The PSIgasm was designed from the start to be able to measure sexual response regardless of sex, gender, or genital anatomy. The devices we have created are designed to be inserted anally. This allows us to compare variables like the contractions of pelvic floor muscles, genital vasocongestion, and thermal properties of genital tissues across the gender spectrum.
A big problem that we have with existing research into sexuality and sexual response is a strong bias toward a gender-binary viewpoint. Male orgasms and female orgasms are typically treated as entirely separate phenomena, to be studied using totally separate equipment without any expectation of related results. After reading papers and taking data, this seems to us to be an inaccurate and limiting picture of human sexual response. Males and females both experience wide varieties of orgasms, and these experiences do not appear to be fundamentally gendered. The trends that we do see in orgasm can be explained by the same genital tissue displaying different morphologies in the two genders, making certain types of stimulation more convenient for one or the other. With this in mind, we wanted to create an apparatus to measure orgasmic response in a sex-agnostic fashion, to test the extent to which orgasms are or are not dependent on sex or sexual anatomy. One of the first research efforts we hope to undertake is to compare orgasm data from cis-men, cis-women, and trans-people at different stages of hormone treatment and/or reassignment surgery.

At some point we do plan to develop tools to take data from vaginas and penises, despite the difficulties comparing the two types of datasets. A vaginal insert would look similar to the present PSIgasm design, but naturally a penile device would have to look different. Our plan is to embed an elongation-sensitive resistor in a silicone cock-ring to monitor tumescence and penile contractions, in addition to the PPG and EDR sensors that the device would share with the vaginal (and anal) sensors.

Thanks for your interest in the project! I hope this helps answer your question.

-Ned Mayhem

Thanks for reading,

E. P.

As you suggest, I’m using lock-in measurement for the driven sensors: the GSRs, the photoplethymographs, and the thermometers (probably overkill, but what the hell). I am doing actual phase sensitive measurement – phase shifting the response signal and mixing it with the drive signal using a switching mixer, then low pass filtering to determine bandwidth. I am doing my measurements at 4KHz, which is chosen fairly arbitrarily. I want them fast enough to avoid most 1/f noise, but not so fast that I need fancy switches or opamps to keep up.

The reflectometer I’m using for the photoplethysmograph shines in the infrared: 950nm. The infrared is the most common band for photoplethysmography. Some folks at the University of Amsterdam make a good case that 800nm is ideal because the absorption spectra of oxygenated and nonoxygenated haemoglobin intersect at this wavelength. If these two types of blood cells have different optical properties at the wavelength we’re using, then our photoplethysmography data will have respiration artifacts. I decided that the cheap sensors I found at 950 nm were close enough, and certainly many research groups have done good photoplethysmography research around this wavelength.

If you don’t mind my asking, what wavelength(s) are you using for the photo-plethy measurements?

Can’t wait for the next Sex Geek Pot Luck. Wheeeeeeeeee!

xREiD

Liz’s good point #1: There’s currently no rigor on PSIgasm.net
The project page states that “we’re all about studying human sexuality with the rigor and candor that it deserves.” That is more of a mission statement than a description of the current state of the project.
Let me be clear that we have not studied anything rigorously yet. Good hard science is the goal, but we’ve just started and we’re definitely not there. We’re still developing the tools necessary to approach the interesting questions of sexuality with scientific rigor. What I’ve posted on the site so far is just some preliminary data; a proof of concept. The rigor will be demonstrated in the next six months, or the project will fail.
The reason I use words like “rigor” on the website now is to make our values on the subject clear. We are a project that values scientific rigor, and I want to get people who share that value to get interested in the project. Like you, Liz, they will supply insight and constructive criticism throughout the process of developing and refining our methodology.

Liz’s good point #2: The PSIgasm project hasn’t even defined “rigor”
This is important, especially in the early stages of the project before we have developed actual rigorous methodology to point to. I would define “rigor” in the scientific sense as a scrupulous dedication to a logically consistent presentation of data that is as unambiguous as possible. This really just means applying the scientific method consistently. We will present as clearly as we can exactly what we did (our methods) and what we observed (our results). We will not claim to have proven anything that we have not actually proven. This seems obvious, but as a physicist I get seriously annoyed reading “scientific” journals that confuse speculation with conclusion. It happens constantly.
So what does rigor mean practically in these experiments? We will be measuring physiological variables that have been shown to correlate with arousal and orgasm. In this context, rigor means calibrating all of our sensors accurately and publishing the calibration procedures for criticism. It means testing the repeatability of the sensors over time during one session with a subject, among different sessions with the same subject, among different subjects, etc. It means using blind control groups for every correlation we claim to observe. It means publishing our data analysis routines. Most importantly, it means acknowledging the inherent shortcomings of our experiments: volunteer biases, limited sample sizes, and environmental circumstances beyond our control that might affect our measurements.

Liz’s good point #3: What’s the point?
This is obviously an important question. I could study the optical properties of the a blind man’s apartment, and no matter how rigorous the measurements were nobody would care. I started this project because I think many people will care. Sex is an experience common to almost every human being. It affects how we interact socially, how we bond with each other, how we fall in love and how we stay in love. And of course, it is the very mechanism through which our species continues to exist.
It is widely acknowledged that a “healthy” sex life is important for a strong relationship. Usually we think of this need in the context of psychology or psychiatry; completely separate from the physiology of sex, which we associate only with reproduction and fertility. In reality, the two are strongly connected. Whether we have orgasms, how they feel, whom we decide to have them with and what we want to do afterwards are connected to how our bodies work physiologically. Understanding the physiological sex responses can give us a context for how we interact with, or judge, our fellow humans. It is no surprise that Masters and Johnson, the pioneers of rigorous sex research, were also the inventors of the field of sex therapy for couples.

I hope this reply helps address your concerns somewhat. Of course, my ideas on the subject will be much more convincing when I can back them up with useful data that I’ve acquired through rigorous scientific methodology. Until then, it’s all just talk.

Thanks again, Liz, for your input.

Cheers!

Ned

I’d be really interested to know what the point of this is, how the results could be used and what the benefits of it are.