When calculating the life of a battery it will be necessary to know the number of charge cycles that can be performed until the battery does not begin to lose its capacity.
Depending on the type of battery these charging cycles can vary, the most common being the mobile batteries, manufactured Li-Ion or Li-Po, which have a duration of between 300 and 500 charging cycles according to model and manufacturer.
Once thisE limit we will notice how the battery loses duration of operation, arriving to lose up to 25% of its capacity of load.
At this point it will be necessary to evaluate a battery change.
It should be noted that usage and charging habits can significantly affect battery life. For example, factors such as heat, charge the battery several times a day without it is almost exhausted, etc. Will be affectedits duration.
Therefore, to get the most out of the battery we must know when a full charge cycle is performed, and try to avoid misuse of charge, to increase its useful life.
A charging cycle is considered when the battery has been discharged or its 100% charge has been used.
The manufacturers advise that the charge is never made below the 58% battery, since the battery voltage would not fall so lowTo, so you could end up winning up to 4000 charge cycles.
Tips to increase the life of a battery.

• Avoid extreme heat or cold or very long applications of the device.
• Charge the battery as often as you can.
• Fully discharge the battery from time to time.
• Do not let the battery run out completely before charging.

Below is a table with theDifferent voltages (V), charge cycles (C) and battery percentage (B).

Within the detection systems we can find different types according to their operation, among them the most common:

1. Infrared sensors
2. Vibration sensors.
3. Photoelectric sensors.
4. Ultrasound sensors.
5. Acoustic sensors

Each type of sensor uses different detection methods and each one is recommended according to the situation.

1. Sensors by infraRrojos, are one of the most used types, thanks to its reliable operation and installation, since we can find this type of wired and wireless sensors.
   The infrared sensor has a phototransistor capable of detecting the infrared electromagnetic radiation emitted by a body, this type of radiation is not visible by the human eye. A change of radiation in its perimeter will activate the relay and proceed to send ato alarm signal.
   Within these, there are two models, passive infrared sensor, which only has a phototransistor and assets, which have an emitter and a receiver.
2. Vibration sensors are used mostly in security systems, such as window sensors. car alarms etc.
   Its operation is based on an accelerometer, through a piezoelectric sensor. This type of sensorDue to its construction material it allows to detect changes and pressure when emitting an electric charge.
3. Photoelectric sensors, these are the sensors that use photoelectric rays, normally a transmitter and a receiver are used, they are commonly used in automatic door systems, elevator doors, production chains, etc.
4. The ultrasonic sensors are those that emit an acoustic signalabout 30 kHz, a signal that is not appreciated by humans. This signal or wave propagates through space, walls, objects, doors, etc. once the signal has spread the sensor is activated and any change will trigger the sensor.
   These types of sensors are also used in devices that require measuring distances and detecting objects.
5. Acoustic sensors, are those that can detect the signal emitted by anyobject and are able to detect the pressures that the acoustic waves emit, such as the noise of the crystals when breaking a window.

ABS material (acrylonitrile butadiene styrene) is a type of thermoplastic that is very resistant to impact or shock.

Its applications are several, for example is a material widely used in the manufacture of interiors or components of cars such as moldings, as well as in products for domestic use such as toys, tools, housings of electrical devices etc.

One of its most important characteristics is its great tenacidad in almost all types of temperatures.

Being a very hard material has good chemical resistance, low water absorption and high resistance to abrasion, where other types of plastics would be more brittle.

This type of material is becoming very famous in the particular field and widely used due to the great growth in the sales of domestic 3D printers, the main printing raw material.next to the PLA.

Identification of ABS
Parts that are made of ABS material must be marked in accordance with ISO 11469 (DIN 58840).

Depending on the need for installation and type of base, trolley or chair, we can find various types of fixation. Among the most common we find:

A - Through hole: It has a hole in which a screw or stem is inserted. It is a very simple installation system. Ideal for wheels that should not support a lot of load.
B - Threaded stem: It has a threaded stem or nut, it is fixed to the surface with a nut. It is usually the most used fastening system.
C - Angular plate: They are usually less used fastening systems, they have lateral plates to fix on the base.
D - Plate: It has a rectangular or square plate on its surface, it includes 4 or more fastening holes to the base, it is one of the most common.
E - Smooth stem: The stem without thread is inserted into the female of the base, we can find it in the typical office chairs with wheels, TV furniture etc ...

The Trendelenburg is a position in which a patient lies down with the head lower than the feet. This position is used in surgery and intensive care to improve blood circulation to the brain and abdominal organs.

For example, it is used for patients who are undergoing surgery in the pelvic or abdominal area, as it helps reduce the amount of bleeding during surgery.

The Trendelenburg position is achieved by placing a board under the bottom of the patient's bed so that the head is lower than the feet. The inclination is usually around 20-30 degrees. This position can help improve blood flow to the brain, as gravity helps increase pressure in the veins of the neck, which in turn helps increase venous return.

Additionally, in patients with heart failure, the Trendelenburg position may help improve blood flow to the heart and abdominal organs, which may be beneficial for organ oxygenation and cardiovascular function.

However, this position is not suitable for all patients, in some cases it can cause problems such as decreased blood flow to the heart, decreased pulmonary oxygenation, or even intraocular or ocular pressure. Therefore, it is necessary to evaluate each particular case and the needs of the patient before making the decision to use the Trendelenburg position.