Abstract
The paper presents research, development and advantage of Radio Frequency IDentification (RFID) technology based system for medical instrument management and safe usage. The system is developed for two scenarios. In the first scenario, a Ultra High Frequency (UHF) is used and the UHF–interrogator system with UHF-antennas is constructed to work as conveyor-belt and instruments are placed between two antennas. Second scenario, suitable for the operating rooms, includes four antennas, placed under the table with instruments, system’s phase shifter, inserted between the antenna and reader in order to reduce the effect of dead spots, caused by the electromagnetic reflections. High reliable identification rate is achieved by synchronizing phase shifters with particular interrogator. The system is software calibrated and can be re-calibrated at run-time to achieve high efficiency of power transmission to the antenna and in order to enable the receiver to decode the tag signals. With currently on the market available RFID tags and previously mentioned technology approaches, detection rate of 87.5% can be achieved.
1 Introduction
The healthcare systems in Europe and in the USA are confronted with immense challenges. It is well known that the demographic change in Europe and in particular in Germany affects the social insurance system. As a consequence, taking in account other factors, the total health expenditures in Germany have increased by 70% since 1995 [1]. Dealing with high expenses requires cutting expenses without reducing the quality of work and services in public and private hospitals.
RFID technology is frequently used in many fields, such as transport automation processes and object identification. The success of RFID-technology in the industry inspired the healthcare sector to introduce it for added value such as management of pharmaceuticals, increasing the patient’s safety and realizing efficient working processes in hospitals. Both previously mentioned scenarios deal with medical instruments. Among others, the following technologies and methods can be used to optimize and secure some ongoing processes in the healthcare: Introduction of Information and Communication Technology (ICT) to healthcare sectors [2], sophisticated management of electronic patients records and networking systems inside and between hospitals. Further, information technology is very useful for drug management and assignment [3]. One of such optimization benefits is the cost reduction.
RFID based approach is one of the technology which can be integrated in already existing ICT, due to existing experiences in other fields and reasonable implementation costs. Although there are many different RFID system structures, a well-known system structure is preferred (Figure 1) for such particular study. This RFID system consists of four main components:
A tag, attached to the target object. A passive tag harvests the energy from the radiated electromagnetic field. If the magnetic field is strong enough to charge and activate the tags, the RFID tag goes into ready mode and starts to listen for interrogator commands.
The RFID reader or interrogator is responsible for powering the tag, writing to or reading from the it by sending radio waves. The approach using passive tags requires an appropriate antenna, where the size of the antenna depends on the used frequency band, tag size and the desired reading range.
The RFID-Middleware layer is the interface between the RFID-reader and the Enterprise- Resource-Planning) (ERP) system. The middleware layer filters, formats and synchronizes the data from different reader systems, also allowing high system scalability. In the majority of cases the middleware is included in the ERP system and is implemented as software layer
The ERP-system allows integration of collected data from middleware with ongoing processes such as inventory management and resource planning.

Components of the RFID system
The RFID technology covers many frequency bands, where low and high frequency bands (125 kHz, 13, 56 MHz) use load modulation for transmitting data. The Transmission of energy and data strongly depends on the coupling factor between antennas of a tag and a reader. Thus, the reading distance of a desired small size tag is only few millimeters. However b scatter technique in the UHF band (868 MHz) allows to receive data from a small size tag with signifi-cantly longer distance between the antenna and the tag. In our application we assume random orientation of surgical instruments inside the identification range, thus a reading distance of 15 centimeters is required. As explained above, the low and high frequencies are not appropriate for this challenging task. Furthermore the UHF band proved on the basis of state-of-the-art as a proper technology for this application.
2 Methods
The development of RFID reader system requires hardware and software components including the development of a UHF interrogator and the add-on modules for signal processing. The UHF interrogator consists of a UHF Analog Front End (AFE) for data modulation, demodulation, coding and decoding. The differential output of the AFE is very small, in the range of 0 dBm. Additionally the output power is reduced by additional signal losses caused by signal filtering, directional coupling element, circuit matching and reflection effects on signal paths between the AFE and antenna load (Figure 2), thus while impelementing the system, the Printed Circuit Board (PCB) was developed and designed for minimum losses. In order to amplify the signal to the desired level, the gain factor is controlled by an analog signal from a Digital-to-Analog Converter (DAC) and the output power is then tuned in the range from 0 dBm to 20 dBm.

