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1.
Am J Occup Ther ; 78(2)2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38478583

RESUMO

IMPORTANCE: Children with unilateral cerebral palsy (UCP) have poor strength and movement control on one side of their body, leading to impaired bimanual coordination skills. OBJECTIVE: To compare duration and intensity of all-day habitual movement of the dominant and nondominant upper extremities (UEs) in typically developing (TD) children and children with UCP. DESIGN: Two-group observational study. SETTING: Children's naturalistic settings. PARTICIPANTS: Convenience sample of 9 TD children and 9 children with UCP. INTERVENTION: Children wore accelerometers on both wrists all day and night for 1 wk. OUTCOMES AND MEASURES: We compared the extent of asymmetry in bilateral arm use (intensity and duration) between the 2 groups. RESULTS: Compared with TD children who use both UEs equally, children with UCP were more likely to use their dominant or unaffected UE than their nondominant or affected UE during daily activities. There were no differences between groups in dominant UE activity. However, children with UCP engaged in lower levels of moderate to vigorous activity and greater levels of light activity with their nondominant or affected UE than their TD peers. CONCLUSIONS AND RELEVANCE: Wrist-worn accelerometry can provide objective information on real-world habitual activity with both arms in children. Accelerometers are nonintrusive, easy to use, and well tolerated by children, and they allow prolonged monitoring of UE activity outside therapeutic contexts. Occupational therapists can use wrist-worn accelerometers as sensitive tools to assess asymmetries in UE use at baseline and as an outcome measure to assess the efficacy of behavioral interventions and carryover into real-world settings among children with UCP. Plain-Language Summary: This pilot study provides promising evidence that supports the use of wrist-worn accelerometry as an accurate, easy-to-use, and objective assessment tool for children with unilateral cerebral palsy (UCP) to detect asymmetries in bilateral real-world arm activity at baseline and after intensive occupational therapy interventions to improve arm function. The authors used wrist-worn accelerometry for one week with 9 typically developing (TD) children and 9 children with UCP to compare dominant or unaffected versus nondominant or affected upper extremity (UE) use for intensity and duration of activity. Compared with TD children, children with UCP had lower relative intensity of activity in the nondominant UE than the dominant UE. Wrist-worn accelerometers seem to be a sensitive measure to detect asymmetries in bilateral all-day UE use in children with UCP. The findings have implications for the use of wrist-worn accelerometers as an outcome measure to assess the efficacy of intensive therapies to improve real-world affected UE activity and bimanual function among children with UCP.


Assuntos
Paralisia Cerebral , Punho , Criança , Humanos , Projetos Piloto , Extremidade Superior , Acelerometria
2.
Am J Occup Ther ; 78(4)2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38836619

RESUMO

IMPORTANCE: Children with hemiplegic cerebral palsy (HCP) require intensive task-oriented training to make meaningful gains in affected upper extremity (UE) motor function. OBJECTIVE: To evaluate the acceptability and utility of single joystick-operated ride-on toy (ROT) navigation training incorporated into a modified constraint-induced movement therapy (CIMT) camp for children with HCP. DESIGN: Single group pretest-posttest design. SETTING: Three-wk structured CIMT camp. PARTICIPANTS: Eleven children with HCP between ages 3 and 14 yr. INTERVENTION: Children received group-based CIMT for 6 hr/day, 5 days/wk, for 3 wk. As part of camp activities, children also received ROT navigation training for 20 to 30 min/day, 5 days/wk, for 3 wk. OUTCOMES AND MEASURES: We assessed children's acceptance of ROT training by monitoring adherence and evaluating child engagement (affect and attention) during training sessions. The effects of ROT training combined with other camp activities on children's affected UE motor function were also assessed with the standardized Quality of Upper Extremity Skills Test (QUEST) and training-specific measures of ROT maneuvering accuracy. RESULTS: Children demonstrated high levels of training adherence, positive affect, and task-appropriate attention across weeks. Positive engagement during ROT sessions was correlated with independent navigation. We also found medium- to large-sized improvements in QUEST scores and toy-maneuvering capabilities after the combined program. CONCLUSIONS AND RELEVANCE: Our pilot data support the use of joystick-operated ROTs as child-friendly therapy adjuncts that can be incorporated into intensive UE training programs to improve adherence and motivation in therapy programs, boost treatment dosing, and promote affected UE motor function in children with HCP. Plain-Language Summary: This pilot study offers promising evidence that supports the use of modified single joystick-operated ride-on toys (ROTs) for children with hemiplegic cerebral palsy (HCP). The study used ROTs as one of several interventions that were part of a constraint-induced movement therapy (CIMT) camp program for children with HCP. The ROTs boosted children's motivation, their engagement with and adherence to training, and their practice in using their affected upper extremity (UE) for goal-directed activities in their natural settings. ROTs are accessible, age-appropriate, and easy-to-use devices for both occupational therapy clinicians and families to encourage children to use their affected UEs by challenging their perceptual, motor-planning, problem-solving, and movement-control skills in an enjoyable and engaging way. ROTs can be used within and outside conventional rehabilitation settings.


