Home Frequency based assessment of surgical activities
Article Open Access

Frequency based assessment of surgical activities

  • Marianne Maktabi EMAIL logo , Sascha T. Vinz and Thomas Neumuth
Published/Copyright: September 12, 2015
Download Article (PDF)
Become an author with De Gruyter Brill
Author Information Explore this Subject
Current Directions in Biomedical Engineering
From the journal Current Directions in Biomedical Engineering Volume 1 Issue 1

Abstract

In hospitals the duration of surgeries plays a decisive role in many areas, such as patient safety or financial aspects. By utilizing accurate automated online prediction efficient surgical patient care and effective resource management can be attained. In this work several surgical activities during an intervention were examined for their potential to forecast the remaining intervention time. The method used was based on analysing in the frequency domain of time series which represented the status of surgical activities during an intervention. A nonparametric estimation of power spectral density was calculated for single surgical tasks during an intervention. The power spectral densities (PSD) of different surgical activities were compared in a leave-one-out cross validation of forty surgical workflow recordings of lumbar discectomies. The results showed that the activity irrigate with a mean prediction error of 26 min 23 s is best-suited for determining the remainder of the intervention. To construct a scheduling support for a wider range of surgery types the actions conducted by the surgeon’s right and left hand would eminently be more suitable; the error of the action right hand was 41 min 39 s, yet. In conclusion sophistication into the presented frequency based method might support time and resource management in a general manner.

Keywords: spectral estimation; spectral analysis; surgery; surgical workflow; time series analysis

1 Motivation

Effective resource management is an important method for enhancing the handling of financial and critical safety aspects in modern hospitals. Especially in the operating room (OR) of the future potentials have to exploited to reduce costs of intensive and the risks of hazardous events [1–3]. Such events emerge for several reasons in the OR, like long idle times between sequenced surgical procedures or cancelled interventions due to poor coordination of staff and devices [4, 5].

A straightforward automated time and resource management system could be used to excellent effect to overcome these conflicts. Several approaches towards the real time prediction of phase and intervention time based on a wide range of surgical activities available online are described in literature [6, 7]. In this work we compared single activities of the surgeon to each other in terms of their suitability for predicting the remaining intervention time. The goal of this work is to clarify how a frequency based analogy can predict remaining intervention time. A novel approach for comparison of low level surgical activities is described here. An advantage of this method is that it works with just one single recordable surgical activity. The method was based on frequency domain analysis of time series for surgical procedures, which are usually complex and hard to predict. The periodogram as a nonparametric spectral estimation method was applied to evaluate the eligibility for time prediction of the surgical activities based on forecast the intervention time.

1.1 Related work

Several approaches addressed the real time prediction of phase and intervention time [6, 7]. In many other works methods are described to support OR management based on information available preoperatively, such as the type of intervention [8, 9]. These methods used Hidden Markov Models or Bayesian analysis to describe surgical procedures. Furthermore, classification and comparison of populations (patients, surgeons or systems) was described in [10] and [11] based on measures of statistical comparison like average and standard deviation. The disadvantage of these methods is that the bulk of data, like surgical activities or intraoperative anaesthesia, are necessary to forecast the intervention time. In this work we determined the single most suitable surgical activity to predict intervention time in real time. Obviously accurate real time recognition of surgical activities is required. Surgical activities can be recognized by medical and video data from endo-scopes, anaesthesia systems or other signals which are already used in surgical activity recognition systems [6, 12]. These methods are limited to a single surgery type and cannot be transferred directly to each surgery type though. Furthermore, the recent developments in the domain of the integrated and networked OR provided new sources for readily available data concerning surgical activities [13]. In conclusion specific signals transmitted inside an OR can be used for automatic real time recording of activities of instruments like a coagulator or a mill.

The purpose of this work is to evaluate which of the activities conducted by a surgeon is most suitable to predict intervention time. Based on spectral estimation and feature extraction sequences surgical activities are compared to one another.

2 Material and methods

In this section we describe four important steps to compare surgical activities in terms of their suitability for intervention time prediction based on spectral estimation.

2.1 Transformation of surgical activities in time series

First off, a cornerstone to compare surgical activities of a specific surgery type is to have recordings of these activities. In our work we relied on recordings in the form of individual Surgical Process Models (iSPM). The iSPM consists of formalized atomic process steps of a surgery; whereby five different perspectives are considered: functional (de-scribes the action), operational (describes the used instruments or devices), spatial (describes the treated body part of the patient), behavioural (describes temporal information) and organizational (describes the executing person) [14]. We concatenated the attributes of the first three perspectives to build an identifier and represented the identified activities’ status over the fourth perspective (recorded intervention time). This was done in the form of binary activity sequences over time x(t); x(t) had level 1 while the activity was being conducted and 0 otherwise. By doing so we generated 35 activity time series for one specific surgery type. For this work we focused on lumbar discectomies. Due to several dependencies inside our identifier, like for instance the action coagulate and the instrument coagulator usually being used in the same activity, we obtained 31 independent activity time series.