Structure of the UHF-Interrogator
The systems is designed to have six controlling units, based on MSP430 microprocessors, where one acts as a master, controls and communicates with all the rest, four control and communicate with AFE and last one controls the DAC. The AFE is configured and read out through Serial Peripehral I (SPI) interface. AFE registers include configu-ration of data rates, data encoding type, frequency of data transfer from the tag to the reader as well as selection of frequency communication channel.
The radiated power of RFID system, while being used in healthcare, is limited to not to interfere with work of life support equipment and any other electronic system, located in range of RFID-identification system. The interrogator is equipped with a power detector, indicating the power level of the received signal from the transponder, in order to find the optimal power level to detect the instruments and not exceed the limitations.
Data acquisition from metallic surgical instruments in the near field and up to few centimeters from the antenna significantly changes the antenna properties, in particularly antenna input impedance. A variation from the given reference impedance (50 ) causes reflection effects appearing between the interrogator and the antenna. Reducing the undesirable effects at run time require a matching network, such as e.g. a Pi-band-pass-filter, which includes digital controllable capacities. Microprocessor controlling the AFE measures in real-time at the moment reflected signals and rapidly digitally adjusts the capacitances to the optimal values.
Simultaneously with AFE sending a few microseconds carrier-wave without modulated data, the reflected signal is tapped by a directional coupler, passed through the power detector and sampled with a ADC inside the of one of the four AFE controlling microprocessors. The measurement procedure is repeated several times with different capacitance combination until the reflected signal is minimized. The automatic impedance matching is done periodically to insure maximal signal transmission and avoiding standing waves on the transmission path.
Due to the used frequency band and the metallic barriers (surgical instruments, metallic box), the electromagnetic waves are reflected causing dead zones, where the signals interfere destructively. Minimizing or avoiding this fundamental problem requires a dynamic phase shifting at run-time. Hence, the majority of hidden transponder in dead zones are then made accessible for the RFID reader. The phase shifting bank is inserted between the UHFInterrogators and antennas. As mentioned previously, one of the microprocessors is controlling the phase shifter hardware with an analog voltage signal, generated with DAC.
3 Results
The system’s hardware was designed, implemented and tested using commercial antennas (linear- and circular polarized). Since the system consists of multiple antennas, used in different constellations, it is necessary to consider a synchronization process and ”listen before talk” technique for preventing the collision effects between the interrogators.
In the first scenario, with a linear polarized antenna, providing wide direction in plane, the tag’s signal quality has still strong signal quality dependency from it’s orientation according to the field generated by the antenna. In some constellations the signal quality drops in the proximity of the tag and is not sufficient for activating it, what leads to reading failures or missing tag in the ERP system. With this kind of antennas at least 30 from 40 instruments are identified.
In the second scenario, circular polarized type antenna is used. 4 near field antennas are placed on top of the table (see Figure 3) where the electromagnetic wave is divided in 90°shifted components. With a reduced reading range, an identification yield of 35 from 40 instruments has been achieved. A system structure is shown in Figures 3, where as real-life implementation is shown in Figure 4. In the third implementation, tunnel RFID reader was build. The main difference to the previous demonstrator is the software and the synchronization procedure (Figure 5). While measuring, the system showed the same performance as in the second scenario.

RFID system structure for identifying instruments on a table

Part of the implemented RFID system
Commercial UHF-tags, used for identifying, are fixed with epoxy on the surface of the surgical instruments. Mechanical structure of some surgical instruments allowed to embed the tags into appropriate opening of the instrument, provided better identification rates and protection against mechanical shocks or damage from impact with other surgical instruments (Figure 6).

Tunnel RFID-System

RFID system structure for identifying instruments on a table
4 Conclusion and future work
Experiments showed, that The developed system and appropriate tags embedded on surgical instruments allow a detection rate of 87.5% in the worst case. The improvement of detections rates up to 100% require implementation of advanced signal processing methods, such like carrier leakage suppression [5, 6] for improving the separation between transmitter and receiver. Furthermore, new anti-collision algorithms can increase data processing speed and reliability of identification [7, 8]. Currently new antenna concepts, optimizing the electromagnetic interferences, are under development.
Acknowledgment
The authors gratefully acknowledge the project consortium for providing instruments and expertise that greatly assisted the research. The project is funded by the Baden-Wurttemberg ministry of economic under reference number 2-4332.62-HSG51.
Author's Statement
Conflict of interest: Authors state no conflict of interest. Material and Methods: Informed consent: Informed consent has been obtained from all individuals included in this study. Ethical approval: The research related to human use has been complied with all the relevant national regulations, institutional policies and in accordance the tenets of the Helsinki Declaration, and has been approved by the authors’ institutional review board or equivalent committee.
