I saw this and thought it would be worth discussion:
Fitted with a blood dispensing mechanism and lower-abdomen-stimulating electrodes, the Menstruation Machine simulates the pain and bleeding of an average 5 day menstruation process of a human.
The Royal College of Art / Design Interactions via wired.co.uk. Saved screenshot.
I’ve anecdotally heard the pain of menstrual cramps compared to that of testicular injury (specifically “getting kicked in the balls”).
How could this be tested?
This artist’s design uses electrodes to stimulate the lower abdomen to simulate pain from menstrual cramps. A researcher examining would need to examine several factors:
- What electrode intensity and placement is comparable to pain from menstrual cramps  in females?
The researcher would need to attach electrodes to female test subjects to deliver painful electric shocks, and have the test subjects evaluate the electrode pain against menstrual cramps. This might need to be done during menstruation to avoid the biases of memories of pain. - What electrode intensity and placement is comparable to pain from testicular injury in males?
The researcher would also need  to attach electrodes to male test subjects to deliver painful electric shocks, and have the test subjects evaluate the electrode pain against testicular injury. This might need to be done during the application of testicular injury to avoid the biases of memories of pain. - Is the range of pain generated by electrodes sufficiently wide to replicate the range of pain generated by either menstrual cramps or testicular injury in the respective test subject gender?
- Do the electrode-generated sensations of pain translate between sexes across the ranges of intensity?
Unethical?
This should  obviously be unethical.  A researcher would need to apply painful shocks to both male and female test subjects, in a variety of locations and at varying intensities. Furthermore, a researcher would need to test while a test subject experiences either  menstrual cramps or testicular injury. While menstrual cramps may occur naturally and predictably, testicular injury is unpredictable. The male test subjects would need to be fitted with sensors on their scrota to measure  the intensity, location, and duration of physical force directed at said scrota. Alternatively, (and significantly less palatable), the researcher would need to repeatedly apply physical force to the male test subjects’ scrota, while varying  intensity, duration, and location.
Furthermore, several studies have already demonstrated that male and female pain tolerance thresholds are significantly different.  For starters: Woodrow, et al. Pain Tolerance: Differences According to Age, Sex and Race. Psychosomatic Medicine.  1972;34(6):548-556, retrieved 2010-06-29 from Psychosomatic Medicine.
Finally, the social value of such a study is questionable at best.
The impetus behind the scientific method is to answer questions. Why is the sky blue? Do objects of different mass fall at different rates? Will ordinary human beings inflict punishment upon other humans – up to and including lethal force – as long as they are told they are not responsible?
Many of these questions can and already have been answered through carefully designed and ethically executed studies.
This Institute is not concerned with those studies.
Some questions may only be answered through studies which could be considered unethical. Other questions may be answered through studies which could be considered ethical, but another, potentially unethical study could also attempt the same.
This Institute exists to catalog, examine, and discuss studies which could potentially violate one or more of widely-accepted ethical principles of conduct or research.
What is ethical?
There is no universally-accepted arbiter of ethical or unethical behavior.
That said, there are several guidelines for defining what would constitute an ethical or unethical study.
The American Psychological Association (APA) lists five General Principles, which I have paraphrased below:
- Beneficence and Nonmaleficence
Essentially, “do no harm” – to those under their care as well as those affected by their work. - Fidelity and Responsibility
Establish and uphold relationships of professional and scientific trust, individually as well as for colleagues. - Integrity
“…promote accuracy, honesty, and truthfulness in the science, teaching, and practice of psychology.” Psychologists should fully and seriously consider the necessity and consequences of situations where deception may be necessary. - Justice
“Psychologists exercise reasonable judgment and take precautions to ensure that their potential biases, the boundaries of their competence, and the limitations of their expertise do not lead to or condone unjust practices.” - Respect for People’s Rights and Dignity
Protect the rights (especially of privacy, confidentiality, and self-determination), dignity and welfare of all people, especially those whose abilities of self-determination are impaired. Attempt to eliminate the effect of personal biases, and refrain from participating or condoning acts of others based upon prejudices.
Other resources include:
- The Hastings Center:
http://www.thehastingscenter.org - The World Health Organization:
http://www.who.int/topics/ethics/en/ - The Berman Institute of Bioethics at Johns Hopkins University:
http://www.bioethicsinstitute.org/ - The Hippocratic Oath (both classical and modern):