Assuntos
Paralisia Cerebral , Hemiplegia , Terapia Ocupacional , Humanos , Paralisia Cerebral/reabilitação , Criança , Projetos Piloto , Pré-Escolar , Masculino , Feminino , Adolescente , Hemiplegia/reabilitação , Terapia Ocupacional/métodos , Jogos e Brinquedos , Extremidade Superior/fisiopatologia
3.
Phys Occup Ther Pediatr ; : 1-21, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38863174

RESUMO

AIM: Our study investigates the feasibility and utility of implementing a dual joystick-operated ride-on-toy navigation training (RNT) program within a 3-week intensive camp based on principles of modified constraint-induced movement therapy and bimanual training, to improve upper extremity (UE) function in children with unilateral cerebral palsy (UCP). METHODS: We employed a single-group pretest posttest, mixed methods study design. Eleven 4-to-10-year-old children with UCP received RNT as part of camp activities. Sessions required children to use both arms together for navigation and completing gross and fine motor UE challenges. We collected exit questionnaires from children, caregivers, and clinicians to assess the feasibility, acceptance, enjoyment, and perceived efficacy of RNT. Videos of training sessions were coded using Datavyu behavioral coding software to assess children's facial expressions and affective states, indicative of their level of engagement during intervention sessions. RESULTS: We found high levels of child engagement during RNT sessions based on video data and stakeholder feedback. The RNT program was smoothly integrated into the camp. Stakeholders acknowledged the highly motivating nature of RNT. When combined with other camp activities, the program led to stakeholder-reported improvements in bimanual skills and spontaneous daily use of the affected UE. CONCLUSIONS: Our pilot study provides promising evidence for using joystick-operated ride-on toys as engaging therapy adjuncts. Our findings call for future studies to systematically assess the efficacy of these devices in improving UE function among children with UCP.

4.
Pediatr Phys Ther ; 34(4): 508-517, 2022 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-36044637

RESUMO

PURPOSE: To evaluate the feasibility of implementation, acceptance, and perceived efficacy of a joystick-operated ride-on-toy intervention to promote upper extremity (UE) function in 3- to 14-year-old children with hemiplegic cerebral palsy. METHODS: Exit questionnaires were collected from children, caregivers, and clinicians/camp staff following a 3-week ride-on-toy training program incorporated within a summer camp for children with hemiplegic cerebral palsy. Training encouraged children to use their affected UE to maneuver the ride-on-toy. Questionnaires included Likert scale and open-ended questions to assess enjoyment, acceptance, feasibility, and perceived efficacy of the training. RESULTS: All stakeholder groups indicated that the training was enjoyable. Clinicians/staff and caregivers indicated that the training increased children's motivation to use their affected UE and reported perceived improvements in UE movement control and function following training. CONCLUSIONS: Our promising preliminary findings call for future research to systematically assess the efficacy of ride-on-toys to promote UE control and function in children with hemiplegic cerebral palsy.Supplemental Digital Content 1 video abstract, available at: http://links.lww.com/PPT/A404.