References
[1] Susanne Erbe, ”Gesundheitsausgaben: Kostenexplosion und Alterslasten?”, Wirtschaftsdienst, pp.420-422, 2012.10.1007/s10273-012-1398-8Suche in Google Scholar
[2] Fichman, R. G., Kohli, K., and Krishnan, R., Editorial Overview-The Role of Information Systems in Healthcare: Current Research and Future Trends. Information Systems Research, pp.419–428, 2011.10.1287/isre.1110.0382Suche in Google Scholar
[3] Cresswell, K.M., and Sheikh, A., ”Information technology-based approaches to reducing repeat drug exposure in patients with known drug allergies” Journal of Allergy and Clinical Immunology, pp.1112–1117, 2008.10.1016/j.jaci.2007.12.1180Suche in Google Scholar PubMed
[4] Floerkemeier, C. & Lampe, M.. RFID Middleware Design: Addressing Application Requirements and RFID Constraints, Smart Objects Conference, ISBN 1-59593-304-2, Grenoble, pp. 219-224, 2005.10.1145/1107548.1107603Suche in Google Scholar
[5] J.-W. Jung, H.-H. Roh, J.-C. Kim, H.-G. Kwak, M. S. Jeong, and J.-S. Park, ”TX leakage cancellation via a micro controller and high TX-to-RX isolations covering an UHF RFID frequency band of 908–914 MHz,” IEEE Microw. Wireless Compon. Lett., vol. 18, no.10, pp. 710–712, 2008.10.1109/LMWC.2008.2003487Suche in Google Scholar
[6] T.Xiong, X.Tan, J.Xi, and H.Min,”HighTX-to-RXisolationin UHF RFID using narrowband leaking carrier canceller” IEEE Microw.Wireless Compon. Lett., vol. 20, no. 2, pp. 124–127, Feb. 2010.10.1109/LMWC.2009.2038620Suche in Google Scholar
[7] S.-R. Lee, S.-D. Joo, and C.-W. Lee, ”An enhanced dynamic framed slotted aloha algorithm for rfid tag identification” in MOBIQUITOUS’05, Washington, DC, pp. 166–174, 2005.10.1109/MOBIQUITOUS.2005.13Suche in Google Scholar
[8] W. Engels and E. Sarma, ”The reader collision problem,” in Proc. IEEE Int. Conf. Syst., Man Cybern., vol. 3, pp. 92–97, 2002.10.1109/ICSMC.2002.1176117Suche in Google Scholar
© 2015 by Walter de Gruyter GmbH, Berlin/Boston
This article is distributed under the terms of the Creative Commons Attribution Non-Commercial License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Artikel in diesem Heft
- Research Article
- Development and characterization of superparamagnetic coatings
- Research Article
- The development of an experimental setup to measure acousto-electric interaction signal
- Research Article
- Stability analysis of ferrofluids
- Research Article
- Investigation of endothelial growth using a sensors-integrated microfluidic system to simulate physiological barriers
- Research Article
- Energy harvesting for active implants: powering a ruminal pH-monitoring system
- Research Article
- New type of fluxgate magnetometer for the heart’s magnetic fields detection
- Research Article
- Field mapping of ballistic pressure pulse sources
- Research Article
- Development of a new homecare sleep monitor using body sounds and motion tracking
- Research Article
- Noise properties of textile, capacitive EEG electrodes
- Research Article
- Detecting phase singularities and rotor center trajectories based on the Hilbert transform of intraatrial electrograms in an atrial voxel model
- Research Article
- Spike sorting: the overlapping spikes challenge
- Research Article
- Separating the effect of respiration from the heart rate variability for cases of constant harmonic breathing
- Research Article
- Locating regions of arrhythmogenic substrate by analyzing the duration of triggered atrial activities
- Research Article
- Combining different ECG derived respiration tracking methods to create an optimal reconstruction of the breathing pattern
- Research Article
- Atrial and ventricular signal averaging electrocardiography in pacemaker and cardiac resynchronization therapy
- Research Article
- Estimation of a respiratory signal from a single-lead ECG using the 4th order central moments
- Research Article
- Compressed sensing of multi-lead ECG signals by compressive multiplexing
- Research Article
- Heart rate monitoring in ultra-high-field MRI using frequency information obtained from video signals of the human skin compared to electrocardiography and pulse oximetry
- Research Article
- Synchronization in wireless biomedical-sensor networks with Bluetooth Low Energy
- Research Article
- Automated classification of stages of anaesthesia by populations of evolutionary optimized fuzzy rules
- Research Article
- Effects of sampling rate on automated fatigue recognition in surface EMG signals
- Research Article
- Closed-loop transcranial alternating current stimulation of slow oscillations
- Research Article
- Cardiac index in atrio- and interventricular delay optimized cardiac resynchronization therapy and cardiac contractility modulation
- Research Article
- The role of expert evaluation for microsleep detection
- Research Article
- The impact of baseline wander removal techniques on the ST segment in simulated ischemic 12-lead ECGs
- Research Article
- Metal artifact reduction by projection replacements and non-local prior image integration
- Research Article
- A novel coaxial nozzle for in-process adjustment of electrospun scaffolds’ fiber diameter
- Research Article
- Processing of membranes for oxygenation using the Bellhouse-effect
- Research Article
- Inkjet printing of viable human dental follicle stem cells
- Research Article
- The use of an icebindingprotein out of the snowflea Hypogastrura harveyi as a cryoprotectant in the cryopreservation of mesenchymal stem cells
