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COSO – The new way of male contraception

COSO is an ultrasound-based and reversible approach to male contraception.

  • COSO - The new way of male contraception.

  • This video shows the application of COSO step by step.

    This video shows the application of COSO step by step.

  • COSO - Small, compact & used at home.

  • COSO Design process - From ideation to prototyping.

  • The Colors - Which COSO suits you?

  • How the COSO works - Take a look inside.

What it does

Many men would like to take on more responsibility in matters of contraception. But the options are limited. COSO is an ultrasound-based, reversible and hormone-free male contraceptive device for home use that temporarily modifies spermatogenesis.

Your inspiration

About a year ago I was diagnosed with cancer precursor cervix due to contraception with the pill. After that, hormonal contraception was no longer an option. When my partner and I were looking for an alternative method, we became aware of the lack of male contraceptives. The problem is not unique to me personally. It affects many others as well. This is also evident in the current growing public discussion about the lack of contraceptive alternatives. So I decided to deal with the development of a new contraceptive approach for men in my master thesis in Industrial Design at the Technical University in Munich.

How it works

The user puts water into the device up to the indicated mark which is set together with a doctor according to individual testicle size. Then the water is heated up to operating temperature. COSO is ready for ultrasound treatment. The user spreads his legs and sits down to place the testicles in the device. The ultrasound process continues for a few minutes. The remaining time can be monitored in real time via the COSO app. After the treatment, the device switches off automatically. The technology of the COSO is based on a study of the Parsemus Foundation from 2012 in which successful research was conducted on ultrasound contraception. So far, the procedure has been applied to animals. Therefore, the technical parameters are hypothetically transferred to humans.

Design process

New technologies only work if they are accepted by users and society. Therefore, user acceptance was the focus of my design process. To identify the user needs, a survey on male contraception was conducted with 422 participants. Based on this, male users between 20 and 30 years in stable relationships were recruited for 25 Co-Design workshops. In the workshops, requirements from the user's point of view were defined as a basis for developing the device. Furthermore the users were asked to draw an ultrasound device according to their own ideas. The sketches were then clustered and transferred into concepts. Subsequently, the approaches were evaluated with experts from urology, andrology, sexual therapy, psychotherapy and research from a professional perspective. After finalising the form by sketches, ergonomic prototypes were made of paper and cardboard to test the dimensions on different test persons. Subsequently, the prototype was checked to the largest common testicular size at the urologist and the shape was adjusted to the testicular anatomy. For the final design a detailed CAD-model was built. In a last step colors and materials were defined and evaluated with users. Brand values, COSO-App and Website were developed in order to communicate the project uniformly.

How it is different

There are only two established methods of contraception for men, the condom and the permanent vasectomy. For men, there have been research approaches to contraception that have not caught on for a variety of reasons. The male contraceptive pill study failed due to its severe side effects. Other approaches like the Vasalgel, which blocks the vas deferens by injections or the surgical Sperm-switch-valve as an implant as well as the contraceptive pants, where the testicles slip into the abdomen couldn’t succeed. According to my research they all failed due to a lack of user-friendliness. COSO, in contrast, offers a user-friendly contraceptive approach that is easy to use without any kind of physical intervention, pain or previously known side effects. A high level of user acceptance could be achieved by including the user's perspective, which is reflected in positive feedback and high interest.

Future plans

The short-term development steps of COSO include a functional prototype to test the technical feasibility with the required components. In addition, the creation of a high-fidelity full-scale prototype is targeted. In order to launch COSO as a contraceptive, it needs financial support for clinical trials. This requires contacts in research or to industrial partners. Without valid data, the project cannot be realised. It is therefore important to give the project attention and space. Here comes a user-centered solution to make a difference in the current contraception situation. COSO has the potential to offer socially relevant added value


Nomination for Franz-Berberich Prize at the Technical University in Munich, Pending interview with political organisation Better Birth Control, which advocates for more contraceptives for men, Pending interview for a contraception magazine and pending part of a documentary about new contraceptive methods.

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