Pulse Shapes Techniques Application to Intense Pulsed Light for skin lesions

Transcription

1 International Journal of Engineering Science Invention ISSN (Online): , ISSN (Print): Volume 6 Issue 6 June 17 PP Pulse Shaes Techniques Alication to Intense Pulsed Light for skin lesions Jeun-Jong Baeg 1, Han-Ho Tac, Whi-Young Kim* 1 (Deartment of Electronic engineering, Gyeongnam National University of Science and Technology, Korea (Deartment of Electronic engineering, Gyeongnam National University of Science and Technology, Korea * (Deartment of Biomedical Engineering Dongju college University, Korea) Abstract: Intense ulsed light causes changes in the blood vessels inside the corium after assing through the skin. In addition, it affects fibroblasts, imarts elasticity to skin collagen and induces filling of the skin eidermis. According to several diagnostic uroses, a method for controlling the oerating time due to the outut ulse can be alied by changing the control ulse. Various outut ulses are needed for different treatment methods of Intense Pulsed Light(IPL) in accordance with the skin color and lesion. Since the heating ulse intensity, ulse width and ulse shae need to be tailored to the skin condition, there is some restriction in terms of the range of treatments as well as the diagnosis with the existing ulse techniques. A oulation inversion was induced by heat uming a Xe Lam through a V ariable Pulse Beam Shaes. The necessary discharge energy was charged through the network to roduce various current ulses. By grafting a one chi Microrocessor and V ariable Pulse Beam Shaes of an AVR affiliation, a circuit was designated from the 1 st to 8 th levels. Xenon gas was used as the medium. The outut, ulse width and ulse count was 15J/ cm ~45J/ cm,.5ms~15ms, and 1 Hz ~3 Hz, resectively. As a result, the corresonding current waveform could be recognized through a PSPICE simulation and the exerimentally determined waveform. Moreover, both the efficiency and maximum outut changed according to the results of the Discharging Light of V ariable Pulse Beam Shaes. Keywords: Intense Pulsed Light, Xe Lam, Pulse Beam Shaes, PSPICE, AT8S8535 I. Introduction Dr. Vitor invented a new treatment method called hoto rejuvenation, which emloys a discharging light of multile wavelengths not a singular wavelength. Lasers are available for artial treatment but only one wavelength is used [1-3]. On the other hand, intense ulsed light (IPL) has an extensive treatment range. A 5nm wavelength is suitable for treating blood vessel disease, whereas a 7nm wavelength is effective for igment disease. However, IPL used a range of wavelengths, 515~ 1,nm. Wavelength filters can remove the light below a certain light waveform length[4-5]. A 5nm filter removes the entire wavelength below 59nm. The IPL variables include the skin tye, energy, waveform length and examination eriod. The treatment is oerated by adjusting 4 variables according to the lesion. Generally, the treatment effect is likely to imrove with increasing energy [6-9]. However, a much shorter wavelength can cause significant damage to the skin and have less enetrability. The energy should be sufficient and the wavelength (515-1nm), ulse width and time, as well as the delay time between ulses should be adjusted accordingly [1]. Theoretically, it would be the best to use the energy aroriate for the skin tye. Nevertheless, a different reaction from that anticiated can occur during treatment. In articular, light with a low wavelength is more effective due to hot flushes and vasodilatation. To cure a stretched blood vessel, the energy should be increased by adjusting with light of a high wavelength because it needs to enetrate dee inside[1]. Adjustments of the light exosure time are needed because the skin can be damaged as the energy is increased. Because there is the ossibility of scab formation caused by the absortion of energy by the igment of dark skin, the energy normally decreases, light with a higher wavelength tends to be exosed, and the adjustment oerates to exose light for a long eriod. 71 Page

2 Fig. 1 Diagram of the roosed Intense Pulsed Light system Therefore, those eole with a dark skin color are less likely to have effective treatment than eole with lighter skin. In this study, a oulation inversion was induced by light uming with a Xe Lam through a Mesh Network[7]. Only the discharge energy was recharged and a range of current ulses that the load demands were obtained. A PSPICE simulation and exeriment waveform characteristic were comared with the Xe Lam outut current waveform, and an AT8S8535 one chi Micro Processor of AVR affiliation was used to drive, control and monitor the screen. The circuit was comosed of a L-C comosition from the 1 st to 8 th levels in a Discharging Light of V ariable Pulse Beam Shaes. to acquire a range of ulse waveforms. Therefore, several outut characteristics were organized according to the lesions in the body. II. Materials And Methods -1. Comosition Figure 1 shows the roosed system, which can be divided into 4 areas. Firstly, the system is driven with one half of a direct current ower suly using a bidirectional device. The rated current was not increased while driving, but the voltage and current control were comosed of a dead-beat controller to maintain a stable outut voltage regardless of the load variations. Secondly, the ulse reetition rate and ulse width were utilized by controlling the current density, which emloys a resonance converter by checking for zero using an AVR one-chi. Thirdly, various treatment ulses can be roduced by the Discharging Light of Multile Wavelengths, which erforms a significant function. Lastly, the discharge tube of a flash lam is used. Fig. AVR-one-chi control and drive circuit 7 Page