- Research Article
- New NIR spectroscopy based method to determine ischemia in vivo in liver – a first study on rats
- Research Article
- QRS and QT ventricular conduction times and permanent pacemaker therapy after transcatheter aortic valve implantation
- Research Article
- Adopting oculopressure tonometry as a transient in vivo rabbit glaucoma model
- Research Article
- Next-generation vision testing: the quick CSF
- Research Article
- Improving tactile sensation in laparoscopic surgery by overcoming size restrictions
- Research Article
- Design and control of a 3-DOF hydraulic driven surgical instrument
- Research Article
- Evaluation of endourological tools to improve the diagnosis and therapy of ureteral tumors – from model development to clinical application
- Research Article
- Frequency based assessment of surgical activities
- Research Article
- “Hands free for intervention”, a new approach for transoral endoscopic surgery
- Research Article
- Pseudo-haptic feedback in medical teleoperation
- Research Article
- Feasibility of interactive gesture control of a robotic microscope
- Research Article
- Towards structuring contextual information for workflow-driven surgical assistance functionalities
- Research Article
- Towards a framework for standardized semantic workflow modeling and management in the surgical domain
- Research Article
- Closed-loop approach for situation awareness of medical devices and operating room infrastructure
- Research Article
- Kinect based physiotherapy system for home use
- Research Article
- Evaluating the microsoft kinect skeleton joint tracking as a tool for home-based physiotherapy
- Research Article
- Integrating multimodal information for intraoperative assistance in neurosurgery
- Research Article
- Respiratory motion tracking using Microsoft’s Kinect v2 camera
- Research Article
- Using smart glasses for ultrasound diagnostics
- Research Article
- Measurement of needle susceptibility artifacts in magnetic resonance images
- Research Article
- Dimensionality reduction of medical image descriptors for multimodal image registration
- Research Article
- Experimental evaluation of different weighting schemes in magnetic particle imaging reconstruction
- Research Article
- Evaluation of CT capability for the detection of thin bone structures
- Research Article
- Towards contactless optical coherence elastography with acoustic tissue excitation
- Research Article
- Development and implementation of algorithms for automatic and robust measurement of the 2D:4D digit ratio using image data
- Research Article
- Automated high-throughput analysis of B cell spreading on immobilized antibodies with whole slide imaging
- Research Article
- Tissue segmentation from head MRI: a ground truth validation for feature-enhanced tracking
- Research Article
- Video tracking of swimming rodents on a reflective water surface
- Research Article
- MR imaging of model drug distribution in simulated vitreous
- Research Article
- Studying the extracellular contribution to the double wave vector diffusion-weighted signal
- Research Article
- Artifacts in field free line magnetic particle imaging in the presence of inhomogeneous and nonlinear magnetic fields
- Research Article
- Introducing a frequency-tunable magnetic particle spectrometer
- Research Article
- Imaging of aortic valve dynamics in 4D OCT
- Research Article
- Intravascular optical coherence tomography (OCT) as an additional tool for the assessment of stent structures
- Research Article
- Simple concept for a wide-field lensless digital holographic microscope using a laser diode
- Research Article
- Intraoperative identification of somato-sensory brain areas using optical imaging and standard RGB camera equipment – a feasibility study
- Research Article
- Respiratory surface motion measurement by Microsoft Kinect
- Research Article
- Improving image quality in EIT imaging by measurement of thorax excursion
- Research Article
- A clustering based dual model framework for EIT imaging: first experimental results
- Research Article
- Three-dimensional anisotropic regularization for limited angle tomography
- Research Article
- GPU-based real-time generation of large ultrasound volumes from freehand 3D sweeps
- Research Article
- Experimental computer tomograph
- Research Article
- US-tracked steered FUS in a respiratory ex vivo ovine liver phantom
- Research Article
- Contribution of brownian rotation and particle assembly polarisation to the particle response in magnetic particle spectrometry
- Research Article
- Preliminary investigations of magnetic modulated nanoparticles for microwave breast cancer detection
- Research Article
- Construction of a device for magnetic separation of superparamagnetic iron oxide nanoparticles
- Research Article
- An IHE-conform telecooperation platform supporting the treatment of dementia patients
- Research Article
- Automated respiratory therapy system based on the ARDSNet protocol with systemic perfusion control
- Research Article
- Identification of surgical instruments using UHF-RFID technology
- Research Article
- A generic concept for the development of model-guided clinical decision support systems
- Research Article
- Evaluation of local alterations in femoral bone mineral density measured via quantitative CT
- Research Article
- Creating 3D gelatin phantoms for experimental evaluation in biomedicine
