Andrew C. Ahn, MD, MPH

portrait of andrew ahn

Home Institution: Beth Israel Deaconess Medical Center, Massachusetts General Hospital

Field: Computational Medicine

Current Positions:

My Driving Question

Can computational analyses of biomedical signals—such as heart rate and blood pressure—lead to personalized treatments and better understanding of human health?

Fellow Project 

Despite substantial advances in diagnostic tools and therapeutics, modern biomedicine continues to struggle with defining terms such as “health” and “wellness”—concepts connoting a holistic characteristic that cannot be readily quantified or measured.

The challenge originates from the simple fact that measurable, meaningful variables become increasingly difficult to identify as the perspective is broadened toward the system as a whole. With advances in complexity and systems-based sciences, however, we are auspiciously poised to overcome these challenges and to use complexity-derived, objective measures that capture the overall state of human health in a way not previously deemed possible.

Although promising in principle, systems-based medicine in practice is attached with many unanswered questions: How should these systems-level measures be reliably derived in a clinical setting? Which measures are most informative about one’s clinical condition? How should the results be interpreted and be related to other more conventional parameters? And can they be practically implemented to generate meaningful improvements in clinical care?

To identify possible answers to these questions, Dr. Ahn is employing a large, intensive care database called the MIMIC II (Multiparameter Intelligent Monitoring in Intensive Care) Database to investigate the utility of systems-level measures in clinical care. This database is ideal because of its size (N=23,000), incorporation of continuous waveforms (N=4,800 with EKG, arterial pressures, respiration, and plethysmography), comprehensiveness (demographics, vitals, lab tests, medications, care notes, and imaging reports), and diversity (data from medical, cardiac, and surgical units).

These analyses will provide not only the preliminary data on the usefulness of systems-approach to the ICU setting, but also the necessary framework to deal with large, complex databases such as MIMIC II, which contains heterogeneous population with varying clinical conditions, stages of disease, ICU settings, and provide teams.


Dr. Ahn is a junior faculty member of both the Massachusetts General Hospital Martinos Center and the Beth Israel Deaconess Medical Center Division of General Medicine and Primary Care, as a hospitalist in the Hospital Medicine Program. He dedicates half his time to research while spending the remaining time to clinical work. His research interest is in computational medicine and in large-scale electrophysiological process within the human body. These interests stemmed from his initial interests in acupuncture.

In 2002, Dr. Ahn joined the three-year combined General Medicine and Complementary Alternative Medicine Fellowship at Harvard Medical School directed by Dr. Russell Phillips. As part of this fellowship, he became credentialed in acupuncture by completing a 300-hour acupuncture course for physicians at Harvard Medical School. He also earned a Master in Public Health degree at the Harvard School of Public Health with a concentration in Clinical Effectiveness.

Much of Dr. Ahn’s fellowship was focused on studying the mechanisms underlying acupuncture treatments. During the fellowship, he evaluated the mechanistic significance of the elusive “acupuncture meridian” by working with Dr. Helene Langevin, a well-established acupuncture and connective tissue researcher at the University of Vermont. They measured the electrical impedance along connective tissue planes associated with meridians compared to parallel control muscle tissue. They found that electrical impedance along the pericardium meridian was significantly lower compared to controls.

To further elaborate the electrical properties of meridian-associated connective tissue, he applied for and received a five-year NIH K23 career development award. This award provided support for pilot research projects, mentorship, and coursework, and it took place at Harvard Medical School, Beth Israel Deaconess Medical Center and MIT. His mentors were Ted Kaptchuk, Helene Langevin, Alan Grodzinsky, and Russell Phillips, who collectively provided expertise in Asian medicine, acupuncture, connective tissue, bioengineering and clinical research.

Dr. Ahn also joined the MIT Advanced Study Fellowship, through which he took graduate courses in physics and engineering and completed coursework equivalent to those required for a PhD in biological engineering. During this time, he published a systematic review on the electrical properties of acupuncture points and meridians and a review on the relevance of collagen piezoelectricity in bone deposition.

He also published a study showing that electrodermal measurements at acupuncture points may be associated with clinical measure in women with chronic pelvic pain. In addition, he collaborated with various engineering and physics experts to study the electrical potential and impedance of loose connective tissue using state-of-the-art devices such as bio-Kelvin probe, impedance gain phase analyzer, and biopotential amplifiers.

Due to these early interests in bioelectricity, his research interests have evolved towards investigating large-scale bioelectrical effects within the human body that may play important physiological roles: specifically, the importance of electrical properties of fibrillar collagen in musculoskeletal physiology, the role of streaming potential and electroosmosis in fluid/circulatory regulation, and the influence of large scale electrical potential gradients on nerve activity.

In March 2010, he joined the MGH Martinos Center for Biomedical Imaging where he has access to a state-of-the-art high-frequency VisualSonics ultrasound to collaborate with Dr. Vitaly Napadow to further evaluate these large-scale electrophysiological processes and to study neurological mechanisms of acupuncture.

