Described herein are implantable devices configured to emit an electrical pulse. An exemplary implantable device includes an ultrasonic transducer configured to receive ultrasonic waves that power the implantable device and encode a trigger signal; a first electrode and a second electrode configured to be in electrical communication with a tissue and emit an electrical pulse to the tissue in response to the trigger signal; and an integrated circuit comprising an energy storage circuit. Also described are systems that include one or more implantable device and an interrogator configured to operate the one or more implantable devices. Further described is a closed loop system that includes a first device configured to detect a signal, an interrogator configured to emit a trigger signal in response to the detected signal, and an implantable device configured to emit an electrical pulse in response to receiving the trigger signal. Further described are computer systems useful for operating one or more implantable devices, as well as methods of electrically stimulating a tissue.

A COVID-19 Symptoms Alert Machine (CSAM) scanner, or apparatus, is described herein. This apparatus employs Artificial Intelligent (AI) technology in combination with the latest mobile device technology (viz. smart phone/smart watch) to quickly help track down people who have COVID-19 symptoms anywhere and anytime, isolate them, and professionally handle them, not allowing SARS-CoV-2 virus to spread. CSAM automatically measures body temperature and assesses lung conditions such as pulmonary fibrosis and B-lines (for asymptomatic people), and other current health vital information (CHVI), furnished by the participant, such as fever, sore throat, headache, and body ache to generate an alert signal when COVID-19 symptoms are found significant and to send it out to a COVID-19 control center. The alerted participant is then immediately required to go to the COVID-19 control center or be picked up by a special COVID-19 emergency vehicle for isolation and further evaluation and testing. If the testing turns out to be COVID-19 positive, the participant will be quarantined and treated appropriately according to COVID-19 protocol until he/she is tested COVID-19 negative. In the meantime, people who have been in close physical contact with this participant will be alerted and requested to be immediately checked for COVID-19 symptoms. If anyone is found to have COVID-19 symptoms, then he/she must go through the same protocol. The process is repeated until all people in the cluster are tested COVID-19 negative. This will ensure that SARS-CoV-2 virus for this cluster has been completely eliminated. A rapid deployment of this type of apparatus throughout communities where people tend to congregate such as superstores, supermarkets, and any other establishments, small or large, can help to contain the rapid spread of the disease, as well as to give more confidence to the general public. People, who pass through this apparatus without an alert signal, should feel more confident in carrying out their activities, though social distancing and other COVID-19 precautionary requirements should still be maintained. The concept can be further expanded to cover shopping malls, concert halls, sports arenas, and any other large events including highways and freeways with the help of mobile phone technologies, transponders, and other mobile devices. By working on the 0.6% (around 2 million infected people in the US as of June 2020) quickly and effectively, instead of on the 99.4% (330 million, the remaining population) by locking people at home and closing down all businesses and activities; we can save a significant amount of money and hassles. (A long lockdown can also lead to a col

In some aspects, the described systems and methods provide for a method comprising transmitting to a brain of a patient, with at least one transducer, acoustic signals. The method further comprises receiving from the brain, with the at least one transducer, data acquired from the brain including information related to standing waves, distribution of acoustic modes, frequency response, and/or impulse/transient response. The method further comprises determining, from the acquired data, intracranial pressure of the person.

In some aspects, the described systems and methods provide for a method comprising transmitting to a skull of a patient, with at least one transducer, acoustic signals. The method further comprises receiving from the skull, with the at least one transducer, data acquired from the skull including information related to guided waves, distribution of acoustic modes, frequency response, and/or impulse/transient response. The method further comprises determining, from the acquired data, intracranial pressure of the person.

In some aspects, the described systems and methods provide for a method comprising transmitting, with at least one transducer, acoustic signals to a brain of a patient, wherein the at least one transducer is configured to induce excitation of a plurality of acoustic modes. The method further comprises receiving, with the at least one transducer, data acquired from the brain including information related to standing waves, frequency response, impulse/transient response, and/or distribution of acoustic modes. The method further comprises determining, from the acquired data, a distribution of intracranial pressure within the brain of the person.

In some aspects, the described systems and methods provide for a method comprising transmitting to a brain of a patient, with at least one transducer, acoustic signals. The method further comprises receiving from the brain, with the at least one transducer, data acquired from the brain including information related to standing waves, distribution of acoustic modes, frequency response, and/or impulse/transient response. The method further comprises detecting, from the acquired data, a seizure of the person.

In some aspects, the described systems and methods provide for a method comprising transmitting to a brain and/or skull of a patient, with at least one transducer, acoustic signals. The method further comprises receiving from the brain and/or skull, with the at least one transducer, data acquired from the brain and/or skull including information related to standing waves, guided waves, distribution of acoustic modes, frequency response, and/or impulse/transient response. The method further comprises determining, from the acquired data, presence of a tumor within the brain of the person.

In some aspects, the described systems and methods provide for a method comprising transmitting, with at least one transducer, acoustic signals to a brain of a patient, wherein the at least one transducer is configured to induce excitation of a plurality of acoustic modes. The method further comprises receiving, with the at least one transducer, data acquired from the brain including information related to standing waves, frequency response, impulse/transient response, and/or distribution of acoustic modes. The method further comprises determining, from the acquired data, a location of a seizure site within the brain of the person.

A thermoacoustic imaging device is provided having a transmitter configured to provide an electromagnetic transmit signal (e.g. a continuous sinusoidal signal) to an object being imaged. The transmit signal is a modulated continuous-wave signal based on a carrier frequency signal f.sub.c modulated at a modulation frequency at or near f.sub.m. The detector is further configured to receive an acoustic signal from the object being imaged, and is responsive to acoustic frequencies at or near 2f.sub.m. A non-linear thermoacoustic effect in the object being imaged generates the acoustic signal from the object being imaged. Spectroscopic maps could be generated and imaged object could be analyzed. The device enhances signal-to-noise ratio of the reconstructed image and reduces the requirement of peak power in thermoacoustic imaging systems. In addition, the generated pressure of the imaged object is separated from microwave leakage and feedthrough in frequency through the nonlinear thermoacoustic effect.

A system includes an ultrasound patch probe and brackets having a body and a base. The body includes a coupler and a hollow interior portion. The coupler is operable to receive the probe at a pre-defined ultrasound acquisition angle. The coupler defines a probe opening to provide the probe access to the hollow interior portion of the body. The coupler of each of the brackets is arranged to receive the probe at a different pre-defined ultrasound acquisition angle. The base surrounds a perimeter of the body and defines a bracket opening that extends through the base to provide access to the hollow interior portion of the body. The base includes a bottom surface operable to be secured against skin of a patient. The ultrasound patch probe is communicatively coupled to an ultrasound imaging system and detachably coupleable to the coupler of any selected one of the brackets.