- Research Article
- Influence of short-term fixation with mixed formalin or ethanol solution on the mechanical properties of human cortical bone
- Research Article
- Analysis of the release kinetics of surface-bound proteins via laser-induced fluorescence
- Research Article
- Tomographic particle image velocimetry of a water-jet for low volume harvesting of fat tissue for regenerative medicine
- Research Article
- Wireless medical sensors – context, robustness and safety
- Research Article
- Sequences for real-time magnetic particle imaging
- Research Article
- Speckle-based off-axis holographic detection for non-contact photoacoustic tomography
- Research Article
- A machine learning approach for planning valve-sparing aortic root reconstruction
- Research Article
- An in-ear pulse wave velocity measurement system using heart sounds as time reference
- Research Article
- Measuring different oxygenation levels in a blood perfusion model simulating the human head using NIRS
- Research Article
- Multisegmental fusion of the lumbar spine a curse or a blessing?
- Research Article
- Numerical analysis of the biomechanical complications accompanying the total hip replacement with NANOS-Prosthetic: bone remodelling and prosthesis migration
- Research Article
- A muscle model for hybrid muscle activation
- Research Article
- Mathematical, numerical and in-vitro investigation of cooling performance of an intra-carotid catheter for selective brain hypothermia
- Research Article
- An ideally parameterized unscented Kalman filter for the inverse problem of electrocardiography
- Research Article
- Interactive visualization of cardiac anatomy and atrial excitation for medical diagnosis and research
- Research Article
- Virtualizing clinical cases of atrial flutter in a fast marching simulation including conduction velocity and ablation scars
- Research Article
- Mesh structure-independent modeling of patient-specific atrial fiber orientation
- Research Article
- Accelerating mono-domain cardiac electrophysiology simulations using OpenCL
- Research Article
- Understanding the cellular mode of action of vernakalant using a computational model: answers and new questions
- Research Article
- A java based simulator with user interface to simulate ventilated patients
- Research Article
- Evaluation of an algorithm to choose between competing models of respiratory mechanics
- Research Article
- Numerical simulation of low-pulsation gerotor pumps for use in the pharmaceutical industry and in biomedicine
- Research Article
- Numerical and experimental flow analysis in centifluidic systems for rapid allergy screening tests
- Research Article
- Biomechanical parameter determination of scaffold-free cartilage constructs (SFCCs) with the hyperelastic material models Yeoh, Ogden and Demiray
- Research Article
- FPGA controlled artificial vascular system
- Research Article
- Simulation based investigation of source-detector configurations for non-invasive fetal pulse oximetry
- Research Article
- Test setup for characterizing the efficacy of embolic protection devices
- Research Article
- Impact of electrode geometry on force generation during functional electrical stimulation
- Research Article
- 3D-based visual physical activity assessment of children
- Research Article
- Realtime assessment of foot orientation by Accelerometers and Gyroscopes
- Research Article
- Image based reconstruction for cystoscopy
- Research Article
- Image guided surgery innovation with graduate students - a new lecture format
- Research Article
- Multichannel FES parameterization for controlling foot motion in paretic gait
- Research Article
- Smartphone supported upper limb prosthesis
- Research Article
- Use of quantitative tremor evaluation to enhance target selection during deep brain stimulation surgery for essential tremor
- Research Article
- Evaluation of adhesion promoters for Parylene C on gold metallization
- Research Article
- The influence of metallic ions from CoCr28Mo6 on the osteogenic differentiation and cytokine release of human osteoblasts
- Research Article
- Increasing the visibility of thin NITINOL vascular implants
- Research Article
- Possible reasons for early artificial bone failure in biomechanical tests of ankle arthrodesis systems
- Research Article
- Development of a bending test procedure for the characterization of flexible ECoG electrode arrays
- Research Article
- Tubular manipulators: a new concept for intracochlear positioning of an auditory prosthesis
- Research Article
- Investigation of the dynamic diameter deformation of vascular stents during fatigue testing with radial loading
- Research Article
- Electrospun vascular grafts with anti-kinking properties
- Research Article
- Integration of temperature sensors in polyimide-based thin-film electrode arrays
- Research Article
- Use cases and usability challenges for head-mounted displays in healthcare
- Research Article
- Device- and service profiles for integrated or systems based on open standards
- Research Article
- Risk management for medical devices in research projects
- Research Article
- Simulation of varying femoral attachment sites of medial patellofemoral ligament using a musculoskeletal multi-body model
- Research Article
- Does enhancing consciousness for strategic planning processes support the effectiveness of problem-based learning concepts in biomedical education?