Assuntos
Paralisia Cerebral , Adolescente , Paralisia Cerebral/reabilitação , Criança , Pré-Escolar , Estudos de Viabilidade , Hemiplegia/reabilitação , Humanos , Projetos Piloto , Resultado do Tratamento , Extremidade Superior
5.
Bioengineering (Basel) ; 11(4)2024 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-38671726

RESUMO

The pilot study assessed the utility of a training program using modified, commercially available dual-joystick-operated ride-on toys to promote unimanual and bimanual upper extremity (UE) function in children with cerebral palsy (CP). The ride-on-toy training was integrated within a 3-week, intensive, task-oriented training camp for children with CP. Eleven children with hemiplegia between 4 and 10 years received the ride-on-toy training program 20-30 min/day, 5 days/week for 3 weeks. Unimanual motor function was assessed using the Quality of Upper Extremity Skills Test (QUEST) before and after the camp. During ride-on-toy training sessions, children wore activity monitors on both wrists to assess the duration and intensity of bimanual UE activity. Video data from early and late sessions were coded for bimanual UE use, independent navigation, and movement bouts. Children improved their total and subscale QUEST scores from pretest to post-test while increasing moderate activity in their affected UE from early to late sessions, demonstrating more equal use of both UEs across sessions. There were no significant changes in the rates of movement bouts from early to late sessions. We can conclude that joystick-operated ride-on toys function as child-friendly, intrinsically rewarding tools that can complement conventional therapy and promote bimanual motor functions in children with CP.

6.
Children (Basel) ; 11(4)2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38671624

RESUMO

Children with unilateral cerebral palsy (UCP) require task-oriented practice several hours per week to produce meaningful gains in affected upper extremity (UE) motor function. Clinicians find it challenging to provide services at the required intensity and sustain child engagement. This pilot study assessed the acceptance and utility of a child-friendly program using dual-joystick-operated ride-on toys incorporated into an intensive UE rehabilitation camp. Eleven children with UCP between four and 10 years received ride-on-toy navigation training for 20-30 min/day, five days/week, for three weeks as part of camp programming. We report session adherence and percent time children spent in task-appropriate attention/engagement across sessions. The overall effects of camp programming on children's motor function were assessed using the Shriner's Hospital Upper Extremity Evaluation (SHUEE) from pretest to posttest and using training-specific measures of bimanual UE use and navigational accuracy. Children showed excellent adherence and sustained task-appropriate engagement across sessions. The combined program led to improved navigational accuracy (p-values ≤ 0.007) as well as spontaneous affected UE use during bimanual activities outside the training context (p < 0.001). Our pilot study provides promising evidence for using modified, commercially available ride-on toys to incentivize rehabilitation and boost repetitive, task-oriented UE practice among children with UCP.

7.
Behav Sci (Basel) ; 13(5)2023 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-37232651

RESUMO

Our research aims to evaluate the utility of joystick-operated ride-on-toys (ROTs) as therapeutic adjuncts to improve upper extremity (UE) function in children with hemiplegic cerebral palsy (HCP). This study assessed changes in affected UE use and function following a three-week ROT navigation training incorporated into an existing constraint-induced movement therapy (CIMT) camp in 11 children (3-14 years old) with HCP. We report changes in scores on the standardized Shriners Hospital Upper Extremity Evaluation (SHUEE) from pretest-to-posttest and changes from early-to-late sessions in percent time spent by the affected arm in: (a) "moderate-to-vigorous activity", "light activity" and "no activity" bouts based on accelerometer data and (b) "independent", "assisted", and "no activity" bouts based on video data. We also explored relationships between standardized measures and training-specific measures of affected UE activity. We found small-to-medium improvements in the SHUEE scores. Between 90 and 100% of children also showed medium-to-large improvements in affected UE activity from early-to-late sessions using accelerometers and small improvements via video-based assessments. Exploratory analyses suggested trends for relationships between pretest-posttest and training-specific objective and subjective measures of arm use and function. Our pilot data suggest that single joystick-operated ROTs may serve as motivating, child-friendly tools that can augment conventional therapies such as CIMT to boost treatment dosing, promote affected UE movement practice during real-world navigation tasks, and ultimately improve functional outcomes in children with HCP.

