Patent Application
20250143677
The present invention provides a device, tool, or accessory used for elicitation of a reflex response through torque and or mechanical advantage along an axis before impacting another object, person, or material with a predictable impulse, percussion, impact force. Among the uses for the invention is the elicitation of deep tendon responses on neurological exams by delivering a consistent and predictable impulse, impact force, or percussion, thereby enabling more reliable assessments while limiting pain via excessively forceful impact.
Percussion hammers, later named reflex hammers, were inspired by the practice of thumbing a wine cast to find the level of fluid within the cast. In 1875 Erb and Westphal first reported the diagnostic utility of the patellar or knee jerk reflex in examination of the nervous system, then by the 20th century there was an influx of percussion hammers with an assortment different types and shapes of the handle, shaft, and striking head of the device. While initially percussion hammers utilized more rigid heads or striking areas, later versions utilized softer or more elastic materials to limit pain or risk of injury to the recipient or handler of the hammer. A common theme in the development of later reflex hammers was the increased weight of the head, combined in some cases with a longer, sometimes flexible, handle, which was shown to increase the hammer's effectiveness. The weight of the reflex hammers was generally between 50 and 250 grams with a length generally between 10 and 40 centimetres. The material for the handle or shaft, along with the weight for the head was made of metal alloy, and the head of the hammer included a rubber piece to cushion and modulate the percussion, impulse, or force exerted by the hammer.
As of the 21st century, most neurologists, neurosurgeons, physiatrists, and many other medical practitioners use reflex hammers to assess the nervous system using different grading systems. An effective reflex hammer is one which can reliably elicit a reflex response when striking a muscle or tendon in a consistent way and while minimizing pain and risk of injury to the recipient of the striking force, which often includes the patient or practitioner. However, common reflex hammers being used may be inconsistent in their delivery of the percussion, impulse, or force elicited by the hammer, may cause excessive force that may potentially leads to injury, may be too bulky, or may be too expensive. Modulating the forces applied by the hammer enables the user to provide a safer and more effective delivery of the force. In addition, freeing the head of the device to be made up of polymer by maintaining a dense weighed portion among or within the shaft of the device allows for greater flexibility in the shapes of the head and directionality of the impact.
The invention provides for a method to construct reflex hammers and or percussion hammers used in the elicitation of impulse, percussion, or impact force by utilizing the elasticity of the head of the device while maintaining the mechanical advantage of the hammer using dense material within or among the distal aspect of the hammer. The invention outlines multiple ways to modulate the elasticity of the hammer head along with the mechanical advantage of the hammer, which includes but is not limited to the length of the shaft, weight of the device, mechanical advantage along the axis of the device, and elasticity of the head of the device. Placing a higher density within or among the distal aspect of the shaft of the device increases its mechanical advantage while freeing the head of the device to be made of a lower density material such as a polymer, which further modulates the force applied while increasing safety and effectiveness of the device. Having greater flexibility in the design of the reflex hammer head allows for greater diversity in the shape of the reflex hammer, which may further be tailored towards mimicry of other shapes such as cars, planes, animals, plants, weapons, living things, objects, real, virtual, or imagined.
The present invention provides the description and specific examples of the methods to construct optimal reflex hammers.
As used herein, a “device” refers to an object made for a particular purpose, especially when used in a mechanical form.
As used herein, a “shaft” refers to a long, narrow part or section forming the body or handle of a device or tool.
As used herein, “percussion” refers to striking of an object with or against another with some degree of force.
As used herein, “density” or “dense” refers to the degree of compactness of a substance or material, especially in the context of mass.
As used herein, “modulation” refers to the exertion of a modifying or controlling influence onto another object, person, or material.
As used herein, “mass” refers to the intrinsic property of matter involving the resistance that the body of mater offers to a change in its speed or position upon application of a force.
As used herein, “polymer” refers to a substance that has a molecular structure consisting of a large number of similar units bonded together.
As used herein, “elastic” refers to an object or material that is able to resume its normal shape spontaneously after contraction, dilation, or distortion.
As used herein, “head” refers to the distal part of an object, person, or animal, often separated from the rest of the body or object. Within the context of the device, “head” refers to any material constructed near the distal portion of the device that may be intended to strike or percuss against another item.
As used herein, “tool” refers to a device or implement, especially held in the hand yet may be used otherwise as well, used to carry out a particular function.
As used herein, “mechanical advantage” refers to the ratio of the force produced by a machine to the force applied to it.
As used herein, “hardness” refers to the quality or measurement of resistance to localized deformation, such as indentation, scratch, induced mechanically either by pressing, pressure, or abrasion established via a shore durometer.
As used herein, “Shore hardness” refers to the measurement or scale of resistance of a material to indentation.
As used herein, “30A” in the context of Shore hardness refers to the hardness of common mouse pads.
As used herein, “40A” in the context of Shore hardness refers to the hardness of common paper erasers.
As used herein, “50A” in the context of Shore hardness refers to the hardness of common pencil erasers.
As used herein, “60A” in the context of Shore hardness refers to the hardness of common tire tread.
As used herein, “70A” in the context of Shore hardness refers to the hardness of common running shoe soles.
As used herein, “80A” in the context of Shore hardness refers to the hardness of common leather belts.
Reflex hammers are used is the elicitation of deep tendon reflex responses. Some of the sites traditionally used for deep tendon reflexes include the biceps tendon, brachioradialis tendon, triceps tendon, pectoralis tendon, patellar tendon, Achilles tendon, yet other reflex responses may be elicited in many other skeletal muscles as well. The deep tendon reflex is caused by the stretch action on the tendon elicited by an outside force, causing a muscle response by the contraction of the muscle triggered by the tendon stretch. However, delivering a consistent impulse against the tendon of a patient is sometimes not sufficient for a reliable tendon response as patients have a diversity of tendon lengths, fatty composition above and below the tendon, along with other individual differences. By enabling modulation of the impact force and limiting excessively high impulses to the patient's tendons we reduce pain and risk of injury to patients.