- Research Article
- SPIO processing in macrophages for MPI: The breast cancer MPI-SNLB-concept
- Research Article
- Numerical simulations of airflow in the human pharynx of OSAHS patients
Artikel in diesem Heft
- Research Article
- Development and characterization of superparamagnetic coatings
- Research Article
- The development of an experimental setup to measure acousto-electric interaction signal
- Research Article
- Stability analysis of ferrofluids
- Research Article
- Investigation of endothelial growth using a sensors-integrated microfluidic system to simulate physiological barriers
- Research Article
- Energy harvesting for active implants: powering a ruminal pH-monitoring system
- Research Article
- New type of fluxgate magnetometer for the heart’s magnetic fields detection
- Research Article
- Field mapping of ballistic pressure pulse sources
- Research Article
- Development of a new homecare sleep monitor using body sounds and motion tracking
- Research Article
- Noise properties of textile, capacitive EEG electrodes
- Research Article
- Detecting phase singularities and rotor center trajectories based on the Hilbert transform of intraatrial electrograms in an atrial voxel model
- Research Article
- Spike sorting: the overlapping spikes challenge
- Research Article
- Separating the effect of respiration from the heart rate variability for cases of constant harmonic breathing
- Research Article
- Locating regions of arrhythmogenic substrate by analyzing the duration of triggered atrial activities
- Research Article
- Combining different ECG derived respiration tracking methods to create an optimal reconstruction of the breathing pattern
- Research Article
- Atrial and ventricular signal averaging electrocardiography in pacemaker and cardiac resynchronization therapy
- Research Article
- Estimation of a respiratory signal from a single-lead ECG using the 4th order central moments
- Research Article
- Compressed sensing of multi-lead ECG signals by compressive multiplexing
- Research Article
- Heart rate monitoring in ultra-high-field MRI using frequency information obtained from video signals of the human skin compared to electrocardiography and pulse oximetry
- Research Article
- Synchronization in wireless biomedical-sensor networks with Bluetooth Low Energy
- Research Article
- Automated classification of stages of anaesthesia by populations of evolutionary optimized fuzzy rules
- Research Article
- Effects of sampling rate on automated fatigue recognition in surface EMG signals
- Research Article
- Closed-loop transcranial alternating current stimulation of slow oscillations
- Research Article
- Cardiac index in atrio- and interventricular delay optimized cardiac resynchronization therapy and cardiac contractility modulation
- Research Article
- The role of expert evaluation for microsleep detection
- Research Article
- The impact of baseline wander removal techniques on the ST segment in simulated ischemic 12-lead ECGs
- Research Article
- Metal artifact reduction by projection replacements and non-local prior image integration
- Research Article
- A novel coaxial nozzle for in-process adjustment of electrospun scaffolds’ fiber diameter
- Research Article
- Processing of membranes for oxygenation using the Bellhouse-effect
- Research Article
- Inkjet printing of viable human dental follicle stem cells
- Research Article
- The use of an icebindingprotein out of the snowflea Hypogastrura harveyi as a cryoprotectant in the cryopreservation of mesenchymal stem cells
- Research Article
- New NIR spectroscopy based method to determine ischemia in vivo in liver – a first study on rats
- Research Article
- QRS and QT ventricular conduction times and permanent pacemaker therapy after transcatheter aortic valve implantation
- Research Article
- Adopting oculopressure tonometry as a transient in vivo rabbit glaucoma model
- Research Article
- Next-generation vision testing: the quick CSF
- Research Article
- Improving tactile sensation in laparoscopic surgery by overcoming size restrictions
- Research Article
- Design and control of a 3-DOF hydraulic driven surgical instrument
- Research Article
- Evaluation of endourological tools to improve the diagnosis and therapy of ureteral tumors – from model development to clinical application
- Research Article
- Frequency based assessment of surgical activities
- Research Article
- “Hands free for intervention”, a new approach for transoral endoscopic surgery
- Research Article
- Pseudo-haptic feedback in medical teleoperation
- Research Article
- Feasibility of interactive gesture control of a robotic microscope
- Research Article
- Towards structuring contextual information for workflow-driven surgical assistance functionalities
- Research Article
- Towards a framework for standardized semantic workflow modeling and management in the surgical domain
- Research Article
- Closed-loop approach for situation awareness of medical devices and operating room infrastructure