2.2 Estimation of the PSD

The second key part is the ascertainment of the similarity between several activities. In order to do this we estimated the PSD for every binary sequence. Based on the straightforward method of power spectrum estimation the so-called periodogram of the discrete activity sequences x[n] is estimated. The periodogram is a classical method and was developed by Schuster [15]. Based on the first derivation of the Fourier Transformation of the activity sequence x[n] the periodogram can be yielded. Thus, the normal form of the spectrum X(Ω) is given by

Pxx′(Ω)=1N|X(Ω)|2[16]

The estimation of the periodogram was done with Matlab2014b. The periodogram is often applied in practice for the purpose of spectral estimation; furthermore, it can be calculated in an uncomplicated manner. The size of segments was calculated by choosing the smallest known time interval of any considered activity time series. The smallest time interval helped in fulfilling the Nyquist criterion, too. To address errors caused by leakage, we used the Kaiser window, which was chosen empirically.

2.3 Feature extraction

The third step is comparing the PSDs of the activity time sequences to each other by the extraction of well-known statistical features. These features provide new periodicity information about the activity time sequences. Using these we can compare the surgeon’s activities. The following five features are calculated for every considered activity sequence: Total Power (is the sum of the intensity), Dominant Frequency (is the frequency of maximum power in the PSD.), Mean Frequency (is calculated as the sum of product of the power spectrum and the frequency divided by the total sum of the power spectrum.) and the Median Frequency (is the first frequency which exceeds half of the power of the spectrum.).

2.4 Comparison of surgical activities

Finally the frequency-based similarities of several surgical workflows of a specific surgery type were calculated with regard to their activity time sequences. For this purpose the surgical workflows of every single activity time series were chosen from those activity sequences which had the smallest deviation of the calculated features’ values to each other.

Figure 1 The remaining intervention time error of the neurosurgical intervention lumbar discectomy in relation to the surgical phase. Green marked areas were an accurate predictor in special phases. Yellow marked areas were accurate predictors for the whole surgical procedure. Grey marked areas were not recorded in these surgical phases.
Figure 1

The remaining intervention time error of the neurosurgical intervention lumbar discectomy in relation to the surgical phase. Green marked areas were an accurate predictor in special phases. Yellow marked areas were accurate predictors for the whole surgical procedure. Grey marked areas were not recorded in these surgical phases.

3 Experiments and results

3.1 Evaluation

Our four step study was performed based on forty recorded surgical workflows of lumbar discectomies. The four steps were further explained in section 2. The surgical work-flows used, were manual recordings from the ICCAS from 2007 and represent lumbar discectomies conducted by surgeons with various skill levels; the neurosurgical work-flows were divided into several surgical phases: approach to disc (preparation), discectomy and closure. The cross leave-one-out validation was started one minute after the cut time of a surgical procedure and the examined interval increased by one minute of the intervention time. Based on the prediction of the remaining intervention time error the several activities were compared. The maximum durations of the different phases were varied; the duration declined from the preparation phase to the final surgical phase.

3.2 Results

In our evaluation study the predicted remaining intervention time error was calculated to investigate the feasibility of a frequency based activity comparison. The prediction error of activities which had the curettes as used instrument in the preparation phase, those which had the drill as used instrument in the discectomy phase and those with the drape as used instrument in the closure phase had the best outcomes. The activity irrigate had a very low prediction error of 21.45% in relation to the maximum possible error and had the smallest mean prediction error (26 min 33s). However, many activities such as those identified by being conducted with the surgeon’s right and left hand of the neurosurgical intervention exhibited high fluctuations which are depicted in the large standard deviation and asymmetric distribution.

Small standard deviation was seen for activities that were performed with cottonoids or a drill. Moreover, the mean prediction error showed a marked increase for many activities performed on the muscle or vertebra of the patient and for cutting in the discectomy phase. On the contrary, surgical activities such as those performed on the patient’s dura unveiled a decrease of prediction error as the intervention progressed.

4 Discussion and conclusion

In this work we investigated every surgical activity during interventions of a specific surgery type based on spectral estimation. The periodogram as nonparametric spectral estimation was calculated. To obtain the significance of every activity we considered the predicted intervention time error of every surgical activity.

The activity irrigate had the best outcome with a mean prediction error of 26 min 33 s. The needed activity information could be provided by an integrated and networked OR based on the signals of an irrigation pump. The drawback is that the ascertained significance is only valid for lumbar discectomies. Thus, a more general available activity would be more significant. The activities of the surgeon’s right and left hand are applicable in a wider range of surgery types. The mean prediction error for activities performed with the right hand was 41 min 39 s and for those done with the left hand 45 min 3 s. Furthermore a disadvantage is the wide variance of prediction error over intervention time. The high standard deviation can be inferred by the long time and by surgical workflow dependencies of the presented method. The influence of the time of the recording and the influence of the type of work-flow that was used have to be investigated more deeply in future works. Additionally further studies have to investigate methods of decreasing fluctuation. The presented method showed a novel approach to compare surgical activities with regard to their similarity. Hence, the presented method can be applied in an effective resource and time management system [17]. The presented method exhibits feasibility for being integrated in assistance systems and thereby enhancing the daily routine inside the OR. Furthermore, the documentation during surgeries can be enhanced e.g. by automatically generated post-operative reports.

