Megan Betts, 22

Monica Brickhouse, 39

Nicholas Cumer, 25

Derrick Fudge, 57

Thomas McNichols, 25

Lois Oglesby, 27

Saeed Saleh, 38

Logan Turner, 30

Beatrice Warren-Curtis, 36

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Jordan Anchondo, 25

Andre Anchondo, 23

Arturo Benavides, 67

Leo Campos

Angie Englisbee, 86

Maria Flores, 77

Raul Flores, 77

Jorge Calvillo Garcia, 61

Adolfo Cerros Hernandez

Maribel Hernandez

Alexander Gerhard Hoffman, 66

David Johnson, 63

Luis Alfonzo Juarez, 90

Maria Eugenia Legarrega Rothe, 58

Elsa Libera Maequez, 57

Maribel Loya, 56

Ivan Manzano

Gloria Irma Marquz, 61

Margie Reckard, 63

Sarah Esther Regaldo Moriel, 66

Javier Amir Rodriguez, 15

Teresa Sanchez, 82

Angelina Sliva-Elisbee, 86

Juan Velazquez, 77

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or, How to measure a heartbeat in approximately twelve steps

 

AN INTRODUCTION

The heart in your chest beats every minute of your life.¹ Accompanying each new beat is an electrical dance whose waves ripple throughout your body. The same is true of every single human being you will ever come across. What you will do is measure those waves between two points in space and thereby detect the exact moment a heart’s muscles contract for a few minutes of someone’s life one fine day.

To do this, you will construct a system, an electrocardiogram, comprising the following: 

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1. Except in those rare instances of individuals with artificial hearts or transplants, techniques being ever more perfected by biomedical engineers and their collaborators.

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MATERIALS

Review material inventory

Begin by reviewing the inventory of your kit. Ensure it contains the following materials: 

• Twenty (20) jumper wires, ~5 cm each (4 red, 4 black, 4 green, 4 yellow, 4 blue)
• Three (3) long wires, unstripped, ~15 cm each (1 red, 1 black, 1 green)
• Three (3) resistors
  • RG: 1.5  kΩ; Actual value: ________________ Ω
  • R1: 330 kΩ; Actual value: ________________ Ω
  • R2: 10 MΩ; Actual value: ________________ Ω
• Two (2) capacitors
  • C1: 10 µF                     Actual value: ________________ F
  • C2: 100 pF                   Actual value: ________________ F
• One (1) AD620 instrumentation amplifier (Figure 1. AD620)
• One (1) LM741 operational amplifier (Figure 2. LM741)

 [Note: You will need to measure each of the passive components (i.e., the resistors and the capacitors) to determine their value. To do this, a volunteer will show you how to measure these values with a multimeter.]

[Note still further: Sometimes smaller valued capacitors can be difficult to measure precisely.]

Review workstation equipment

Please also check your workstation for the following equipment:

• A breadboard (Twin Industries TW-E41-1060, Figure 3. A breadboard with posts, rails, trench, and terminals)
• A power supply (Agilent E3630A, Figure 4. A power supply with (A) voltage adjustment, (B) port selection, and (C) output ports)
• An oscilloscope (Tektronix TDS 2012C, Figure 5. An oscilloscope with (A) position and vertical scaling, (B) input, and C) horizontal scaling)
• Three (3) 2m banana cables (one red, two black; with connectors, Figure 6. Banana cables (2m))
• Three (3) 1m banana cables (one red, two black, Figure 7. Banana cables (1m))
• One (1) BNC-to-splitter cable (Figure 8. BNC-to-splitter cable)

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1. POWER A BOARD

The instructions that follow assume you build your circuit in a vertical orientation. That means centering work around a breadboard “trench” (Figure 3). To follow along, locate one trench on the breadboard. From here on, everything to the right side of that trench is on the “right” and everything to the left side is on the “left”.  Feel free to consult the Reference sheet or to ask any of the volunteers any questions you may have.

Step 1. Connect a power supply to a breadboard

1. ¡Turn on! the power supply

1. 1. To adjust a particular output port voltage, push in the “METER” button to select that port voltage, and adjust the voltage via the “VOLTAGE ADJUST” knobs
   2. Set the +20 V port voltage to be approximately +5 V
   3. Set the –20 V port voltage to be approximately –5 V
2. Attach a 1m red cable from the +20 V port of the power supply to the red breadboard post
3. Attach a 1m black cable from the –20 V port of the power supply to the black breadboard post
4. Attach another 1m black cable from the COM port of the power supply to the green breadboard post, this will serve as a reference point, where voltage is 0

Step 2. Wire the breadboard posts to its power rails

1. Wire the red breadboard post to the red (+) column of the right rail
2. Wire the black breadboard post to the blue (–) column of the left rail
3. Wire the green breadboard post to the blue (–) column of the right rail

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Check in 

• Where on the board is it +5 V?

