Penile Function

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. 

Penile Function

How to Perform Penile Function Tests

Performing a penile function test using a vascular machine involves using various techniques like Doppler ultrasound, Systolic Blood Pressures, and PVR (Pulse Volume Recording) to assess the vascular health of the penile region. 

Required Equipment

ED Test

Learn More
ED Test
CW Doppler Probes for Viasonix Falcon systems


Falcon Toeclips PPG


Falcon Inflatable Cuffs

Inflatable Cuffs

Here’s how you can perform the an Erectile Dysfunction test:

  1. Preparation:
    • Make sure the patient is in a comfortable position, preferably lying down.
    • Ensure the room is appropriately lit and maintained at a comfortable temperature.
    • Explain the procedure to the patient, obtain consent, and provide appropriate draping.
  2. Gather Equipment:
    • You’ll need a vascular machine with Doppler ultrasound capabilities, PPG sensors, and PVR cuffs.
    • Make sure you have the appropriate gel for the Doppler probe.
  3. Doppler Ultrasound:
    • Apply a small amount of ultrasound gel to the penile area to ensure good acoustic contact between the skin and the Doppler probe.
    • Place the Doppler probe on the penile dorsal artery at the base of the penis.
    • Use the Doppler function of the machine to detect and record blood flow velocities.
  4. Blood Pressure Measurements:
    • Perform a blood pressure test on the Brachial to get a baseline systolic pressure that will be used later to calculate the PBI (Penile to Brachial Index)
    • Use appropriately sized blood pressure cuffs for the patient’s penis. Perform a blood pressure while the Doppler probe is aimed at the Penile Dorsal artery.
    • Repeat until a systolic pressure is obtained for both sides of the Penile Dorsal artery and both sides of the Penile Cavernosal Artery. 
  5. PVR Measurements:
    • Wrap PVR cuffs around the penile shaft. These cuffs will inflate and measure the pulse volume changes in the penis.
    • It is possible to also perform a PVR on the digit to serve as a comparison waveform.
  6. Data Collection and Analysis:
    • Doppler ultrasound will provide blood flow velocity measurements.
    • Systolic blood pressure values will be used for calculating the PBI (Penile-Brachial Index).
    • PVR sensors will generate pulse volume waveforms.
  7. Interpretation:
    • Calculate the PBI using the penile blood pressure (systolic) and the higher of the right/left brachial pressures. The formula is PBI = Penile BP / Higher Brachial BP.
    • Analyze Doppler blood flow velocity measurements for velocity related parameters such as peak systolic velocity and resistance index (RI).
    • Interpret blood pressure values based on established ranges for normalcy.
    • Analyze PVR waveforms for abnormalities in the pulse volume pattern.
  8. Documentation and Reporting:
    • The vascular machine will often provide automatic calculations and measurements for parameters like PBI (Penile-Brachial Index) based on collected data.
    • Interpret the results based on established ranges for PBI and Doppler velocities, as mentioned in your provided content.
    • Include the measurements, waveforms, and any abnormalities observed during the test.

This step-by-step guide for performing an Erectile Dysfunction test is for informational purposes only. Healthcare professionals should rely on their expertise, clinical judgment, and institutional protocols for accurate administration and interpretation. Additional clinical information, patient history, physical examination, and other diagnostic tests may be necessary for comprehensive evaluation.

Using the Falcon for Penile Function Tests

The Falcon, a specialized vascular system, offers several benefits for conducting Erectile Dysfunction (ED) tests, including the assessment of penile function. 

Here are the advantages of using the Falcon for ED testing:

  1. Dedicated Penile Function Protocol: A dedicated protocol specifically designed for penile function tests. This protocol enables a comprehensive assessment and diagnosis of Erectile Dysfunction, particularly focusing on vasculogenic sources of impotence.

  2. Complete Physiological Testing: Wide range of standard methods for penile physiological testing and diagnosis. This includes measurements of penile pressure, calculation of the Penile-Brachial Index (PBI), Pulse Volume Recordings (PVR), Doppler blood flow measurements, and PPG penile measurements. 

  3. Variety of Cuffs and Probes: An assortment of small pressure cuffs of various sizes designed specifically for penile pressure and PVR testing. Additionally, the vascular machine provides a range of Doppler probes with various frequencies, including the ideal 10 MHz probe for superficial artery measurements. 

  4. Specialized PPG Sensors: Specialized small disk PPG sensors that can be attached to the penis using dedicated transparent adhesive stickers. 

  5. Automatic Calculations and Displays: Automatic calculation of parameters such as the Penile-Brachial Index (PBI) and display of Doppler blood flow velocity parameters for each Doppler measurement including Peak, Mean, End-Diastolic blood flow velocity, Pulsatility Index, Resistance Index, Systolic to Diastolic Ratio, and Systolic Rise Time. 

  6. Enhanced Examination Report: The calculated PBI and Doppler measurements are not only displayed on-screen but are also included in the examination report. 

  7. High Quality Measurements: The Falcon’s high-resolution PVR waveform and excellent quality of spectral Doppler provides easier measurement of the penile function test.

  8. Efficiency and User-Friendly Interface: User-friendly interface and automated calculations streamline the testing process.

  9. Clinical Applications Beyond ED Testing: In addition to penile function tests, the Falcon supports a wide range of clinical applications in the field of vascular and angiology diagnostics, making it a versatile tool for healthcare professionals.

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:

RangeCommon Diagnosis
0.7 ≤ PBI < 1.0Normal
0.6 ≤ PBI < 7Borderline
PBI ≤ 0.6Abnormal

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

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

Noninvasive vascular evaluation in male impotence: Technique, Cindy Ramirez, Mike Box and Leonard Gottesman, Bruit, 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. Depalma, Bruit, Vol VII, March 1983, pp. 29-31

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

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

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The content of Viasonix Ltd. website is for information only, not advice or guarantee of outcome. Information is gathered and shared from reputable sources; however, Viasonix Ltd. Management is not responsible for errors or omissions in reporting or explanation. No individuals, including those under our active care, should use the information, resources or tools contained within this self-diagnosis or self-treat any health-related condition. Viasonix Ltd. Management gives no assurance or warranty regarding the accuracy, timeliness or applicability or the content.