PULSE WAVE ANALYSIS: THE CENTRAL NERVOUS SYSTEM - MYPULSES

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Pulse Wave Analysis:
The Central Nervous System
In Traditional Chinese medicine (TCM), pulse reading is not meant to give a direct indication of the level or flow
of Qi. Rather, it provides a diagnosis of the quality and level of blood flow. Personal energy or Qi is not a physical
phenomenon as sometimes believed in Western interpretation of TCM but is instead a result of the underlining
flow of blood. Indications of blood flow from pulse taking is an indirect indication of energy flow. The strength
of the pulse as per the blood force, strength and speed felt from the pulse is also an indication of the strength or
level of personal energy. Clearly, the better the blood flow, the more the body is being nourished with oxygen,
nourishment, etc.
Another important element in pulse reading - as is the case in the West - is the pulse or heart rate frequency. This
white paper also discusses heart rate frequency as well as heart rate variability as an integral part of pulse wave
analysis.

This document contains unpublished confidential and proprietary information of My-Vitality.                 April 4, 2019
No disclosure or use of any portion of these materials may be made without the express
written consent of My-Vitality.

2    Pulse and nervous system                                                                        April 4, 2019

1      The Central Nervous System
For our narrower focus – understanding personal energy or vitality – arguably one of the biggest misconceptions
regarding TCM is the notion of Qi itself. In the narrower practical and clinical sense of the term, Qi is the force
within us that gives us the energy to among many things: motivate us, move us, provide awareness, create desire,
the capacities to work, make efforts, etc. Briefly put, it is our vitality.
In Western medicine, the nervous system is a critical part of human health and practice. The human nervous
system consists in the medical parlance of two parts: the central nervous system (CNS), which comprises the brain
and the spinal cord, and the peripheral nervous system (PNS), which is composed of nerves and nerve networks
throughout the body. The CNS is the center of the body’s communication system with all sensations, experiences
and thoughts processed and communicated through this network. The PNS is a further extension of the central
nervous system with an intricate and complicated network of nerves and nerve networks that connect the entire
body together.
In TCM, there is no notion of the central nervous system. Instead, considerable attention is placed on the 12
meridians that are described and drawn in diagrams from even the earliest of the TCM doctrines. The meridians
and their locations are an all-important aspect of acupuncture. Depending on the diagnosis taken, needles are
optimally placed along these meridians in carefully studied locations to achieve various therapeutic objectives.
There are twelve meridians, each corresponding to the 11 organs considered important in TCM as shown in below
illustration: 1
Figure 1: The 12 Meridians

                                                       Figure 1: 12 Meridians
    1 wikipedia.org/wiki/meridian   chinese medicine pg 1

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No disclosure or use of any portion of these materials may be made without the express
written consent of My-Vitality.

April 4, 2019                                                                           3   Pulse and nervous system

Accordingly, if the therapeutic goal is to improve, say, digestion it is likely that one or several of the numerous
needle(s) placed along the meridians will be strategically placed along the stomach meridian, which starts at the
nose and wraps vertically down along the chest and intestines along the lower leg, ending up at the second toe.
Ditto for other ailments related to meridians corresponding to the lung, large intestine, liver, spleen, heart, small
intestine, bladder, kidney, pericardium and gall bladder.
Anyone that has experienced needles poked into one or more of these meridians can testify to the sudden feeling of
shock. The needles cause a shock albeit the feeling of shock will vary depending on their placement. Synonymous
to a finger inadvertently placed in an electric wall socket, it is like a bolt of electricity suddenly electrifying the
area around the needle. Since electricity is closely associated with energy, it is erroneously assumed that it is Qi
that is passing through these meridians and causing these electric bolts sensations. When a TCM therapist feels
one’s pulse, it is assumed that he is detecting the amount and flow of Qi or energy flowing through the radial
artery. Many books and articles make this assumption, which is incorrect and clouds our understanding of personal
energy.
Rather, one should view the meridians in a similar way as one understands the central nervous system. This is
not difficult to do considering that the meridians are located over major neural pathways as is known in modern
medicine. The acupuncture points are also typically located where there are concentrations of sensory nerve fibers.
However, it is not the flow of Qi but rather the stimulation of the underlying neural pathways that can account
for the physiological effects and clinical responses to acupuncture in patients not the flow of energy. 2 A good
example of this is the use of acupuncture for therapeutic purposes targeted at the cardio vascular system. Points
5 and 6 in the left diagram below are commonly used in acupuncture (in conjunction with other points) to elicit a
strong cardiovascular effect. To the right below is an illustration of the two main nerves on the peripheral nervous
system located on the arm (as per Western medicine). As seen, Points 5 and 6 lie just along the Median nerve.
Figure 2: Meridian and Nerves Along Arm

