices. To build up such an interoperable system we use the proposed IEEE 11073 SDC standards (IEEE P11073-10207, -20701, -20702) for networked point-of-care (PoC) and surgical devices. One of the major problems within the OR is that typically every device has its own control unit. This leads to unsatisfying situations like a high number of foot switches that causes operating errors or the problem that the physician cannot reach the control unit of the device where parameters have to be changed or an activation should be triggered. Dynamically assignable controls will solve these problems. This paper describes mechanisms that allow a safe remote activation of safety critical device functionalities based on a potentially unsafe off-the-shelf network with problems like connection loss and jitter. The proposed systems is based on a periodic reactivation of the device functionality and the additional use safety related information that is included into the activate operation command. The main advantage is that all described mechanisms make use of the self-description capability provided by the IEEE 11073 SDC. This enables a real interoperability and plug-and-play functionality because both the medical device and the control client do not need any a priori knowledge about each other.

New IEEE 11073 Standards for interoperable, networked Point-of-Care Medical Devices

Surgical procedures become more and more complex and the number of medical devices in an operating room (OR) increases continuously. Today's vendor-dependent solutions for integrated ORs are not able to handle this complexity. They can only form isolated solutions. Furthermore, high costs are a result of vendor-dependent approaches. Thus we present a service-oriented device communication for distributed medical systems that enables the integration and interconnection between medical devices among each other and to (medical) information systems, including plug-and-play functionality. This system will improve patient's safety by making technical complexity of a comprehensive integration manageable. It will be available as open standards that are part of the IEEE 11073 family of standards. The solution consists of a service-oriented communication technology, the so called Medical Devices Profile for Web Services (MDPWS), a Domain Information & Service Model, and a binding between the first two mechanisms. A proof of this concept has been done with demonstrators of real world OR devices.