Author's Statement

  1. 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] K. Cleary and A. Kinsella, “OR 2020: the operating room of the future,” Journal of laparoendoscopic & advanced surgical techniques. Part A, vol. 15, no. 5, pp. 495, 497-573, 2005.10.1089/lap.2005.15.495Search in Google Scholar PubMed

[2] H. U. Lemke and M. W. Vannier, “The operating room and the need for an IT infrastructure and standards,” Int J CARS, vol. 1, no. 3, pp. 117–121, 2006.10.1007/s11548-006-0051-7Search in Google Scholar

[3] J. V. Sutherland, van den Heuvel, Willem-Jan, T. Ganous, M. M. Burton, and A. Kumar, “Towards an intelligent hospital environment: OR of the future,” Stud Health Technol Inform, vol. 118, pp. 278–312, 2005.Search in Google Scholar

[4] J. G. Wright, A. Roche, and A. E. Khoury, “Improving on-time surgical starts in an operating room,” Can J Surg, vol. 53, no. 3, pp. 167–170, 2010.Search in Google Scholar

[5] B. Denton, J. Viapiano, and A. Vogl, “Optimization of surgery sequencing and scheduling decisions under uncertainty,” Health Care Manag Sci, vol. 10, no. 1, pp. 13–24, 2007.10.1007/s10729-006-9005-4Search in Google Scholar PubMed

[6] N. Padoy, T. Blum, S.-A. Ahmadi, H. Feussner, M.-O. Berger, and N. Navab, “Statistical modeling and recognition of surgical workflow,” Med Image Anal, vol. 16, no. 3, pp. 632–641, 2012.10.1016/j.media.2010.10.001Search in Google Scholar PubMed

[7] S. Franke, J. Meixensberger, and T. Neumuth, “Intervention time prediction from surgical low-level tasks,” Journal of Biomedical Informatics, vol. 46, no. 1, pp. 152–159, 2013.10.1016/j.jbi.2012.10.002Search in Google Scholar PubMed

[8] B. J. Ammori, M. Larvin, and M. J. McMahon, “Elective laparoscopic cholecystectomy: preoperative prediction of duration of surgery,” Surg Endosc, vol. 15, no. 3, pp. 297–300, 2001.10.1007/s004640000247Search in Google Scholar PubMed

[9] R. Alvarez, R. Bowry, and M. Carter, “Prediction of the time to complete a series of surgical cases to avoid cardiac operating room overutilization,” Can J Surg, vol. 57, no. 11, pp. 973–979, 2010.10.1007/s12630-010-9371-8Search in Google Scholar PubMed

[10] L. Riffaud, T. Neumuth, X. Morandi, C. Trantakis, J. Meixensberger, O. Burgert, B. Trelhu, and P. Jannin, “Recording of surgical processes: a study comparing senior and junior neurosurgeons during lumbar disc herniation surgery,” Neuro-surgery, vol. 67, no. 2 Suppl Operative, pp. 325–332, 2010.10.1227/NEU.0b013e3181f741d7Search in Google Scholar PubMed

[11] G. Forestier, F. Lalys, L. Riffaud, B. Trelhu, and P. Jannin, “Classification of surgical processes using dynamic time warping,” Journal of Biomedical Informatics, vol. 45, no. 2, pp. 255–264, 2012.10.1016/j.jbi.2011.11.002Search in Google Scholar PubMed

[12] T. Blum, H. Feussner, and N. Navab, “Modeling and segmentation of surgical workflow from laparoscopic video,” Med Image Comput Comput Assist Interv, vol. 13, no. Pt 3, pp. 400–407, 2010.10.1007/978-3-642-15711-0_50Search in Google Scholar PubMed

[13] Bohn S, Lindner D, Franke S, Neumuth T, “An interoperability architecture for networked medical devices and its application to neurosurgery,” in The 15th International Conference on Biomedical Engineering (ICBME 2013), Singapore, 2013.Search in Google Scholar

[14] T. Neumuth, F. Loebe, and P. Jannin, “Similarity metrics for surgical process models,” Artificial intelligence in medicine, vol. 54, no. 1, pp. 15–27, 2012.10.1016/j.artmed.2011.10.001Search in Google Scholar PubMed

[15] A. Schuster, “On the investigation of hidden periodicities with application to a supposed 26 day period of meteorological phenomena,” J. Geophys. Res, vol. 3, no. 1, p. 13–13, 1898.10.1029/TM003i001p00013Search in Google Scholar

[16] P. A. Lynn and W. Fuerst, Introductory digital signal processing with computer applications, 2nd ed. Chichester [u.a.]: Wiley, 1998.Search in Google Scholar

[17] C. Herfarth, “’Lean’ surgery through changes in surgical work flow,” The British journal of surgery, vol. 90, no. 5, pp. 513– 514, 2003.10.1002/bjs.4165Search in Google Scholar PubMed

Published Online: 2015-9-12
Published in Print: 2015-9-1

© 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.