                                    Figure 2: Meridians and Nerves Along the Arm

Comparison of Meridians as per TCM (on left) with nerves as per Western medicine on right
There are numerous peer reviews linking the peripheral nervous system with the meridians. While the evidence
is not entirely conclusive, the similarities between these two systems are nonetheless striking. Even more so
considering that several thousand years separate the theoretical development of these two systems.
    2 John C Longhurst ”Defining Meridians: A Modern Basis of Understanding Journal of Acupuncture and Meridian Studies Volume

3, Issue 2, June 2010, Page 69

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No disclosure or use of any portion of these materials may be made without the express
written consent of My-Vitality.

4    Pulse and nervous system                                                                                   April 4, 2019

Many books and articles that interpret TCM as it pertains to Qi and energy assume claim that one can feel the
Qi on the pulse, namely, in the popular wrist location. It is therefore assumed that the more “one feels” Qi, the
better. Along this reasoning, one needs to stimulate and de-block the flow of Qi in the body through acupuncture
and other therapeutic techniques. In other words, they equate the level of Qi with the physical quantity and flow
of Qi through the body. However, a closer examination of the notion of Qi or energy as TCM coins it, reveals
something very different. Interviews with long term scholars and practitioners of TCM also tell a quite different
story.
In TCM, the pulse reading is not meant to indicate the level or flow of Qi but rather the quality and level of
blood flow. The finger pulsations indicate the quality of the arteries and the amount, strength and flow of blood.
Looking through the eyes of western medicine, TCM therapists are observing the quality of the cardio-vascular
system not the actual level of Qi. Qi is not a physical phenomenon one can touch. Nor is it a central nervous
system or meridian electrical flow. Rather, “where there is blood there is Qi and where there is Qi there is blood”.
3
   “Any pulse, as long as being forceful, indicates a strong vital Qi and hence a good prognosis; while a pulse that
is felt forceless, indicates deficiency of Vital Qi”. 4 More accurately, Qi is a dynamic process not a physical human
body element as so often misinterpreted. TCM therapy especially acupuncture is about controlling and improving
the cardiovascular function indirectly through the stimulation and manipulation of the meridians (or presumably
the neurons in the nervous system).
The takeaway here is not to explore the relationships between meridians and the nervous system nor to provide
a full description of TCM pulse reading. Rather, the point is to try to get away from the direct cause and effect
explanations prevalent in Western interpretations of TCM. There is nothing physical about Qi. Full stop. Therapy
such as acupuncture is part of a dynamic process involving indirectly the manipulation of the meridians to improve
cardiovascular function and, in turn, Qi, using a holistic view of the human body function.
Pulse taking is a way to determine the quality of blood flow.