8.
BMJ Open ; 13(5): e071742, 2023 05 09.
Artigo em Inglês | MEDLINE | ID: mdl-37160396

RESUMO

INTRODUCTION: Children with unilateral cerebral palsy (UCP) face significant limitations in upper extremity (UE) function and require effective interventions that promote intensive goal-directed practice while maximising motivation and adherence with therapy. This study builds on our past work and will assess the effects of a 6-week researcher-caregiver codelivered, home-based ride-on-toy navigation training (RNT) programme in young children with UCP. We hypothesise that the RNT programme will be acceptable, feasible to implement, and lead to greater improvements in unimanual and bimanual function when combined with conventional therapy, compared with conventional therapy provided alone. METHODS AND ANALYSIS: 15 children with UCP between 3 and 8 years will be recruited. During the 6-week control phase, participants will receive treatement-as-usual alone. During the subsequent 6-week intervention phase, in addition to conventional therapy, RNT will be provided 4-5 times/week (2 times by researchers, 2-3 times by caregivers), 30-45 min/session. We will assess UE function using standardised tests (Quality of Upper Extremity Skills Test and Shriner's Hospital Upper Extremity Evaluation), reaching kinematics, wrist-worn accelerometry, caregiver-rated ABILHAND-Kids questionnaire, and training-specific measures of movement control during RNT. Programme feasibility and acceptance will be assessed using device use metrics, child and caregiver exit questionnaires, training-specific measures of child engagement, and the Physical Activity Enjoyment Scale. All assessments will be conducted at pretest, following the control phase (midpoint), and after completion of the intervention phase (post-test). ETHICS AND DISSEMINATION: The study is approved by the Institutional Review Board of the University of Connecticut (# H22-0059). Results from this study will be disseminated through peer-reviewed manuscripts in scientific journals in the field, through national and international conferences, and through presentations to parent advocacy groups and other support organisations associated with CP. TRIAL REGISTRATION NUMBER: NCT05559320.


Assuntos
Paralisia Cerebral , Criança , Humanos , Pré-Escolar , Paralisia Cerebral/terapia , Extremidade Superior , Punho , Acelerometria , Benchmarking
9.
Opt Lett ; 36(13): 2501-3, 2011 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-21725458

RESUMO

A fast, simple, and low-cost optical time-gating scheme for counting single photons is presented. Its construction consists of a silicon photodiode connected in series with a 50 Ω resistor and that operates in the photoconductive mode. The temporal resolution at the FWHM of the photon counting system was measured to be 62 ps. The profile of a single-photon pulse measured with the counting system agreed well with analytical results. The system was also used to successfully resolve a pair of targets with 4 mm separation inside a highly scattering medium by the use of time-gated early-arriving photons.


Assuntos
Condutividade Elétrica , Luz , Fótons , Espalhamento de Radiação , Fatores de Tempo
10.
Photoacoustics ; 9: 1-9, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29201646

RESUMO

The development of low-cost and fast photoacoustic microscopy systems enhances the clinical applicability of photoacoustic imaging systems. To this end, we present a laser scanning laser diode-based photoacoustic microscopy system. In this system, a 905 nm, 325 W maximum output peak power pulsed laser diode with 50 ns pulsewidth is utilized as the light source. A combination of aspheric and cylindrical lenses is used for collimation of the laser diode beam. Two galvanometer scanning mirrors steer the beam across a focusing aspheric lens. The lateral resolution of the system was measured to be ∼21 µm using edge spread function estimation. No averaging was performed during data acquisition. The imaging speed is ∼370 A-lines per second. Photoacoustic microscopy images of human hairs, ex vivo mouse ear, and ex vivo porcine ovary are presented to demonstrate the feasibility and potentials of the proposed system.