Articles in the same Issue

  1. Research Article
  2. Development and characterization of superparamagnetic coatings
  3. Research Article
  4. The development of an experimental setup to measure acousto-electric interaction signal
  5. Research Article
  6. Stability analysis of ferrofluids
  7. Research Article
  8. Investigation of endothelial growth using a sensors-integrated microfluidic system to simulate physiological barriers
  9. Research Article
  10. Energy harvesting for active implants: powering a ruminal pH-monitoring system
  11. Research Article
  12. New type of fluxgate magnetometer for the heart’s magnetic fields detection
  13. Research Article
  14. Field mapping of ballistic pressure pulse sources
  15. Research Article
  16. Development of a new homecare sleep monitor using body sounds and motion tracking
  17. Research Article
  18. Noise properties of textile, capacitive EEG electrodes
  19. Research Article
  20. Detecting phase singularities and rotor center trajectories based on the Hilbert transform of intraatrial electrograms in an atrial voxel model
  21. Research Article
  22. Spike sorting: the overlapping spikes challenge
  23. Research Article
  24. Separating the effect of respiration from the heart rate variability for cases of constant harmonic breathing
  25. Research Article
  26. Locating regions of arrhythmogenic substrate by analyzing the duration of triggered atrial activities
  27. Research Article
  28. Combining different ECG derived respiration tracking methods to create an optimal reconstruction of the breathing pattern
  29. Research Article
  30. Atrial and ventricular signal averaging electrocardiography in pacemaker and cardiac resynchronization therapy
  31. Research Article
  32. Estimation of a respiratory signal from a single-lead ECG using the 4th order central moments
  33. Research Article
  34. Compressed sensing of multi-lead ECG signals by compressive multiplexing
  35. Research Article
  36. 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
  37. Research Article
  38. Synchronization in wireless biomedical-sensor networks with Bluetooth Low Energy
  39. Research Article
  40. Automated classification of stages of anaesthesia by populations of evolutionary optimized fuzzy rules
  41. Research Article
  42. Effects of sampling rate on automated fatigue recognition in surface EMG signals
  43. Research Article
  44. Closed-loop transcranial alternating current stimulation of slow oscillations
  45. Research Article
  46. Cardiac index in atrio- and interventricular delay optimized cardiac resynchronization therapy and cardiac contractility modulation
  47. Research Article
  48. The role of expert evaluation for microsleep detection
  49. Research Article
  50. The impact of baseline wander removal techniques on the ST segment in simulated ischemic 12-lead ECGs
  51. Research Article
  52. Metal artifact reduction by projection replacements and non-local prior image integration
  53. Research Article
  54. A novel coaxial nozzle for in-process adjustment of electrospun scaffolds’ fiber diameter
  55. Research Article
  56. Processing of membranes for oxygenation using the Bellhouse-effect
  57. Research Article
  58. Inkjet printing of viable human dental follicle stem cells
  59. Research Article
  60. The use of an icebindingprotein out of the snowflea Hypogastrura harveyi as a cryoprotectant in the cryopreservation of mesenchymal stem cells
  61. Research Article
  62. New NIR spectroscopy based method to determine ischemia in vivo in liver – a first study on rats
  63. Research Article
  64. QRS and QT ventricular conduction times and permanent pacemaker therapy after transcatheter aortic valve implantation
  65. Research Article
  66. Adopting oculopressure tonometry as a transient in vivo rabbit glaucoma model
  67. Research Article
  68. Next-generation vision testing: the quick CSF
  69. Research Article
  70. Improving tactile sensation in laparoscopic surgery by overcoming size restrictions
  71. Research Article
  72. Design and control of a 3-DOF hydraulic driven surgical instrument
  73. Research Article
  74. Evaluation of endourological tools to improve the diagnosis and therapy of ureteral tumors – from model development to clinical application
  75. Research Article
  76. Frequency based assessment of surgical activities
  77. Research Article
  78. “Hands free for intervention”, a new approach for transoral endoscopic surgery
  79. Research Article
  80. Pseudo-haptic feedback in medical teleoperation
  81. Research Article
  82. Feasibility of interactive gesture control of a robotic microscope
  83. Research Article
  84. Towards structuring contextual information for workflow-driven surgical assistance functionalities
  85. Research Article
  86. Towards a framework for standardized semantic workflow modeling and management in the surgical domain
  87. Research Article
  88. Closed-loop approach for situation awareness of medical devices and operating room infrastructure
  89. Research Article
  90. Kinect based physiotherapy system for home use
  91. Research Article
  92. Evaluating the microsoft kinect skeleton joint tracking as a tool for home-based physiotherapy
  93. Research Article
  94. Integrating multimodal information for intraoperative assistance in neurosurgery
  95. Research Article
  96. Respiratory motion tracking using Microsoft’s Kinect v2 camera
  97. Research Article
  98. Using smart glasses for ultrasound diagnostics
  99. Research Article
  100. Measurement of needle susceptibility artifacts in magnetic resonance images
  101. Research Article
  102. Dimensionality reduction of medical image descriptors for multimodal image registration
  103. Research Article
  104. Experimental evaluation of different weighting schemes in magnetic particle imaging reconstruction
  105. Research Article
  106. Evaluation of CT capability for the detection of thin bone structures
  107. Research Article
  108. Towards contactless optical coherence elastography with acoustic tissue excitation
  109. Research Article
  110. Development and implementation of algorithms for automatic and robust measurement of the 2D:4D digit ratio using image data
  111. Research Article
  112. Automated high-throughput analysis of B cell spreading on immobilized antibodies with whole slide imaging
  113. Research Article
  114. Tissue segmentation from head MRI: a ground truth validation for feature-enhanced tracking
  115. Research Article
  116. Video tracking of swimming rodents on a reflective water surface
  117. Research Article
  118. MR imaging of model drug distribution in simulated vitreous
  119. Research Article
  120. Studying the extracellular contribution to the double wave vector diffusion-weighted signal
  121. Research Article
  122. Artifacts in field free line magnetic particle imaging in the presence of inhomogeneous and nonlinear magnetic fields
  123. Research Article
  124. Introducing a frequency-tunable magnetic particle spectrometer
  125. Research Article
  126. Imaging of aortic valve dynamics in 4D OCT
  127. Research Article
  128. Intravascular optical coherence tomography (OCT) as an additional tool for the assessment of stent structures
  129. Research Article
  130. Simple concept for a wide-field lensless digital holographic microscope using a laser diode
  131. Research Article
  132. Intraoperative identification of somato-sensory brain areas using optical imaging and standard RGB camera equipment – a feasibility study
  133. Research Article
  134. Respiratory surface motion measurement by Microsoft Kinect
  135. Research Article
  136. Improving image quality in EIT imaging by measurement of thorax excursion
  137. Research Article
  138. A clustering based dual model framework for EIT imaging: first experimental results
