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| 2. |
- Black, David, et al.
(författare)
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Auditory display for Fluorescence-guided open brain tumor surgery
- 2018
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Ingår i: International Journal of Computer Assisted Radiology and Surgery. - : Elsevier. - 1861-6410 .- 1861-6429. ; 13:1, s. 25-35
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE:Protoporphyrin (PpIX) fluorescence allows discrimination of tumor and normal brain tissue during neurosurgery. A handheld fluorescence (HHF) probe can be used for spectroscopic measurement of 5-ALA-induced PpIX to enable objective detection compared to visual evaluation of fluorescence. However, current technology requires that the surgeon either views the measured values on a screen or employs an assistant to verbally relay the values. An auditory feedback system was developed and evaluated for communicating measured fluorescence intensity values directly to the surgeon.METHODS:The auditory display was programmed to map the values measured by the HHF probe to the playback of tones that represented three fluorescence intensity ranges and one error signal. Ten persons with no previous knowledge of the application took part in a laboratory evaluation. After a brief training period, participants performed measurements on a tray of 96 wells of liquid fluorescence phantom and verbally stated the perceived measurement values for each well. The latency and accuracy of the participants' verbal responses were recorded. The long-term memorization of sound function was evaluated in a second set of 10 participants 2-3 and 7-12 days after training.RESULTS:The participants identified the played tone accurately for 98% of measurements after training. The median response time to verbally identify the played tones was 2 pulses. No correlation was found between the latency and accuracy of the responses, and no significant correlation with the musical proficiency of the participants was observed on the function responses. Responses for the memory test were 100% accurate.CONCLUSION:The employed auditory display was shown to be intuitive, easy to learn and remember, fast to recognize, and accurate in providing users with measurements of fluorescence intensity or error signal. The results of this work establish a basis for implementing and further evaluating auditory displays in clinical scenarios involving fluorescence guidance and other areas for which categorized auditory display could be useful.
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| 3. |
- Haj-Hosseini, Neda, 1980-, et al.
(författare)
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5-ALA fluorescence and laser Doppler flowmetry for guidance in a stereotactic brain tumor biopsy
- 2018
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Ingår i: Biomedical Optics Express. - : Optical Society of America. - 2156-7085. ; 9:5, s. 2284-2296
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Tidskriftsartikel (refereegranskat)abstract
- A fiber optic probe was developed for guidance during stereotactic brain biopsy procedures to target tumor tissue and reduce the risk of hemorrhage. The probe was connected to a setup for the measurement of 5-aminolevulinic acid (5-ALA) induced fluorescence and microvascular blood flow. Along three stereotactic trajectories, fluorescence (n = 109) and laser Doppler flowmetry (LDF) (n = 144) measurements were done in millimeter increments. The recorded signals were compared to histopathology and radiology images. The median ratio of protoporphyrin IX (PpIX) fluorescence and autofluorescence (AF) in the tumor was considerably higher than the marginal zone (17.3 vs 0.9). The blood flow showed two high spots (3%) in total. The proposed setup allows simultaneous and real-time detection of tumor tissue and microvascular blood flow for tracking the vessels.
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| 4. |
- Haj-Hosseini, Neda, 1980-, et al.
(författare)
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Blood interference in fiber-optical based fluorescence guided resection of glioma using 5-aminolevulinic acid
- 2011
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Ingår i: Photonic Therapeutics and Diagnostics VII. - : SPIE - International Society for Optical Engineering. - 9780819484208 ; , s. 78833R-1-78833R-10
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Konferensbidrag (refereegranskat)abstract
- Fluorescence guidance in brain tumor resection is performed intra-operatively where bleeding is included. When using fiber-optical probes, the transmission of light to and from the tissue is totally or partially blocked if a small amount of blood appears in front of the probe. Sometimes even after rinsing with saline, the remnant blood cells on the optical probe head, disturb the measurements. In such a case, the corresponding spectrum cannot be reliably quantified and is therefore discarded. The optimal case would be to calculate and take out the blood effect systematically from the collected signals. However, the first step is to study the pattern of blood interference in the fluorescence spectrum. In this study, a fiber-optical based fluorescence spectroscopy system with a laser excitation light of 405 nm (1.4 J/cm2) was used during fluorescence guided brain tumor resection using 5-aminolevulinic acid (5-ALA). The blood interference pattern in the fluorescence spectrum collected from the brain was studied in two patients. The operation situation was modeled in the laboratory by placing blood drops from the finger tip on the skin of forearm and the data was compared to the brain in vivo measurements. Additionally, a theoretical model was developed to simulate the blood interference pattern on the skin autofluorescence. The blood affects the collected fluorescence intensity and leaves traces of oxy and deoxy-hemoglobin absorption peaks. According to the developed theoretical model, the autofluorescence signal is considered to be totally blocked by an approximately 500 μm thick blood layer.