11.
Biomed Opt Express ; 9(11): 5503-5510, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-30460143

RESUMO

We present a low-cost, compact, and multispectral spatial frequency domain imaging prototype. Illumination components, including 9 LEDs (660 nm - 950 nm) placed on a custom-designed printed circuit board, linear and rotational motors, a printed sinusoidal pattern, and collimation and projection optics as well as the detection components are incorporated in a compact custom-designed 3D-printed probe. Reconstruction of absorption and reduced scattering coefficients is evaluated via imaging tissue mimicking phantoms and potentials of the probe for biological tissue imaging are evaluated via imaging human ovarian tissue ex vivo.

12.
J Biomed Opt ; 21(10): 101402, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26822943

RESUMO

A spatial frequency domain imaging (SFDI) system was developed for characterizing ex vivo human ovarian tissue using wide-field absorption and scattering properties and their spatial heterogeneities. Based on the observed differences between absorption and scattering images of different ovarian tissue groups, six parameters were quantitatively extracted. These are the mean absorption and scattering, spatial heterogeneities of both absorption and scattering maps measured by a standard deviation, and a fitting error of a Gaussian model fitted to normalized mean Radon transform of the absorption and scattering maps. A logistic regression model was used for classification of malignant and normal ovarian tissues. A sensitivity of 95%, specificity of 100%, and area under the curve of 0.98 were obtained using six parameters extracted from the SFDI images. The preliminary results demonstrate the diagnostic potential of the SFDI method for quantitative characterization of wide-field optical properties and the spatial distribution heterogeneity of human ovarian tissue. SFDI could be an extremely robust and valuable tool for evaluation of the ovary and detection of neoplastic changes of ovarian cancer.


Assuntos
Diagnóstico por Imagem/métodos , Ovário/química , Ovário/patologia , Diagnóstico por Imagem/instrumentação , Desenho de Equipamento , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Distribuição Normal , Neoplasias Ovarianas/química , Neoplasias Ovarianas/patologia , Imagens de Fantasmas , Espalhamento de Radiação
13.
J Biomed Opt ; 21(4): 46006, 2016 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-27086690

RESUMO

Most ovarian cancers are diagnosed at advanced stages due to the lack of efficacious screening techniques. Photoacoustic tomography (PAT) has a potential to image tumor angiogenesis and detect early neovascular changes of the ovary. We have developed a coregistered PAT and ultrasound (US) prototype system for real-time assessment of ovarian masses. Features extracted from PAT and US angular beams, envelopes, and images were input to a logistic classifier and a support vector machine (SVM) classifier to diagnose ovaries as benign or malignant. A total of 25 excised ovaries of 15 patients were studied and the logistic and SVM classifiers achieved sensitivities of 70.4 and 87.7%, and specificities of 95.6 and 97.9%, respectively. Furthermore, the ovaries of two patients were noninvasively imaged using the PAT/US system before surgical excision. By using five significant features and the logistic classifier, 12 out of 14 images (86% sensitivity) from a malignant ovarian mass and all 17 images (100% specificity) from a benign mass were accurately classified; the SVM correctly classified 10 out of 14 malignant images (71% sensitivity) and all 17 benign images (100% specificity). These initial results demonstrate the clinical potential of the PAT/US technique for ovarian cancer diagnosis.


Assuntos
Interpretação de Imagem Assistida por Computador/métodos , Neoplasias Ovarianas/diagnóstico por imagem , Ovário/diagnóstico por imagem , Técnicas Fotoacústicas/métodos , Ultrassonografia/métodos , Adulto , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Máquina de Vetores de Suporte
14.
J Biomed Opt ; 20(1): 016002, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25554971

