Violet Laser Acupuncture Part 1: Effects on Brain Circulation

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1 J Acupunct Meridian Stud 2010;3(4): RESEARCH ARTICLE Violet Laser Acupuncture Part 1: Effects on Brain Circulation Gerhard Litscher 1 *, Tao Huang 1,2, Lu Wang 1, Weibo Zhang 2 1 Research Unit of Biomedical Engineering in Anesthesia and Intensive Care Medicine and TCM Research Center Graz, Medical University of Graz, Graz, Austria 2 Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China Received: Sep 16, 2010 Accepted: Oct 12, 2010 KEY WORDS: basilar artery; cerebral blood flow velocity; multidirectional transcranial Doppler sonography; traditional Chinese medicine; violet laser acupuncture; 405 nm Abstract Violet laser acupuncture using a wavelength of 405 nm has been investigated in only a few scientific studies. The aim of this study was to provide selective evidence of a specific effect of violet laser acupuncture on mean cerebral blood flow velocity using a Doppler ultrasound technique. A transcranial Doppler sonography construction was developed especially for this study to monitor blood flow profiles in the basilar and middle cerebral arteries simultaneously and continuously. The acupuncture point Dazhui on the upper back was tested in a controlled study with 10 healthy volunteers (24.9 ± 3.3 years, mean age ± SD; 5 females, 5 males). In addition to an on/off-effect, violet laser stimulation increased the blood flow velocity in the basilar artery significantly (p < 0.001) compared with the reference interval before laser acupuncture. In the middle cerebral artery, only minimal, nonsignificant changes in blood flow velocity were seen. Metal needle acupuncture at the same point intensified the effects; however, blood flow profiles did not change significantly during and after stimulation with a deactivated violet laser. 1. Introduction Acupuncture is a very important component of Tra ditional Chinese Medicine (TCM) and has a long history [1]. Many take the various applications of lasers in medicine for granted, but even though the invention of the laser is celebrating its 50th anniversary in 2010 [2], there are still some areas in traditional medicine that require intensive translational laser re search. One of these areas is innovative laser acupuncture. Whittaker [3] defined laser acupuncture as the stimulation of traditional acupuncture points with low-intensity, nonthermal, laser irradiation. The ther ap eutic use of laser acupuncture is rapidly gaining in popularity and, at this moment (September 16, 2010), exactly 503 studies on laser acupuncture are listed in the scientific database PubMed (www. pubmed.gov). Laser acupuncture uses different wave lengths in the red, infrared, and green ranges [4,5], but to date 405 nm violet laser acupuncture has been investigated in only two studies, both performed by our research group in the last year [6 8]. The goal of this study was to investigate for the first time the effects of continuous violet laser acupuncture on blood flow velocity in the basilar (BA) and middle cerebral artery (MCA). Measurements with a deactivated laser (placebo) and a metal needle served as controls. *Corresponding author. Research Unit of Biomedical Engineering in Anesthesia and Intensive Care Medicine and TCM Research Center Graz Medical University Graz, Auenbruggerplatz 29, A-8036 Graz, Austria. gerhard.litscher@medunigraz.at 2010 Korean Pharmacopuncture Institute

