Pacemaker longevity: the world's longest-lasting VVI pacemaker

The world's longest lasting VVI pacemaker device for over 40 years

INTRODUCTION

Implantable permanent pacemaker function is supported by their energy sources for a mean period of 8.8-12.4 years. We previously published this case of a patient with a normally functioning VVI pacemaker, 31 years after implantation.

METHODS AND RESULTS

In this report, we state that the device is still functioning normally 40 years after implantation. The most recent device interrogation revealed pacing threshold of 0.9 V/0.5 ms. Holter monitoring for 24 hours recorded a total of 98.707 beats with 97.78% paced beats, without any indication of pacemaker malfunction and with stable heart rate at 70-71 bpm.

CONCLUSION

Most patients with implantable devices have the appropriate follow-up and settings of low energy consumption. Manufacturing companies should focus on prolonging device longevity, to produce future devices with higher energy capacity.

Neuromuscular implants: Interfacing with skeletal muscle for improved clinical translation of prosthetic limbs

After an amputation, advanced prosthetic limbs can be used to interface with the nervous system and restore motor function. Despite numerous breakthroughs in the field, many of the recent research advancements have not been widely integrated into clinical practice. This review highlights recent innovations in neuromuscular implants-specifically those that interface with skeletal muscle-which could improve the clinical translation of prosthetic technologies. Skeletal muscle provides a physiologic gateway to harness and amplify signals from the nervous system. Recent surgical advancements in muscle reinnervation surgeries leverage the "bio-amplification" capabilities of muscle, enabling more intuitive control over a greater number of degrees of freedom in prosthetic limbs than previously achieved. We anticipate that state-of-the-art implantable neuromuscular interfaces that integrate well with skeletal muscle and novel surgical interventions will provide a long-term solution for controlling advanced prostheses. Flexible electrodes are expected to play a crucial role in reducing foreign body responses and improving the longevity of the interface. Additionally, innovations in device miniaturization and ongoing exploration of shape memory polymers could simplify surgical procedures for implanting such interfaces. Once implanted, wireless strategies for powering and transferring data from the interface can eliminate bulky external wires, reduce infection risk, and enhance day-to-day usability. By outlining the current limitations of neuromuscular interfaces along with potential future directions, this review aims to guide continued research efforts and future collaborations between engineers and specialists in the field of neuromuscular and musculoskeletal medicine.

Implications of wound healing on subcutaneous photovoltaic energy harvesting

OBJECTIVE

Implanted cardiac pacemakers must be regularly replaced due to depleted batteries. A possible alternative is proposed by subcutaneous photovoltaic energy harvesting. The bodys reaction to an implant can cause device encapsulation. Potential changes in spectral light transmission of skin can inuence the performance of subcutaneous photovoltaic cells and has not yet been studied in large animal studies.

METHODS

Subcutaneous implants measuring changes in the light reaching the implant were developed. Three pigs received those implants and were analyzed for seven weeks. Spectral measurements with known irradiation were performed to identify possible changes in the transparency of the tissues above the implant during the wound healing process. A histological analysis at the end of the trial investigated the skin tissue above the subcutaneous photovoltaic implants.

RESULTS

The implants measured decreasing light intensity and shifts in the lights spectrum during the initial wound healing phase. In a later stage of tissue recovery, the implants measured a generally reduced light intensity compared to the healthy tissue after implantation. The spectral distribution of the measured light at the end of the trial was similar to the rst measurements. The histological analysis showed subcutaneous granulation tissue formation for all devices.

CONCLUSION

The varying reduction of light intensity reaching the implants means that safety margins must be sufciently high to ensure the power. At the end of the wound healing process, the spectral distribution of the light reaching the implant is similar to healthy tissue. Signicance: Optimizations of spectral sensitivity of photovoltaic cells are possible.

Single-Chamber Cardiac Pacemaker Implantation in a Donkey with Complete AV Block: A Long-Term Follow-Up

A five-month-old African jenny was presented with a history of exercise intolerance and syncopal episodes. Severe bradycardic arrhythmia due to a high-grade second-degree atrioventricular (AV) block with progression to complete AV block was diagnosed. The jenny underwent a transvenous single-chamber pacemaker implantation. The implantation procedure was performed in a lateral recumbency and the ventricular lead was inserted through the jugular vein. Positioning of the lead was guided by echocardiography. The pacemaker was programmed to VVI mode with a minimal ventricular rate of 40 pulses per minute, a pulse amplitude of 2.4 V, a pulse width of 0.5 ms and sensing amplitude of 2.5 mV. Short-term complications associated with the procedure included lead dislodgement and pacemaker pocket infection. The long-term outcome was satisfactory; the jenny showed improvement in heart function and quality of life after pacemaker implantation. The pulse generator replacement was performed twice (at nine-year intervals) and the intervention was always associated with a local inflammatory reaction around the pacing device. Cardiac examination 18 years after pacemaker implantation revealed no morphological changes in the heart; the electrode lead was still in the correct position and successful pacing and sensing of the ventricle were obtained. Regular follow-up checks are important to evaluate pacemaker function.

