Current clinical standards for endoscopy in thegastrointestinal (GI) tract combine high definition optics andultrasound imaging to view the lumen superficially and throughits thickness. However, these instruments are limited to thelength of an endoscope and the only clinically available,autonomous devices able to travel the full length of the GI tracteasily offer only video capsule endoscopy (VCE). Our work seeksto overcome this limitation with a device (“Sonopill”) formultimodal capsule endoscopy, providing optical andmicroultrasound (µUS) imaging and supporting sensors1.µUS transducers have been developed with multiplepiezoelectric materials operating across a range of centrefrequencies to study viability in the GI tract. Because of thecombined constraints of µUS imaging and the low power / heattolerance of autonomous devices, a hybrid approach has beentaken to the transducer design, with separate transmit andreceive arrays allowing multiple manufacturing approaches tomaximise system efficiency. To explore these approaches fully,prototype devices have been developed with PVDF, highfrequencyPZT and PMN-PT composites, and piezoelectricmicromachined ultrasonic transducer arrays. Test capsules havebeen developed using 3D printing to investigate issues includingpower consumption, heat generation / dissipation, acousticcoupling, signal strength and capsule integrity. Because of thehigh functional density of the electronics in our proposed system,application specific integrated circuits (ASICs) have beendeveloped to realise the ultrasound transmit and receive circuitryalong with white-light and autofluorescence imaging with singlephotonavalanche detectors (SPADs).The ultrasound ASIC has been developed and the SPADelectronics and optical subsystem have been validatedexperimentally. The functionality of various transducer materialsThis work is supported by the UK Engineering and Physical SciencesResearch Council under its Sonopill and Multicorder programmes(EP/K034537 and EP/K021966) .has been examined as a function of frequency and ultrasoundtransducers have been developed to operate at centre frequenciesin the range 15 - 50 MHz. Ex vivo testing of porcine tissue hasbeen performed, generating images of interest to the clinicalcommunity, demonstrating the viability of the Sonopill concept.
|Name||IEEE International Ultrasonics Symposium : proceedings|
|Conference||2016 IEEE International Ultrasonics Symposium|
|Abbreviated title||IUS 2016|
|Period||18/09/16 → 21/09/16|