A Hulda Clark zapper is a small battery device that pulses one fixed square wave through two electrodes. A Rife machine works with lists of specific frequencies, and bioresonance claims to read and return the body's own signals. No controlled trial shows that a zapper kills parasites or cures disease. ResoField is browser software and sends no current.
Type "zapper" into Google and you get bug zappers, a payments app and a Nintendo light gun. This article is about none of those. It is about the frequency zapper: a small battery device that sends a weak pulsed current through your hands, made famous by Hulda Clark in the 1990s.
People who come to frequency work often meet three names at once: the zapper, the Rife machine and bioresonance. They get mixed up all the time, even by sellers. They come from different people, rest on different ideas and do different things. Below I go through each of them, including the criticism, and then explain where software like ResoField fits and where it does not.
Who was Hulda Clark?
Hulda Regehr Clark was born in 1928 in Rosthern, Saskatchewan, Canada. She earned a doctorate at the University of Minnesota in 1958; the university register lists it as zoology. Later she obtained a naturopathy degree from Clayton College of Natural Health, a correspondence school without accreditation.
She became known through her books The Cure for All Cancers (1993) and The Cure for All Diseases (1995). Her central claim was that cancer and many other diseases are caused by parasites, above all the intestinal fluke Fasciolopsis buski, together with solvents and other toxins. Her answer was a three part programme: an herbal parasite cleanse (black walnut hull, wormwood and cloves), avoiding toxins, and the zapper.
Clark ran a clinic in Tijuana, Mexico. Mexican authorities closed it in 2001. She died in 2009 in Chula Vista, California. According to her family, her doctors considered multiple myeloma, a blood cancer, the most likely cause.
What a zapper is and how it works
A Clark zapper is a battery powered pulse generator with two electrodes, traditionally copper tubes that you hold in your hands. Wristbands or pads are also used. The device sends a low voltage square wave through the body.
Two technical details set it apart. First, the signal has a positive offset: it switches between zero and a positive voltage and never goes negative. Second, the frequency is fixed. In her book Clark allowed a wide range, but the classic zapper runs at around 30 kHz, and that is the figure most products still use. A vendor summary of Clark's own specifications lists battery operation, a positively offset square wave of 5 to 10 volts and sessions of seven minutes.
Clark's idea was that this one pulse would kill viruses, bacteria and parasites all at once, without harming human tissue. Her routine was three sessions of seven minutes with a rest of about twenty minutes in between. The thinking was that the second and third rounds would catch what the first released.
Modern zappers often add programs with other frequencies, a display and a rechargeable battery. Some are sold in the EU with medical device approval, usually as a stimulator in the same family as a TENS device. That approval covers a specific stated purpose. It is not a confirmation of Clark's parasite theory.
What critics, scientists and regulators say
This is where an honest article has to be blunt. There is no controlled clinical study showing that a zapper kills parasites in the body or cures any disease.
- Science Feedback reviewed the claims in January 2024 and rated them incorrect. Fasciolopsis buski is found mainly in South and Southeast Asia and cannot pass from person to person, so it cannot explain cancer in Europe or America.
- In 2004 the US Federal Trade Commission settled with the Dr. Clark Research Association and its Swiss sister company over the Super Zapper Deluxe and the Syncrometer. The FTC settlement banned unsubstantiated health claims and required full refunds to American buyers.
- Quackwatch describes Clark's Syncrometer as a simple skin resistance meter and her case histories as lacking proper diagnosis and follow up.
- In 2004 the New England Journal of Medicine described a patient whose pacemaker was disturbed by an alternative medicine device; Quackwatch and German Wikipedia identify it as a zapper.
The biggest risk is not the weak current itself. It is people skipping effective treatment because they believe the zapper will handle it. Clark advised her own patients against surgery, radiation and chemotherapy. If you have a pacemaker or another electronic implant, even the people who sell and build zappers tell you not to use one.
I find the history uncomfortable, and I would rather say so than pretend otherwise. You can find frequency work interesting and still reject the claim that one 30 kHz pulse cures everything.
Zapper vs Rife machine
The zapper and the Rife machine are related but start from opposite ideas.
Royal Raymond Rife worked in the 1930s on the notion that every microorganism has its own "mortal oscillatory rate", a frequency at which it would fall apart. A Rife approach is therefore specific: you look up a frequency or a series of frequencies for a target and run them one after the other. Community lists such as the CAFL contain thousands of these programs.
Clark also believed that every organism has its own range of frequencies. Yet the zapper she became known for goes the other way. One fixed pulse, the same for everybody, meant to hit everything at once. You do not choose a program.
In hardware the two can look surprisingly alike. Wikipedia cites an analysis in Electronics Australia of a typical Rife device that turned out to be a simple circuit almost identical to Clark's zapper. Larger Rife systems such as Spooky2 use programmable generators with contact pads, plasma tubes or other accessories, and the price rises with every mode.