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| 5. |
- Haj-Hosseini, Neda, 1980-, et al.
(författare)
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Early Detection of Oral Potentially Malignant Disorders: A Review on Prospective Screening Methods with Regard to Global Challenges
- 2024
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Ingår i: Journal of Maxillofacial & Oral Surgery. - New Delhi, India : Springer Science and Business Media LLC. - 0972-8279 .- 0974-942X. ; 23:1, s. 23-32
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Tidskriftsartikel (refereegranskat)abstract
- Oral cancer is a cancer type that is widely prevalent in low-and middle-income countries with a high mortality rate, and poor quality of life for patients after treatment. Early treatment of cancer increases patient survival, improves quality of life and results in less morbidity and a better prognosis. To reach this goal, early detection of malignancies using technologies that can be used in remote and low resource areas is desirable. Such technologies should be affordable, accurate, and easy to use and interpret. This review surveys different technologies that have the potentials of implementation in primary health and general dental practice, considering global perspectives and with a focus on the population in India, where oral cancer is highly prevalent. The technologies reviewed include both sample-based methods, such as saliva and blood analysis and brush biopsy, and more direct screening of the oral cavity including fluorescence, Raman techniques, and optical coherence tomography. Digitalisation, followed by automated artificial intelligence based analysis, are key elements in facilitating wide access to these technologies, to non-specialist personnel and in rural areas, increasing quality and objectivity of the analysis while simultaneously reducing the labour and need for highly trained specialists.
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| 6. |
- Haj-Hosseini, Neda, 1980-, et al.
(författare)
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Evaluation of a Fiber-Optic Based Pulsed Laser System for Fluorescence Spectroscopy
- 2008
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Ingår i: 14TH NORDIC-BALTIC CONFERENCE ON BIOMEDICAL ENGINEERING AND MEDICAL PHYSICS. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 1680-0737. - 9783540693666 ; 20, s. 363-366
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Konferensbidrag (refereegranskat)abstract
- A fiber optic based continous wave laser setup has been developed to record the 5-aminolevulinic (5-ALA) induced Protoporfyrin IX (PpIX) fluorescence signals from cerebral gliomas. To reduce the energy delivered to the tissue as well as suppression of the ambient lamp artifact from the recorded spectra, a pulsed laser setup has been developed and evaluated. This setup has been calibrated and first evaluations were performed on the 5-ALA treated skin showing PpIX fluorescence peaks from the ALA treated skin at 635 and 704 nm wavelengths. The system controls laser pulses through a computer interface and labview software package. Pulses as short as 50 ms over a period time of 500 ms are generated and optimally detected. The results from primary measurements on skin show an effective suppression of room fluorescent lamp artifact from the recorded spectra.