2      Heart Rate
The heart rate is an important part of Western medicine and one important element in Eastern pulse taking.
While the autonomous nervous system (discussed in next section) is an important regulator here, precise heart
rate frequencies were historically measured near the heart. With the advent of PPG, heart rates were also more-and-
more measured in the peripheral such as the back of the wrist. The medical field has been using Electrocardiography
since the early 1900’s as a process of producing an electrocardiogram (ECG), which is a recording of the electrical
activity of the heart using electrodes placed on the skin near and around the heart. These electrodes detect
the small electrical changes that are a consequence of cardiac muscle movements caused by heartbeats. Precise
measurements of this kind will indicate cardiac abnormalities such as atrial fibrillation.
Subsequently, photoplethysmogram (PPG) was used to obtain heart beat frequencies as a more convenient method
and where less accuracy was needed. With each cardiac cycle, the heart pumps blood through the arteries. A
PPG illuminates the skin and measures changes in light absorption. The change in volume caused by the pressure
pulse thereby records these changes. There are obstacles to this signal processing often referred to as artifacts.
This can be caused by body movements or ambient light, which may distort the pulse signals. This also depends
on the location of the signal collection as PPG can be obtained wherever there is convenient exposure to an artery
or capillary such as the finger, wrist, neck ear, arm, etc.
The solution to obtaining signals with less distortion caused by body movement or ambient light is to filter the
signal. With filtering, the pulse peaks are accentuated, and other pulse wave details filtered out. Accordingly, one
gets clearer peak-to-peak signals allowing one to count heart rate frequency. Filtering the signal also permitted
the movement of pulse wave analysis not only from around the heart to the wrist and other parts of the body
considered more accessible. It also brought in a large wave of wearables, which could measure heart rate frequency
in otherwise difficult environments such as on the track field, in the swimming pool, while skiing, etc.

    3 www.sacredlotus.com/go/foundations-chinese-medicine/get/relationship-of-blood-in-tcm
   4 Pulse Diagnosis, The Series of Traditional Chinese Medicine for Foreign Readers, Lu Yubin. Shandong Science and Technology

Press 1996 pg 12

This document contains unpublished confidential and proprietary information of My-Vitality.
No disclosure or use of any portion of these materials may be made without the express
written consent of My-Vitality.

April 4, 2019                                                                        5    Pulse and nervous system

Figure 3: Filtered Pulse Wave

                                            Figure 3: Filtered Pulse Wave

With the accurate measurement of heart rates under many or most conditions (thanks, in part, to improved signal
processing as shown above), the age of determining such things as activity intensity has come to full fruition. Indeed,
there is a plethora of wearables whether on the finger, wrist, arm, etc. that can detect heart rate frequency, a good
indication of activity intensity. Running for 45- minutes at an average heart rate of 130 is clearly more demanding
(and a bigger calorie burner) than walking for one hour at a heart rate of 80. Adding the distance walked/run
through either GPS or by counting paces with an accelerometer, we can then combine activity intensity with
performance.
Taking pulse analysis one step further with heart rate frequency is measuring the variability of heart rates (HRV).

This document contains unpublished confidential and proprietary information of My-Vitality.
No disclosure or use of any portion of these materials may be made without the express
written consent of My-Vitality.

6   Pulse and nervous system                                                                               April 4, 2019

3    Heart Rate Variability
A window exists that is relatively easy to use to get a direct look at the functioning of our Nervous System and our
Autonomous Nervous System (ANS). Generally termed Heart Rate Variability (HRV), this assessment technique
has been in use with the advent of digital signal processing techniques in the 1960s. There have also been many
scientific studies demonstrating the efficacy of using HRV for diagnostic purposes.
Yet, this relatively easy technique to apply has gained little traction in health circles. Active athletes use it to help
monitor training and determine optimal training programs. HRV has also been used to a considerably less extent
in stress management. Perhaps the name itself “Heart Rate Variability” turns people off as it suggests complexity
and difficulty of comprehension. It might also have a negative undertone as it could imply cardiac arrest, coronary
problems, etc. One large sport watch manufacturer even couches HRV in other terms such as “comfort” training
zones. Likely, HRV will be more commonly used in the future as HRV awareness increases together with the recent
craze for fitness watches and bands.
Heart rate varies with every heartbeat. (HRV) is the variation of beat to beat intervals, also known as R-R
intervals. HRV indicates the fluctuations of heart rate around an average heart rate. An average heart rate of 60
beats per minute (bpm) does not mean that the interval between successive heartbeats would be exactly 1.0 sec,
instead they may fluctuate from, say, 0.5 sec up to 2.0 sec
Figure 4 Heart Rate Variability

