What is Penile Function Test?

Penile function or impotence test is used for determination of whether penile function disorders such as Erectile Dysfunction (ED) are of vascular or vasculogenic nature. Several causes may be responsible for Erectile Dysfunction. The main causes of erectile failure include vasculogenic, neurogenic, hormonal, and psychological factors.


How to Perform Penile Function Tests

The purpose of penile physiological tests is to diagnose vascular causes of ED or rule this factor out. All common risk factors for cardiovascular disease also serve as vasculogenic risk factors for impotence or penile function failure.


The physiological assessment of penile function includes the measurements of penile blood pressure and the corresponding penile-brachial index (PBI), Pulse Volume Recordings (PVR) on the penis, Doppler blood flow measurements on the penile arteries, and particularly the penile dorsal arteries, and PPG penile measurements.


Doppler Probes
Gold Standard ABI Measurement Method


PPG Sensors
Secondary Method of ABI Assessment

Inflatable Cuffs High quality available in a variety of sizes

Inflatable Cuffs
High quality available in a variety of sizes

Using the Falcon for Penile Function Tests


The Falcon has a dedicated Penile function protocol that allows complete assessment and diagnosis of Erectile Dysfunction and vasculogenic sources of impotence. The Falcon supports all standard methods for penile physiological testing and diagnosis, including measurements of penile pressure and calculation of the corresponding PBI Penile-Brachial Index, PVR, Doppler, and PPG penile measurements. In addition, the Falcon supports Reactive Hyperemia, and all of the physiological tests can then be repeated under RH stress conditions for improved diagnosis.


The Falcon has an assortment of small pressure cuffs of various sizes that are designed for penile pressure and PVR testing. In addition, a range of Doppler probes of various frequencies is available for penile blood flow testing, and in particular, the 10 MHz probe is considered ideal for measurements in superficial arteries. Special small disk PPG sensors can be ideal for blood pressure measurements as well and can be attached to the penis via a special dedicated, transparent adhesive sticker.


The Penile Function protocol can be configured to include a combination of any number of the physiological tests described above for optimal and complete vascular and physiological diagnosis for the vasculogenic sources of impotence. PBI is calculated automatically and clearly displayed both on-screen and in the examination report. All Doppler blood flow velocity parameters are also displayed automatically for each Doppler measurement. These include:


  • Peak
  • Mean,
  • End-Diastolic blood flow velocity,
  • Pulsatility Index,Resistance Index,
  • Systolic to Diastolic Ratio,
  • Systolic Rise Time.


For PVR assessment, the Falcon provides the waveform Amplitude and Systolic Rise Time parameters, in addition to the high-resolution PVR waveform.

Expected Results

PBI is defined as the penile blood pressure divided by the higher of the right/left brachial pressure. According to several international guidelines PBI is diagnosed and evaluated as follows:


Range Common Diagnosis
0.7 ≤ PBI < 1.0 Normal
0.6 ≤ PBI < 7 Borderline
PBI ≤ 0.6 Abnormal


For Doppler assessment of penile function, a peak systolic blood flow velocity above 30 cm/s is generally considered normal. In addition, an RI (Resistance Index) above 0.8 is also considered normal.


PVR measurements that are considered normal include a short systolic rise time and a high amplitude, with a Dicrotic Notch in the waveform that may be present or absent.

Selected Literature


Guidelines on Male Sexual Dysfunction: Erectile dysfunction and premature ejaculationE. Wespes et al.European Association of Urology 2012


Techniques in noninvasive vascular diagnosis, An Encyclopedia of Vascular TestingRobert J. DaigleSummer Publishing LLC., Third edition Nov 2008, Ch. 14, pp. 239-246


Noninvasive vascular evaluation in male impotence: Technique, Cindy Ramirez, Mike Box and Leonard GottesmanBruit, Vol IV, June 1980, pp. 14-16


A Comparison of Penile-Brachial Index (PBI) and Penile Pulse Volume Recordings for Diagnosis of Vasculogenic Impotence, Donna Stauffer and Ralph G. DepalmaBruit, Vol VII, March 1983, pp. 29-31


The noninvasive diagnosis of vasculogenic impotenceBruce M. Elliott et al.J VASC SURG 1986; 3:493-7


Usefulness of power Doppler ultrasonography in evaluating erectile dysfunctionA.J. Golubinski and A. SikorskiBJU International (2002), 89, 779–782


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