2 256 G. Litscher et al 2. Materials and Methods 2.1. Violet laser acupuncture Laser acupuncture was performed using a previously described method for laser needles [4,5]. Laser needles are not pricked into the skin, but fixed onto the skin. The needles for laser acupuncture were developed to provide a noninvasive, therapeutically and methodologically similar instrument to mimic the classic metal needle (Figure 1) [5]. The needle used here emitted 405 nm violet light, often also referred to as a blue laser (e.g., as in our previous papers). We also want to point out as we have done in these previous reports that 405 nm is not in fact blue, but appears to the eye as violet, a color for which the human eye has a very limited sensitivity (Figure 1) [7]. The laser radiation was coupled into optical fibers at 110 mw and the laser needle arranged at the distal end of this fiber. Due to coupling losses, the laser needle output power was reduced to about 100 mw. The fiber core diameter was about 500 μm and the irradiation time of an acupuncture point was 10 minutes. A research system from Laserneedle EG GmbH (Wehrden, Germany) was used. Further methodological details of the optical laser acupuncture technique are summarized in previous reports [4,9 15] A new construction for monitoring blood flow velocity in different brain arteries Continuous and simultaneous monitoring of blood flow velocities in the BA and MCA before, during, and after violet laser stimulation was performed using a newly developed probe holder construction. Doppler sonographic signals were recorded in the BA and MCA with a Multi-Dop T system (DWL nm violet ( blue ) laser acupuncture nm Figure 1 Noninvasive violet laser needle (405 nm) for laser acupuncture. Electronic Systems GmbH, Sipplingen, Germany). Two rotating and axially shiftable 2 MHz probes were affixed to a head holder construction designed especially for this study (Figure 2, right). The blood flow profiles of the BA and MCA were assessed in an average depth of 67.4 ± 13.5 mm and 58.2 ± 5.8 mm, respectively. The mean blood flow velocity V m of each artery was calculated as an evaluation parameter Healthy volunteers and measurement procedure Ten healthy volunteers (mean ± SD; age, 24.9 ± 3.3 years; range years; 5 female, 5 male; height, ± 9.7 cm; weight, 68.3 ± 16.3 kg) were studied. None of the volunteers was under the influence of medication and all were free of neurological disorders. They were informed of the nature of the investigation as far as the study design allowed. The study was approved by the local ethics committee and all persons gave written informed consent. Participants lay face down on a bed in our lab, which was at a constant room temperature of 25ºC, and with their face in a sponge rubber mask similar to those used for the positioning of patients undergoing neurosurgery to allow unhindered respiration. After a resting period of 10 minutes, a recording session started with a 5-minute control phase, followed by 10 minutes of violet laser stimulation, and then a 5-minute control phase. The measurement profile including the measurement points before (a), during (b,c), and after (d) stimulation can be seen in Figure 2. Two participants were investigated with laser stimulation as well as needle and placebo (deactivated laser) stimulation to produce controls. Stimulation was performed at the acupoint Dazhui (GV14), located below the spinal process of the 7th cervical vertebra. In TCM, this is an important point for treating the common cold, occipital headache, cervical spondylosis, and torticollis; it is also used in cases of psychiatric disorders such as depression and schizophrenia [16]. In addition to cerebral blood flow profiles, standard vital parameters such as heart rate (medilog AR12; Huntleigh Healthcare, Cardiff, UK) and blood pressure (Cardiocap; Datex, Hoevelaken, Nether lands) were measured Statistical analysis Data were analyzed with one-way repeated measures analysis of variance (SigmaPlot 11.0; Systat Software Inc., Chicago, IL, USA) and the Tukey test used for post hoc analysis. The level of significance was defined as p < 0.05.

3 Violet laser acupuncture and brain circulation 257 A B C b c 2.5 min a 7 min 10 min 14 min 19 min d 5 min 5 min Figure 2 (A) Healthy volunteer during investigation with violet laser stimulation at the Medical University of Graz. (B) Head holder construction for simultaneous measurement of blood flow velocities in basilar (BA) and middle cerebral artery (MCA). (C) Measurement profile; measurement points indicated as before (a), during (b,c), and after (d) 10 minutes of violet laser acupuncture. Figure 3 Typical example of on/off-effect on mean blood flow velocity at beginning and end of violet laser acupuncture in a healthy female volunteer. 3. Results In the majority of the volunteers, there was an on/ off-effect when the laser was activated/deactivated; a typical example is shown in Figure 3. In general, the laser acupuncture at the acupoint Dazhui led to a significant increase in V m in the BA during (p < 0.001) and after (p = 0.025) stimulation. On the other hand, in the MCA there was no significant change in V m (Figure 4). Stimulation using needle acupuncture enhanced the observed effect in the BA, whereas the placebo procedure did not show any significant effect. An example is shown in Figure 4 for one of the two subjects investigated with needle and placebo stimulation; similar effects were found in the second person and neither person showed significant V m alterations in the MCA. None of the stimulation methods resulted in significant changes in standard monitoring parameters, blood pressure and heart rate. 4. Discussion Research in the field of acupuncture modernization using high technology methods, such as laser acupuncture, is a fascinating challenge. An innovative violet laser acupuncture method was investigated which bridges ancient medicine with modern science. Evidence developed here showing that new violet laser stimulation using a special laser needle

