AuRelia: Autonomous and Reliable SCG-Sensor System for Human Space Exploration
Project Period: 01.08.2023 - 31.12.2025
The challenges of dealing with health sensors on lunar missions are associated with factors such as strong sensor autonomy and extremely high reliability. In AuRelia, these challenges are primarily addressed for SCG (Seismocardiography) sensors. Furthermore, AuRelia serves as a foundation for further fundamental research on SCG, as it marks the first investigation into artifact formation on SCG.
A scenario analysis for space conditions, along with thorough component selection, is undertaken to counter potential influences from cosmic radiation. A Mixed-Criticality Design is developed to mitigate effects directly at the hardware level. Data and signal processing paths are additionally secured, and mechanisms for anomaly detection, self-testing, and data encoding are combined into an FDIR (Fault-Detection, Fault-Isolation, and Recovery) system tailored to the sensor system.
Moreover, an extension for clock-synchronous fusion of acceleration and angular velocity data is implemented to enable artifact formation evaluation. The sensor is intended to be highly integrated and portable, making autonomy another key focus of AuRelia. Mechanisms to reduce power loss are developed and integrated, considering enhanced efficiency for data processing and FDIR.
Ultimately, data forwarding is established by connecting to a data sink, allowing the data to be utilized in further platforms, such as health platforms. The entire development process is continuously accompanied by technical evaluations that consider autonomy and reliability equally. Additionally, a concurrent application-specific evaluation is conducted with expertise in cardiology.
Scientifically, artifact formation is consistently considered during development and evaluations. The project concludes with early planning and execution of a parabolic flight campaign.
ARTIFACTS
Ballistocardiography (BCG) and Seismocardiography (SCG) are non-invasive methods for measuring oscillating recoil movements of the whole body or the chest, respectively, caused – among others - by ballistic forces generated by the heart’s mechanical actions and blood flow. The accelerations of these movements can be derived from digital 3D-acceleration sensors (accelerometers) on the body surface and analyzed to retrieve the heartrate and physiological information on the blood flow and valvular actions. Despite numerous research, there is still a fundamental uncertainty in characterizing the SCG/BCG signals, making interpretation extremely difficult. The sensors roll, pitch and yaw due to the movements generated by the heart and blood flow which are transmitted to the body surface as well as due to earth’s gravity. As a result, some of the acceleration data in the BCG/SCG signal is not due to acceleration of the heart, but to movements of the sensor itself (the so-called intrinsic rotation of the sensors), which are not of interest if conclusions are to be drawn about the heart. This is referred to as BCG-/SCG-like acceleration artifacts on the axes. As a consequence of these sensor movements, constructive or destructive interference with the actual BCG/SCG signal can occur which can lead to deformation and, thus, misinterpretations of the signal. ARTIFACTS is an observational study which aims at detecting and understanding the formation of such acceleration artifacts and at their differentiation from heart-induced sensor accelerations. Like this, the BCG/SCG signals can be characterized more precisely. Once, these signals are better understood, research can begin into whether this method is suitable for future cardiovascular diagnostics.
Technical description of the experiment
In order to be able to detect and, consequently, eliminate acceleration artifacts that result from the intrinsic rotation of accelerometers and to differentiate them from heart-induced sensor accelerations, intra- and inter-individual multi-axial movements (angular velocity, measured by using gyroscopes (6 Degrees of Freedom (6-DOF) sensors), and acceleration, measured by synchronous accelerometers) and electrocardiogram (ECG) data are collected at different gravitational states (µg to hypergravity) under physiological real-life conditions in parabolic flights. The SCG sensor system is a custom development of TUHH im frame of AuRelia and SArES which is able to measure 6-DoF SCG signals with high precision, high reliability and high synchronization in time.
Impressions from the measurement campaign VP-185
People
Publications
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MOCAST
Conference
SORN-based Cross-Correlation for SCG Signal Peak Detection in Resource-Constrained Systems -
2025 14th International Conference on Modern Circuits and Systems Technologies (MOCAST)2025.
10.1109/MOCAST65744.2025.11083906 [BibTex]
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NorCAS
Conference
Hardware-accelerated Compression Core on RISC-V for Online-BCG Data Reduction -
IEEE Nordic Circuits and Systems Conference (IEEE NorCAS)2024.
10.1109/NorCAS64408.2024.10752448 [BibTex]
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JMIR
Journal
Identifying Gravity-Related Artifacts on Ballistocardiography Signals by Comparing Weightlessness and Normal Gravity Recordings (ARTIFACTS): Protocol for an Observational Study -
JMIR Research Protocols132024.
10.2196/63306 [BibTex]
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DCOSS
Conference
ISFD: Efficient and Fault-Tolerant In-System-Failure-Detection for LP FPGA-Based Smart-Sensors in Space Expeditions -
2024 20th International Conference on Distributed Computing in Smart Systems and the Internet of Things (DCOSS-IoT)2024.
10.1109/DCOSS-IoT61029.2024.00021 [BibTex]
External Partners
We also work closely together with Universitat Bielefeld, Medizinsiche Fakultat OWL, AG Digitale Medizin and DSI Aerospace GmbH.
Sponsor
The AuRelia project line is funded and administered by German Space Agency at DLR, supported by the Federal Ministry for Economic Affairs and Climate Action (FKZ 50RP2350)