RESUMO

A composite set of ovarian tissue features extracted from photoacoustic spectral data, beam envelope, and co-registered ultrasound and photoacoustic images are used to characterize malignant and normal ovaries using logistic and support vector machine (SVM) classifiers. Normalized power spectra were calculated from the Fourier transform of the photoacoustic beamformed data, from which the spectral slopes and 0-MHz intercepts were extracted. Five features were extracted from the beam envelope and another 10 features were extracted from the photoacoustic images. These 17 features were ranked by their p-values from t -tests on which a filter type of feature selection method was used to determine the optimal feature number for final classification. A total of 169 samples from 19 ex vivo ovaries were randomly distributed into training and testing groups. Both classifiers achieved a minimum value of the mean misclassification error when the seven features with lowest p-values were selected. Using these seven features, the logistic and SVM classifiers obtained sensitivities of 96.39 ± 3.35% and 97.82 ± 2.26%, and specificities of 98.92 ± 1.39% and 100%, respectively, for the training group. For the testing group, logistic and SVM classifiers achieved sensitivities of 92.71 ± 3.55% and 92.64 ± 3.27%, and specificities of 87.52 ± 8.78% and 98.49 ± 2.05%, respectively.


Assuntos
Processamento de Imagem Assistida por Computador/métodos , Neoplasias Ovarianas/diagnóstico , Neoplasias Ovarianas/patologia , Ovário/patologia , Técnicas Fotoacústicas/métodos , Feminino , Análise de Fourier , Humanos , Ovário/anatomia & histologia , Máquina de Vetores de Suporte
15.
Photoacoustics ; 3(3): 114-22, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26640774

RESUMO

A hand-held transvaginal probe suitable for co-registered photoacoustic and ultrasound imaging of ovarian tissue was designed and evaluated. The imaging probe consists of an ultrasound transducer and four 1-mm-core multi-mode optical fibers both housed in a custom-made sheath. The probe was optimized for the highest light delivery output and best beam uniformity on tissue surface, by simulating the light fluence and power output for different design parameters. The laser fluence profiles were experimentally measured through chicken breast tissue and calibrated intralipid solution at various imaging depths. Polyethylene tubing filled with rat blood mimicking a blood vessel was successfully imaged up to ∼30 mm depth through porcine vaginal tissue at 750 nm. This imaging depth was achieved with a laser fluence on the tissue surface of 20 mJ/cm(2), which is below the maximum permissible exposure (MPE) of 25 mJ/cm(2) recommended by the American National Standards Institute (ANSI). Furthermore, the probe imaging capability was verified with ex vivo imaging of benign and malignant human ovaries. The co-registered images clearly showed different vasculature distributions on the surface of the benign cyst and the malignant ovary. These results suggest that our imaging system has the clinical potential for in vivo imaging and characterization of ovarian tissues.

16.
Biomed Opt Express ; 5(9): 3053-8, 2014 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-25401019

RESUMO

Photoacoustic microscopy (PAM) is capable of mapping microvasculature networks in biological tissue and has demonstrated great potential for biomedical applications. However, the clinical application of the PAM system is limited due to the use of bulky and expensive pulsed laser sources. In this paper, a low-cost optical-resolution PAM system with a pulsed laser diode excitation has been introduced. The lateral resolution of this PAM system was estimated to be 7 µm by imaging a carbon fiber. The phantoms made of polyethylene tubes filled with blood and a mouse ear were imaged to demonstrate the feasibility of this PAM system for imaging biological tissues.

17.
Biomed Opt Express ; 5(9): 3074-9, 2014 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-25401021

RESUMO

A novel lens-array based illumination design for a compact co-registered photoacoustic/ultrasound transvaginal probe has been demonstrated. The lens array consists of four cylindrical lenses that couple the laser beams into four 1-mm-core multi-mode optical fibers with optical coupling efficiency of ~87%. The feasibility of our lens array was investigated by simulating the lenses and laser beam profiles using Zemax. The laser fluence on the tissue surface was experimentally measured and was below the American National Standards Institute (ANSI) safety limit. Spatial distribution of hemoglobin oxygen saturation (sO2) of a mouse tumor was obtained in vivo using photoacoustic measurements at multiple wavelengths. Furthermore, benign and malignant ovaries were imaged ex vivo and evaluated histologically. The co-registered images clearly showed different patterns of blood vasculature. These results highlight the clinical potential of our system for noninvasive photoacoustic and ultrasound imaging of ovarian tissue and cancer detection and diagnosis.