                                           Figure 4: Heart Rate Variability

HRV or the amount of heart rate fluctuations around the mean heart rate is caused because of the continuous
changes in the sympathetic (SNS) and parasympathetic (PNS) balance which, in turn, causes the cardiac rhythm
to fluctuate around the mean heart rate. Frequent small adjustments in heart rate are made by cardiovascular
control mechanisms. SNS and PNS are the two components of the autonomous nervous system (ANS): ANS is
discussed in more detail in Pulse Wave Analysis: The Autonomous Nervous System (Part 3).
HRV decreases under situations of stress – either emotional, mental or physical, whereas it increases with rest.
In healthy – rested - individuals, the HRV is going to fluctuate a lot as the ANS constantly adjusts to changing
circumstances, getting up from a chair, running, relaxing in front of the TV, etc. The more these adjustments
occur the higher the HRV. Conversely, a lower HRV signifies that the individual is not self-adjusting heart rate
speeds from changing circumstances, indicating a stressed ANS. In absolute terms, older and less fit people will
have lower HRV. On a relative bases, where HRV measurements are compared at different time points with the

This document contains unpublished confidential and proprietary information of My-Vitality.
No disclosure or use of any portion of these materials may be made without the express
written consent of My-Vitality.

April 4, 2019                                                                        7    Pulse and nervous system

same person, HRV is a good indication of the ANS functioning. One would expect lower HRV to be associated
with a person that is stressed either physically or mentally. Athletes use the HRV measurement to determine
whether they need to take a break from an ambitious training program as they have generally been running SNS
over time. As the HRV rises, the athlete may determine that the PNS system has kicked-in and the body is rested
enough to take on more training.
It is important to not confuse heart rate (HR) with HRV, a common source of confusion for learners of HRV.
Running up steps or other physical demands will cause the HR to jump in order to provide oxygen and nutrition
to the cells. This does not necessarily change the HRV. Similarly, HRV may move up even though the body is
resting at a relatively low HR. Bodily functions determine HR; ANS imbalances and rebalances move the HRV
needle.
Where there is complexity is in the methods of calculating HRV. Generally, the longer the period HRV is measured
the more accurate the calibration. This is because errors due to missing HRs or noise distortions work themselves
out in the long-term averages. Ideally, HRV should be calculated during sleep as this provides for 7+ hours of
HR measurements in a quiet environment. For practical purposes, HRV applications typically call for 3- 5-minute
measurement periods even though the calculations could be slightly off but give nonetheless a pretty good picture
of HRV. The HRV methodology calls also for measurements either in a supine or sitting position (or both). The
HRV results will vary depending on the method used.
The exact contributions of the parasympathetic and the sympathetic divisions of the autonomic nervous system
to this variability are controversial and remain the subject of active investigation and debate. Regardless, HRV is
a valuable tool as evidenced by the large number of peer reviews published, many of them showing positive results
under different conditions and applications.
For a more complete picture of pulse wave analysis, we now turn to Part 3 in our white paper series on Pulse Wave
Analysis and examine the pulse wave form itself, a rich source of information.

This document contains unpublished confidential and proprietary information of My-Vitality.
No disclosure or use of any portion of these materials may be made without the express
written consent of My-Vitality.

8   Pulse and nervous system                                                                             April 4, 2019

4    Conclusion
Pulse wave analysis both from a traditional Chinese point-of-view and in the eyes of Western medicine is about
examining blood flow. Personal energy is part of blood flow. It is not a direct measurable physical property felt
on the pulse as some have claimed. The pulse has been a rich source of information on the body for thousands
of years. An important element of pulse analysis is the pulse rate, which includes heart rate variability. To get a
fuller, more complete, picture of the pulse one needs to also look at the pulse wave form.

5    References
1. ”Traditional Chinese Medicine,” www.wikipedia/Traditional Chinese Medicine
2. John C Longhurst ”Defining Meridians: A Modern Basis of Understanding” Journal of Acupuncture and Meridian
Studies. Voulme 3, Issue 2, June 2010 pg 69 3. www.sacredlotus.com/go/foundations-chinese-medicine/get/relationship-of-
blood-in-tcm
4. Pulse Diagnosis, The Series of Traditional Chinese Medicine for Foreign Readers, Lu Yubin. Shandong Science and
technology Press 1996. pg 12.

This document contains unpublished confidential and proprietary information of My-Vitality.
No disclosure or use of any portion of these materials may be made without the express
written consent of My-Vitality.