• Where is it –5 V?

• What voltage is it at the reference point?
  

Before you continue: ¡Turn off! the power supply (for now)!

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2. BUILD AN AMPLIFIER

In your kit there should be two eight-legged chips that look quite similar. They both should have a little notch at the “top”. Only one of them will have a polished circle next to that notch. That is the LM741 and it will be used to CONSTRUCT A FILTER. For this step, find the AD620, the instrumentation amplifier. It will not have a polished circle.

Step 3. Place an instrumentation amplifier on the breadboard 

1. Orient the instrumentation amplifier to align with the top of the board and place across the trench so that each of the “legs” of the amplifier is electrically independent
2. Center the amplifier between the powered rails

Step 4. Wire the instrumentation amplifier for power 

1. Wire the positive rail (the one with +5 V) to Pin 7 of the amplifier (+Vs)
2. Wire the negative rail (the one with –5 V) to Pin 4 (–Vs)
3. Wire the reference rail (the one with how many volts?) to Pin 5 (REF)

Step 5. Create gain, inputs, and an output for the instrumentation amplifier 

1. Use RG to connect Pin 1 to Pin 8
   • This will enable the amplifier to increase the difference in voltage by a predetermined amount known as gain
2. Create two loose wires and insert one into each Pin 2 and Pin 3 
   • These two points will be the inputs across which you DETECT A HEARTBEAT
3. Wire Pin 6 to a free space to the left of the trench and below the amplifier

• • This output will contain the amplified signal

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Check in 

• The gain, G, of the amplifier is defined by the following formula 

G = (49.4 kohm / RG) + 1

What is the gain of your signal, G, given the measured value of your RG resistor?

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3. CONSTRUCT A FILTER

The LM741, the chip with the polished circle on its upper-left hand side, is a generic operational amplifier, “op-amp” for short. The particular wiring used here allows one to construct a “filter” that gets rid of parts of the signal that are not wanted. Specifically, we are creating a “bandpass filter” that will get rid of low frequencies and high frequencies.

Step 6. Place an op-amp on the breadboard

1. Place the op-amp across the same trench as the instrumentation amplifier, oriented such that the op-amp’s top side aligns with the top of the board
2. Wire R1 and C1 in series from the output wire of the instrumentation amplifier to Pin 2 (–IN) of the op-amp 

[Note: electrolytic capacitors have a specific direction they are designed to work in. Connect the big leg of C1 to R1 and its little leg to Pin 2]

Step 7. Wire the op-amp for power

1. Wire the positive rail to Pin 7 (+Vs)
2. Wire the negative rail to Pin 4 (–Vs)
3. Wire the reference rail to Pin 3 (+IN)

Step 8. Finish the filter

1. Use a parallel combination of R2 and C2 to connect Pin 2 (–IN)  to Pin 6 (OUTPUT)
2. Create a loose output wire and connect it to Pin 6; this will be our “system output”

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Check in 

• The “lower corner frequency”, C.F.L is the region below which we attenuate low frequencies and the “higher corner frequency”, C.F.H is the region above which we attenuate  higher frequencies. These are calculated by 

C.F.L = 1/(2*pi*R1*C1)

C.F.H = 1/(2*pi*R2*C2)

Using your values of R1 and C1, what is your lower corner frequency? 

Using your values of R2 and C2, what is your higher corner frequency?

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4. DETECT A HEARTBEAT

In this portion of the activity, you will actually be measuring actual heartbeats from an actual person. To observe the heart’s signal, you will use an oscilloscope, an instrument that allows for the precise measurement of electrical signals detected by our system – a humble electrocardiogram. Before moving on to the next steps, work with a volunteer to ensure your circuit is correct, then ¡turn on! the power supply and the oscilloscope.

Step 9. Connect an oscilloscope to the output

1. Using a BNC-to-splitter cable, attach the BNC-end of the cable to the Channel 1 terminal of the oscilloscope
2. Using the same cable, attach the black portion of the splitter to the reference post on the breadboard
3. Connect the red portion of the splitter (the one with the alligator clip) to the loose wire with the system output

Step 10. Connect a participant to the inputs

1. Attach two electrodes to the wrists of a (willing) participant
   [Note: the electrodes are sticky, but not too sticky. So if one of them falls off, just replace it with another!]
2. Connect one of the electrodes via a 2m cable to one of the inputs of the instrumentation amplifier (loose wire at Pin 2 of the AD620)
3. Connect the other electrode via a 2m cable to the other input of instrumentation amplifier (loose wire at Pin 3 of the AD620)

1. Attach a third electrode, a “reference electrode” to an electrically neutral part of the participant’s body (generally a body part like your elbow or your ankle)
2. Connect the reference electrode to breadboard’s reference post via a 2m cable

Step 11. Ask someone to let you measure their heartbeat

1. Use the oscilloscope to observe the signal coming from the participant’s heart (it may require adjustment of the oscilloscope’s abscissa and ordinate scales)

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Check in 

• Can you think of a way to determine a heart rate?
• What is the participant’s heart rate (in beats per minute) right now?

