Fast and Fun: A Pilot Feasibility Study Using Dual Joystick-Operated Ride-on Toys for Upper Extremity Rehabilitation in Children with Hemiplegia.

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.

Joystick-Operated Ride-On Toy Navigation Training for Children With Hemiplegic Cerebral Palsy: A Pilot Study.

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.

A Pilot Feasibility Study on the Use of Dual-Joystick-Operated Ride-on Toys in Upper Extremity Rehabilitation for Children with Unilateral Cerebral Palsy.

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.

Measuring Upper Extremity Activity of Children With Unilateral Cerebral Palsy Using Wrist-Worn Accelerometers: A Pilot Study.

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.

Low-cost compact multispectral spatial frequency domain imaging prototype for tissue characterization.

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 .

Laser scanning laser diode photoacoustic microscopy system.

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.

Coregistered photoacoustic and ultrasound imaging and classification of ovarian cancer: ex vivo and in vivo studies.

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.

Characterizing optical properties and spatial heterogeneity of human ovarian tissue using spatial frequency domain imaging.

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.

Design of optimal light delivery system for co-registered transvaginal ultrasound and photoacoustic imaging of ovarian tissue.

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.

Design of miniaturized illumination for transvaginal co-registered photoacoustic and ultrasound imaging.

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.

A low-cost photoacoustic microscopy system with a laser diode excitation.

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.

Characterization of ovarian tissue based on quantitative analysis of photoacoustic microscopy images.

In this paper, human ovarian tissue with malignant and benign features was imaged ex vivo using an optical-resolution photoacoustic microscopy (OR-PAM) system. The feasibility of PAM to differentiate malignant from normal ovarian tissues was explored by comparing the PAM images morphologically. Based on the observed differences between PAM images of normal and malignant ovarian tissues in microvasculature features and distributions, seven features were quantitatively extracted from the PAM images, and a logistic model was used to classify ovaries as normal or malignant.

Indocyanine green enhanced co-registered diffuse optical tomography and photoacoustic tomography.

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.

Photoacoustic imaging enhanced by indocyanine green-conjugated single-wall carbon nanotubes.

A photoacoustic contrast agent that is based on bis-carboxylic acid derivative of indocyanine green (ICG) covalently conjugated to single-wall carbon nanotubes (ICG/SWCNT) is presented. Covalently attaching ICG to the functionalized SWCNT provides a more robust system that delivers much more ICG to the tumor site. The detection sensitivity of the new contrast agent in a mouse tumor model is demonstrated in vivo by our custom-built photoacoustic imaging system.

Co-registered pulse-echo/photoacoustic transvaginal probe for real time imaging of ovarian tissue.

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.

Application of laser pulse stretching scheme for efficiently delivering laser energy in photoacoustic imaging.

High-energy and short-duration laser pulses are desirable to improve the photoacoustic image quality when imaging deeply seated lesions. In many clinical applications, the high-energy pulses are coupled to tissue using optical fibers. These pulses can damage fibers if the damage threshold is exceeded.

Investigation of a diffuse optical measurements-assisted quantitative photoacoustic tomographic method in reflection geometry.

Photoacoustic tomography provides the distribution of absorbed optical energy density, which is the product of optical absorption coefficient and optical fluence distribution. We report the experimental investigation of a novel fitting procedure that quantitatively determines the optical absorption coefficient of chromophores. The experimental setup consisted of a hybrid system of a 64-channel photoacoustic imaging system with a frequency-domain diffused optical measurement system.

Integrated optical coherence tomography, ultrasound and photoacoustic imaging for ovarian tissue characterization.

Ovarian cancer has the lowest survival rate of the gynecologic cancers because it is predominantly diagnosed in Stages III or IV due to the lack of reliable symptoms, as well as the lack of efficacious screening techniques. Detection before the malignancy spreads or at the early stage would greatly improve the survival and benefit patient health. In this report, we present an integrated optical coherence tomography (OCT), ultrasound (US) and photoacoustic imaging (PAI) prototype endoscopy system for ovarian tissue characterization.

Potential role of a hybrid intraoperative probe based on OCT and positron detection for ovarian cancer detection and characterization.

Ovarian cancer has the lowest survival rate of the gynecologic cancers because it is predominantly diagnosed in the late stages due to the lack of reliable symptoms and efficacious screening techniques. A novel hybrid intraoperative probe has been developed and evaluated for its potential role in detecting and characterizing ovarian tissue. The hybrid intraoperative dual-modality device consists of multiple scintillating fibers and an optical coherence tomography imaging probe for simultaneously mapping the local activities of (18)F-FDG uptake and imaging of local morphological changes of the ovary.

Time-gating scheme based on a photodiode for single-photon counting.

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.

Effect of ultrasound transducer face reflectivity on the light fluence inside a turbid medium in photoacoustic imaging.

Many endoscopic, intravascular, and transvaginal applications require light to be delivered through optical fibers in a reflection mode. For photoacoustic imaging in reflection geometry, the front-face reflectivity of the ultrasound transducer face imposes a boundary condition that affects the light fluence and its distribution inside a turbid medium. Understanding and characterizing this boundary condition is critical for maximizing tissue illumination and therefore the signal-to-noise ratio of the photoacoustic signal.