The Role of Quantitative Schlieren Assessment of Physiotherapy Ultrasound Fields in Describing Variations Between Tissue Heating Rates of Different Transducers

Experimental Verification of Modeled Thermal Distribution Produced by a Piston Source in Physiotherapy Ultrasound

“…Quality assurance studies would permit analyzing the device ultrasonic radiation for determining better treatment protocols to produce and standardize methods that make all the physiotherapy ultrasonic devices interchangeable. This is a clear necessity because at this moment the produced thermal effects depend on the device used [1, 3, 8, 40]. Our research group is motivated on identifying the machine and transducer critical parameters to produce an adequate acoustic field that generates the expected thermal distribution.…”

“…The latter parameter depends on the measured acoustic intensity distribution which, as analyzed in this work, is related to the produced thermal distribution. The former parameter was already studied by Johns et al [3] Better treatment protocols and safer standards could be the result of a thorough study of the acoustic radiation of these ultrasonic applications.…”

“…Each transducer produces a unique acoustic field pattern due to the particular vibration conditions of the piezoelectric disks related to the variability of transducers manufacturing process [1–3]. These variations in the radiation pattern should influence the temperature distributions and could be the cause of unexpected acoustic radiations [1].…”

“…These variations in the radiation pattern should influence the temperature distributions and could be the cause of unexpected acoustic radiations [1]. Even though many efforts have been made in order to establish standards to increase the effectiveness of the treatment [4–7], other important aspects have not yet been considered, such as the effects of intrinsic focusing related to the transducer manufacturing [3], the effect of the transducer front-face heating due to ineffective ultrasound emission [6, 8], and the relation between radiation patterns and temperature distribution (exposed in this paper). Although isolated evidence points out the potential of using ultrasound in the treatment of many illnesses [9–12], in practice, conclusive physiological improvement when using ultrasound in controlled trials has not been accomplished [13–17].…”

Short-term sensory and cutaneous vascular responses to therapeutic ultrasound in the forearms of healthy volunteers

“…Physiological and therapeutic properties of US are attributed to various nonthermal and thermal responses [4,6-9]. The tissue response to nonthermal ultrasound includes acceleration of tissue healing through cavitation and its associated effects [3,6,8,10,11], while the responses to thermal ultrasound include increases in tissue temperature at superficial and deep levels such as tendons, ligaments, joint capsules, and fascia without overheating underlying fat [3,7,10-13]. Both continuous and pulsed ultrasound are thought to show nonthermal effects and accelerate tissue repair [1-3,6,11,14,15], while continuous ultrasound is thought to add additional therapeutic effects due to heating [6,11,13,16].…”