Potential of subdermal solar energy harvesting for medical device applications based on worldwide meteorological data

SIGNIFICANCE

Active implants require batteries as power supply. Their lifetime is limited and may require a second surgical intervention for replacement. Intracorporal energy harvesting techniques generate power within the body and supply the implant. Solar cells below the skin can be used to harvest energy from light.

AIM

To investigate the potential of subdermal solar energy harvesting.

APPROACH

We evaluated global radiation data for defined time slots and calculated the output power of a subdermal solar module based on skin and solar cell characteristics. We assumed solar exposure profiles based on daily habits for an implanted solar cell. The output power was calculated for skin types VI and I/II.

RESULTS

We show that the yearly mean power in most locations on Earth is sufficient to power modern cardiac pacemakers if 10 min midday solar irradiation is assumed. All skin types are suitable for solar harvesting. Moreover, we provide a software tool to predict patient-specific output power.

CONCLUSIONS

Subdermal solar energy harvesting is a viable alternative to primary batteries. The comparison to a human case study showed a good agreement of the results. The developed code is available open source to enable researchers to investigate further applications of subdermal solar harvesting.

Electrogenetic cellular insulin release for real-time glycemic control in type 1 diabetic mice

Sophisticated devices for remote-controlled medical interventions require an electrogenetic interface that uses digital electronic input to directly program cellular behavior. We present a cofactor-free bioelectronic interface that directly links wireless-powered electrical stimulation of human cells to either synthetic promoter–driven transgene expression or rapid secretion of constitutively expressed protein therapeutics from vesicular stores. Electrogenetic control was achieved by coupling ectopic expression of the L-type voltage-gated channel CaV1.2 and the inwardly rectifying potassium channel Kir2.1 to the desired output through endogenous calcium signaling. Focusing on type 1 diabetes, we engineered electrosensitive human β cells (Electroβ cells). Wireless electrical stimulation of Electroβ cells inside a custom-built bioelectronic device provided real-time control of vesicular insulin release; insulin levels peaked within 10 minutes. When subcutaneously implanted, this electrotriggered vesicular release system restored normoglycemia in type 1 diabetic mice.

Pacing and Sensing of Human Heart for over 31 Years with the Same Apparatus (Generator and Lead)

Several patients receive a permanent pacemaker in a relatively young age, with multiple subsequent reoperations for pacemaker replacement. Pulse generator replacement is an invasive procedure, associated with the risk of various complications, mainly infection and skin erosion. A case of an extremely long-lasting pacemaker with a totally uneventful longevity period over 31 years is presented. The explanation for this quite rare pacemaker longevity (possibly unique) is analyzed and discussed.

Powering biomedical devices with body motion

Energy harvesting from body motion is an alternative power source that can be used to energize miniature electronic biomedical devices. This technology can make it possible to recharge batteries to reduce the frequency of or eliminate surgeries to replace depleted cells. Power availability evaluation from walking and running at several body locations and different speeds is presented. Treadmill tests were performed on 11 healthy subjects to measure the accelerations at the ankle, knee, hip, chest, wrist, elbow, upper arm, and side of the head. Power was estimated from the treadmill results since it is proportional to the acceleration magnitudes and the frequency of occurrence. Available power output from walking was found to be more than 0.5 mW/cm(3) for all body locations while being more than 10 mW/cm(3) for the ankle and knee. Running results were at least 10 times higher than those from walking. An axial flux miniature electric dynamo using electromagnetic induction was evaluated for power generation. The device was composed of a rotor with multiple-pole permanent magnets positioned on an annular ring having an eccentric mass, and stacked planar coils as a stator. A 2 cm(3) prototype was found to generate 117 microW of power from the generator placed laterally on the ankle while walking.

Body motion for powering biomedical devices

Kinetic energy harvesting has been demonstrated as a useful technique for powering portable electronic devices. Body motion can be used to generate energy to power small electronic devices for biomedical applications. These scavengers can recharge batteries, extending their operation lifetime or even replace them. This paper addresses the generation of energy from human activities. An axial flux generator is presented using body motion for powering miniature biomedical devices. This generator presents a gear-shaped planar coil and a multipole NdFeB permanent magnet (PM) ring with an attached eccentric weight. The device generates energy by electromagnetic induction on the planar coil when subject to a changing magnetic flux due to the generator oscillations produced by body motion. A 1.5 cm(3) prototype has generated 3.9 microW of power while walking with the generator placed laterally on the ankle.