F-k domain imaging for synthetic aperture sequential beamforming

Single pulse frequency compounding protocol for superharmonic imaging

Second harmonic imaging is currently accepted as the standard in commercial echographic systems. A new imaging technique, coined as superharmonic imaging (SHI), combines the third till the fifth harmonics, arising during nonlinear sound propagation. It could further enhance the resolution and quality of echographic images. To meet the bandwidth...

Mode vibrations of a matrix transducer for three-dimensional second harmonic transesophageal echocardiography

Transesophageal echocardiography (TEE) uses the esophagus as an imaging window to the heart. This enables cardiac imaging without interference from the ribs or lungs and allows for higher frequency ultrasound to be used compared with transthoracic echocardiography (TTE). TEE facilitates the successful imaging of obese or elderly patients, where...

Dual-pulse frequency compounded superharmonic imaging

Tissue second-harmonic imaging is currently the default mode in commercial diagnostic ultrasound systems. A new modality, superharmonic imaging (SHI), combines the third through fifth harmonics originating from nonlinear wave propagation through tissue. SHI could further improve the resolution and quality of echographic images. The...

Parametric array technique for microbubble excitation

This study investigates the use of an acoustic parametric array as a means for microbubble excitation. The excitation wave is generated during propagation in a nonlinear medium of two high-frequency carrier waves, whereby the frequency of the excitation wave is the difference frequency of the carrier waves. Carrier waves of around 10 and 25 MHz...

Comparison of fundamental, second harmonic, and superharmonic imaging: A simulation study

In medical ultrasound, fundamental imaging (FI) uses the reflected echoes from the same spectral band as that of the emitted pulse. The transmission frequency determines the trade-off between penetration depth and spatial resolution. Tissue harmonic imaging (THI) employs the second harmonic of the emitted frequency band to construct images....

Avoiding pitfalls in the road from idea to certified product (and the harsh clinical environment thereafter) when innovating medical devices

Innovation in medical technology is a critical chain of events, ideally leading to an improved situation for patient and staff as well as a nice profit for the supplier of the innovation. Unfortunately many innovative ideas are not successful in practice. This is often due to lack of: • Medical relevance, • Validity of the underlying technical...

In Vitro demonstration of an SpO2-Camera

Feasibility of pulse oxigraphy is examined using an in- vitro phantom, perfused with human blood by a heart- lung machine. 29 different oxygen saturation levels, measured with our experimental camera and a clinical pulse oximeter, were matched against laboratory blood gas analysis. Discrete transfer functions between measurements & laboratory...

Contrast enhancement of coronary arteries in cardiac surgery: A new multispectral stereoscopic camera technique

Remote non-invasive stereoscopic imaging of blood vessels: First in-vivo results of a new multispectral contrast enhancement technology

We describe a contactless optical technique selectively enhancing superficial blood vessels below variously pigmented intact human skin by combining images in different spectral bands. Two CMOS-cameras, with apochromatic lenses and dual-band LED-arrays, simultaneously streamed Left (L) and Right (R) image data to a dual-processor PC. Both...

Contactless multiple wavelength photoplethysmographic imaging: A first step toward "spO2 camera" technology

We describe a route toward contactless imaging of arterial oxygen saturation (SpO2) distribution within tissue, based upon detection of a two-dimensional matrix of spatially resolved optical plethysmographic signals at different wavelengths. As a first step toward SpO 2-imaging we built a monochrome CMOS-camera with apochromatic lens and 3λ-LED...