- Research Article
- Kinect based physiotherapy system for home use
- Research Article
- Evaluating the microsoft kinect skeleton joint tracking as a tool for home-based physiotherapy
- Research Article
- Integrating multimodal information for intraoperative assistance in neurosurgery
- Research Article
- Respiratory motion tracking using Microsoft’s Kinect v2 camera
- Research Article
- Using smart glasses for ultrasound diagnostics
- Research Article
- Measurement of needle susceptibility artifacts in magnetic resonance images
- Research Article
- Dimensionality reduction of medical image descriptors for multimodal image registration
- Research Article
- Experimental evaluation of different weighting schemes in magnetic particle imaging reconstruction
- Research Article
- Evaluation of CT capability for the detection of thin bone structures
- Research Article
- Towards contactless optical coherence elastography with acoustic tissue excitation
- Research Article
- Development and implementation of algorithms for automatic and robust measurement of the 2D:4D digit ratio using image data
- Research Article
- Automated high-throughput analysis of B cell spreading on immobilized antibodies with whole slide imaging
- Research Article
- Tissue segmentation from head MRI: a ground truth validation for feature-enhanced tracking
- Research Article
- Video tracking of swimming rodents on a reflective water surface
- Research Article
- MR imaging of model drug distribution in simulated vitreous
- Research Article
- Studying the extracellular contribution to the double wave vector diffusion-weighted signal
- Research Article
- Artifacts in field free line magnetic particle imaging in the presence of inhomogeneous and nonlinear magnetic fields
- Research Article
- Introducing a frequency-tunable magnetic particle spectrometer
- Research Article
- Imaging of aortic valve dynamics in 4D OCT
- Research Article
- Intravascular optical coherence tomography (OCT) as an additional tool for the assessment of stent structures
- Research Article
- Simple concept for a wide-field lensless digital holographic microscope using a laser diode
- Research Article
- Intraoperative identification of somato-sensory brain areas using optical imaging and standard RGB camera equipment – a feasibility study
- Research Article
- Respiratory surface motion measurement by Microsoft Kinect
- Research Article
- Improving image quality in EIT imaging by measurement of thorax excursion
- Research Article
- A clustering based dual model framework for EIT imaging: first experimental results
- Research Article
- Three-dimensional anisotropic regularization for limited angle tomography
- Research Article
- GPU-based real-time generation of large ultrasound volumes from freehand 3D sweeps
- Research Article
- Experimental computer tomograph
- Research Article
- US-tracked steered FUS in a respiratory ex vivo ovine liver phantom
- Research Article
- Contribution of brownian rotation and particle assembly polarisation to the particle response in magnetic particle spectrometry
- Research Article
- Preliminary investigations of magnetic modulated nanoparticles for microwave breast cancer detection
- Research Article
- Construction of a device for magnetic separation of superparamagnetic iron oxide nanoparticles
- Research Article
- An IHE-conform telecooperation platform supporting the treatment of dementia patients
- Research Article
- Automated respiratory therapy system based on the ARDSNet protocol with systemic perfusion control
- Research Article
- Identification of surgical instruments using UHF-RFID technology
- Research Article
- A generic concept for the development of model-guided clinical decision support systems
- Research Article
- Evaluation of local alterations in femoral bone mineral density measured via quantitative CT
- Research Article
- Creating 3D gelatin phantoms for experimental evaluation in biomedicine
- Research Article
- Influence of short-term fixation with mixed formalin or ethanol solution on the mechanical properties of human cortical bone
- Research Article
- Analysis of the release kinetics of surface-bound proteins via laser-induced fluorescence
- Research Article
- Tomographic particle image velocimetry of a water-jet for low volume harvesting of fat tissue for regenerative medicine
- Research Article
- Wireless medical sensors – context, robustness and safety
- Research Article
- Sequences for real-time magnetic particle imaging
- Research Article
- Speckle-based off-axis holographic detection for non-contact photoacoustic tomography
- Research Article
- A machine learning approach for planning valve-sparing aortic root reconstruction
- Research Article
- An in-ear pulse wave velocity measurement system using heart sounds as time reference
- Research Article
- Measuring different oxygenation levels in a blood perfusion model simulating the human head using NIRS
- Research Article
- Multisegmental fusion of the lumbar spine a curse or a blessing?