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5. BECOME A BIOMEDICAL ENGINEER

Step 12. Experiment!

1. Think of a way to make the heart rate of the participant go lower. How low do you think the rate can go? Test your hypothesis if the participant is still willing and record the results
   
   Lowest heart rate observed?
   
   What did you do to make it go so low?

2. Think of a way to make the heart rate of the participant go higher. How high do you think the rate can go? If the participant is still willing, test your hypothesis and record the results
   
   Highest heart rate observed?
   
   What did you do to make it go so high?

3. ¡Turn off! all equipment. Return everything to the order you founding it in,
   if not a little better

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Check in 

• The filter you built actually snuck a little extra gain into our system. The filter amplifies by an amount H = R2/R1, thereby making the Overall Gain 

Overall Gain = G x H = (          ) x ( ) = __________ 

• If the signal you are measuring has been amplified by the Overall Gain, what is the size of the original signal? [Hint: The measured signal is the original signal multiplied by the Overall Gain.]

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GO BEYOND

Next steps. Share what you learn, learn how to share

1. Write down one or two things you learned today.²
2. Is it important to ask someone’s permission before measuring their heart beats?
3. Can you think of other biomedical data whose integrity, security, and privacy we want to guarantee?
4. How could we secure such guarantees?
5. What can we do to make healthcare better?
   

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2. Are you interested in learning more about biomedical engineering? (If so, consider visiting https://bme.umich.edu.)

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Stephen Romero, 6

Keyla Salazar, 13

Trevor Irby, a 2017 graduate of Keuka College

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Section 3 of the Senate Committee on Science and Technology’s substitution to H.B. 481 begins “Chapter 2 of Title 1 of the Official Code of Georgia Annotated, relating to persons and their rights, is amended by revising Code Section 1-2-1, relating to classes of persons generally, corporations deemed artificial persons, and nature of corporations generally, as follows:”  

[I provide an image of the text below for posterity. The image having .a powerful effect on history.]

Should we find it disconcerting that at least some subset of us are now playing the game of life under a legislated “two classes of persons: natural and artificial”? To be a  “natural person”, one need merely be a human, “including [as] an unborn child”. To be artificial, look to those “creatures of the law”, look to those “subject to be changed, modified, or destroyed at the will of their creator”, look to those, “Corporations”. That, on the one hand, we persons are as meager as those with “steady and repetitive rhythmic contraction of the heart within the gestational sac [and who are] a member of the species Homo sapiens”. There, on the other, is the plain and hidden fact: “Corporations are artificial persons […] except insofar as the law forbids”.

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We are told of “a practice knot used in fishing” as having been the “rope resembling a noose found inside University Hospital” found a Thursday afternoon, late June, in Ann Arbor, Michigan. The rope, “typically used for traction after surgical procedures” was tied in a “Uni Knot” an investigation by University of Michigan Division of Public Safety & Security concluded as of at least a Tuesday in mid-July.

“An employee came forward to clear the air after the incident was reported” Heather Young, Division of Public Safety & Security, Director of Strategic Communications is to have said.

University Police do not believe that the incident was a hate crime, “based on multiple witness interviews and other evidence”. This having been conveyed a few weeks after the Executive Vice President for Medical Affairs and Dean of the University of Michigan Medical School, Marschall Runge, said that “in one of our hospitals, a noose – a symbol of hate and discrimination – was found”, prompting an “investigation” into “an  act of hate [that] violates all the values [] we hold dear”. Division of Public Safety & Security Director of Strategic Communications Heath Young is to have added “there was no evidence to indicate that a crime, motivated by bias, had been committed.” This on the day (or approximately the day before that) in which the U.S. House of Representatives, by a tally of 240 to 187, voted to approve H. Res. 489, “strongly condemn[ing the] President[…]’s racist comments that have legitimized and increased fear and hatred of new Americans and people of color”.

In clouds there is shade and silver linings. Sometimes rain.

Over time, enrichment, erosion.

Here find the clouds, here be the rain.