  139. Research Article
  140. Three-dimensional anisotropic regularization for limited angle tomography
  141. Research Article
  142. GPU-based real-time generation of large ultrasound volumes from freehand 3D sweeps
  143. Research Article
  144. Experimental computer tomograph
  145. Research Article
  146. US-tracked steered FUS in a respiratory ex vivo ovine liver phantom
  147. Research Article
  148. Contribution of brownian rotation and particle assembly polarisation to the particle response in magnetic particle spectrometry
  149. Research Article
  150. Preliminary investigations of magnetic modulated nanoparticles for microwave breast cancer detection
  151. Research Article
  152. Construction of a device for magnetic separation of superparamagnetic iron oxide nanoparticles
  153. Research Article
  154. An IHE-conform telecooperation platform supporting the treatment of dementia patients
  155. Research Article
  156. Automated respiratory therapy system based on the ARDSNet protocol with systemic perfusion control
  157. Research Article
  158. Identification of surgical instruments using UHF-RFID technology
  159. Research Article
  160. A generic concept for the development of model-guided clinical decision support systems
  161. Research Article
  162. Evaluation of local alterations in femoral bone mineral density measured via quantitative CT
  163. Research Article
  164. Creating 3D gelatin phantoms for experimental evaluation in biomedicine
  165. Research Article
  166. Influence of short-term fixation with mixed formalin or ethanol solution on the mechanical properties of human cortical bone
  167. Research Article
  168. Analysis of the release kinetics of surface-bound proteins via laser-induced fluorescence
  169. Research Article
  170. Tomographic particle image velocimetry of a water-jet for low volume harvesting of fat tissue for regenerative medicine
  171. Research Article
  172. Wireless medical sensors – context, robustness and safety
  173. Research Article
  174. Sequences for real-time magnetic particle imaging
  175. Research Article
  176. Speckle-based off-axis holographic detection for non-contact photoacoustic tomography
  177. Research Article
  178. A machine learning approach for planning valve-sparing aortic root reconstruction
  179. Research Article
  180. An in-ear pulse wave velocity measurement system using heart sounds as time reference
  181. Research Article
  182. Measuring different oxygenation levels in a blood perfusion model simulating the human head using NIRS
  183. Research Article
  184. Multisegmental fusion of the lumbar spine a curse or a blessing?
  185. Research Article
  186. Numerical analysis of the biomechanical complications accompanying the total hip replacement with NANOS-Prosthetic: bone remodelling and prosthesis migration
  187. Research Article
  188. A muscle model for hybrid muscle activation
  189. Research Article
  190. Mathematical, numerical and in-vitro investigation of cooling performance of an intra-carotid catheter for selective brain hypothermia
  191. Research Article
  192. An ideally parameterized unscented Kalman filter for the inverse problem of electrocardiography
  193. Research Article
  194. Interactive visualization of cardiac anatomy and atrial excitation for medical diagnosis and research
  195. Research Article
  196. Virtualizing clinical cases of atrial flutter in a fast marching simulation including conduction velocity and ablation scars
  197. Research Article
  198. Mesh structure-independent modeling of patient-specific atrial fiber orientation
  199. Research Article
  200. Accelerating mono-domain cardiac electrophysiology simulations using OpenCL
  201. Research Article
  202. Understanding the cellular mode of action of vernakalant using a computational model: answers and new questions
  203. Research Article
  204. A java based simulator with user interface to simulate ventilated patients
  205. Research Article
  206. Evaluation of an algorithm to choose between competing models of respiratory mechanics
  207. Research Article
  208. Numerical simulation of low-pulsation gerotor pumps for use in the pharmaceutical industry and in biomedicine
  209. Research Article
  210. Numerical and experimental flow analysis in centifluidic systems for rapid allergy screening tests
  211. Research Article
  212. Biomechanical parameter determination of scaffold-free cartilage constructs (SFCCs) with the hyperelastic material models Yeoh, Ogden and Demiray
  213. Research Article
  214. FPGA controlled artificial vascular system
  215. Research Article
  216. Simulation based investigation of source-detector configurations for non-invasive fetal pulse oximetry
  217. Research Article
  218. Test setup for characterizing the efficacy of embolic protection devices
  219. Research Article
  220. Impact of electrode geometry on force generation during functional electrical stimulation
  221. Research Article
  222. 3D-based visual physical activity assessment of children
  223. Research Article
  224. Realtime assessment of foot orientation by Accelerometers and Gyroscopes
  225. Research Article
  226. Image based reconstruction for cystoscopy
  227. Research Article
  228. Image guided surgery innovation with graduate students - a new lecture format
  229. Research Article
  230. Multichannel FES parameterization for controlling foot motion in paretic gait
  231. Research Article
  232. Smartphone supported upper limb prosthesis
  233. Research Article
  234. Use of quantitative tremor evaluation to enhance target selection during deep brain stimulation surgery for essential tremor
  235. Research Article
  236. Evaluation of adhesion promoters for Parylene C on gold metallization
  237. Research Article
  238. The influence of metallic ions from CoCr28Mo6 on the osteogenic differentiation and cytokine release of human osteoblasts
  239. Research Article
  240. Increasing the visibility of thin NITINOL vascular implants
  241. Research Article
  242. Possible reasons for early artificial bone failure in biomechanical tests of ankle arthrodesis systems
  243. Research Article
  244. Development of a bending test procedure for the characterization of flexible ECoG electrode arrays
  245. Research Article
  246. Tubular manipulators: a new concept for intracochlear positioning of an auditory prosthesis
  247. Research Article
  248. Investigation of the dynamic diameter deformation of vascular stents during fatigue testing with radial loading
  249. Research Article
  250. Electrospun vascular grafts with anti-kinking properties
  251. Research Article
  252. Integration of temperature sensors in polyimide-based thin-film electrode arrays
  253. Research Article
  254. Use cases and usability challenges for head-mounted displays in healthcare
  255. Research Article
  256. Device- and service profiles for integrated or systems based on open standards
  257. Research Article
  258. Risk management for medical devices in research projects
  259. Research Article
  260. Simulation of varying femoral attachment sites of medial patellofemoral ligament using a musculoskeletal multi-body model
  261. Research Article
  262. Does enhancing consciousness for strategic planning processes support the effectiveness of problem-based learning concepts in biomedical education?
  263. Research Article
  264. SPIO processing in macrophages for MPI: The breast cancer MPI-SNLB-concept
  265. Research Article
  266. Numerical simulations of airflow in the human pharynx of OSAHS patients
https://doi.org/10.1515/cdbme-2015-0038
Keywords for this article
spectral estimation; spectral analysis; surgery; surgical workflow; time series analysis
Creative Commons
BY-NC-ND 3.0