3 Fig. 3 Shows a circuit for the dislay and control PCB board. -. Installation The ower suly is largely formed by a bidirectional device (comensating circuit of a generating current) and a half bridge (ZCS resonance converter). A smooth condenser with a arallel frequency and a large outut caacitor were adated because an excessive eak current is roduced by the main circuit of the ZCS direct current resonance converter of a comensated generating current. The ZCS series resonance converter consisted of a switching device (S1, S), resonance inductor (L1) and caacitor (c1, c), and a generating current device (S3). The current flowed through the switching device and a caacitor erformed the on/off function. Hence, there is no switching loss and high reetition movement as fundamentals. Figure 1 resents the comosition of the basic circuit to stabilize the unstable lam oeration after oerating an inductor (L 1uH) between the IGBT drive and rotection circuit, and the magnetic switch to the simmer of the additional Xenon Lam. Figure 1 shows that the existing method drives the simmer using the high voltage with the chalk method using the Xenon Lam to Full Bridge of the indirect method. Although the simmer has a noise inside system with a large number of roblems during NG, the exeriment can be miniaturized with a stable simmer and high insulation effect by adating a ulse transformer and trilication insulation wire method into the simmer circuit. -3. Pulse Shaes A flash lam can form a oulation inversion of a medium with light uming and construct a MW that consists of a resistance (R), caacitance (C) and inductance (L) to suly energy towards the uming light source. The flash lam is oerated as a single or MW. The network recharges the discharging energy to have demanded current ulse when being sent to the flash lam. If the discharge is insufficient, an inverse current flows into the flash lam, which shortens the lifesan of the flash. In addition, the discharging efficiency decreases, which results in critical daming of the current ulse flowing into the flash lam. The condition of critical daming is indicated in equation (1) and (). The voltage-current characteristics of such a high current flash are the same as follows: K i (1) V K Kl () d [ A ] where l, d, and K indicate the variable related to the length of flash lam, diameter and tye of gas, and ressure, resectively. A nonlinear differential equation of the circuit can be exressed as follows: di [ ] r I I Idr 1 (3) dr 73 Page

4 I i LC (4) V r t (5) LC k (6) V Z r LC (7) Z LC (8) Where R is the total resistance of circuit excet self-resistance of flash lam and α is the daming arameter, which indicates the discharging characteristic of the flash lam. When the resistance of a circuit is very low, the discharging characteristic of the flash lam is determined by the caacitance C, entry voltage V and inductance L in the case of roer MW (β ). The equation can be exressed as follows: C L E t 3.9 (9) 4 9 C K t (1) 1 E CV (11) Z LC (1) k (13) V Z The demanded ulse form can be obtained by determining L and C using equation (13) from equation (9). These ulse forms have a significant relationshi with the discharge of the flash lam, and whether the discharging current of the flash lam erforms critical daming with time can be confirmed when the daming arameter is α=.75. At this oint, critical daming means considerable discharge over a short eriod. An aroximate equation of the multile circuits determined by the articular imedance of the electric network in a V ariable Pulse Beam Shaes circuit is indicated. L T (14) Z n C T L T (15) t C t C (16) Z t n L (17) V i n Z E (18) V Z C T n T (19) Where, Zn: Particular imedance of the electric network [Ω] L T : Total inductance of the mesh network [μh] C T : Total caacitance of the mesh network [ μf ] t : Current ulse width [s] V : Recharging voltage [V] E: Flash lam entry energy [J] i : Maximum current flowing over the flash lam [A] 74 Page