- Research Article
- Numerical analysis of the biomechanical complications accompanying the total hip replacement with NANOS-Prosthetic: bone remodelling and prosthesis migration
- Research Article
- A muscle model for hybrid muscle activation
- Research Article
- Mathematical, numerical and in-vitro investigation of cooling performance of an intra-carotid catheter for selective brain hypothermia
- Research Article
- An ideally parameterized unscented Kalman filter for the inverse problem of electrocardiography
- Research Article
- Interactive visualization of cardiac anatomy and atrial excitation for medical diagnosis and research
- Research Article
- Virtualizing clinical cases of atrial flutter in a fast marching simulation including conduction velocity and ablation scars
- Research Article
- Mesh structure-independent modeling of patient-specific atrial fiber orientation
- Research Article
- Accelerating mono-domain cardiac electrophysiology simulations using OpenCL
- Research Article
- Understanding the cellular mode of action of vernakalant using a computational model: answers and new questions
- Research Article
- A java based simulator with user interface to simulate ventilated patients
- Research Article
- Evaluation of an algorithm to choose between competing models of respiratory mechanics
- Research Article
- Numerical simulation of low-pulsation gerotor pumps for use in the pharmaceutical industry and in biomedicine
- Research Article
- Numerical and experimental flow analysis in centifluidic systems for rapid allergy screening tests
- Research Article
- Biomechanical parameter determination of scaffold-free cartilage constructs (SFCCs) with the hyperelastic material models Yeoh, Ogden and Demiray
- Research Article
- FPGA controlled artificial vascular system
- Research Article
- Simulation based investigation of source-detector configurations for non-invasive fetal pulse oximetry
- Research Article
- Test setup for characterizing the efficacy of embolic protection devices
- Research Article
- Impact of electrode geometry on force generation during functional electrical stimulation
- Research Article
- 3D-based visual physical activity assessment of children
- Research Article
- Realtime assessment of foot orientation by Accelerometers and Gyroscopes
- Research Article
- Image based reconstruction for cystoscopy
- Research Article
- Image guided surgery innovation with graduate students - a new lecture format
- Research Article
- Multichannel FES parameterization for controlling foot motion in paretic gait
- Research Article
- Smartphone supported upper limb prosthesis
- Research Article
- Use of quantitative tremor evaluation to enhance target selection during deep brain stimulation surgery for essential tremor
- Research Article
- Evaluation of adhesion promoters for Parylene C on gold metallization
- Research Article
- The influence of metallic ions from CoCr28Mo6 on the osteogenic differentiation and cytokine release of human osteoblasts
- Research Article
- Increasing the visibility of thin NITINOL vascular implants
- Research Article
- Possible reasons for early artificial bone failure in biomechanical tests of ankle arthrodesis systems
- Research Article
- Development of a bending test procedure for the characterization of flexible ECoG electrode arrays
- Research Article
- Tubular manipulators: a new concept for intracochlear positioning of an auditory prosthesis
- Research Article
- Investigation of the dynamic diameter deformation of vascular stents during fatigue testing with radial loading
- Research Article
- Electrospun vascular grafts with anti-kinking properties
- Research Article
- Integration of temperature sensors in polyimide-based thin-film electrode arrays
- Research Article
- Use cases and usability challenges for head-mounted displays in healthcare
- Research Article
- Device- and service profiles for integrated or systems based on open standards
- Research Article
- Risk management for medical devices in research projects
- Research Article
- Simulation of varying femoral attachment sites of medial patellofemoral ligament using a musculoskeletal multi-body model
- Research Article
- Does enhancing consciousness for strategic planning processes support the effectiveness of problem-based learning concepts in biomedical education?
- Research Article
- SPIO processing in macrophages for MPI: The breast cancer MPI-SNLB-concept
- Research Article
- Numerical simulations of airflow in the human pharynx of OSAHS patients