Articles in the same Issue

  1. Research Article
  2. Development and characterization of superparamagnetic coatings
  3. Research Article
  4. The development of an experimental setup to measure acousto-electric interaction signal
  5. Research Article
  6. Stability analysis of ferrofluids
  7. Research Article
  8. Investigation of endothelial growth using a sensors-integrated microfluidic system to simulate physiological barriers
  9. Research Article
  10. Energy harvesting for active implants: powering a ruminal pH-monitoring system
  11. Research Article
  12. New type of fluxgate magnetometer for the heart’s magnetic fields detection
  13. Research Article
  14. Field mapping of ballistic pressure pulse sources
  15. Research Article
  16. Development of a new homecare sleep monitor using body sounds and motion tracking
  17. Research Article
  18. Noise properties of textile, capacitive EEG electrodes
  19. Research Article
  20. Detecting phase singularities and rotor center trajectories based on the Hilbert transform of intraatrial electrograms in an atrial voxel model
  21. Research Article
  22. Spike sorting: the overlapping spikes challenge
  23. Research Article
  24. Separating the effect of respiration from the heart rate variability for cases of constant harmonic breathing
  25. Research Article
  26. Locating regions of arrhythmogenic substrate by analyzing the duration of triggered atrial activities
  27. Research Article
  28. Combining different ECG derived respiration tracking methods to create an optimal reconstruction of the breathing pattern
  29. Research Article
  30. Atrial and ventricular signal averaging electrocardiography in pacemaker and cardiac resynchronization therapy
  31. Research Article
  32. Estimation of a respiratory signal from a single-lead ECG using the 4th order central moments
  33. Research Article
  34. Compressed sensing of multi-lead ECG signals by compressive multiplexing
  35. Research Article
  36. 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
  37. Research Article
  38. Synchronization in wireless biomedical-sensor networks with Bluetooth Low Energy
  39. Research Article
  40. Automated classification of stages of anaesthesia by populations of evolutionary optimized fuzzy rules
  41. Research Article
  42. Effects of sampling rate on automated fatigue recognition in surface EMG signals
  43. Research Article
  44. Closed-loop transcranial alternating current stimulation of slow oscillations
  45. Research Article
  46. Cardiac index in atrio- and interventricular delay optimized cardiac resynchronization therapy and cardiac contractility modulation
  47. Research Article
  48. The role of expert evaluation for microsleep detection
  49. Research Article
  50. The impact of baseline wander removal techniques on the ST segment in simulated ischemic 12-lead ECGs
  51. Research Article
  52. Metal artifact reduction by projection replacements and non-local prior image integration
  53. Research Article
  54. A novel coaxial nozzle for in-process adjustment of electrospun scaffolds’ fiber diameter
  55. Research Article
  56. Processing of membranes for oxygenation using the Bellhouse-effect
  57. Research Article
  58. Inkjet printing of viable human dental follicle stem cells
  59. Research Article
  60. The use of an icebindingprotein out of the snowflea Hypogastrura harveyi as a cryoprotectant in the cryopreservation of mesenchymal stem cells
  61. Research Article
  62. New NIR spectroscopy based method to determine ischemia in vivo in liver – a first study on rats
  63. Research Article
  64. QRS and QT ventricular conduction times and permanent pacemaker therapy after transcatheter aortic valve implantation
  65. Research Article
  66. Adopting oculopressure tonometry as a transient in vivo rabbit glaucoma model
  67. Research Article
  68. Next-generation vision testing: the quick CSF
  69. Research Article
  70. Improving tactile sensation in laparoscopic surgery by overcoming size restrictions
  71. Research Article
  72. Design and control of a 3-DOF hydraulic driven surgical instrument
  73. Research Article
  74. Evaluation of endourological tools to improve the diagnosis and therapy of ureteral tumors – from model development to clinical application
  75. Research Article
  76. Frequency based assessment of surgical activities
  77. Research Article
  78. “Hands free for intervention”, a new approach for transoral endoscopic surgery
  79. Research Article
  80. Pseudo-haptic feedback in medical teleoperation
  81. Research Article
  82. Feasibility of interactive gesture control of a robotic microscope
  83. Research Article
  84. Towards structuring contextual information for workflow-driven surgical assistance functionalities
  85. Research Article
  86. Towards a framework for standardized semantic workflow modeling and management in the surgical domain
  87. Research Article
  88. Closed-loop approach for situation awareness of medical devices and operating room infrastructure
  89. Research Article
  90. Kinect based physiotherapy system for home use
  91. Research Article
  92. Evaluating the microsoft kinect skeleton joint tracking as a tool for home-based physiotherapy
