PMID- 31635195
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20200928
IS  - 1996-1944 (Print)
IS  - 1996-1944 (Electronic)
IS  - 1996-1944 (Linking)
VI  - 12
IP  - 20
DP  - 2019 Oct 20
TI  - Ultrasound Axicon: Systematic Approach to Optimize Focusing Resolution through 
      Human Skull Bone.
LID - 10.3390/ma12203433 [doi]
LID - 3433
AB  - The use of axicon lenses is useful in many high-resolution-focused ultrasound 
      applications, such as mapping, detection, and have recently been extended to 
      ultrasonic brain therapies. However, in order to achieve high spatial resolution 
      with an axicon lens, it is necessary to adjust the separation, called stand-off 
      (delta), between a conventional transducer and the lens attached to it. Comprehensive 
      ultrasound simulations, using the open-source k-Wave toolbox, were performed for 
      an axicon lens attached to a piezo-disc type transducer with a radius of 14 mm, 
      and a frequency of about 0.5 MHz, that is within the range of optimal frequencies 
      for transcranial transmission. The materials properties were measured, and the 
      lens geometry was modelled. Hydrophone measurements were performed through a 
      human skull phantom. We obtained an initial easygoing design model for the lens 
      angle and optimal stand-off using relatively simple formulas. The skull is not an 
      obstacle for focusing of ultrasound with optimized axicon lenses that achieve an 
      identical resolution to spherical transducers, but with the advantage that the 
      focusing distance is shortened. An adequate stand-off improves the lateral 
      resolution of the acoustic beam by approximately 50%. The approach proposed 
      provides an effective way of designing polydimethylsiloxane (PDMS)-based axicon 
      lenses equipped transducers.
FAU - Acquaticci, Fabian
AU  - Acquaticci F
AD  - Instituto de Ingenieria Biomedica, Universidad de Buenos Aires, Buenos Aires 
      C1063ACV, Argentina. facquaticci@inti.gob.ar.
AD  - Instituto Nacional de Tecnologia Industrial, Ministerio de Produccion y Trabajo, 
      San Martin, Buenos Aires B1650WAB, Argentina. facquaticci@inti.gob.ar.
FAU - Lew, Sergio E
AU  - Lew SE
AD  - Instituto de Ingenieria Biomedica, Universidad de Buenos Aires, Buenos Aires 
      C1063ACV, Argentina. slew@fi.uba.ar.
FAU - Gwirc, Sergio N
AU  - Gwirc SN
AD  - Departamento de Investigaciones Tecnologicas, Universidad Nacional de La Matanza, 
      San Justo, Buenos Aires B1754JEC, Argentina. sgwirc@unlam.edu.ar.
LA  - eng
PT  - Journal Article
DEP - 20191020
PL  - Switzerland
TA  - Materials (Basel)
JT  - Materials (Basel, Switzerland)
JID - 101555929
PMC - PMC6829233
OTO - NOTNLM
OT  - axicon lens
OT  - focused ultrasound
OT  - transcranial ultrasound
OT  - ultrasonic lens
COIS- The authors declare no conflict of interest.
EDAT- 2019/10/23 06:00
MHDA- 2019/10/23 06:01
PMCR- 2019/10/20
CRDT- 2019/10/23 06:00
PHST- 2019/08/16 00:00 [received]
PHST- 2019/10/16 00:00 [revised]
PHST- 2019/10/17 00:00 [accepted]
PHST- 2019/10/23 06:00 [entrez]
PHST- 2019/10/23 06:00 [pubmed]
PHST- 2019/10/23 06:01 [medline]
PHST- 2019/10/20 00:00 [pmc-release]
AID - ma12203433 [pii]
AID - materials-12-03433 [pii]
AID - 10.3390/ma12203433 [doi]
PST - epublish
SO  - Materials (Basel). 2019 Oct 20;12(20):3433. doi: 10.3390/ma12203433.