4 258 G. Litscher et al V m [cm/sec] One way repeated measures ANOVA (Tukey test) a MCA n.s. p = p n = 10 leads not only to general changes in blood flow velocity in the brain, but also to specific changes. One of the main advantages of a laser needle technique is its noninvasiveness. It is possible to apply the laser in such a manner that the test person or patient cannot feel optical stimulation of the acupuncture point (using a red or infrared laser, 685 or 785 nm, respectively, mw intensity, 500 μm diameter)[4]. Although the violet laser used in these investigations does not have the same penetration depth in human skin as the red and infrared laser (violet, about 1 mm vs. red/infrared, 2 3 cm) [4,17, 18], the evoked de qi sensation, which is a prerequisite for effective acupuncture stimulation, warrants further scientific investigation regarding violet laser stimulation, as the results of this present investigation clearly show. Laser acupuncture has been clinically applied since the 1970s. In the literature, studies in the USSR between 1970 and 1972 which included treatment of hypertension and asthma can be found referenced in a review [19]. Friedrich Plog [20] began his experiments with laser stimulation of acupuncture points in ; these resulted in the first commercial laser acupuncture system [3]. The majority of the studies performed with this system was not randomized or controlled [21,22]. The development of laser acupuncture systems has been mainly influenced by Mester et al [23] who employed lasers to stimulate wound healing, and these methods were subsequently used for pain relief [24]. BA b c d a b c d N PL VL Figure 4 Box plot illustration of changes of mean blood flow velocity (V m ) in the middle cerebral artery (MCA; left) and basilar artery (BA; right) of 10 healthy volunteers. Note significant changes during (p < 0.001) and after (p = 0.025) violet laser acupuncture (VL, solid line); typical example of needle-induced changes in basilar artery (N, dotted line); no changes found during placebo measurements (PL, dashed line); ends of boxes define 25th and 75th percentiles with a line at median; error bars define 10th and 90th percentiles. One of the most recent technological developments in the field of acupuncture has been the introduction of multichannel laser acupuncture [4]. The basic idea of the so-called needles of light or laser needles originated from an analysis of laser acupuncture. Similar to needle acupuncture in TCM, simultaneous stimulation of different acupoints using laser beams and optical fibers was possible for the first time in These laser needles were developed at the University of Paderborn/ Germany (Dr. Detlef Schikora) and the first clinical investigations were performed in Lauenförde/ Germany (Dr. Michael Weber). The first scientific experiments and publications in this research field started in 2002 at our Medical University of Graz, Austria [25]. As mentioned before, according to TCM one must first attain de qi for acupuncture to be effective. Patients and volunteers describe this feeling as heaviness or as an electrical current running along the treated meridians, which are channels in TCM. De qi sensation is also achieved with violet laser light of sufficient intensity (405 nm, 110 mw, 500 μm), which was used here. Laser light may be concentrated to achieve high intensities and low average power output, accomplished by reducing the crosssectional area of the beam. If red or infrared lasers are used, patients normally do not notice when stimulation is started, such that, in the beginning of a treatment, they also do not feel any de qi sensation. Many patients report a pleasant, warm, and sometimes vibrating feeling in some areas 5 10 minutes later, as described by Rindge [26]. In our study, however, with violet laser acupuncture at a wrist acupoint, Asian volunteers described that the violet laser induced feelings similar to an ant-like bite followed by a feeling similar to a slight electrical current, which is similar to de qi evoked by a metal needle; these experiences were found by our group in 2009 and 2010 [7,27]. The immediate de qi sensation evoked by the violet laser might be a possible explanation for the present observation of the violet laser on/off effect on cerebral blood flow velocity. It was also interesting that, in addition to this short-term effect, there was a long-term effect not only was there an increase in V m in the BA during the entire phase of violet laser stimulation, but also after stimulation the V m values were significantly higher than at the start. Our volunteers were studied using sophisticated modern technology while undergoing acupuncture using modern stimulation techniques. We found here that applying violet laser stimulation at the acupoint Dazhui significantly increased blood flow velocity in the BA compared with a reference interval before acupuncture, while in the MCA, only minimal, insignificant changes were detected.

5 Violet laser acupuncture and brain circulation 259 Our technology and study design demonstrated that violet laser acupuncture produced specific and reproducible effects on brain blood flow velocity but did not explain the underlying mechanism. Analyses in further studies concerning local changes in microcirculation and temperature using violet laser applications are in progress. 5. Conclusion The following conclusions were drawn from the present results: Firstly, violet laser acupuncture (405 nm, 110 mw, 500 μm) at the acupoint Dazhui (GV14) induced an on/off-effect in the blood flow velocity of cerebral arteries and also evoked a de qi sensation similar to that of manual needle acupuncture. Secondly, mean blood flow velocity in the BA was significantly increased during and after violet laser acupuncture at Dazhui and, concurrently, only insignificant changes in the middle cerebral artery were registered. Thirdly, blood flow velocity did not change significantly during and after stimulation with the deactivated violet laser, but the alterations of V m in the BA were intensified using metal needle acupuncture at the same point in the same volunteers. Acknowledgments The authors wish to thank Ms. Ingrid Gaischek, MSc, for help in manuscript and figure preparation. The work was carried out within the project Bioengineering and clinical assessment of hightech acupuncture A Sino-Austrian research pilot study (Austrian Ministries of Health and of Science and Research and the Eurasia-Pacific Uninet) and was supported by the Science Department of the City of Graz. The measurements were performed within the areas Sustainable Health Research and Neuroscience at the Medical University of Graz. References 1. Ping C, ed. History and Development of Traditional Chinese Medicine. Beijing: Science Press, Anscombe N, Graydon O. 50th anniversary. Nat Photonics 2010;4: Whittaker P. 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