5 As shown in Figure 1, the 1 st column mesh set, C T, of the main circuit is 48 F, L T = 4 H. Therefore, the caacitance of the nd column mesh circuit, which can recharge the same entry energy, C 1 and C, becomes 4 F, and the inductance L 1 and L becomes 1 H. The 3 rd mesh caacitance, C 1, C and C 3, are 16 μf, and the inductance L 1, L and L 3 become 8 H. C and L of the 6 th and 8 th mesh are also determined automatically by each singular. The C and L value of each singular is determined automatically using the same method based on an increasing number of meshes when C T = 96 F, C T = 4 F, when L T = 48 H and L T = 1 H. -4. Control Unit Figure shows the role of the IGBT drive that is formed using the AVR one-chi Micro Processor and time control circuit. Fig, AVR-one-chi control and drive circuit. Fig 3, Shows a circuit for the dislay and control PCB board. Fig 4, measure waveform of the ZCS Inverter (1: Timing signal AVR, : S1, S control signal AVR 1, 3: S4 control signal AVR 1, 4: S3 control signal AVR 1). The drive is formed into 4 sections by the control circuit. The first is comosed of a keyboard to enter the time control, and the second is a LCD indication unit that indicates the entered control state. The third section is the AVR Microsoft Processor of ATMEL, which is a core of the control circuit that rovides many interfaces. The fourth section erforms amlification to turn on the IGBT and MW as the drive suort. The oeration of the control circuit is the same as follows. If the information of the delay time is entered through a keyboard, it is delivered to the AVR, which rints out each different signal caused by the arranged rogram. The series of the signals rinted out from the AVR is the LCD dislay signal and the signal to drive the IGBT with each demanded delay time in the switching circuit. The IGBT drive signals oerate the related signals with accurate confirmation as the time entered through the key board after driving S1, S and S3. Figure shows the inverter outut current waveform and control signal, and Figure shows all tyes of exerimental timing signals. Fig measured waveform of the ZCS Inverter (1: Inverter outut current, : Recharging current, 3: S1, S signal waveform, 4: S4 control signal). Figure 4 Measured Waveform of the ZCS Inverter (1: Timing signal AVR, : S1, S control signal AVR 1, 3: S4 control signal AVR 1, 4: S3 control signal AVR 1). Fig 1, 3 Schematic figure of intense ulse light with variable ulse beam shaes. Fig. 7 Exerimental aaratus( includes Otics and caacitor charger ). When the total caacitance CT(48uF) and total inductance LT(4uH) are on the 6 th level(a) Flash Lam current simulation waveform (b) Flash Lam current waveform and the outut beam. The observed flash lam and current waveform as well as the mesh and beam rofile when CT = 48 F and LT = 4 H. The rofile of the IPL outut beam was measured using a in-tye hoto diode (model name: An-tel ARS-1). When the mesh number was 6, the current ulse width t was aroximately 68μs. Figure (b) shows the current waveform and Figure (a) resents the rofile of the outut beam. Q TH is the discharging quantity of the electric charge consumed for the reversal distribution formation and Q L is the discharging quantity of the electric charge contributing to the actual IPL outut. Significant IPL outut occurs when Q L makes a larger contribution to the IPL outut than the actual current waveform. Fig 5, Power module of intense ulse light with variable ulse beam shaes. Fig 6, Exerimental aaratus( includes Otics and caacitor charger ). Fig 8, When the total caacitance CT(48uF) and total inductance LT(4uH) are on the 6th level (a) Flash Lam current simulation waveform (b) Flash Lam current waveform and the outut beam. Fig 8, When the total caacitance CT(48uF) and total inductance LT(4uH) are on the 8 th level (a) Flash Lam current simulation waveform (b) Flash Lam current waveform and exerimental waveform of the outut beam. III. Exeriment Results The results of the PSPICE simulation waveform, which aears to be similar to the current waveform of the actual flash lam. The IPL outut was measured using an energy meter (model name: Scientech D3C), as the entry energy increased with increasing authorized voltage. When the entry energy is 4J, the mesh at the 1st, 6th, and 8th levels has an IPL outut of 44mJ, 88mJ, and 39mJ, resectively. Therefore, the otimum mesh is at the 6th level. The discharging quantity of the electric charge consumed immediately before oscillation was determined to be 5.3 by obtaining the area where QTH and QL take over the current waveform of the LeCroy 934A. The bottom art of when the number of meshes is the 8th level and the discharging quantity of the electric charge consumed immediately before oscillation is Therefore, the mesh at the 6th level contains a lower QTH of consumed discharging quantity of electric charge immediately before oscillation than the mesh at the 8th level. On the other hand, QL, which contributes to the 75 Page

