Introduction
Penile plethysmography is a measure of the sexual arousal of the male in response to a certain sequence of erotic and neutral stimuli. This measures the blood flow to the penis, and so it is known as the most reliable objective method of assessing male sexual arousal to distinct stimuli. The blood flow to the penis is a vital physiologic phenomenon in erection (the penis becomes hard and enlarged due to raised blood flow). This device contributes to diagnosing and treating men with paraphilic interests. It can also be used to assess men who have committed sex crimes.
What Is Penile Plethysmography?
Penile plethysmography, also called phallometry, is a device used to measure blood flow to the penis. So, it is generally used as a substitute or adjunct for measuring sexual arousal. It measures blood flow since it is essential for sexual erections and the overall sexual life. So, penile plethysmography can be helpful, particularly for assessing and diagnosing the erectile function of a man.
Erection and Blood Flow:
During sexual arousal of the male genitals, the blood vessels of the genital organs expand, intending to supply sufficient blood to the penis. Consequently, the veins carrying the blood from the penis constrict, so excess blood resides inside the genitalia. This makes the testicles expand and the penis enlarged, engorged, and hard (erect). This physiologic phenomenon in which the penis of a male becomes erect is called erection. Consequently, the individual needs to have an orgasm (sexual climax) and sexual ejaculation (semen discharge) for the male genitals, including the penis, to return to their actual position.
What Are the Different Types of Penile Plethysmography?
Penile plethysmography can be done in varied ways to measure the oxygenated blood flow to the penis.
The two significant types of penile plethysmography include
1. Volumetric Air Chamber: The air chamber measures the air displaced while the tumescence (normal enforcement with the blood in the erectile tissues) rises. In this method, a glass tube-like device is placed over the penis, followed by induction of erection. The blood flow is learned by calculating the changes in air volume in the glass tube between the flaccid (not tight or not erect) and erect states.
2. Circumferential Transducer: A circumferential transducer measures blood flow by measuring changes in the circumference. Here, an electromechanical strain gauge, a mercury-in-rubber ring, or an indium and gallium-in-rubber ring can be used. So, the ring is placed around the shaft of the individual's penis. Then the changes in circumference are measured. The two different types of strain gauges used here are as follows:
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An electromechanical strain gauge is composed of a lightweight metal that can be wrapped around the penis. This metal changes its shape during the occurrence of erection. So, the comparison between the erect and flaccid measurements of the strain gauge makes up for the changes in blood flow to the penis.
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The mercury-in-rubber strain gauge is typically a rubber ring permeated with mercury. This ring's circumference modifies and alters its mercury distribution when the penis drives from a flaccid state to an erect state. These changes in mercury distribution can help determine blood flow discrepancies.
The most commonly used penile plethysmography method is the circumferential transducer. But, the experts say that the volumetric method gives more accurate findings even at low arousal levels.
How Does Penile Plethysmography Work?
The penile plethysmography test is typically used to measure a man’s level of sexual arousal. Firstly, a pressure-sensitive device is placed over or around the penis. Then, various sexually stimulating presentations in the form of movies and pictures are put forth. Using different types of devices or methods, the level of sexual attraction is determined by measuring minute changes in erectile responses.
How To Pass Penile Plethysmography Test?
During the session, it is essential to sit back and relax. If the individual becomes aroused, let that happen and if they do not become aroused, that is okay too. The rubber belt is placed across the stomach to monitor breathing. The individual will be sitting on the pressure cushion that will be measuring movement and tightening of the muscles. These gauges are used to measure arousal, movement, and attempts to fake responses.
What Are the Applications of Penile Plethysmography?
In addition to its assessment and diagnostic usage, penile plethysmography can be beneficial in the following conditions:
1. Erectile Dysfunction: Erectile dysfunction, also called impotence, is difficulty getting or sustaining an erection. Penile plethysmography is a great tool for screening contractions between organic (physiologic) and psychogenic forms of erectile dysfunction. This can be used during nerve-sparing surgery (saving the nerves proximal to the tissues to be removed). This device seems helpful in planning for future erectile function treatments.
2. Distinguishing a Specified Population: The clinical studies show that penile plethysmography can be efficiently used to distinguish men with offending sexual interests from men without. Certain meta-analytical research has demonstrated that sexual offenders against certain populations responded more to this penile plethysmograph than the controls. For sexual offenders, this device determines the sexual arousal level when the subject is exposed to sexual-based content like audio, movies, and pictures. So, it has been proven that penile plethysmography could be used to distinguish the following specified sexual offenders from non-offending men.
- Pedophilia: Pedophilia is a psychiatric condition known for sexual feelings towards children. Penile plethysmography can be used to distinguish pedophilic men from non-pedophilic men.
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Hebephilia: Hebephilia is the strong and persistent sexual interest of adults, particularly in pubescent children or early adolescents. The device can differentiate men with hebephilia and men without it.
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Biastophilia: It is a paraphilia (a disorder of sexual preference) condition in which the only way for an individual to attain sexual satisfaction is rape. There is some clinical evidence that penile plethysmography can aid in distinguishing a group of individuals with biastophilia from those without it.
What Are the Pitfalls of Penile Plethysmography?
Certain literature and case law say that penile plethysmography and its outcome can be scientifically unreliable. So, there is still a claim about whether the information emitted from penile plethysmography is a reliable or valid approach to monitoring sexual preference.
Conclusion:
Penile plethysmography comprises a device that measures the blood flow to the penis. So, it is typically used for measuring sexual arousal in erectile dysfunction since good blood flow to the penis is essential for erection. This test can also be performed by men themselves at home. This test has a device that can help distinguish between physical and psychological forms of erectile dysfunction as the man listens to, reacts to, or watches the sexual material.