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| 9. |
- Haj-Hosseini, Neda, 1980-
(författare)
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Fluorescence Spectroscopy for Quantitative Demarcation of Glioblastoma Using 5-Aminolevulinic Acid
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Total resection of glioblastoma, the highly malignant brain tumor, is difficult to accomplish due to its diffuse growth and similarity to the surrounding brain tissue. A total resection is proven to increase patient survival. The aim of this thesis was to evaluate fiber-optical based fluorescence spectroscopy for quantitative demarcation of malignant brain tumors during the surgery. Five-aminolevulinic acid (5-ALA) was used as a fluorescence contrast agent that accumulated as protoporphyrin IX (PpIX) in the tumor.The method was evaluated at the Department of Neurosurgery, Linköping University Hospital. The patients (n = 22) received an oral dose of 5 mg/kg body weight 5-ALA two hours prior to craniotomy. Measurements with a developed fluorescence spectroscopy system were performed under the general procedure of surgery. The collected fluorescence spectra were quantified by defining a fluorescence ratio and the main challenges of measuring and quantifying spectra were investigated. The fluorescence ratio was compared to visual diagnosis of the surgeon, histopathological examination and ultrasound-based neuronavigation. The main challenges of using a fluorescence spectroscopy system in the operating room were the disturbing ambient light, photobleaching and blood interference which affect the signal quantification. The superimposition of ambient light was removed by modulating the system.Using principal component analysis (PCA) the photobleaching sequences could be described by three spectral components of autofluorescence, PpIX fluorescence and blue-shift. To investigate the photobleaching induced prior to the measurements, a dynamic model was developed based on the PCA derived spectral components. Modulation and increased power of the excitation light resulted in a faster photobleaching; however, photobleaching was saturated at higher excitation powers. The system was adjusted to induce minimal photobleaching. In addition, effect of blood absorption on the fluorescence spectrum was investigated experimentally by placing blood drops on skin and theoretically by using Beer-Lambert law. The theoretical model was used to compensate for the distorted fluorescence ratio. According to the theoretical model of blood interference, a total 300 µm blood layer blocked the brain fluorescence signal totally and when the fluorescence signal was partially blocked, the fluorescence ratio was overestimated. The fluorescence ratio was corrected for blood layers thinner than 50 µm.The tissue in and around the tumor was categorized into necrosis, low and high grade tumor and gliosis. The median fluorescence ratio confirmed with histopathological examination (n = 45) had a lower fluorescence ratio for low grade malignancies (0.3) than high grade malignancies (2.4) (p < 0.05). Gliosis (1.6) and necrosis (1.0) showed a moderate fluorescence ratio. Ultrasound-based navigation in combination with fluorescence spectroscopy showed improvement in the results; however, a more extensive study is needed to confirm benefits of the method combination. In conclusion, fluorescence spectroscopy of 5-ALA induced PpIX provided an objective method for differentiating tumor from the healthy tissue intra-operatively. Fluorescence ratios were indicative of tissue type and tumor malignancy degree.
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| 10. |
- Haj-Hosseini, Neda, 1980-, et al.
(författare)
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Interactive remote electrical safety laboratory module in biomedical engineering education
- 2024
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Ingår i: Education and Information Technologies. - : Springer. - 1360-2357 .- 1573-7608.
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Tidskriftsartikel (refereegranskat)abstract
- To enable interactive remote education on electrical safety in biomedical engineering, a real-life problem-based laboratory module is proposed, implemented and evaluated. The laboratory module was implemented in a freestanding distance course in hospital safety for three consecutive years and was based on electrical safety for medical devices, where standard equipment existing in most hospitals could be used. The course participants were from a total of 42 geographical locations in or near Sweden. To allow a high level of interaction, especially among peer students, a graphical digital platform (Gather Town) was used. The digital platform was additionally used in two group work sessions. The experience of the participants in terms of usefulness and satisfaction was rated on a range of [-2, 2] using a van der Laan 5-point Likert-based acceptance scale questionnaire. The laboratory module overall was scored 4.1/5 by the participants (n= 29) in the final course assessments. The evaluation of the digital platform alone showed that in the first usage instance, the participants (n=21) found the platform to be useful (0.54±0.67) and satisfactory (0.37±0.60). The participants’ experience of the digital platform improved when comparing two identical group work assignments so that ratings of usefulness and satisfaction were 1.11±0.59 and 1±0.71, respectively, after they had used it in the second group work session (n=38). This study provides an instance of an interactive remote electrical safety laboratory module that is envisioned to contribute to further implementations of sustainable education in biomedical engineering.
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