Neither approach has clinical proof. Cancer Research UK states there is no reliable evidence that the Rife machine works as a cure for cancer.
Zapper vs bioresonance
Bioresonance has yet another starting point. It was developed in Germany in 1977 by Franz Morell and engineer Erich Rasche, first under the name MORA. The idea is that the body gives off its own electromagnetic oscillations. A bioresonance device picks those up through electrodes, processes them (for example inverted) and sends them back.
So where a zapper always sends the same pulse and a Rife device sends a chosen frequency, bioresonance claims to work with the client's own signal. Practitioners also use it for testing, which a zapper does not do at all. Devices such as MORA and BICOM cost thousands of euros.
The scientific status is comparable. The Wikipedia article on bioresonance notes that studies have found no effect beyond placebo, and the US FDA has acted against sellers making false health claims.
The three side by side
| Aspect | Zapper (Clark) | Rife machine | Bioresonance |
|---|---|---|---|
| Origin | Hulda Clark, 1990s | Royal Rife, 1930s | Morell and Rasche, 1977 |
| Signal | One fixed square wave, about 30 kHz, positive offset | Chosen frequencies per program | The body's own signal, processed and returned |
| Choice per target | No | Yes | Yes, often after testing |
| Typical hardware | Small battery box with two electrodes | Generator with pads, plasma tube or other output | Professional device with electrodes |
| Clinical proof | None | None | None beyond placebo |
Where ResoField fits
ResoField is not a zapper, and it is not a Rife generator or a bioresonance device either. It is free browser software. It produces no current, no audio, no PEMF and no other physical signal. Anyone who wants the physical output of a zapper or a generator needs hardware.
What ResoField does is the work around frequencies and remedies. It has a RIFE library where you can open a program, switch individual frequencies on or off and keep your own frequencies in lists. Next to it are a bioresonance bank (meridians and other groups), a homeopathy bank with potency scales and the Banerji protocols. You link everything to a client profile, and you broadcast digitally to that client with name and date of birth as the witness, in person or at a distance. Plans, protocols and session history keep track of what was sent and when. How ResoField works explains this step by step.
If you are mainly interested in the Rife side and wonder whether you need hardware, the comparison Spooky2 vs ResoField puts the two side by side.
Sources
- Hulda Regehr Clark, Wikipedia
- Clark Therapie, German Wikipedia
- Swiss Company to Provide Refund to U.S. Consumers, FTC, 3 December 2004
- Hulda Clark's "zapper" device is based on pseudoscience, Science Feedback, 12 January 2024
- The Bizarre Claims of Hulda Clark, Stephen Barrett, Quackwatch
- Hazards of an alternative medicine device in a patient with a pacemaker, Furrer, Naegeli and Bertel, N Engl J Med 2004
- What is a Dr. Hulda Clark Zapper?, summary of Clark's specifications by a zapper vendor
- Royal Rife, Wikipedia
- Bioresonance therapy, Wikipedia
FAQ
What is a zapper?
A frequency zapper is a small battery device that sends a weak pulsed current through the body via two electrodes, usually copper tubes held in the hands. The best known version follows Hulda Clark's design: a square wave of around 30 kHz with a positive offset.
Does a zapper really work?
No controlled clinical study shows that a zapper kills parasites in the body or cures any disease. Science Feedback rated Clark's claims incorrect, and the FTC banned the Dr. Clark Research Association from making unsubstantiated health claims. The device does produce a current; the health claims have not been demonstrated.
How long and how often do people zap?
Clark's routine was three sessions of seven minutes with a rest of about twenty minutes in between. Modern devices often use their own timers and programs. These routines come from Clark and the manufacturers, not from clinical research.
Who should not use a zapper?
People with a pacemaker or another electronic implant should not use one; the New England Journal of Medicine described a pacemaker disturbed by such a device. A zapper is never a reason to postpone a visit to a doctor.
Is a zapper the same as a Rife machine?
No. A Clark zapper sends one fixed pulse that is supposed to affect everything at once. A Rife machine uses specific frequencies or programs per target. Simple Rife devices can be technically almost identical to a zapper, but the idea behind them differs.
Can ResoField replace a zapper?
Not as a device. ResoField sends no current and has no electrodes. It is free browser software for RIFE programs, a bioresonance bank, homeopathy, client profiles and digital broadcasting with a witness. If you want a physical signal, you need hardware.
This article does not provide medical advice. Sources were checked on 11 October 2026.
Matt
Matt is a software developer and self-taught homeopathy practitioner who founded ResoField in 2025. Together with his wife, who runs a resonance therapy practice, he has 7+ years of hands-on experience and 100+ clients treated. With personal experience using devices like QEST4, Sulis, and Mora, he bridges the gap between IT and holistic health.