Dr. Ahn has also developed an interest in applying systems/complexity theory to medicine and has written about the applications of complexity/systems theory to clinical practice. He published a widely-cited two-part series in PLOS Medicine discussing the limitations of reductionism in medicine and exploring the role for a systems approach in clinical medicine. He also co-authored a NIH-NCCAM sponsored position paper on the applications of complexity theory to CAM research.

Education and Training
  • Fellowship, General Medicine/CAM, Harvard Medical School
  • Graduate Courses, Biological Engineering, MIT
  • MPH, Clinical Effectiveness, Harvard School of Public Health
  • Residency, Internal Medicine, University of Michigan Medical Center
  • MD, New York University
  • BA, Biophysics, University of California Berkeley
Selected Honors
  • Patient-Oriented Career Development Award (K23), National Center for Complementary and Alternative Medicine
Selected Publications

Healing is facilitated through safety, persistence, and trust.

  • Persistence: “People did not simply progress through this sequence and experience healing. The healing journey was a recursive, back and forth process. They found helpers, used the skills/resources that those helpers provided, found other helpers that provided more resources and used those skills and resources. As this process continued, people experienced a gradual amelioration of their suffering. Although many despaired at times, all demonstrated the quality of persistence—they refused to give up.”
  • Safety & Trust: “To connect to helpers, it was essential for people to feel safe in those relationships and able to trust that the person would be a helper and not a barrier to healing. Persons whose wounds included a violation of trust were especially careful about testing the safety of new relationships.”

Resources support us as we heal. They include reframing, responsibility, and positivity. “Making connections enabled participants to acquire and refine resources and skills that were essential in their healing journey. People also brought their own personal strengths to the journey.”

  • Reframing: “A particularly important skill was the ability to reframe—that is to look at suffering through a different lens.” This does NOT mean minimizing trauma or pain, but rather it often means the opposite: understanding what happened was wrong, unfair, or uncontrollable and that we are not to blame for it.
  • Responsibility: While we don’t have control over what happened to us, we are the only ones who can help ourselves heal. “A third essential resource that people acquired or refined was the ability to take an appropriate amount of responsibility for their healing journeys. They participated actively in the process of healing. Once again, some participants already had developed this skill, and some acquired or refined it from their helpers.”
  • Positivity: “Another resource that people acquired or refined during their healing journey was choose to be positive—that is to have some optimism about their situation.” People have varying predispositions to positivity. In the study, positivity was important in helping people heal. This doesn’t mean a toxic positivity, but rather simply finding some good in life and feeling hopeful about our situations.

“Connection to others was an essential part of all the healing journeys.” Humans are social creatures, and even the most introverted of us need close relationships. Friends and family add meaning and value to life and help support us, in good times and bad. 

When we experience relational trauma, relationships can feel scary, but reestablishing safety and trust in relationships is where the healing happens. (To be clear, we do not mean reestablishing safety and trust with abusers, but rather finding other healing relationships.) 

“When safety and trust had been established, people were able to connect with helpers. The nature of the behaviours of helpers that fostered healing ranged from small acts of kindness to unconditional love.”

  • “Moving from being wounded, through suffering to healing, is possible. It is facilitated by developing safe, trusting relationships and by positive reframing that moves through the weight of responsibility to the ability to respond.”
  • “Relationships with health professionals were among these but were not necessarily any more important to the healing journey than other kinds of helpers, which included family members, friends, spirituality and their God, pets, support groups, administrators, case workers and supervisors.”

Healing probably means different things to different people, but one definition that emerged from the study is: “The re-establishment of a sense of integrity and wholeness.” 

Healing was an emergent property that resulted from each individuals’ complex healing journey, a result of bridged connections between resources and relationships. “…they gradually found relief from suffering and began to exhibit emergent characteristics: a sense of hope, self-acceptance, and a desire to help others—the immediate precursors to healing.”

 In varying degrees, “they were able to transcend their suffering and in some sense to flourish.” 

  • Helping Others: We find meaning in helping others. “Understanding that suffering gives the strength and experience to help others in similar situations.”
  • Hope: We begin to have hope that we will not always feel this bad. A Crohn’s patient said, “I think gradually I realized that I was going to feel better. I did have days when I actually didn’t vomit, when I did feel better. And I think gradually I came to believe that maybe I could have a normal life again.”
  • Self-Acceptance: We see our inherent value and understand that we are not to blame for our suffering. A participant living with HIV said, “I’m really proud of myself. I think that now I still want to live. I don’t want to die, and I really love myself a lot. I have a lot of comfort in myself.”

Suffering is the ongoing pain from wounding. 

There is some debate about whether people always experience suffering on the path to healing.

Wounding happens when we experience physical or emotional harm. It can stem from chronic illness or by physical or psychological trauma for which we do not have the tools to cope, or a combination of those factors. 

“The degree and quality of suffering experienced by each individual is framed by contextual factors that include personal characteristics, timing of their initial or ongoing wounding in the developmental life cycle and prior and current relationships.”

Characteristics: How predisposed someone may be to wounding/how many tools and resources someone may have to deal with trauma/illness.

Lifestages: Developmental timing plays an important role in the impact of trauma — young children often do not have the same resources as older adults.

Relationships: Relationships can provide solace and support for those suffering, while lack of healthy relationships can prolong suffering.