6 IPL outut, is larger. Figure (a) and (b) shows the results of the PSPICE simulation waveform, which is similar to the current waveform of the actual flash lam. As a result of the PSPICE simulation, increasing the mesh causes an increase in rate but when mesh is at the 6th level, the area that QL occuies is comaratively large comared to the entire area (integral area) so that the IPL outut tends to be higher Fig. 4 Power module of intense ulse light with variable ulse beam shaes Fig.5 Exerimental aaratus( includes Otics and caacitor charger ) IV. Discussions Figure 8 shows the IPL outut in accordance with the mesh after setting CT = 4 and LT = 1. In the case of an authorizing entered energy of 4J, the mesh at the 1st, 3rd and 6th levels has an IPL outut of 568J,,71mJ and,568mj, resectively. Therefore, the ideal mesh is at the 3rd level. When CT = 4 μf and LT = 1μH in figure, the current waveform of the mesh is at the 3rd and 6th level. The increase in time is faster when the mesh is at the 6th level but QL of the mesh at the 3rd level occuies a much larger area comared to the entire area (integral area). Therefore, the IPL outut becomes higher. Figure 9(a) shows the simulation waveform towards Figure (b). When CT = 96 and LT = 48 in Figure, the current waveform of the mesh is at the 3rd, 6th and 8th levels. 76 Page

7 Fig.6 Measured waveform of the ZCS Inverter (1: Timing signal AVR, : S1, S control signal AVR 1, 3: S4 control signal AVR 1, 4: S3 control signal AVR 1) (a) (b) Fig. 7 When the total caacitance CT(48uF) and total inductance LT(4uH) are on the 6 th level (a) Flash Lam current simulation waveform (b) Flash Lam current waveform and the outut beam (a) (b) Fig. 8 When the total caacitance CT(48uF) and total inductance LT(4uH) are on the 8th level (a) Flash Lam current simulation waveform (b) Flash Lam current waveform and exerimental waveform of the outut beam 77 Page

8 Therefore, the mesh at the 6th level occuies a comaratively larger area for QL than the mesh at the 3rd or 8th levels. Therefore, an increasing IPL outut can be recognized. Figure shows the IPL outut in accordance with the mesh after setting CT = 96 and LT = 48. In the case of authorizing an entered energy of 4J, the mesh at the 3rd, 6th and 8th levels has an IPL outut of 54mJ, 1,11mJ and 836mJ, resectively. Therefore, the ideal mesh is at the 6th level. Fig 8, When the total caacitance CT(48uF) and total inductance LT(4uH) are on the 8th level (a) Flash Lam current simulation waveform (b) Flash Lam current waveform and exerimental waveform of the outut beam. Fig. 9 (a) the black, yellow, white, Pigment for the clinical treatment algorithm. (b) the black, yellow, white, vascular clinical treatment algorithm for (c) the black, yellow, white, clinical treatment algorithm for the rejuvenation (d) the black, yellow, white, hair removal for the clinical treatment algorithm shows. Fig, Total caacitance CT [96 μf ] and total inductance LT [48μH] outut energy vs. the number of intense ulse light with variable ulse beam shaes V. Conclusion The existing oval tye as well as the erformance and efficiency were comared through the rearation and roduction of an IPL. This study examined the cross-check current waveform IPL beam rofile and IPL outut at mesh levels between the 1 st and 8 th levels, which is identical to the total caacitance of the main ower suly and total inductance. The oerating exeriment by lanning and roducing a bidirectional device, resonance converter and V ariable Pulse Beam Shaes, revealed a maximum efficiency of aroximately 8.1%, which is more likely to be comact comared to the existing tye. Moreover, lanning and roducing is simle. A comarison of the authorized outut characteristics of the circuit at the 1 st to 8 th levels, where the same ower is entered when the current ulse width is < 5 μs, revealed a maximum outut of,71mj from the mesh at the 3 rd level, which conforms to the PSPICE simulation. A comarison of the authorized outut characteristic of the circuit at the 1 st to 8 th levels, where the same ower was entered when the current ulse width is > 5 μs, revealed a maximum outut of 88mJ from the mesh at the 6 th level, which conforms to the PSPICE simulation. (a) (b) Fig. 9 (a) the black, yellow, white, Pigment for the clinical treatment algorithm. (b) the black, yellow, white, vascular clinical treatment algorithm for the black, yellow, white, clinical treatment algorithm for the rejuvenation the black, yellow, white, hair removal for the clinical treatment algorithm shows. Acknowledgements This work was suorted by Piece College (U.S.A.) Grant 17. References [1]. Hyun-mo Koo, Changes in Poly ADP ribose olymerase immune resonse cells of Cerebral Ischaemia Induced rat by Transcranial Magnetic Stimulation of Alternating Current aroach. J of Magnetics., 14, 19(4) []. Wassermann E, Oxford Handbook of Transcranial Magnetic Stimulation, Oxford University Press, Oxford, 7. [3]. Frackowiak RSJ, Friston KJ, Frith C et al., Human Brain Function, nd edn., Academic Press, San Diego, 3. [4]. Devinsky O, Beric A, Electrical and Magnetic Stimulation of the Brain and Sinal Cord, Raven Press, Page

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