title: Photoacoustic-Based-Close-Loop Temperature Control for Nanoparticle Hyperthermia.
abstract: OBJECTIVE
  Hyperthermia therapy requires tight temperature control to achieve selective killing of cancerous tissue with minimal damage on surrounding healthy tissues.
  
  
  METHODS
  To this end, accurate temperature monitoring and subsequent heating control are critical. However, an economic, portable, and real-time temperature control solution is currently lacking. To bridge this gap, we present a novel portable close-loop system for hyperthermia temperature control, in which photoacoustic technique is proposed for noninvasive real-time temperature measurement. Exploiting the high sensitivity of photoacoustics, the temperature is monitored with an accuracy of around 0.18 °C and then fed back to a controller implemented on field programmable gate array (FPGA) for temperature control. Dubbed as portable hyperthermia feedback controller (pHFC), it stabilizes the temperature at preset values by regulating the hyperthermia power with a proportional-integral-derivative (PID) algorithm; and to facilitate digital implementation, the pHFC further converts the PID output into switching values (0 and 1) with the pulse width modulation (PWM) algorithm.
  
  
  RESULTS
  Proof-of-concept hyperthermia experiments demonstrate that the pHFC system is able to bring the temperature from baseline to predetermined value with an accuracy of 0.3° and a negligible temperature overshoot.
  
  
  CONCLUSIONS
  The pHFC can potentially be translated to clinical applications with customized hyperthermia system design.
  
  
  CONCLUSIONS
  This paper can facilitate future efforts in seamless integration of close-loop temperature control solution and various clinical hyperthermia systems.
authors.affiliation: School of Electrical and Electronic Engineering, Nanyang Technological University.
authors.forename: Feng
authors.initials: F
authors.lastname: Xiaohua
authors.affiliation: School of Electrical and Electronic Engineering, Nanyang Technological University.
authors.forename: Gao
authors.initials: G
authors.lastname: Fei
authors.affiliation: School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Yuanjin
mesh_terms: D005246:Feedback; D006801:Humans; D006979:Hyperthermia, Induced / Q000379:methods*; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D008954:Models, Biological; D019047:Phantoms, Imaging; D061088:Photoacoustic Techniques / Q000295:instrumentation / Q000379:methods*; D012815:Signal Processing, Computer-Assisted
chemical_list: D058185:Magnetite Nanoparticles