  93. Research Article
  94. Integrating multimodal information for intraoperative assistance in neurosurgery
  95. Research Article
  96. Respiratory motion tracking using Microsoft’s Kinect v2 camera
  97. Research Article
  98. Using smart glasses for ultrasound diagnostics
  99. Research Article
  100. Measurement of needle susceptibility artifacts in magnetic resonance images
  101. Research Article
  102. Dimensionality reduction of medical image descriptors for multimodal image registration
  103. Research Article
  104. Experimental evaluation of different weighting schemes in magnetic particle imaging reconstruction
  105. Research Article
  106. Evaluation of CT capability for the detection of thin bone structures
  107. Research Article
  108. Towards contactless optical coherence elastography with acoustic tissue excitation
  109. Research Article
  110. Development and implementation of algorithms for automatic and robust measurement of the 2D:4D digit ratio using image data
  111. Research Article
  112. Automated high-throughput analysis of B cell spreading on immobilized antibodies with whole slide imaging
  113. Research Article
  114. Tissue segmentation from head MRI: a ground truth validation for feature-enhanced tracking
  115. Research Article
  116. Video tracking of swimming rodents on a reflective water surface
  117. Research Article
  118. MR imaging of model drug distribution in simulated vitreous
  119. Research Article
  120. Studying the extracellular contribution to the double wave vector diffusion-weighted signal
  121. Research Article
  122. Artifacts in field free line magnetic particle imaging in the presence of inhomogeneous and nonlinear magnetic fields
  123. Research Article
  124. Introducing a frequency-tunable magnetic particle spectrometer
  125. Research Article
  126. Imaging of aortic valve dynamics in 4D OCT
  127. Research Article
  128. Intravascular optical coherence tomography (OCT) as an additional tool for the assessment of stent structures
  129. Research Article
  130. Simple concept for a wide-field lensless digital holographic microscope using a laser diode
  131. Research Article
  132. Intraoperative identification of somato-sensory brain areas using optical imaging and standard RGB camera equipment – a feasibility study
  133. Research Article
  134. Respiratory surface motion measurement by Microsoft Kinect
  135. Research Article
  136. Improving image quality in EIT imaging by measurement of thorax excursion
  137. Research Article
  138. A clustering based dual model framework for EIT imaging: first experimental results
  139. Research Article
  140. Three-dimensional anisotropic regularization for limited angle tomography
  141. Research Article
  142. GPU-based real-time generation of large ultrasound volumes from freehand 3D sweeps
  143. Research Article
  144. Experimental computer tomograph
  145. Research Article
  146. US-tracked steered FUS in a respiratory ex vivo ovine liver phantom
  147. Research Article
  148. Contribution of brownian rotation and particle assembly polarisation to the particle response in magnetic particle spectrometry
  149. Research Article
  150. Preliminary investigations of magnetic modulated nanoparticles for microwave breast cancer detection
  151. Research Article
  152. Construction of a device for magnetic separation of superparamagnetic iron oxide nanoparticles
  153. Research Article
  154. An IHE-conform telecooperation platform supporting the treatment of dementia patients
  155. Research Article
  156. Automated respiratory therapy system based on the ARDSNet protocol with systemic perfusion control
  157. Research Article
  158. Identification of surgical instruments using UHF-RFID technology
  159. Research Article
  160. A generic concept for the development of model-guided clinical decision support systems
  161. Research Article
  162. Evaluation of local alterations in femoral bone mineral density measured via quantitative CT
  163. Research Article
  164. Creating 3D gelatin phantoms for experimental evaluation in biomedicine
  165. Research Article
  166. Influence of short-term fixation with mixed formalin or ethanol solution on the mechanical properties of human cortical bone
  167. Research Article
  168. Analysis of the release kinetics of surface-bound proteins via laser-induced fluorescence
  169. Research Article
  170. Tomographic particle image velocimetry of a water-jet for low volume harvesting of fat tissue for regenerative medicine
  171. Research Article
  172. Wireless medical sensors – context, robustness and safety
  173. Research Article
  174. Sequences for real-time magnetic particle imaging
  175. Research Article
  176. Speckle-based off-axis holographic detection for non-contact photoacoustic tomography
  177. Research Article
  178. A machine learning approach for planning valve-sparing aortic root reconstruction
  179. Research Article
  180. An in-ear pulse wave velocity measurement system using heart sounds as time reference
  181. Research Article
  182. Measuring different oxygenation levels in a blood perfusion model simulating the human head using NIRS
  183. Research Article
  184. Multisegmental fusion of the lumbar spine a curse or a blessing?