18.
J Biomed Opt ; 19(7): 76020, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25069009

RESUMO

Coregistered ultrasound (US) and photoacoustic imaging are emerging techniques for mapping the echogenic anatomical structure of tissue and its corresponding optical absorption. We report a 128-channel imaging system with real-time coregistration of the two modalities, which provides up to 15 coregistered frames per second limited by the laser pulse repetition rate. In addition, the system integrates a compact transvaginal imaging probe with a custom-designed fiber optic assembly for in vivo detection and characterization of human ovarian tissue. We present the coregistered US and photoacoustic imaging system structure, the optimal design of the PC interfacing software, and the reconfigurable field programmable gate array operation and optimization. Phantom experiments of system lateral resolution and axial sensitivity evaluation, examples of the real-time scanning of a tumor-bearing mouse, and ex vivo human ovaries studies are demonstrated.


Assuntos
Ovário/diagnóstico por imagem , Técnicas Fotoacústicas/instrumentação , Técnicas Fotoacústicas/métodos , Ultrassonografia/instrumentação , Ultrassonografia/métodos , Animais , Desenho de Equipamento , Feminino , Humanos , Camundongos , Neoplasias Ovarianas/diagnóstico por imagem
19.
J Biomed Opt ; 18(12): 126006, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24343437

RESUMO

To overcome the intensive light scattering in biological tissue, diffuse optical tomography (DOT) in the near-infrared range for breast lesion detection is usually combined with other imaging modalities, such as ultrasound, x-ray, and magnetic resonance imaging, to provide guidance. However, these guiding imaging modalities may depend on different contrast mechanisms compared to the optical contrast in the DOT. As a result, they cannot provide reliable guidance for DOT because some lesions may not be detectable by a nonoptical modality but may have a high optical contrast. An imaging modality that relies on optical contrast to provide guidance is desirable for DOT. We present a system that combines a frequency-domain DOT and real-time photoacoustic tomography (PAT) systems to detect and characterize deeply seated targets embedded in a turbid medium. To further improve the contrast, the exogenous contrast agent, indocyanine green (ICG), is used. Our experimental results show that the combined system can detect a tumor-mimicking phantom, which is immersed in intralipid solution with the concentrations ranging from 100 to 10 µM and with the dimensions of 0.8 cm × 0.8 cm × 0.6 cm, up to 2.5 cm in depth. Mice experiments also confirmed that the combined system can detect tumors and monitor the ICG uptake and washout in the tumor region. This method can potentially improve the accuracy to detect small breast lesions as well as lesions that are sensitive to background tissue changes, such as the lesions located just above the chest wall.


Assuntos
Verde de Indocianina/química , Técnicas Fotoacústicas/métodos , Tomografia Óptica/métodos , Absorção , Animais , Meios de Contraste/química , Meios de Contraste/metabolismo , Feminino , Verde de Indocianina/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Imagens de Fantasmas , Técnicas Fotoacústicas/instrumentação , Tomografia Óptica/instrumentação
20.
J Biophotonics ; 6(6-7): 475-84, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23450770

RESUMO

We present the design and construction of a prototype imaging probe capable of co-registered pulse-echo ultrasound and photoacoustic (optoacoustic) imaging in real time. The probe consists of 36 fibers of 200 micron core diameter each that are distributed around a commercial transvaginal ultrasound transducer, and housed in a protective shield. Its performance was demonstrated by two sets of experiments. The first set involved imaging of blood flowing through a tube mimicking a blood vessel, the second set involved imaging of human ovaries ex vivo. The results suggest that the system along with the probe has great potential for imaging and characterizing of ovarian tissue in vivo.


Assuntos
Processamento de Imagem Assistida por Computador , Imagem Molecular/instrumentação , Ovário , Técnicas Fotoacústicas/instrumentação , Ultrassom/instrumentação , Vagina , Adulto , Feminino , Humanos , Método de Monte Carlo , Fibras Ópticas , Ovário/anatomia & histologia , Ovário/citologia , Fatores de Tempo
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