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Self

1. Borges and I
2. Full-body illusions and minimal phenomenal selfhood
3. Identity, Self-Awareness, and Self-Deception: Ethical Implications for Leaders and Organizations
4. Individuals are Inadequate: Recognizing the Family-Centeredness of Chinese Bioethics and Chinese Health System

Body modification

1. Body Modification: An Introduction
2. Confounding Extremities: Surgery at the Medico-ethical Limits of Self-Modification
3. Should we prevent non-therapeutic mutilation and extreme body modification?
4. Nonmainstream Body Modification- Genital Piercing, Branding, Burning, and Cutting

Body art

1. Anchoring the (Postmodern) Self?: Body modification, fashion, and identity
2. Bodyworlds: The Art of Plastinated Cadavers
3. Bodyworlds and the ethics of using human remains: a preliminary discussion
4. What Should We Do about Eduard Pernkopf’s Atlas?

Fear

1. Fear
2. A Method for Evaluating the Ethics of Fear Appeals
3. Does fear of retaliation deter requests for ethics consultation?
4. The Two Faces of Fear: A History of Hard-Hitting Public Health Campaigns Against Tobacco and AIDS
5. Professor Nobody’s Little Lectures on Supernatural Horror

Body politics

1. Bioethics as Politics
2. ‘Fat Ethics’: The Obesity Discourse and Body Politics
3. HB 481
4. A Man, Burning: Communicative Suffering and the Ethics of Images

Cities

1. Health and Urban Living
2. Urban Bioethics: Adapting Bioethics to the Urban Context
3. The Experience of Living in Cities
4. From the Urban to the Civic: The Moral Possibilities of the City

Antinatalism

1. The Last Messiah
2. Why It Is Better Never to Come into Existence
3. Every Conceivable Harm: A Further Defence of Anti-Natalism
4. The Ethics of Procreation and Adoption

Others

1. Neuroethics and the Problem of Other Minds: Implications of Neuroscience for the Moral Status of Brain-Damaged Patients and Nonhuman Animals
2. Undocumented Patients: Undocumented Immigrants and Access to Health Care
3. Bioethics and International Human Rights
4. Against culturally sensitive bioethics

Michigan

1. 2019 State of the State
2. Michigan Health Policy for the Incoming 2019 Gubernatorial Administration
3. ACA Exchange Competitiveness in Michigan
4. Flint Water Crisis: What Happened and Why?

Love

1. The Neurobiology of Love
2. The Medicalization of Love
3. Self-Transcendence, the True Self, and Self-Love 
4. Love yourself: The relationship of the self with itself in popular self-help texts

Overpopulation

1. Having Children: Reproductive Ethics in the Face of Overpopulation
2. The Ethics of Controlling Population Growth in the Developing World
3. Overpopulation and the Threat of Ecological Disaster: The Need for Global Bioethics
4. Threats and burdens: Challenging scarcity-driven narratives of “overpopulation”

Public Health

1. The right to public health
2. Ethics and Public Health: Forging a Strong Relationship
3. Old Myths, New Myths: Challenging Myths in Public Health
4. A Bridge Back to the Future: Public Health Ethics, Bioethics, and Environmental Ethics

Solitude

1. The Solitude of Self
2. An overview of systematic reviews on the public health consequences of social isolation and loneliness
3. Individual Good and Common Good: A Communitarian Approach to Bioethics
4. Solitude: An Exploration of Benefits of Being Alone

Responsibility

1. Social Responsibilities of Bioethics
2. The Concept of Responsibility: Three Stages in Its Evolution within Bioethics
3. Bioethics for Whom?
4. Towards an Ethics of Blame

History

1. Bioethics and History
2. The History of Bioethics: Its Rise and Significance
3. What can History do for Bioethics?
4. “My Story Is Broken; Can You Help Me Fix It?”: Medical Ethics and the Joint Construction of Narrative

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A Day to Remember by Liu Wei, 2005

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“Survivors from the June 4, 1989, Tiananmen Square protests and massacre shared their stories at a House Foreign Affairs subcommittee hearing marking the 25th anniversary of the student protests.”

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Laquita C. Brown, Right-of-Way Agent for four years

Ryan Keith Cox worked as an account clerk in the same division for almost 13 years

Tara Welch Gallagher, an engineer for six years

Mary Louise Gayle, Right-of-Way agent for over 24 years  

Alexander Mikhail Gusev, Right-of-Way agent for nine years 

Joshua A. Hardy, an engineering technician with Public Utilities for over four years

Michelle “Missy” Langer, an administrative assistant with the Public Utilities division for 12 years

Richard H. Nettleton, an engineer with Public Utilities for 28 years

Katherine A. Nixon, an engineer with Public Utilities for 10 years

Christopher Kelly Rapp, an engineer with the Public Works for 11 months

Herbert Snelling, a contractor from Virginia Beach

Robert “Bobby” Williams, a Public Utilities Special Projects Coordinator for 41 years.

 

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