  185. Research Article
  186. Numerical analysis of the biomechanical complications accompanying the total hip replacement with NANOS-Prosthetic: bone remodelling and prosthesis migration
  187. Research Article
  188. A muscle model for hybrid muscle activation
  189. Research Article
  190. Mathematical, numerical and in-vitro investigation of cooling performance of an intra-carotid catheter for selective brain hypothermia
  191. Research Article
  192. An ideally parameterized unscented Kalman filter for the inverse problem of electrocardiography
  193. Research Article
  194. Interactive visualization of cardiac anatomy and atrial excitation for medical diagnosis and research
  195. Research Article
  196. Virtualizing clinical cases of atrial flutter in a fast marching simulation including conduction velocity and ablation scars
  197. Research Article
  198. Mesh structure-independent modeling of patient-specific atrial fiber orientation
  199. Research Article
  200. Accelerating mono-domain cardiac electrophysiology simulations using OpenCL
  201. Research Article
  202. Understanding the cellular mode of action of vernakalant using a computational model: answers and new questions
  203. Research Article
  204. A java based simulator with user interface to simulate ventilated patients
  205. Research Article
  206. Evaluation of an algorithm to choose between competing models of respiratory mechanics
  207. Research Article
  208. Numerical simulation of low-pulsation gerotor pumps for use in the pharmaceutical industry and in biomedicine
  209. Research Article
  210. Numerical and experimental flow analysis in centifluidic systems for rapid allergy screening tests
  211. Research Article
  212. Biomechanical parameter determination of scaffold-free cartilage constructs (SFCCs) with the hyperelastic material models Yeoh, Ogden and Demiray
  213. Research Article
  214. FPGA controlled artificial vascular system
  215. Research Article
  216. Simulation based investigation of source-detector configurations for non-invasive fetal pulse oximetry
  217. Research Article
  218. Test setup for characterizing the efficacy of embolic protection devices
  219. Research Article
  220. Impact of electrode geometry on force generation during functional electrical stimulation
  221. Research Article
  222. 3D-based visual physical activity assessment of children
  223. Research Article
  224. Realtime assessment of foot orientation by Accelerometers and Gyroscopes
  225. Research Article
  226. Image based reconstruction for cystoscopy
  227. Research Article
  228. Image guided surgery innovation with graduate students - a new lecture format
  229. Research Article
  230. Multichannel FES parameterization for controlling foot motion in paretic gait
  231. Research Article
  232. Smartphone supported upper limb prosthesis
  233. Research Article
  234. Use of quantitative tremor evaluation to enhance target selection during deep brain stimulation surgery for essential tremor
  235. Research Article
  236. Evaluation of adhesion promoters for Parylene C on gold metallization
  237. Research Article
  238. The influence of metallic ions from CoCr28Mo6 on the osteogenic differentiation and cytokine release of human osteoblasts
  239. Research Article
  240. Increasing the visibility of thin NITINOL vascular implants
  241. Research Article
  242. Possible reasons for early artificial bone failure in biomechanical tests of ankle arthrodesis systems
  243. Research Article
  244. Development of a bending test procedure for the characterization of flexible ECoG electrode arrays
  245. Research Article
  246. Tubular manipulators: a new concept for intracochlear positioning of an auditory prosthesis
  247. Research Article
  248. Investigation of the dynamic diameter deformation of vascular stents during fatigue testing with radial loading
  249. Research Article
  250. Electrospun vascular grafts with anti-kinking properties
  251. Research Article
  252. Integration of temperature sensors in polyimide-based thin-film electrode arrays
  253. Research Article
  254. Use cases and usability challenges for head-mounted displays in healthcare
  255. Research Article
  256. Device- and service profiles for integrated or systems based on open standards
  257. Research Article
  258. Risk management for medical devices in research projects
  259. Research Article
  260. Simulation of varying femoral attachment sites of medial patellofemoral ligament using a musculoskeletal multi-body model
  261. Research Article
  262. Does enhancing consciousness for strategic planning processes support the effectiveness of problem-based learning concepts in biomedical education?
  263. Research Article
  264. SPIO processing in macrophages for MPI: The breast cancer MPI-SNLB-concept
  265. Research Article
  266. Numerical simulations of airflow in the human pharynx of OSAHS patients
Sign up now to receive a 20% welcome discount
Institutional Access
How does access work?
Have an idea on how to improve our website?
Please write us.
© 2025 De Gruyter Brill
Downloaded on 7.9.2025 from https://www.degruyterbrill.com/document/doi/10.1515/cdbme-2015-0038/html
Scroll to top button